Academia.eduAcademia.edu

Figure 9 – uploaded by Ilan Tsarfaty

See full PDFdownloadDownload figure
Abbreviations: mn = modal number of chromosomes. *The outcome has improved with intensive chemotherapy.

Table 9 Abbreviations: mn = modal number of chromosomes. *The outcome has improved with intensive chemotherapy.

Related Figures (88)

Contents Normal cells become tumorigenic after multiple genetic and epigenetic alterations. This process alters complex signaling networks within these cells as well Normal cells become tumorigenic after multiple
Contents Normal cells become tumorigenic after multiple genetic and epigenetic alterations. This process alters complex signaling networks within these cells as well Normal cells become tumorigenic after multiple
Activation of the c-Met receptor initiates a wide variety of signal pathways in the target cell. The c-Met receptor is a cell surface glycoprotein com- posed of an extracellular a-subunit and a transmem- brane B-subunit. Binding of HGF/SF to c-Met, causes an increase in the tyrosine kinase activity of the B-subunit resulting in receptor autophosphorylation [145-147]. C-Met signaling is controlled through a multifunctional docking site comprised of two tandem arranged phosphotyrosines [146]. Mutational analysis Considerable data exist upon the individual roles of these signaling molecules and adapters in C-Met- mediated tumor progression. GRB2 is essential for Fig. 2.1 Abbreviated signaling pathway mediated by protein tyrosine kinase receptors. Overexpression of receptors often contributes to malignant progression, and leads to activation of “downstream” proto-oncogenes. As discussed In the text, activation of these downstream signaling molecules may occur independently of receptor activation. Some of most frequent tumors in which activation occurs are shown in the Figure; however, many other tumors have these alterations.
Activation of the c-Met receptor initiates a wide variety of signal pathways in the target cell. The c-Met receptor is a cell surface glycoprotein com- posed of an extracellular a-subunit and a transmem- brane B-subunit. Binding of HGF/SF to c-Met, causes an increase in the tyrosine kinase activity of the B-subunit resulting in receptor autophosphorylation [145-147]. C-Met signaling is controlled through a multifunctional docking site comprised of two tandem arranged phosphotyrosines [146]. Mutational analysis Considerable data exist upon the individual roles of these signaling molecules and adapters in C-Met- mediated tumor progression. GRB2 is essential for Fig. 2.1 Abbreviated signaling pathway mediated by protein tyrosine kinase receptors. Overexpression of receptors often contributes to malignant progression, and leads to activation of “downstream” proto-oncogenes. As discussed In the text, activation of these downstream signaling molecules may occur independently of receptor activation. Some of most frequent tumors in which activation occurs are shown in the Figure; however, many other tumors have these alterations.
* Adapted from National Academy of Sciences [31] > Average effective dose to soft tissues “Average effective dose to bronchial epithelium alone
* Adapted from National Academy of Sciences [31] > Average effective dose to soft tissues “Average effective dose to bronchial epithelium alone
“The units listed are those of the International System [4] and have largely replaced the earlier units; namely, the rad (1 rad = 100 ergs/gm = 0.01 Gy), the rem (1 rem = 0.01 Sv), and the curie (1 Ci = 3.7 x 10!° disintegrations per second = 3.7 x 10!°Bq).
“The units listed are those of the International System [4] and have largely replaced the earlier units; namely, the rad (1 rad = 100 ergs/gm = 0.01 Gy), the rem (1 rem = 0.01 Sv), and the curie (1 Ci = 3.7 x 10!° disintegrations per second = 3.7 x 10!°Bq).
Fig. 3.1 Dose-response relationship for relative risk of can- cer, all types combined, excluding leukemia, in a-bomb sur- vivors, 1958-1994 (from 100). The data represent age-specific incidence rates in irradiated survivors relative to those in non- irradiated survivors, averaged over the follow-up period and over sex, and for exposure at age 30. The straight line represents the linear risk estimate computed over the 0-2 Sv dose range, and the dashed curves represent + curve t 1 standard error for the smoothed In a-bomb survivors, the total incidence of solid can- cers during the first 50 years after irradiation appears to have increased as a linear-nonthreshold function of the dose over the range 0-2 Sv (Fig. 3.1). A signifi- cant elevation of the risk is detectable at doses below
Fig. 3.1 Dose-response relationship for relative risk of can- cer, all types combined, excluding leukemia, in a-bomb sur- vivors, 1958-1994 (from 100). The data represent age-specific incidence rates in irradiated survivors relative to those in non- irradiated survivors, averaged over the follow-up period and over sex, and for exposure at age 30. The straight line represents the linear risk estimate computed over the 0-2 Sv dose range, and the dashed curves represent + curve t 1 standard error for the smoothed In a-bomb survivors, the total incidence of solid can- cers during the first 50 years after irradiation appears to have increased as a linear-nonthreshold function of the dose over the range 0-2 Sv (Fig. 3.1). A signifi- cant elevation of the risk is detectable at doses below
Modified from [4, 124] Percentage by which the spontaneous, “background” risk would be increased The use of this type of model has yielded a range of risk estimates for cancers of different sites (e.g., Table 3.3).
Modified from [4, 124] Percentage by which the spontaneous, “background” risk would be increased The use of this type of model has yielded a range of risk estimates for cancers of different sites (e.g., Table 3.3).
Contents Cancer is a multi-factorial disease. The primary cause of cancer is genetic instability in the cellular fidelity of DNA replication. When DNA is not copied correctly, the resulting mutations may lead to cancer. The causes of these mutations can be single or multi-factorial. Many things are known to cause these mutations. The major factors or agents include: viruses (e.g. sv40, ebv, etc [1]), physical factors (e.g. asbestos, radiation,
Contents Cancer is a multi-factorial disease. The primary cause of cancer is genetic instability in the cellular fidelity of DNA replication. When DNA is not copied correctly, the resulting mutations may lead to cancer. The causes of these mutations can be single or multi-factorial. Many things are known to cause these mutations. The major factors or agents include: viruses (e.g. sv40, ebv, etc [1]), physical factors (e.g. asbestos, radiation,
Table 5.1 Tissue culture review references
Table 5.1 Tissue culture review references
Fig. 5.1 Use of tissue culture to study human carcinogenesis. Cells and explants are cultured from tumor tissue to characterize their morphologic and biologic properties (e.g. metastatic poten- tial, susceptibility to chemotherapeutic drugs). Normal cells and explants are cultured in protocols which expose these cells to carcinogens in order to induce transformation in vitro. The trans- formed tissues can then be assayed the same way as the tumor tissues are studied eee OE EI II I OO Our previous chapter [16] described advances in the field of in vitro cancer research, particularly the use of human tissues in vitro to study cancer. We also documented the relationship and comparison between animal models and human systems. Figure 5.1 from our earlier chapter summarizes the original work. The fundamental premise of the original chapter was that one could understand carcinogenesis in humans by studying cells, tissues, and organs in vitro. The original work described how one could take a well- characterized animal model of cancer and isolate the cells, tissues, or organs that developed into cancer in that animal, and maintain the cells in vitro. The genet- ics, phenotype, and metabolism of the animal could then be studied in vitro for similarities and differences. Human cells obtained through donation, autopsy, and surgery could be similarly studied. Human in vivo studies are not ethically possible. However, if there It can be a monolayer, mixed population, and can be Cell culture is the growth of dispersed, disaggre- gated, single cells of a unique cell type, which do not necessarily retain the histologic structural relationships of the cells and tissues from which they were removed. It can be a monolayer, mixed population, and can be
Fig. 5.1 Use of tissue culture to study human carcinogenesis. Cells and explants are cultured from tumor tissue to characterize their morphologic and biologic properties (e.g. metastatic poten- tial, susceptibility to chemotherapeutic drugs). Normal cells and explants are cultured in protocols which expose these cells to carcinogens in order to induce transformation in vitro. The trans- formed tissues can then be assayed the same way as the tumor tissues are studied eee OE EI II I OO Our previous chapter [16] described advances in the field of in vitro cancer research, particularly the use of human tissues in vitro to study cancer. We also documented the relationship and comparison between animal models and human systems. Figure 5.1 from our earlier chapter summarizes the original work. The fundamental premise of the original chapter was that one could understand carcinogenesis in humans by studying cells, tissues, and organs in vitro. The original work described how one could take a well- characterized animal model of cancer and isolate the cells, tissues, or organs that developed into cancer in that animal, and maintain the cells in vitro. The genet- ics, phenotype, and metabolism of the animal could then be studied in vitro for similarities and differences. Human cells obtained through donation, autopsy, and surgery could be similarly studied. Human in vivo studies are not ethically possible. However, if there It can be a monolayer, mixed population, and can be Cell culture is the growth of dispersed, disaggre- gated, single cells of a unique cell type, which do not necessarily retain the histologic structural relationships of the cells and tissues from which they were removed. It can be a monolayer, mixed population, and can be
Table 5.2 Tissue culture methods references
Table 5.2 Tissue culture methods references
Fig. 5.2 CLSM analysis of 293-T cells transiently co- transfected with GFP-Mimp and ECFP-mitochondrial marker (BD Biosciences Clontech, CA). GFP-Mimp localizes to the mitochondrial membrane while ECFP-mitochondrial marker stains the mitochondrial lumen Factor (HGF/SF), which is normally produced by mes- enchymal cells. Binding of HGF/SF to Met leads to autophosphorylation of several tyrosine residues in the tyrosine kinase domain of the receptor and at its dock- ing site [106]. The multi-substrate docking site of Met recruits adapter signalling molecules such as Grb2, She, Gab1, Src and Crk/CRKL as well as signalling transducers such as phosphotidylinositol-3-OH kinase (PI3K), the signal transducer and activator of tran- scription 3 (Stat3), phospholipase C-y (PLC-y) and Src [107]. These interactions occur either directly or indirectly via other adapter proteins and signal trans- ducers [reviewed in 108]. It was shown that Met, and its activation, are important for Met-HGF/SF-mediated cell migration and transformation [109-110] as well as differentiation [111]. Recently, a protein was identi- fied, that is up-regulated in cells upon Met activation, named Mimp (Met-induced mitochondrial protein). Mimp encodes a 33 kDa protein, and exhibits both sequence and a structural homology to the family of mitochondrial carrier proteins. It is expressed in a wide range of tissues with an expression pattern similar to that of Met [112]. Using a Mimp tagged to GFP,
Fig. 5.2 CLSM analysis of 293-T cells transiently co- transfected with GFP-Mimp and ECFP-mitochondrial marker (BD Biosciences Clontech, CA). GFP-Mimp localizes to the mitochondrial membrane while ECFP-mitochondrial marker stains the mitochondrial lumen Factor (HGF/SF), which is normally produced by mes- enchymal cells. Binding of HGF/SF to Met leads to autophosphorylation of several tyrosine residues in the tyrosine kinase domain of the receptor and at its dock- ing site [106]. The multi-substrate docking site of Met recruits adapter signalling molecules such as Grb2, She, Gab1, Src and Crk/CRKL as well as signalling transducers such as phosphotidylinositol-3-OH kinase (PI3K), the signal transducer and activator of tran- scription 3 (Stat3), phospholipase C-y (PLC-y) and Src [107]. These interactions occur either directly or indirectly via other adapter proteins and signal trans- ducers [reviewed in 108]. It was shown that Met, and its activation, are important for Met-HGF/SF-mediated cell migration and transformation [109-110] as well as differentiation [111]. Recently, a protein was identi- fied, that is up-regulated in cells upon Met activation, named Mimp (Met-induced mitochondrial protein). Mimp encodes a 33 kDa protein, and exhibits both sequence and a structural homology to the family of mitochondrial carrier proteins. It is expressed in a wide range of tissues with an expression pattern similar to that of Met [112]. Using a Mimp tagged to GFP,
5.6.1 Advantages of Quantitative Analysis
5.6.1 Advantages of Quantitative Analysis
Likewise, cell branching may be quantified by relat- ing the circumference of the cell to its area. A perfectly spherical cell has the lowest surface area: volume ratio (it is for this reason that lipid drops in aqueous solu- tion form spherical droplets, since this arrangement minimizes hydrophobic interactions and thereby rep- resents the free energy minimum.) Similarly, in two dimensions, a section through a spherical cell yields a circular structure with the smallest possible circumfer- ence: area ratio. As the cell becomes more branched, the resulting sections through the cell become more tortuous, and the circumference increases relative to the area. The ratio of circumference to area, then, may be used as a quantitative measure of cell branching. For convenience, our laboratory typically performs a mathematical transformation of this ratio based on the geometric relationship between area and circumfer- ence such that the minimum branching coefficient in | (the grid based blob algorithm leads to some rounding error such that coefficients slightly less than 1 may result). This approach to quantifying cell branching is illustrated schematically in Fig. 5.5a, b, and illustrative images from cell culture with corresponding computed quantitative data are shown in Fig. 5.5 c, d.
Likewise, cell branching may be quantified by relat- ing the circumference of the cell to its area. A perfectly spherical cell has the lowest surface area: volume ratio (it is for this reason that lipid drops in aqueous solu- tion form spherical droplets, since this arrangement minimizes hydrophobic interactions and thereby rep- resents the free energy minimum.) Similarly, in two dimensions, a section through a spherical cell yields a circular structure with the smallest possible circumfer- ence: area ratio. As the cell becomes more branched, the resulting sections through the cell become more tortuous, and the circumference increases relative to the area. The ratio of circumference to area, then, may be used as a quantitative measure of cell branching. For convenience, our laboratory typically performs a mathematical transformation of this ratio based on the geometric relationship between area and circumfer- ence such that the minimum branching coefficient in | (the grid based blob algorithm leads to some rounding error such that coefficients slightly less than 1 may result). This approach to quantifying cell branching is illustrated schematically in Fig. 5.5a, b, and illustrative images from cell culture with corresponding computed quantitative data are shown in Fig. 5.5 c, d.
5.7 Conclusion the work of computational pathology. Computers are well suited to rigorous and reproducible application of rules (something that humans are less well suited to), while humans are well suited to creativity, adap- tation, and recognition of exceptions (something that computers are less well suited to). As such, the rela- tionship is synergistic and not competitive, Deep Blue notwithstanding.! Cancer is a multi-factorial disease, influenced by a combination of genetic and environmental factors. Imaging of the molecular, cellular and organism changes that document the sequence and steps in this process is one of the key reasons tissue culture has been so important in unraveling the process of carcinogenesis. Cancer is a multi-factorial disease, influenced by a Imaging of the molecular, cellular and organism changes that document the sequence and steps in
5.7 Conclusion the work of computational pathology. Computers are well suited to rigorous and reproducible application of rules (something that humans are less well suited to), while humans are well suited to creativity, adap- tation, and recognition of exceptions (something that computers are less well suited to). As such, the rela- tionship is synergistic and not competitive, Deep Blue notwithstanding.! Cancer is a multi-factorial disease, influenced by a combination of genetic and environmental factors. Imaging of the molecular, cellular and organism changes that document the sequence and steps in this process is one of the key reasons tissue culture has been so important in unraveling the process of carcinogenesis. Cancer is a multi-factorial disease, influenced by a Imaging of the molecular, cellular and organism changes that document the sequence and steps in
In the era of kinase inhibition, the cytogenetic and molecular analysis of genetic abnormalities in CML takes on increasing importance, in part because the treatment itself now relies on the presence of the
In the era of kinase inhibition, the cytogenetic and molecular analysis of genetic abnormalities in CML takes on increasing importance, in part because the treatment itself now relies on the presence of the
Fig. 6.2 A G-banded karyogram showing the presence of trisomy 8 (+8) in addition to the Philadelphia translocation, t(9;22)(q34;q11.2)
Fig. 6.2 A G-banded karyogram showing the presence of trisomy 8 (+8) in addition to the Philadelphia translocation, t(9;22)(q34;q11.2)
Fig. 6.4 T(8;14)(q24:q32) in Burkitt lymphoma and in ALL
Fig. 6.4 T(8;14)(q24:q32) in Burkitt lymphoma and in ALL
practical and theoretic interest is the fact that APL with certain variant translocations, wherein PML is fused to a gene other than RARA, such as PLZF, treatment with tretinoin may be ineffective [78]. practical and theoretic interest is the fact that APL with
practical and theoretic interest is the fact that APL with certain variant translocations, wherein PML is fused to a gene other than RARA, such as PLZF, treatment with tretinoin may be ineffective [78]. practical and theoretic interest is the fact that APL with
Table 6.1 Main recurrent cytogenetic/genetic lesions with clinical impact on outcome in ALL
Table 6.1 Main recurrent cytogenetic/genetic lesions with clinical impact on outcome in ALL
Fig.6.8 Detection of the TEL/AML] gene fusion that occurs as a result of a t(12;21)(p13;q22) using the Vysis LSI TEL/AML ES Dual Color Translocation Probe. In a normal interphase nucleus lacking the TEL/AML1 fusion gene, two green (TEL) and two orange/red (AML1) signals can be seen. In an abnor- mal cell containing the TEL/AML1 fusion, the expected signal pattern is one green (native TEL), one large orange/red (native AML1), one smaller orange/red signal (residual AML1), and one fused orange/red/green (yellow) signal The q23 region of chromosome 11 is a relatively common site of structural rearrangements in pediatric patients with hematologic neoplasms. In infants with ALL, the incidence of 11q23 abnormalities ranges from 70 to 90%, whereas in children with ALL is from 4.5 to 5.7% [90-91]. Children who have ALL with 11q23 abnormalities are usually young and have high leukocyte counts, organomegaly, and central nervous system (CNS) involvement. The leukemic cells have an early pre-B immunophenotype, CD10 —negative,
Fig.6.8 Detection of the TEL/AML] gene fusion that occurs as a result of a t(12;21)(p13;q22) using the Vysis LSI TEL/AML ES Dual Color Translocation Probe. In a normal interphase nucleus lacking the TEL/AML1 fusion gene, two green (TEL) and two orange/red (AML1) signals can be seen. In an abnor- mal cell containing the TEL/AML1 fusion, the expected signal pattern is one green (native TEL), one large orange/red (native AML1), one smaller orange/red signal (residual AML1), and one fused orange/red/green (yellow) signal The q23 region of chromosome 11 is a relatively common site of structural rearrangements in pediatric patients with hematologic neoplasms. In infants with ALL, the incidence of 11q23 abnormalities ranges from 70 to 90%, whereas in children with ALL is from 4.5 to 5.7% [90-91]. Children who have ALL with 11q23 abnormalities are usually young and have high leukocyte counts, organomegaly, and central nervous system (CNS) involvement. The leukemic cells have an early pre-B immunophenotype, CD10 —negative,
Fig. 6.9 Schematic representation of the Vysis LSI MLL Dual Color, Break Apart Rearrangement Probe for the detection of 11q23 structural chromosomal abnormalities. This probe con- sists of a centromeric (proximal) portion labeled in green and a telomeric (distal) portion labeled in orange/red. The sig- nal pattern observed in a cell lacking the MLL rearrangement is expected to show a two orange/red/green (yellow) fusion signal pattern. In a cell possessing a MLL translocation, the expected pattern is one orange/red/green (yellow) fusion sig- nal, one orange/red signal, and one green signal. (a) Normal cell with no MLL rearrangement, showing two orange/red/green (yellow) fusion signals (top). (b) Abnormal cell with a MLL rearrangement, showing one orange/red, one green and one orange/red/green (yellow) fusion signal (bottom) Some MLL gene rearrangements can not be detected by conventional cytogenetic methods. The commer- cially available dual-color MLL probe allows FISH evaluation of derivatives of a translocation involving MLL in metaphase chromosomes and the splitting of signals in interphase nuclei (Fig. 6.9) [95]. In rare instances, FISH based on this probe detects not only the reciprocal translocation but also a deletion of at least 190 kb from the 3’ region of MLL gene [96].
Fig. 6.9 Schematic representation of the Vysis LSI MLL Dual Color, Break Apart Rearrangement Probe for the detection of 11q23 structural chromosomal abnormalities. This probe con- sists of a centromeric (proximal) portion labeled in green and a telomeric (distal) portion labeled in orange/red. The sig- nal pattern observed in a cell lacking the MLL rearrangement is expected to show a two orange/red/green (yellow) fusion signal pattern. In a cell possessing a MLL translocation, the expected pattern is one orange/red/green (yellow) fusion sig- nal, one orange/red signal, and one green signal. (a) Normal cell with no MLL rearrangement, showing two orange/red/green (yellow) fusion signals (top). (b) Abnormal cell with a MLL rearrangement, showing one orange/red, one green and one orange/red/green (yellow) fusion signal (bottom) Some MLL gene rearrangements can not be detected by conventional cytogenetic methods. The commer- cially available dual-color MLL probe allows FISH evaluation of derivatives of a translocation involving MLL in metaphase chromosomes and the splitting of signals in interphase nuclei (Fig. 6.9) [95]. In rare instances, FISH based on this probe detects not only the reciprocal translocation but also a deletion of at least 190 kb from the 3’ region of MLL gene [96].
associated with inferior outcome in the context of antimetabolite-based therapy but subsequent studies have shown that the poorer prognosis can be largely overcome by more intensive chemotherapy [107]. The t(1;19) leads to the fusion of TCF3 (E2A), which is on chromosome 19 and encodes a helix-loop-helix (HLH) protein, with PBX/, a homeobox-containing gene on chromosome | [108-109]. The resulting hybrid gene, TCF3-PBX1, is a potent oncogene and can be detected by RT-PCR and/or FISH [110-112]. In about 5-10% the t(1;19) detected by conventional cytogenetics does not involve TCF3 or PBX1 but involves other genes [113-115]. 6.5.6.5 t(17;19)(q22;p13.3) and inv(19)(p13.3q13.4) associated with inferior outcome in the context of Other rare, nonrandom chromosomal translocations affecting 19p13.3 also involve the TCF3 gene. The t(17;19)(q22;p13.3) is found in approximately 1% of patients with B-lineage leukemia, most of whom do not respond to therapy [116]. The majority of t(17;19) generate a fusion gene consisting of TCF3 and the hep- atic leukemia factor gene (HLF) on chromosome 17 [117]. In a few cases in which the t(17;19)(q22;p13.3) is present, neither TCF3 nor HLF rearrangements have been noted. Thus, this translocation, like the t(1;19), Other rare, nonrandom chromosomal translocations
associated with inferior outcome in the context of antimetabolite-based therapy but subsequent studies have shown that the poorer prognosis can be largely overcome by more intensive chemotherapy [107]. The t(1;19) leads to the fusion of TCF3 (E2A), which is on chromosome 19 and encodes a helix-loop-helix (HLH) protein, with PBX/, a homeobox-containing gene on chromosome | [108-109]. The resulting hybrid gene, TCF3-PBX1, is a potent oncogene and can be detected by RT-PCR and/or FISH [110-112]. In about 5-10% the t(1;19) detected by conventional cytogenetics does not involve TCF3 or PBX1 but involves other genes [113-115]. 6.5.6.5 t(17;19)(q22;p13.3) and inv(19)(p13.3q13.4) associated with inferior outcome in the context of Other rare, nonrandom chromosomal translocations affecting 19p13.3 also involve the TCF3 gene. The t(17;19)(q22;p13.3) is found in approximately 1% of patients with B-lineage leukemia, most of whom do not respond to therapy [116]. The majority of t(17;19) generate a fusion gene consisting of TCF3 and the hep- atic leukemia factor gene (HLF) on chromosome 17 [117]. In a few cases in which the t(17;19)(q22;p13.3) is present, neither TCF3 nor HLF rearrangements have been noted. Thus, this translocation, like the t(1;19), Other rare, nonrandom chromosomal translocations
segment next to the constant (C) region gene. This mRNA will encode a heavy chain that appears on the surface of the pre-B cell together with the surrogate light chain, which is encoded by genes that do not undergo rearrangement. As the pre-B cell con- tinues to mature, the immunoglobulin light-chain genes undergo rearrangement; the resulting light chain replaces the surrogate light chain, and thereby produces a mature IgM B-cell recep- tor on the cell surface. The B-cell receptors at this stage also usually include IgD antibodies with the same specificity as the IgM molecule, produced by alternative splicing of the rearranged VDJ to either the C,, or the Cs gene. The expression of RAG/ and RAG2 is then switched off. After encountering an antigen, and in the presence of costimulatory signals, the B cell further differen- tiates into a plasma cell, which secretes high levels of the specific antibody (or into a memory B cell). The same general principles regarding the rearrangement process apply to the generation of a/B and y/8 T-cell receptors. The gene segments in the figure are not drawn to scale (From: Delves and Roitt [74]) Fig. 7.1 Diversity of antigen receptors. The enormously diverse specificities of the antigen receptors are produced by gene rear- rangements during the early developmental stages of the lym- phocyte. The events involved in generating a coding sequence for the immunoglobulin heavy chain are shown. Early in B-cell development, pro-B cells mature into pre-B cells, at which stages they express the recombination-activating genes RAG/ and RAG2. The recombinases encoded by these genes mediate the random rearrangement of | of 25 diversity (D) gene segments next to any | of 6 joining (J) gene segments. This is followed by the rearrangement of any | of 50 variable (V) gene segments next to the already rearranged DJ segment. Different B cells will rearrange a different segment in each pool, thereby creating one level of diversity. Further diversity is brought about by splicing inaccuracies and by the incorporation of nucleotides mediated by the enzyme terminal deoxyribonucleotidyltransferase (TdT). The heavy-chain primary RNA transcript is processed into mes- senger RNA (mRNA), with splicing of the rearranged VDJ
segment next to the constant (C) region gene. This mRNA will encode a heavy chain that appears on the surface of the pre-B cell together with the surrogate light chain, which is encoded by genes that do not undergo rearrangement. As the pre-B cell con- tinues to mature, the immunoglobulin light-chain genes undergo rearrangement; the resulting light chain replaces the surrogate light chain, and thereby produces a mature IgM B-cell recep- tor on the cell surface. The B-cell receptors at this stage also usually include IgD antibodies with the same specificity as the IgM molecule, produced by alternative splicing of the rearranged VDJ to either the C,, or the Cs gene. The expression of RAG/ and RAG2 is then switched off. After encountering an antigen, and in the presence of costimulatory signals, the B cell further differen- tiates into a plasma cell, which secretes high levels of the specific antibody (or into a memory B cell). The same general principles regarding the rearrangement process apply to the generation of a/B and y/8 T-cell receptors. The gene segments in the figure are not drawn to scale (From: Delves and Roitt [74]) Fig. 7.1 Diversity of antigen receptors. The enormously diverse specificities of the antigen receptors are produced by gene rear- rangements during the early developmental stages of the lym- phocyte. The events involved in generating a coding sequence for the immunoglobulin heavy chain are shown. Early in B-cell development, pro-B cells mature into pre-B cells, at which stages they express the recombination-activating genes RAG/ and RAG2. The recombinases encoded by these genes mediate the random rearrangement of | of 25 diversity (D) gene segments next to any | of 6 joining (J) gene segments. This is followed by the rearrangement of any | of 50 variable (V) gene segments next to the already rearranged DJ segment. Different B cells will rearrange a different segment in each pool, thereby creating one level of diversity. Further diversity is brought about by splicing inaccuracies and by the incorporation of nucleotides mediated by the enzyme terminal deoxyribonucleotidyltransferase (TdT). The heavy-chain primary RNA transcript is processed into mes- senger RNA (mRNA), with splicing of the rearranged VDJ
ible 7.1 Characteristics of some matures B-cell lymphomas. Somatic hypermutation (SHM), Diffuse large B-cell lymphoma (DLBCL), Germinal Center (GC), Marginal-zon¢ sociated lymphoid tissue (MALT). Adapted from “Table 1” in Shaffer et al. [75], and “Table 2” in Kuppers [63]
ible 7.1 Characteristics of some matures B-cell lymphomas. Somatic hypermutation (SHM), Diffuse large B-cell lymphoma (DLBCL), Germinal Center (GC), Marginal-zon¢ sociated lymphoid tissue (MALT). Adapted from “Table 1” in Shaffer et al. [75], and “Table 2” in Kuppers [63]
a very small subgroup in the peripheral blood of some people. Somatically mutated B-cells in the peripheral blood are descen- dants of pre-germinal-center (naive) B cells that have passed through the germinal center in lymphoid organs where they acquired somatic mutations (From: Kuppers et al. [33]) Fig. 7.2 Cellular composition of the peripheral-blood B-cell repertoire in humans. Shown are the phenotypically defined sub- groups of B cells, the average frequency of mutations of the heavy-chain variable-region genes, and the percentages of the respective subgroups among all peripheral-blood B cells. Cells with only IgD are not discussed, because they comprise only
a very small subgroup in the peripheral blood of some people. Somatically mutated B-cells in the peripheral blood are descen- dants of pre-germinal-center (naive) B cells that have passed through the germinal center in lymphoid organs where they acquired somatic mutations (From: Kuppers et al. [33]) Fig. 7.2 Cellular composition of the peripheral-blood B-cell repertoire in humans. Shown are the phenotypically defined sub- groups of B cells, the average frequency of mutations of the heavy-chain variable-region genes, and the percentages of the respective subgroups among all peripheral-blood B cells. Cells with only IgD are not discussed, because they comprise only
lymphomas, and large-cell anaplastic lymphomas of B type. Diffuse large-cell lymphomas may represent primary diseases or transformations from low-grade lymphomas. Lymphomas in which intraclonal variable-region gene diversity is absent or is only occasionally present (except in the case of clas- sic Hodgkin’s disease) may be derived from progenitors in the germinal center or from post-germinal-center (memory) B cells. Nevertheless, as outlined in the text, important steps in the transformation process take place in the germinal center in lymphomas in which the tumor B cells resemble post-germinal- center B cells. MALT denotes mucosa-associated lymphoid tissue (From: Kuppers et al. [33]) Fig. 7.3. Assignment of human B-Cell lymphomas to their nor- mal B-Cell counterparts. Naive B cells that recognize antigen with their antigen receptors establish germinal centers. In these structures the cells vigorously proliferate. The genomic DNA of these cells may then be subjected to somatic hypermuta- tion, class switching, and perhaps variable-region gene recom- bination. The extent of variable-region gene recombination is unknown. Acute lymphoblastic leukemia represents a cancer of B-cell progenitors. Germinal-center B cells that acquire affinity- increasing mutations are positively selected and differentiate into memory B cells or plasma cells. The diffuse large-cell lym- phomas include centroblastic lymphomas, immunoblastic lym- phomas, T-cell-rich B-cell lymphomas, mediastinal sclerosing
lymphomas, and large-cell anaplastic lymphomas of B type. Diffuse large-cell lymphomas may represent primary diseases or transformations from low-grade lymphomas. Lymphomas in which intraclonal variable-region gene diversity is absent or is only occasionally present (except in the case of clas- sic Hodgkin’s disease) may be derived from progenitors in the germinal center or from post-germinal-center (memory) B cells. Nevertheless, as outlined in the text, important steps in the transformation process take place in the germinal center in lymphomas in which the tumor B cells resemble post-germinal- center B cells. MALT denotes mucosa-associated lymphoid tissue (From: Kuppers et al. [33]) Fig. 7.3. Assignment of human B-Cell lymphomas to their nor- mal B-Cell counterparts. Naive B cells that recognize antigen with their antigen receptors establish germinal centers. In these structures the cells vigorously proliferate. The genomic DNA of these cells may then be subjected to somatic hypermuta- tion, class switching, and perhaps variable-region gene recom- bination. The extent of variable-region gene recombination is unknown. Acute lymphoblastic leukemia represents a cancer of B-cell progenitors. Germinal-center B cells that acquire affinity- increasing mutations are positively selected and differentiate into memory B cells or plasma cells. The diffuse large-cell lym- phomas include centroblastic lymphomas, immunoblastic lym- phomas, T-cell-rich B-cell lymphomas, mediastinal sclerosing
cells (FDCs), is selected for improved binding to the immu- nizing antigen. Newly generated centrocytes that produce an unfavourable antibody undergo apoptosis and are removed. A subset of centrocytes undergoes immunoglobulin class-switch recombination (CSR). Cycling of centroblasts and centrocytes between dark and light zones seems to be mediated by a chemokine gradient, presumably established by stromal cells in the respective zones (not shown). Antigen-selected centrocytes eventually differentiate into memory B cells or plasma cells (From: Klein and Dalla-Favera [21]) Fig. 7.4 The germinal centre microenvironment. Antigen- activated B cells differentiate into centroblasts that undergo clonal expansion in the dark zone of the germinal centre. During proliferation, the process of somatic hypermutation (SHM) introduces base-pair changes into the V(D)J region of the rear- ranged genes encoding the immunoglobulin variable region (igV) of the heavy chain and light chain; some of these base- pair mutations lead to a change in the amino-acid sequence. Centroblasts then differentiate into centrocytes and move to the light zone, where the modified antigen receptor, with help from immune helper cells including T cells and follicular dendritic
cells (FDCs), is selected for improved binding to the immu- nizing antigen. Newly generated centrocytes that produce an unfavourable antibody undergo apoptosis and are removed. A subset of centrocytes undergoes immunoglobulin class-switch recombination (CSR). Cycling of centroblasts and centrocytes between dark and light zones seems to be mediated by a chemokine gradient, presumably established by stromal cells in the respective zones (not shown). Antigen-selected centrocytes eventually differentiate into memory B cells or plasma cells (From: Klein and Dalla-Favera [21]) Fig. 7.4 The germinal centre microenvironment. Antigen- activated B cells differentiate into centroblasts that undergo clonal expansion in the dark zone of the germinal centre. During proliferation, the process of somatic hypermutation (SHM) introduces base-pair changes into the V(D)J region of the rear- ranged genes encoding the immunoglobulin variable region (igV) of the heavy chain and light chain; some of these base- pair mutations lead to a change in the amino-acid sequence. Centroblasts then differentiate into centrocytes and move to the light zone, where the modified antigen receptor, with help from immune helper cells including T cells and follicular dendritic
Table 8.1 Tumor suppressor genes involved in human neoplasms (From: Isaacs [41]) Proto-oncogenes encode a variety of cellular proteins involved in a normal cell growth, proliferation and differentiation. These include growth factors, growth factor receptors, intracellular transducers and nuclear transcription factors. They have distinctive spatial and temporal expression patterns in developing organs, and this supports the view that they have important Anti-oncogenes, which suppress the formation of malignant tumors, have been identified [18, 37] (Table 8.1). One example of an antioncogene is the retinoblastoma gene (Rb). Individuals with the loss of one or both of these two protective genes have an increased susceptibility to retinoblastoma. An impor- tant relationship exists between the integrity (homozy- gosity) of the 13q14 Rb gene and the development of certain childhood cancers [35, 36]. The findings indi- cate that both copies of the 13q14 Rb gene must be
Table 8.1 Tumor suppressor genes involved in human neoplasms (From: Isaacs [41]) Proto-oncogenes encode a variety of cellular proteins involved in a normal cell growth, proliferation and differentiation. These include growth factors, growth factor receptors, intracellular transducers and nuclear transcription factors. They have distinctive spatial and temporal expression patterns in developing organs, and this supports the view that they have important Anti-oncogenes, which suppress the formation of malignant tumors, have been identified [18, 37] (Table 8.1). One example of an antioncogene is the retinoblastoma gene (Rb). Individuals with the loss of one or both of these two protective genes have an increased susceptibility to retinoblastoma. An impor- tant relationship exists between the integrity (homozy- gosity) of the 13q14 Rb gene and the development of certain childhood cancers [35, 36]. The findings indi- cate that both copies of the 13q14 Rb gene must be
gene rearrangements characteristic of most cancers. Increasing gene expression occurs by increasing the number of DNA copies of that gene (gene amplifica- tion). Human folate resistant cell cultures are seen in aggressive neuroblastomas that amplify NMYC. The new controlling mechanisms offer novel means for understanding and manipulating developmental gene regulation. The relevance of new, non-classical path- ways which control gene expression is reinforced by progressive DNA expansions/contractions and myriad gene rearrangements characteristic of most cancers. An important relationship exits between certain congenital malformations and syndromes and _ the development of neoplasms [3, 17, 40-42] (Tables 8.2, 8.3, and 8.4). An example is the increased occurrence of neoplasms associated with gonadal dysgenesis in patients having a Y chromosome where gonadoblas- toma and germinoma arise in the dysgenetic gonads [2, 17, 43]. Wilms tumor, hepatoblastoma and adreno- cortical tumors in patients with hemihypertrophy and Wiedemann-Beckwith syndrome are other examples. Aniridia and malformations of the genitourinary tract have been found in infants and children with Wilms tumor [3, 44]. The list of inherited syndromes and
gene rearrangements characteristic of most cancers. Increasing gene expression occurs by increasing the number of DNA copies of that gene (gene amplifica- tion). Human folate resistant cell cultures are seen in aggressive neuroblastomas that amplify NMYC. The new controlling mechanisms offer novel means for understanding and manipulating developmental gene regulation. The relevance of new, non-classical path- ways which control gene expression is reinforced by progressive DNA expansions/contractions and myriad gene rearrangements characteristic of most cancers. An important relationship exits between certain congenital malformations and syndromes and _ the development of neoplasms [3, 17, 40-42] (Tables 8.2, 8.3, and 8.4). An example is the increased occurrence of neoplasms associated with gonadal dysgenesis in patients having a Y chromosome where gonadoblas- toma and germinoma arise in the dysgenetic gonads [2, 17, 43]. Wilms tumor, hepatoblastoma and adreno- cortical tumors in patients with hemihypertrophy and Wiedemann-Beckwith syndrome are other examples. Aniridia and malformations of the genitourinary tract have been found in infants and children with Wilms tumor [3, 44]. The list of inherited syndromes and
WAGR -— Wilms tumor, aniridia, genitourinary defects, retardation oncogenes [46]. In cancers, there is often a decreased expression of DNA methyltransferase which leads to a nonspecific demethylation of 5-methylcytosine. It appears that this demethylation can reactivate the expression of proto-oncogenes which thus act as unregulated growth-promoting agents (e.g., onco- genes, telomerases, etc.) and of genes involved in cell migration, leading to the emergence of progressively more aggressive clones (clonal evolution). Abnormal methylation (hence inactivation) of anti-oncogenes similarly plays a major role in cancer.
WAGR -— Wilms tumor, aniridia, genitourinary defects, retardation oncogenes [46]. In cancers, there is often a decreased expression of DNA methyltransferase which leads to a nonspecific demethylation of 5-methylcytosine. It appears that this demethylation can reactivate the expression of proto-oncogenes which thus act as unregulated growth-promoting agents (e.g., onco- genes, telomerases, etc.) and of genes involved in cell migration, leading to the emergence of progressively more aggressive clones (clonal evolution). Abnormal methylation (hence inactivation) of anti-oncogenes similarly plays a major role in cancer.
Fig. 8.1 Molecular characterization in development and neoplasia. A developmental pathway from DNA sequence to complex structure is envisioned, with parallel regulatory steps contributing to neoplasia (middle panel) or birth defects (From: Wilson and Oligny [133])
Fig. 8.1 Molecular characterization in development and neoplasia. A developmental pathway from DNA sequence to complex structure is envisioned, with parallel regulatory steps contributing to neoplasia (middle panel) or birth defects (From: Wilson and Oligny [133])
Fig.8.2 (a) Imprinted gene cluster on chromosome 11p15 illus- trating selected genes. Red boxes represent maternally expressed alleles and blue boxes represent paternally expressed alleles. Arrows represent the direction of transcription. Black boxes denote imprinted alleles that are not expressed. Yellow boxes denote the location of differentially methylated imprinting cen- ters | and 2 (DMRI and DMR2). Light blue circles with CH3 represent DNA methylation. Two diagonal lines represent an interval of genetic distance not shown. Insulator protein CTCF is shown in purple. (b) Loss of methylation at DMR2 of BWS patients result in two copies of paternal epigenotype for domain 2. (c) Gain of methylation at DMR1 results in H-19 depen- dent IGF2 biallelic expression with loss of H-19 expression, i.e., two copies of paternal genotype for domain 1. (d) Shows mutations in CDKNIC. (e) Shows paternal UPD. Patients have two copies of the paternal epigenotypeDomains for | and 2. (f) Rare paternal duplications (<1%) carry two copies of the paternal genotype and one copy of the maternal genotype. (g) Translocations/inversions (<1%) of maternal origin seen in BWS. The epigenotypes are not yet well characterized (From: Weksberg et al. [102])
Fig.8.2 (a) Imprinted gene cluster on chromosome 11p15 illus- trating selected genes. Red boxes represent maternally expressed alleles and blue boxes represent paternally expressed alleles. Arrows represent the direction of transcription. Black boxes denote imprinted alleles that are not expressed. Yellow boxes denote the location of differentially methylated imprinting cen- ters | and 2 (DMRI and DMR2). Light blue circles with CH3 represent DNA methylation. Two diagonal lines represent an interval of genetic distance not shown. Insulator protein CTCF is shown in purple. (b) Loss of methylation at DMR2 of BWS patients result in two copies of paternal epigenotype for domain 2. (c) Gain of methylation at DMR1 results in H-19 depen- dent IGF2 biallelic expression with loss of H-19 expression, i.e., two copies of paternal genotype for domain 1. (d) Shows mutations in CDKNIC. (e) Shows paternal UPD. Patients have two copies of the paternal epigenotypeDomains for | and 2. (f) Rare paternal duplications (<1%) carry two copies of the paternal genotype and one copy of the maternal genotype. (g) Translocations/inversions (<1%) of maternal origin seen in BWS. The epigenotypes are not yet well characterized (From: Weksberg et al. [102])
9.1 Introduction Contents Malignant melanoma is a burgeoning public health concern. In recent decades, the incidence of primary cutaneous melanoma has increased throughout most of the world including the United States. The overall age- adjusted incidence of melanoma has increased nearly 200% among Caucasians in the US between 1973 and 2002 (21.9 cases per 100,000 in 2002). This increased incidence of melanoma has been seen in all age groups, with a disproportionate increase in individuals over 55 years. The incidence of melanoma has also increased among African Americans and Hispanics in the US [1]. Yo rs es i ee: a ae |e Malignant melanoma is a burgeoning public health
9.1 Introduction Contents Malignant melanoma is a burgeoning public health concern. In recent decades, the incidence of primary cutaneous melanoma has increased throughout most of the world including the United States. The overall age- adjusted incidence of melanoma has increased nearly 200% among Caucasians in the US between 1973 and 2002 (21.9 cases per 100,000 in 2002). This increased incidence of melanoma has been seen in all age groups, with a disproportionate increase in individuals over 55 years. The incidence of melanoma has also increased among African Americans and Hispanics in the US [1]. Yo rs es i ee: a ae |e Malignant melanoma is a burgeoning public health
the diagnosis in patients who have typical clinical Hemotoxylin and eosin staining of formalin-fixed and paraffin-embedded tissue sections has shown ES to be morphologically composed of homogenous small, blue, round cells arranged in sheets with or with- out pseudorosette formation. Intracytoplasmic glyco- gen can be detected using periodic acid-Schiff stain with and without diastase digestion. However, results are not specific. With the use of immunohistochemi- cal analysis, ES is shown to characteristically express CD99 and FLI-/] [15]. CD99 is a 32-kDa cell sur- face glycoprotein encoded by the MIC2 gene. FLI-1 nuclear reactivity is typically detected in 71% of cases of ES and PNET, which may also have EWS-FLI-1 fusion. Both markers are very useful in assisting the diagnosis in patients who have typical clinical
the diagnosis in patients who have typical clinical Hemotoxylin and eosin staining of formalin-fixed and paraffin-embedded tissue sections has shown ES to be morphologically composed of homogenous small, blue, round cells arranged in sheets with or with- out pseudorosette formation. Intracytoplasmic glyco- gen can be detected using periodic acid-Schiff stain with and without diastase digestion. However, results are not specific. With the use of immunohistochemi- cal analysis, ES is shown to characteristically express CD99 and FLI-/] [15]. CD99 is a 32-kDa cell sur- face glycoprotein encoded by the MIC2 gene. FLI-1 nuclear reactivity is typically detected in 71% of cases of ES and PNET, which may also have EWS-FLI-1 fusion. Both markers are very useful in assisting the diagnosis in patients who have typical clinical
or what potential targets can be explored for the devel- opment of successful therapeutic modalities, we must first examine the molecular mechanism of metastasis. Although the steps outlined in the preceding para- graphs identify the basic steps of the metastatic pro- cess, the molecular mechanisms are far more complex and challenging. Many of the molecules and pathways are involved in several different steps of metastasis and often influence multiple pathophysiologic com- ponents such as growth, proliferation, angiogenesis, apoptosis and migration. Many of these actions occur concurrently, and frequently are interdependent. Although the steps outlined in the preceding para-
or what potential targets can be explored for the devel- opment of successful therapeutic modalities, we must first examine the molecular mechanism of metastasis. Although the steps outlined in the preceding para- graphs identify the basic steps of the metastatic pro- cess, the molecular mechanisms are far more complex and challenging. Many of the molecules and pathways are involved in several different steps of metastasis and often influence multiple pathophysiologic com- ponents such as growth, proliferation, angiogenesis, apoptosis and migration. Many of these actions occur concurrently, and frequently are interdependent. Although the steps outlined in the preceding para-
Fig. 11.2 Microscopically, the lesions are frequently well- delineated from adjacent brain which demonstrates reactive gliosis. Formalin fixed, paraffin embedded, Hematoxylin and Eosin stained section — original magnification 200 Fig. 11.1 Multiple, well delineated, solid and focally necrotic nodules of metastatic adenocarcinoma (arrows) are seen on this coronal section through the cerebral hemispheres
Fig. 11.2 Microscopically, the lesions are frequently well- delineated from adjacent brain which demonstrates reactive gliosis. Formalin fixed, paraffin embedded, Hematoxylin and Eosin stained section — original magnification 200 Fig. 11.1 Multiple, well delineated, solid and focally necrotic nodules of metastatic adenocarcinoma (arrows) are seen on this coronal section through the cerebral hemispheres
degredation of RB1 and p53. RB1 and p53 are tumor suppressor factors. Loss of RB1 and p53 will increase the risk of developing carcinoma Fig 12.1 Carcinogenesis of HPV. The integration of HPV into human genome interruptes E2 of human genome. The loss of E2 causes over expression of E6 and E7, which eventually results in
degredation of RB1 and p53. RB1 and p53 are tumor suppressor factors. Loss of RB1 and p53 will increase the risk of developing carcinoma Fig 12.1 Carcinogenesis of HPV. The integration of HPV into human genome interruptes E2 of human genome. The loss of E2 causes over expression of E6 and E7, which eventually results in
Fig. 13.1 Comparison of the ratio of estrogen receptor (ER) positive and negative cases of 456 breast carcinomas diag- nosed in postmenopausal women according to use of combined hormone replacement therapy (HRT)
Fig. 13.1 Comparison of the ratio of estrogen receptor (ER) positive and negative cases of 456 breast carcinomas diag- nosed in postmenopausal women according to use of combined hormone replacement therapy (HRT)
‘ig. 13.2 A. Invasive arcinoma “with ductal and obular features”. The tumor ells focally show a single file nfiltrating pattern reminiscent f lobular carcinoma. Small reas of lobular-like growth attern can be often seen in therwise usual ductal (no pecial type, NST) arcinomas and their presence loes not warrant a diagnosis f mixed type carcinoma. B. ‘he foci of carcinoma howing lobular-like growth atterns retain strong nembrane staining for i-cadherin. C. Invasive arcinoma, mixed ductal NST nd lobular type. The NST omponent of the carcinoma ; composed of cohesive nests nd glands, while the distinct obular component shows lyscohesive cells growing ina ingle file infiltrative patter. ). E-cadherin mmunostaining shows strong nembrane reactivity in the (ST carcinoma component nd complete lack of staining n the lobular component
‘ig. 13.2 A. Invasive arcinoma “with ductal and obular features”. The tumor ells focally show a single file nfiltrating pattern reminiscent f lobular carcinoma. Small reas of lobular-like growth attern can be often seen in therwise usual ductal (no pecial type, NST) arcinomas and their presence loes not warrant a diagnosis f mixed type carcinoma. B. ‘he foci of carcinoma howing lobular-like growth atterns retain strong nembrane staining for i-cadherin. C. Invasive arcinoma, mixed ductal NST nd lobular type. The NST omponent of the carcinoma ; composed of cohesive nests nd glands, while the distinct obular component shows lyscohesive cells growing ina ingle file infiltrative patter. ). E-cadherin mmunostaining shows strong nembrane reactivity in the (ST carcinoma component nd complete lack of staining n the lobular component
infiltrating pattern to carcinomas having clearly dis- tinct components of classic lobular and ductal (NST) areas (Fig. 13.2). In fact, the only study using central pathology review [85] indicated that HRT is associated with low tumor grade, rather than a specific histologic type. In this study, the agreement rates for the diagno- sis of lobular and “mixed ductal-lobular’” carcinomas were only 68 and 18%, respectively, highlighting the with low tumor grade, rather than a specific histologic Table 13.1 Summary of results of epidemiological studies on HRT use and breast cancer histology
infiltrating pattern to carcinomas having clearly dis- tinct components of classic lobular and ductal (NST) areas (Fig. 13.2). In fact, the only study using central pathology review [85] indicated that HRT is associated with low tumor grade, rather than a specific histologic type. In this study, the agreement rates for the diagno- sis of lobular and “mixed ductal-lobular’” carcinomas were only 68 and 18%, respectively, highlighting the with low tumor grade, rather than a specific histologic Table 13.1 Summary of results of epidemiological studies on HRT use and breast cancer histology
stimulation of growth of established breast cancers and concluded that invasive breast cancers diagnosed in women who use HRT may have a worse prognosis. A recent systematic review of 25 studies on the influence of hormone use on prognostic factors of breast cancers concluded that, because of their methodology, the epi- demiological studies cannot negate the findings of the WHI [113]. of hormone use on prognostic factors of breast cancers
stimulation of growth of established breast cancers and concluded that invasive breast cancers diagnosed in women who use HRT may have a worse prognosis. A recent systematic review of 25 studies on the influence of hormone use on prognostic factors of breast cancers concluded that, because of their methodology, the epi- demiological studies cannot negate the findings of the WHI [113]. of hormone use on prognostic factors of breast cancers
Importantly, there are profound differences between benign and malignant breast tissue concerning the hor- mone dependent regulation of cell proliferation. In the resting normal mammary tissue ERa and PR are expressed in very few epithelial cells, while ERB is present in 70% of the cells. The minority (approxi- mately 2%) of epithelial cells which are proliferating, do not contain ER and the mitoses are probably con- trolled by paracrine interactions of adjacent epithelial cells [152, 153]. In contrast, the transition of benign to malignant mammary tissue is characterized by a switch from paracrine to autocrine regulation of epithe- lial cell proliferation by sex steroids, i.e., in breast tumors ERa and PR are also expressed in proliferating cells [154-156]. Studies have shown that the mitotic rate of both ER/PR positive and ER/PR negative breast Studies of patients with invasive breast carcinoma have shown that early changes (<3 weeks) in cell proliferation and PR expression occur after anti- estrogen therapy in ER positive but not in ER negative tumors [162—165]. These changes are accepted surro- gate markers of clinical tumor response. In one study [165], the decrease in proliferation correlated with sub- sequent reduction in tumor size in patients receiving tamoxifen therapy. Despite its clear clinical impor- tance, there is only a single study reported in the lit- erature investigating the effect of HRT withdrawal on erature investigating the effect of HRT withdrawal on
Importantly, there are profound differences between benign and malignant breast tissue concerning the hor- mone dependent regulation of cell proliferation. In the resting normal mammary tissue ERa and PR are expressed in very few epithelial cells, while ERB is present in 70% of the cells. The minority (approxi- mately 2%) of epithelial cells which are proliferating, do not contain ER and the mitoses are probably con- trolled by paracrine interactions of adjacent epithelial cells [152, 153]. In contrast, the transition of benign to malignant mammary tissue is characterized by a switch from paracrine to autocrine regulation of epithe- lial cell proliferation by sex steroids, i.e., in breast tumors ERa and PR are also expressed in proliferating cells [154-156]. Studies have shown that the mitotic rate of both ER/PR positive and ER/PR negative breast Studies of patients with invasive breast carcinoma have shown that early changes (<3 weeks) in cell proliferation and PR expression occur after anti- estrogen therapy in ER positive but not in ER negative tumors [162—165]. These changes are accepted surro- gate markers of clinical tumor response. In one study [165], the decrease in proliferation correlated with sub- sequent reduction in tumor size in patients receiving tamoxifen therapy. Despite its clear clinical impor- tance, there is only a single study reported in the lit- erature investigating the effect of HRT withdrawal on erature investigating the effect of HRT withdrawal on
metastatic adenocarcinoma from primary lung poorly differentiated adenocarcinoma. Immunoperoxidase stains are helpful in making this distinction in most instances. Lung adenocarcinoma is immunoreactive for CK 7 and TTF-1 in a majority of cases, except in mucinous BAC and adenocarcinomas that are very poorly differentiated. CDX-2 reactivity in metastatic lesion from colorectal adenocarcinomas is helpful in differentiating it from lung primary adenocarcinomas which are usually nonreactive. TTF-1 reactivity does not entirely rule in primary lung adenocarcinoma since
metastatic adenocarcinoma from primary lung poorly differentiated adenocarcinoma. Immunoperoxidase stains are helpful in making this distinction in most instances. Lung adenocarcinoma is immunoreactive for CK 7 and TTF-1 in a majority of cases, except in mucinous BAC and adenocarcinomas that are very poorly differentiated. CDX-2 reactivity in metastatic lesion from colorectal adenocarcinomas is helpful in differentiating it from lung primary adenocarcinomas which are usually nonreactive. TTF-1 reactivity does not entirely rule in primary lung adenocarcinoma since
Fig. 15.1 Esophago-gastrectomy specimen showing the salmon-colored Barrett’s mucosa replacing the pearly white esophageal squamous mucosa at the esophago-gastric junction
Fig. 15.1 Esophago-gastrectomy specimen showing the salmon-colored Barrett’s mucosa replacing the pearly white esophageal squamous mucosa at the esophago-gastric junction
Fig. 15.3 Barrett’s esophagus with low grade dysplasia. Barrett’s mucosa showing glands with mild architectural distor- tion and gland lined by cells containing elongated (cigar shaped) and stratified nuclei which still retain nuclear polarity
Fig. 15.3 Barrett’s esophagus with low grade dysplasia. Barrett’s mucosa showing glands with mild architectural distor- tion and gland lined by cells containing elongated (cigar shaped) and stratified nuclei which still retain nuclear polarity
Fig. 15.2 Barrett’s esophagus. Transition of esophageal squa- mous mucosa into a columnar epithelium containing scattered goblet cells (intestinal metaplasia)
Fig. 15.2 Barrett’s esophagus. Transition of esophageal squa- mous mucosa into a columnar epithelium containing scattered goblet cells (intestinal metaplasia)
Fig. 15.4 Barrett’s esophagus with high grade dysplasia. Intestinalized mucosa showing distorted and crowded glands containing enlarged cells. The cellular nuclei are polygonal, hyperchromatic, and exhibit anisocytosis and prominent nucle- oli. Most importantly for the diagnosis, there is loss of nuclear polarity
Fig. 15.4 Barrett’s esophagus with high grade dysplasia. Intestinalized mucosa showing distorted and crowded glands containing enlarged cells. The cellular nuclei are polygonal, hyperchromatic, and exhibit anisocytosis and prominent nucle- oli. Most importantly for the diagnosis, there is loss of nuclear polarity
Fig. 15.5 Barrett’s esophagus with intramucosal carcinoma. Barrett’s mucosa with high grade dysplasia and glands exhibit- ing early syncytial pattern of growth. There are cellular clusters or single cells infiltrating the lamina propria. An attempt to desmoplastic reaction around these infiltrating cells is also noted (arrow)
Fig. 15.5 Barrett’s esophagus with intramucosal carcinoma. Barrett’s mucosa with high grade dysplasia and glands exhibit- ing early syncytial pattern of growth. There are cellular clusters or single cells infiltrating the lamina propria. An attempt to desmoplastic reaction around these infiltrating cells is also noted (arrow)
Fig. 15.6 Invasive adenocarcinoma arising in Barrett’s esoph- agus. A poorly differentiated adenocarcinoma infiltrating the esophageal mucosa and surrounding vascular structures. Some of the tumor cells are seen within the vascular wall (arrow)
Fig. 15.6 Invasive adenocarcinoma arising in Barrett’s esoph- agus. A poorly differentiated adenocarcinoma infiltrating the esophageal mucosa and surrounding vascular structures. Some of the tumor cells are seen within the vascular wall (arrow)
Fig. 16.3 Grades of dysplasia in PanIN 2. The nuclei are enlarged, hyperchromatic and elongated. They are crowded and overlapping but remain oriented to the basal layer
Fig. 16.3 Grades of dysplasia in PanIN 2. The nuclei are enlarged, hyperchromatic and elongated. They are crowded and overlapping but remain oriented to the basal layer
Fig. 16.2 Grades of dysplasia in PanIN 1b. The lining epithe- lium becomes architecturally complex, and is thrown into small papillae. The nuclei remain basally located, with minimal atypia Fig. 16.1 Grades of dysplasia in PanIN la. The normal ductal epithelium in this small caliber duct is replaced by tall, columnar, mucinous epithelium
Fig. 16.2 Grades of dysplasia in PanIN 1b. The lining epithe- lium becomes architecturally complex, and is thrown into small papillae. The nuclei remain basally located, with minimal atypia Fig. 16.1 Grades of dysplasia in PanIN la. The normal ductal epithelium in this small caliber duct is replaced by tall, columnar, mucinous epithelium
Fig. 16.4 Grades of dysplasia in PanIN 3. The nuclei are enlarged with vesicular nuclei and prominent nucleoli. There is significant mitotic activity, and the mitoses extend to the surface. The nuclei show loss of polarity, extending to the luminal surface
Fig. 16.4 Grades of dysplasia in PanIN 3. The nuclei are enlarged with vesicular nuclei and prominent nucleoli. There is significant mitotic activity, and the mitoses extend to the surface. The nuclei show loss of polarity, extending to the luminal surface
Table 16.1 Regulatory processes or pathways altered in pan- creatic carcinoma, identified using global genomic analysis signaling pathways merit further discussion since these are relatively recently identified alterations in pan- creatic carcinoma, and both pathways play a role in normal pancreatic development.
Table 16.1 Regulatory processes or pathways altered in pan- creatic carcinoma, identified using global genomic analysis signaling pathways merit further discussion since these are relatively recently identified alterations in pan- creatic carcinoma, and both pathways play a role in normal pancreatic development.
Fig. 16.5 Acinar-ductal metaplasia in human pancreas. This image is taken from a pancreatic resection specimen. This duct is lined by mucinous epithelium. Evident within the duct are also acinar cells. A transition from the acinar cells to the ductal mucinous cells is evident
Fig. 16.5 Acinar-ductal metaplasia in human pancreas. This image is taken from a pancreatic resection specimen. This duct is lined by mucinous epithelium. Evident within the duct are also acinar cells. A transition from the acinar cells to the ductal mucinous cells is evident
The table is reproduced from the WHO monograph on Pathology and Genetics, “Tumors of Endocrine Organs, 3rd edition”, 2004. Table 17.1 Phenotyping and clinical features of the different types of PENs (Heitz 2004) Classifying PENs according to size, proliferative activity, angioinvasion, organ invasion, metastases, Current genetic and molecular techniques have found that the biology of PENs is complex, without a well-recognized pathway being strongly influential. These tumors appear to develop in stages with multiple sequential mutations required to progress to malig- nancy (Fig. 17.1) [17]. Myriads of factors interact in complex ways to influence development, differentia- tion, secretion, and the interaction of tumor with its environment [18].
The table is reproduced from the WHO monograph on Pathology and Genetics, “Tumors of Endocrine Organs, 3rd edition”, 2004. Table 17.1 Phenotyping and clinical features of the different types of PENs (Heitz 2004) Classifying PENs according to size, proliferative activity, angioinvasion, organ invasion, metastases, Current genetic and molecular techniques have found that the biology of PENs is complex, without a well-recognized pathway being strongly influential. These tumors appear to develop in stages with multiple sequential mutations required to progress to malig- nancy (Fig. 17.1) [17]. Myriads of factors interact in complex ways to influence development, differentia- tion, secretion, and the interaction of tumor with its environment [18].
PRAD-1, parathyroid adenoma-telated protein; TGF, transform- ing growth factor; TSC1 and TSC2, tuberous sclerosis genes; VEGF, vasculoendothelial growth factor; VHL, von Hippel- Lindau genes Fig. 17.1 [17] Diagram summaryizing the of major events involved in pancreatic endocrine tumor initiation, progression, and the pathogenic mechanisms involved in metastasis. bFGF, basic fibroblast growth factor; FHIT, fragile histidine triad; MENI, multiple endocrine neoplasia type 1; NF1, neurofibro- matosis type 1 (neurofibromin); NGF, nerve growth factor;
PRAD-1, parathyroid adenoma-telated protein; TGF, transform- ing growth factor; TSC1 and TSC2, tuberous sclerosis genes; VEGF, vasculoendothelial growth factor; VHL, von Hippel- Lindau genes Fig. 17.1 [17] Diagram summaryizing the of major events involved in pancreatic endocrine tumor initiation, progression, and the pathogenic mechanisms involved in metastasis. bFGF, basic fibroblast growth factor; FHIT, fragile histidine triad; MENI, multiple endocrine neoplasia type 1; NF1, neurofibro- matosis type 1 (neurofibromin); NGF, nerve growth factor;
Fig. 17.2 [24] A schematic model for the process of pancre- atic differentiation. The identified transcription factors and other molecules that are candidates for islet progenitor markers are shown. + + + : high expression; + + : relative high expres- sion; + : moderate expression; +/— : very low expression; — : no expression. n.d. : not determined Other mechanisms implicated in the neogenesis of B-cells include transdifferentiation of adult ductal, aci- nar, or even extra-pancreatic cells such as liver [32-35] or intestine [36]. Multipotential adult tissues (differen- tiated or stem cells) have been shown to cross lineage boundaries. For example, under proper stimulation, cells within the pancreas have been shown to give rise to hepatocytes [24, 37, 38]. Adenovirus-mediated uptake of PDX-1 into liver cells in vivo induced a B-cell phenotype that produced insulin and controlled the hyperglycemia of streptozocin-induced diabetes in rats [39]. Another study showed overexpression of an activated form of PDX-1-induced liver cells to become pancreatic cells in vitro and in vivo [33]. Hepatic stem/progenitor cells (also known as oval cells) can differentiate into insulin-producing cells [32]. There are several possible mechanisms of transdifferentia- tion. It is likely that a common progenitor cell from the The inability to find islet stem/progenitor cells is due to the lack of specific cell markers [24]. Evidence exists that there may be more than one kind of stem cell. Studies have identified possible stem cell candidates expressing varied progenitor markers. These include glucose transporter 2, insulin, somato- statin (SST), nestin, pancreatic duodenal homeobox 1 (PDX-1), and islet neogenesis-associated protein [24, 29-31]. There are multiple transcription factors and other molecules that are potential candidates for islet progenitor markers (Fig. 17.2) [24]. 24, 29-31]. There are multiple transcription factors
Fig. 17.2 [24] A schematic model for the process of pancre- atic differentiation. The identified transcription factors and other molecules that are candidates for islet progenitor markers are shown. + + + : high expression; + + : relative high expres- sion; + : moderate expression; +/— : very low expression; — : no expression. n.d. : not determined Other mechanisms implicated in the neogenesis of B-cells include transdifferentiation of adult ductal, aci- nar, or even extra-pancreatic cells such as liver [32-35] or intestine [36]. Multipotential adult tissues (differen- tiated or stem cells) have been shown to cross lineage boundaries. For example, under proper stimulation, cells within the pancreas have been shown to give rise to hepatocytes [24, 37, 38]. Adenovirus-mediated uptake of PDX-1 into liver cells in vivo induced a B-cell phenotype that produced insulin and controlled the hyperglycemia of streptozocin-induced diabetes in rats [39]. Another study showed overexpression of an activated form of PDX-1-induced liver cells to become pancreatic cells in vitro and in vivo [33]. Hepatic stem/progenitor cells (also known as oval cells) can differentiate into insulin-producing cells [32]. There are several possible mechanisms of transdifferentia- tion. It is likely that a common progenitor cell from the The inability to find islet stem/progenitor cells is due to the lack of specific cell markers [24]. Evidence exists that there may be more than one kind of stem cell. Studies have identified possible stem cell candidates expressing varied progenitor markers. These include glucose transporter 2, insulin, somato- statin (SST), nestin, pancreatic duodenal homeobox 1 (PDX-1), and islet neogenesis-associated protein [24, 29-31]. There are multiple transcription factors and other molecules that are potential candidates for islet progenitor markers (Fig. 17.2) [24]. 24, 29-31]. There are multiple transcription factors
Fig. 17.3 [46] Proposed mechanisms for the phenotypic switch from a solid islet to a regeneration-competent DEC. (a) Direct transformation of islet mantle cells to duct-like cells, with con- comitant loss of centrally located B-cells. (b) Activation and proliferation of an intra-islet progenitor cell that comes to form all cells of the cystic structure. (c) Cells of the newly formed duct-like structure are derived from both direct transformation of mantle endocrine cells and putative intra-islet progenitor cells. (d) The cystic duct-like structure forms solely through direct transformation of mantle endocrine cells, while an intra-islet progenitor cell remains associated with the duct-like structure
Fig. 17.3 [46] Proposed mechanisms for the phenotypic switch from a solid islet to a regeneration-competent DEC. (a) Direct transformation of islet mantle cells to duct-like cells, with con- comitant loss of centrally located B-cells. (b) Activation and proliferation of an intra-islet progenitor cell that comes to form all cells of the cystic structure. (c) Cells of the newly formed duct-like structure are derived from both direct transformation of mantle endocrine cells and putative intra-islet progenitor cells. (d) The cystic duct-like structure forms solely through direct transformation of mantle endocrine cells, while an intra-islet progenitor cell remains associated with the duct-like structure
Fig. 17.4 [46] Islet-to-DEC transformation. Freshly isolated adult human islets expressed (a) insulin and (b) glucagon + somatostatin + pancreatic polypeptide. (ce) Inverted microscopy and (d) CK-19 immunoreactivity demonstrated a typical islet- to-DEC transformation, starting from a freshly isolated islet (day 0), through a transitional structure (day 3), to a fully formed DEC (day 10, scale bars 100 mm)
Fig. 17.4 [46] Islet-to-DEC transformation. Freshly isolated adult human islets expressed (a) insulin and (b) glucagon + somatostatin + pancreatic polypeptide. (ce) Inverted microscopy and (d) CK-19 immunoreactivity demonstrated a typical islet- to-DEC transformation, starting from a freshly isolated islet (day 0), through a transitional structure (day 3), to a fully formed DEC (day 10, scale bars 100 mm)
Fig. 17.5 [46] DECs can be transformed back to ILS that are morphologically similar to isolated islets. (a) INGAP104- 118 induced the formation of neoislets, starting from a DEC (day 10), through a transitional structure (day 12), into an ILS (day 14). (b) Neither control medium, GLP-1 nor exendin-4, resulted in any phenotypic transformation (representative pho- tomicrographs; scale bars 100 mm). Immunodetection of (c) insulin and (d) glucagon + somatostatin + pancreatic polypeptide established the reemergence of normal islet architecture during DEC-to-ILS progression (days 10, 12 and 14), while (e) CK-19 immunoreactivity was lost (scale bars 100 mm). (f) The effect of INGAP104-118 was inhibited in a dose-responsive manner by a rabbit polyclonal a-INGAP101—121 antibody (mean + S.E.M: *P<0.05 versus INGAP104—-118)
Fig. 17.5 [46] DECs can be transformed back to ILS that are morphologically similar to isolated islets. (a) INGAP104- 118 induced the formation of neoislets, starting from a DEC (day 10), through a transitional structure (day 12), into an ILS (day 14). (b) Neither control medium, GLP-1 nor exendin-4, resulted in any phenotypic transformation (representative pho- tomicrographs; scale bars 100 mm). Immunodetection of (c) insulin and (d) glucagon + somatostatin + pancreatic polypeptide established the reemergence of normal islet architecture during DEC-to-ILS progression (days 10, 12 and 14), while (e) CK-19 immunoreactivity was lost (scale bars 100 mm). (f) The effect of INGAP104-118 was inhibited in a dose-responsive manner by a rabbit polyclonal a-INGAP101—121 antibody (mean + S.E.M: *P<0.05 versus INGAP104—-118)
Table 17.3, Hormones and growth factors affecting islet cell mass [1] type 1 (MEN! gene), von Hippel-Lindau disease (VHL gene), neurofibromatosis (NF-1 gene), and tuberous sclerosis (TSC1 and TSC2 genes). Understanding the development of PENs as a part of these syndromes contributes to better understanding of the genesis of sporadic PENs.
Table 17.3, Hormones and growth factors affecting islet cell mass [1] type 1 (MEN! gene), von Hippel-Lindau disease (VHL gene), neurofibromatosis (NF-1 gene), and tuberous sclerosis (TSC1 and TSC2 genes). Understanding the development of PENs as a part of these syndromes contributes to better understanding of the genesis of sporadic PENs.
Table 17.4 Genetic syndromes associated with an increased incidence of PENs [71] neoplasia of the pancreatic neuroendocrine cells is the second most common endocrine manifestation and eventually occurs in about 60% or more of MEN-1 patients. The most common enteropancreatic tumors are gastrinomas [76, 77], which often occur in the wall of the duodenum and in peri-pancreatic lymph nodes. Gastrinomas and insulinomas are the most com- mon functional PENs associated with MEN-1. Non- functioning tumors are also common [76]. Clustering of subvariants of MEN-1 such as insulinomas [78, 79] and aggressive gastrinomas [80] within small MEN-1 families suggest specific MEN-1 mutations may corre- late with specific clinical variants. Pancreatic neuroen- docrine tumors in MEN-| are invariably multifocal and may be widely dispersed in the pancreas and duode- num [76]. Consequently, the role of surgical manage- ment is controversial [81, 82]. PENs in MEN-I may also present as multiple clinically silent enteropan- creatic macroadenomas, discussed later, which may be found at surgery or at autopsy in almost 100% of MEN-1 patients older than 40 years [74, 78, 83]. Approximately 80% of MENI cases are familial, whereas 20% appear to be associated with mutations based on negative familial history [84]. that potentially interact with menin include SMAD1, SMAD3, SMAD5, PEM, NM23, nuclear factor kB, runx2, and several others, the importance of which is also unknown [89-95]. The precise physiologic role of menin has not been elucidated, and it is not clear why its absence results in endocrine tumor pathogenesis.
Table 17.4 Genetic syndromes associated with an increased incidence of PENs [71] neoplasia of the pancreatic neuroendocrine cells is the second most common endocrine manifestation and eventually occurs in about 60% or more of MEN-1 patients. The most common enteropancreatic tumors are gastrinomas [76, 77], which often occur in the wall of the duodenum and in peri-pancreatic lymph nodes. Gastrinomas and insulinomas are the most com- mon functional PENs associated with MEN-1. Non- functioning tumors are also common [76]. Clustering of subvariants of MEN-1 such as insulinomas [78, 79] and aggressive gastrinomas [80] within small MEN-1 families suggest specific MEN-1 mutations may corre- late with specific clinical variants. Pancreatic neuroen- docrine tumors in MEN-| are invariably multifocal and may be widely dispersed in the pancreas and duode- num [76]. Consequently, the role of surgical manage- ment is controversial [81, 82]. PENs in MEN-I may also present as multiple clinically silent enteropan- creatic macroadenomas, discussed later, which may be found at surgery or at autopsy in almost 100% of MEN-1 patients older than 40 years [74, 78, 83]. Approximately 80% of MENI cases are familial, whereas 20% appear to be associated with mutations based on negative familial history [84]. that potentially interact with menin include SMAD1, SMAD3, SMAD5, PEM, NM23, nuclear factor kB, runx2, and several others, the importance of which is also unknown [89-95]. The precise physiologic role of menin has not been elucidated, and it is not clear why its absence results in endocrine tumor pathogenesis.
Fig. 17.6 [112] Proposed development of pancreatic microade- nomas in MENI1. Monohormonal endocrine cell clusters (MECCs) develop most frequently within normal islets (middle) but also in ducts (bottom) and hyperplastic islets (top) through 11q13 LOH. MECCs progress to microadenomas (MA). The development of MECCs and their progression to microadenomas cause disruption of the normal islet structure. The pathogenetic mechanism leading to islet cell hyperplasia is unknown Evidence for microadenomas includes hyperplas- tic foci of gastrin cells seen by light microscopy in the duodenum of gastrinoma specimens from MEN-1 but not from sporadic gastrinomas [113]. Furthermore, in the heterozygous knockout of the MENI gene in mice, giant hyperplastic islets precede the devel- opment of insulinoma, suggesting that subtle islet hyperplasia may be an unrecognized precursor lesion in MEN-1! of humans despite the presence of one normal MEN allele. One could speculate that hyper- plasia is an expression of MEN1 heterozygosity [114, 115]. Further studies are needed to link these findings with an as yet undiscovered genetic basis of tumor development.
Fig. 17.6 [112] Proposed development of pancreatic microade- nomas in MENI1. Monohormonal endocrine cell clusters (MECCs) develop most frequently within normal islets (middle) but also in ducts (bottom) and hyperplastic islets (top) through 11q13 LOH. MECCs progress to microadenomas (MA). The development of MECCs and their progression to microadenomas cause disruption of the normal islet structure. The pathogenetic mechanism leading to islet cell hyperplasia is unknown Evidence for microadenomas includes hyperplas- tic foci of gastrin cells seen by light microscopy in the duodenum of gastrinoma specimens from MEN-1 but not from sporadic gastrinomas [113]. Furthermore, in the heterozygous knockout of the MENI gene in mice, giant hyperplastic islets precede the devel- opment of insulinoma, suggesting that subtle islet hyperplasia may be an unrecognized precursor lesion in MEN-1! of humans despite the presence of one normal MEN allele. One could speculate that hyper- plasia is an expression of MEN1 heterozygosity [114, 115]. Further studies are needed to link these findings with an as yet undiscovered genetic basis of tumor development.
Fig. 17.7 [145] Schematic representation of the signaling molecules and pathways involved in insulinoma tumorigenesis. The upper part of the figure represents the proteins playing a role in MEN-1-associated insulinomas and the lower part those suggested to be involved in sporadic insulinoma tumorigenesis. Proteins with a loss of function are highlighted in red and those with a gain of function are highlighted in green. Proteins, whose role in insulinoma tumorigenesis has been suggested but is not yet clear, are represented in white
Fig. 17.7 [145] Schematic representation of the signaling molecules and pathways involved in insulinoma tumorigenesis. The upper part of the figure represents the proteins playing a role in MEN-1-associated insulinomas and the lower part those suggested to be involved in sporadic insulinoma tumorigenesis. Proteins with a loss of function are highlighted in red and those with a gain of function are highlighted in green. Proteins, whose role in insulinoma tumorigenesis has been suggested but is not yet clear, are represented in white
Table 17.5 Candidate genes for insulinoma tumorigenesis [145]
Table 17.5 Candidate genes for insulinoma tumorigenesis [145]
17.11.1 Comparative Genomic Hybridization chromosomes 19, 5, 14p, 12q, 17, 20g, 15, 18, 9q, and 17p, as well as losses of chromosomes Ip, 6, 11q, 3q, 11p, and Xq [146-151]. Nonfunctional PENs contained more genetic aberrations than functional tumors [146], metastases had a higher average number of chromosomal aberrations than matched primaries [147], and 11q losses and 7q gains were commonali- ties between all 5 studies, pointing to their importance in PEN development.
17.11.1 Comparative Genomic Hybridization chromosomes 19, 5, 14p, 12q, 17, 20g, 15, 18, 9q, and 17p, as well as losses of chromosomes Ip, 6, 11q, 3q, 11p, and Xq [146-151]. Nonfunctional PENs contained more genetic aberrations than functional tumors [146], metastases had a higher average number of chromosomal aberrations than matched primaries [147], and 11q losses and 7q gains were commonali- ties between all 5 studies, pointing to their importance in PEN development.
Table 17.6 Genetic alterations described to occur in PENs [14, 145] A number of chromosomal aberrations have been identified in PENs. Most common abnormalities are found in chromosomes I, 3 and 6 as summarized in Table 17.7. Loss of heterozygosity at chromosome | was found in 34% of PETs and was found to be more common in tumors with hepatic metastasis [154, 155]. LOH for chromosome | has also been reported in sev- eral other tumors, including colorectal carcinoma, neu- roblastoma, breast cancer, hepatocellular carcinoma, and melanoma [156]. In these tumors, the most fre- quently involved region is 1p36, the recently identified location of p73 [157], a possible tumor suppressor gene. One of two regions of LOH on chromosome 1 associated with malignant PENs includes a region of Ip between D1S1597 and pter, the region of 1p36 lost in other tumor types. Chen et al. [158] identi- fied chromosome 1 LOH on 1q31-32 and 1q21-—23 in almost half of the gastrinomas studied and found
Table 17.6 Genetic alterations described to occur in PENs [14, 145] A number of chromosomal aberrations have been identified in PENs. Most common abnormalities are found in chromosomes I, 3 and 6 as summarized in Table 17.7. Loss of heterozygosity at chromosome | was found in 34% of PETs and was found to be more common in tumors with hepatic metastasis [154, 155]. LOH for chromosome | has also been reported in sev- eral other tumors, including colorectal carcinoma, neu- roblastoma, breast cancer, hepatocellular carcinoma, and melanoma [156]. In these tumors, the most fre- quently involved region is 1p36, the recently identified location of p73 [157], a possible tumor suppressor gene. One of two regions of LOH on chromosome 1 associated with malignant PENs includes a region of Ip between D1S1597 and pter, the region of 1p36 lost in other tumor types. Chen et al. [158] identi- fied chromosome 1 LOH on 1q31-32 and 1q21-—23 in almost half of the gastrinomas studied and found
Fig. 17.8 [16] In this pancreatic endocrine tumor (PET) chro- mosomal aberration pyramid, chromosomal losses or gains from comparative genomic hybridization studies are listed from the most frequent (bottom) to the least frequent (top). An aster- isk identifies the chromosomal aberrations that were associated most frequently with metastatic tissue, suggesting a possible role in tumor progression toward metastatic behavior. Adapted by Zikusoka, et al. [16] from Speel et al. [146]; Stumpf et al. [147]; Zhao et al. [148]; Tonnies et al. [149]; Terris et al. [150]; and Kytola et al. [151]
Fig. 17.8 [16] In this pancreatic endocrine tumor (PET) chro- mosomal aberration pyramid, chromosomal losses or gains from comparative genomic hybridization studies are listed from the most frequent (bottom) to the least frequent (top). An aster- isk identifies the chromosomal aberrations that were associated most frequently with metastatic tissue, suggesting a possible role in tumor progression toward metastatic behavior. Adapted by Zikusoka, et al. [16] from Speel et al. [146]; Stumpf et al. [147]; Zhao et al. [148]; Tonnies et al. [149]; Terris et al. [150]; and Kytola et al. [151]
LIV: Liver LN: Lymph Node PPT: Peripancreatic Tissue O: Ovary P: Peritoneum
LIV: Liver LN: Lymph Node PPT: Peripancreatic Tissue O: Ovary P: Peritoneum
Fig. 17.9 [206] A schematic representation of RIPTag tumori- genesis. T-antigen expression commences during embryogenesis but is without apparent effect until 4-5 weeks when sporadic islets become hyperplastic (H); over time 50-70% become hyperplastic. At 7-9 weeks, angiogenic islets (A) appear. From these angiogenic islets emerge encapsulated tumors (10-12 weeks; T) (adenomas) of which a subset develop into invasive carcinoma (IC). “Incidence at all stages The CpG island methylation of the estrogen recep- ‘or gene, located on chromosome 6q24 [210], has also HER-2 neu, found on chromosome 11q21 [207], is a well-known oncogene that is overexpressed in some cases of breast carcinoma and is associated with increased malignant behavior, proliferation, and metastasis [208]. HER-2 neu has been studied in gas- trinomas, where its overexpression was found in a minority of these tumors, and was associated with liver metastasis [209].
Fig. 17.9 [206] A schematic representation of RIPTag tumori- genesis. T-antigen expression commences during embryogenesis but is without apparent effect until 4-5 weeks when sporadic islets become hyperplastic (H); over time 50-70% become hyperplastic. At 7-9 weeks, angiogenic islets (A) appear. From these angiogenic islets emerge encapsulated tumors (10-12 weeks; T) (adenomas) of which a subset develop into invasive carcinoma (IC). “Incidence at all stages The CpG island methylation of the estrogen recep- ‘or gene, located on chromosome 6q24 [210], has also HER-2 neu, found on chromosome 11q21 [207], is a well-known oncogene that is overexpressed in some cases of breast carcinoma and is associated with increased malignant behavior, proliferation, and metastasis [208]. HER-2 neu has been studied in gas- trinomas, where its overexpression was found in a minority of these tumors, and was associated with liver metastasis [209].
(n = 6) — are shown in the rows below. The PEN number cor- responds to the position on the tissue array. Tumor cell staining is indicated by asterisks, endothelial cell staining by arrows, and immune cell staining by arrowheads. (Y) The cathepsin staining for each tissue specimen was scored as negative (0) or positive [three levels: weak (1); moderate (2); strong (3)] and graphed as the percentage of staining intensity for each stage. For each cathepsin, an overall test of differences among any of the groups (normal and tumor) was performed. An exact version of Mantel Haenszel’s test for trend was performed to look for differences in staining in each tumor group compared with the normal controls and to calculate P values, which are shown next to each data set. Bars, 50 ~m Fig. 17.10 Increased levels of cathepsins B and L are positively associated with tumor progression in human PEN lesions and associated metastases. A TMA was constructed from a panel of human PEN and normal pancreas tissues. (A—X) Tissue arrays were stained with antibodies against cathepsins B, L, S, and C as indicated. Cathepsin-positive cells are stained in brown, and hematoxylin (blue) was used as a counterstain. Representative images of normal human pancreas (n = 6) stained for each anti- body are shown in the first row, with normal islets indicated with a dotted black line, surrounded by normal exocrine cells. Representative images for each of the tumor stages — Benign Tumor (n = 22), Vascular Invasive Tumor (n = 12), Invasive Tumor (n = 11), Metastatic Primary (n = 23), and Metastasis
(n = 6) — are shown in the rows below. The PEN number cor- responds to the position on the tissue array. Tumor cell staining is indicated by asterisks, endothelial cell staining by arrows, and immune cell staining by arrowheads. (Y) The cathepsin staining for each tissue specimen was scored as negative (0) or positive [three levels: weak (1); moderate (2); strong (3)] and graphed as the percentage of staining intensity for each stage. For each cathepsin, an overall test of differences among any of the groups (normal and tumor) was performed. An exact version of Mantel Haenszel’s test for trend was performed to look for differences in staining in each tumor group compared with the normal controls and to calculate P values, which are shown next to each data set. Bars, 50 ~m Fig. 17.10 Increased levels of cathepsins B and L are positively associated with tumor progression in human PEN lesions and associated metastases. A TMA was constructed from a panel of human PEN and normal pancreas tissues. (A—X) Tissue arrays were stained with antibodies against cathepsins B, L, S, and C as indicated. Cathepsin-positive cells are stained in brown, and hematoxylin (blue) was used as a counterstain. Representative images of normal human pancreas (n = 6) stained for each anti- body are shown in the first row, with normal islets indicated with a dotted black line, surrounded by normal exocrine cells. Representative images for each of the tumor stages — Benign Tumor (n = 22), Vascular Invasive Tumor (n = 12), Invasive Tumor (n = 11), Metastatic Primary (n = 23), and Metastasis
18.1 Introduction Contents Colorectal cancer (CRC) is the third most common malignancy and the fourth cause of cancer mortality, with over 1 million new cases diagnosed worldwide each year. The lifetime incidence for patients at aver- age risk is 5%, with 90% of cases occurring after age 50. Approximately | in 3 people who develop CRC die of this disease [1, 2]. The prognosis of CRC is closely associated with disease stage at the time of diagnosis. While early stage CRC is frequently cur- able with surgery, unresectable metastatic CRC is a fatal disease. Compelling evidence indicates that early detection and prevention by removal of premalignant polyps can reduce colorectal cancer mortality. Colorectal cancer (CRC) is the third most common Shaokun Shu and Jin Q. Cheng
18.1 Introduction Contents Colorectal cancer (CRC) is the third most common malignancy and the fourth cause of cancer mortality, with over 1 million new cases diagnosed worldwide each year. The lifetime incidence for patients at aver- age risk is 5%, with 90% of cases occurring after age 50. Approximately | in 3 people who develop CRC die of this disease [1, 2]. The prognosis of CRC is closely associated with disease stage at the time of diagnosis. While early stage CRC is frequently cur- able with surgery, unresectable metastatic CRC is a fatal disease. Compelling evidence indicates that early detection and prevention by removal of premalignant polyps can reduce colorectal cancer mortality. Colorectal cancer (CRC) is the third most common Shaokun Shu and Jin Q. Cheng
Contents Bladder cancer is a major cause of health expenses. It is
Contents Bladder cancer is a major cause of health expenses. It is
Fig. 20.1 The p53 pathway. Mutations of p53 or components of its pathway, i.e., p21 or Bax, interrupt cellular growth and apoptosis, leading to neoplastic transformation. The p53 gene is regulated through p14 which inhibits Mdm2 function. Mdm2 is known to suppress p53 activity and trigger its degradation. P53 also plays a role in angiogenesis and the transcription of genes involved in DNA repair survival rates as 61% versus 26% (P < 0.001) [15]. Cellular transition through the Gl to S phase is regulated by cyclin-dependent kinases (CDKs). P53 protein inhibits cell cycle progression at G1-S cell phase thereby arresting cell growth. P53 implements its control and influences tumor progression through the transcriptional activation of the p21WAFV/CIP! [6, 8, 15, 16, 23] gene, an integral part of the p53 path- way. The p21 WAFI/CIP! gene encodes the p21 protein, a universal cyclin-dependent kinase inhibitor (CDKID that can arrest cells in the G1 phase by inhibiting DNA replication [6, 15, 22, 29, 30] (Fig. 20.1). p21 WAFI/CIP! is upregulated by p53 in response to DNA dam- age and cellular stress. p21 arrests the cell cycle by inhibiting cyclin/CDK complexes, and in this man- ner prevents Rb phosphorylation [6, 15, 16, 23, 31]. Unphosphorylated Rb can then bind and sequester the transcription factor E2F thus preventing it from tran- scribing genes necessary for DNA synthesis [6, 15, 32]. Hence, there is an essential interaction between the components of the p53, p21 and Rb pathways [6, 15]. Rb also arrests cells in the G1/S phase in response to DNA damage, suggesting a possible link between Rb and p21 [6, 16, 22]. Loss of expression of p21 is considered to be abnormal [6, 16, 33, 34]. Loss of p21 expression has been shown to be a predictor of UC progression, tumor recurrence and decreased over- all survival [6, 8, 15, 16, 33, 34]. The p21/WAF1 gene, itself, is not a target for mutations [35]. A p21-negative ie a, eee The Mdm2 proto-oncogene, encoded on chromo- some 12q14.3-q15, is also an integral part of the p53 pathway. Mdm2 is involved in an autoregulatory feedback loop with p53 and is known to stabilize p53 [6, 8, 36]. p53 upregulates expression of Mdm2. Activated mdm2 then binds to p53 and serves as a negative regulator, inactivating its function by inhibit- ing its transcriptional activity [6, 16, 36-38]. Mdm2 is amplified in UC and the frequency of nuclear ampli- fication increases with tumor grade and stage. Mdm2- positive tumors are associated with early tumor stage and poor survival [6, 16, 33, 34]. Deregulation of the p53 pathway, associated with overexpression of mdm2 (mdm?2-positive) and loss of p21 (p21-negative) phenotypes, influences prognosis and outcome in UC [16]. Lymph node negative patients with p21-negative, p53-mutated, mdm2-positive tumors show a greater recurrence and lower survival rate than those with p21- positive, p53-negative, mdm2-negative tumors, inde- pendent of tumor grade or pathologic stage [6, 8, 16]. Studies have shown that p21 mutations and mdm2 amplification, by themselves, may not be clinically sig- nificant. However, in conjunction with mutated p53, it has been shown that p21 and mdm? can exert a cooper- ative effect impacting tumor progression and survival [16]. It is postulated that alterations of p53 and mdm2 influence clinical outcome during initial stages of UC, possibly accredited to their inhibition of apoptosis and cell growth. On the other hand, additive effects of other molecular defects, such as lack of p21, are postulated to influence later stages of UC progression [16]. molecular defects, such as lack of p21, are postulated
Fig. 20.1 The p53 pathway. Mutations of p53 or components of its pathway, i.e., p21 or Bax, interrupt cellular growth and apoptosis, leading to neoplastic transformation. The p53 gene is regulated through p14 which inhibits Mdm2 function. Mdm2 is known to suppress p53 activity and trigger its degradation. P53 also plays a role in angiogenesis and the transcription of genes involved in DNA repair survival rates as 61% versus 26% (P < 0.001) [15]. Cellular transition through the Gl to S phase is regulated by cyclin-dependent kinases (CDKs). P53 protein inhibits cell cycle progression at G1-S cell phase thereby arresting cell growth. P53 implements its control and influences tumor progression through the transcriptional activation of the p21WAFV/CIP! [6, 8, 15, 16, 23] gene, an integral part of the p53 path- way. The p21 WAFI/CIP! gene encodes the p21 protein, a universal cyclin-dependent kinase inhibitor (CDKID that can arrest cells in the G1 phase by inhibiting DNA replication [6, 15, 22, 29, 30] (Fig. 20.1). p21 WAFI/CIP! is upregulated by p53 in response to DNA dam- age and cellular stress. p21 arrests the cell cycle by inhibiting cyclin/CDK complexes, and in this man- ner prevents Rb phosphorylation [6, 15, 16, 23, 31]. Unphosphorylated Rb can then bind and sequester the transcription factor E2F thus preventing it from tran- scribing genes necessary for DNA synthesis [6, 15, 32]. Hence, there is an essential interaction between the components of the p53, p21 and Rb pathways [6, 15]. Rb also arrests cells in the G1/S phase in response to DNA damage, suggesting a possible link between Rb and p21 [6, 16, 22]. Loss of expression of p21 is considered to be abnormal [6, 16, 33, 34]. Loss of p21 expression has been shown to be a predictor of UC progression, tumor recurrence and decreased over- all survival [6, 8, 15, 16, 33, 34]. The p21/WAF1 gene, itself, is not a target for mutations [35]. A p21-negative ie a, eee The Mdm2 proto-oncogene, encoded on chromo- some 12q14.3-q15, is also an integral part of the p53 pathway. Mdm2 is involved in an autoregulatory feedback loop with p53 and is known to stabilize p53 [6, 8, 36]. p53 upregulates expression of Mdm2. Activated mdm2 then binds to p53 and serves as a negative regulator, inactivating its function by inhibit- ing its transcriptional activity [6, 16, 36-38]. Mdm2 is amplified in UC and the frequency of nuclear ampli- fication increases with tumor grade and stage. Mdm2- positive tumors are associated with early tumor stage and poor survival [6, 16, 33, 34]. Deregulation of the p53 pathway, associated with overexpression of mdm2 (mdm?2-positive) and loss of p21 (p21-negative) phenotypes, influences prognosis and outcome in UC [16]. Lymph node negative patients with p21-negative, p53-mutated, mdm2-positive tumors show a greater recurrence and lower survival rate than those with p21- positive, p53-negative, mdm2-negative tumors, inde- pendent of tumor grade or pathologic stage [6, 8, 16]. Studies have shown that p21 mutations and mdm2 amplification, by themselves, may not be clinically sig- nificant. However, in conjunction with mutated p53, it has been shown that p21 and mdm? can exert a cooper- ative effect impacting tumor progression and survival [16]. It is postulated that alterations of p53 and mdm2 influence clinical outcome during initial stages of UC, possibly accredited to their inhibition of apoptosis and cell growth. On the other hand, additive effects of other molecular defects, such as lack of p21, are postulated to influence later stages of UC progression [16]. molecular defects, such as lack of p21, are postulated
phosphorylation of Rb. Phosphorylated Rb releases E2F which then causes transcription of genes that promote proliferation. This process is also regulated by the p53 pathway. EGF, epider- mal growth factor; Ras-MAPK, Ras-mitogen activated protein kinase; CDK, cyclin-dependent kinase; Rb, retinoblastoma Fig. 20.2 Interactions of the p53 (yellow) and retinoblas- toma (blue) pathways in urothelial carcinogenesis. Extracellular growth signals, i.e., EGF, stimulate the Ras-MAPK signal transduction pathway. The Ras-MAPK pathway then transfers signals to the nucleus, where cyclin‘/CDK complexes induce
phosphorylation of Rb. Phosphorylated Rb releases E2F which then causes transcription of genes that promote proliferation. This process is also regulated by the p53 pathway. EGF, epider- mal growth factor; Ras-MAPK, Ras-mitogen activated protein kinase; CDK, cyclin-dependent kinase; Rb, retinoblastoma Fig. 20.2 Interactions of the p53 (yellow) and retinoblas- toma (blue) pathways in urothelial carcinogenesis. Extracellular growth signals, i.e., EGF, stimulate the Ras-MAPK signal transduction pathway. The Ras-MAPK pathway then transfers signals to the nucleus, where cyclin‘/CDK complexes induce
Fig. 20.3 The Rb pathway. Active dephosphorylated Rb binds transcription factor E2F. Rb releases E2F after phosphoryla- tion by CDKs. Unbound released E2F can then transcribe genes required for DNA synthesis and activate genes necessary fot G1 to S cell cycle phase transition. Rb, retinoblastoma; E2F, transcriptional factor; CDK, cyclin dependent kinases
Fig. 20.3 The Rb pathway. Active dephosphorylated Rb binds transcription factor E2F. Rb releases E2F after phosphoryla- tion by CDKs. Unbound released E2F can then transcribe genes required for DNA synthesis and activate genes necessary fot G1 to S cell cycle phase transition. Rb, retinoblastoma; E2F, transcriptional factor; CDK, cyclin dependent kinases
Fig. 22.1 Koilocytic atypia (HPV changes) involving cervical squamous mucosa, H&E stain Other immunohistochemical stains used in evaluat- ng cervical lesions for HPV and dysplasia are Ki-67 HPV can be detected using immunohistochemical methods. These stains are performed on formalin-fixed paraffin embedded tissues. The monoclonal or poly- clonal antibodies are targeted at the L1 capsid protein for most known papilloma viruses.
Fig. 22.1 Koilocytic atypia (HPV changes) involving cervical squamous mucosa, H&E stain Other immunohistochemical stains used in evaluat- ng cervical lesions for HPV and dysplasia are Ki-67 HPV can be detected using immunohistochemical methods. These stains are performed on formalin-fixed paraffin embedded tissues. The monoclonal or poly- clonal antibodies are targeted at the L1 capsid protein for most known papilloma viruses.
Fig. 22.2 Ki-67, the Koilocytes demonstrate nuclear staining
Fig. 22.2 Ki-67, the Koilocytes demonstrate nuclear staining
Fig. 22.3 Severe dysplasia of the cervix, H&E stain
Fig. 22.3 Severe dysplasia of the cervix, H&E stain
Fig. 22.4 P-16 staining of the dysplastic epithelium
Fig. 22.4 P-16 staining of the dysplastic epithelium
Related topics:
GeneticsMultiphoton MicroscopyLaser Scanning Confocal Microscopy
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved