Papers by Tobias Sinnberg
Proteogenomics reveals perturbed signalling networks in Malignant Melanoma Cells Resistant to BRAF inhibition
Molecular & Cellular Proteomics
Cancers
New therapeutic concepts such as anti-PD-1-based immunotherapy or targeted therapy with BRAF and ... more New therapeutic concepts such as anti-PD-1-based immunotherapy or targeted therapy with BRAF and MEK inhibitors have significantly improved the survival of melanoma patients. However, about 20% of patients with targeted therapy and up to 50% with immunotherapies do not respond to their first-line treatment or rapidly develop resistance. In addition, there is no approved targeted therapy for certain subgroups, namely BRAF wild-type melanomas, although they often bear aggressive tumor biology. A repurposing of already approved drugs is a promising strategy to fill this gap, as it will result in comparatively low costs, lower risks and time savings. Disulfiram (DSF), the first drug to treat alcoholism, which received approval from the US Food and Drug Administration more than 60 years ago, is such a drug candidate. There is growing evidence that DSF has great potential for the treatment of various human cancers, including melanoma. Several mechanisms of its antitumor activity have been...
IgA autoantibodies target pulmonary surfactant in patients with severe COVID-19
ABSTRACTComplications affecting the lung are hallmarks of severe coronavirus disease 2019 (COVID-... more ABSTRACTComplications affecting the lung are hallmarks of severe coronavirus disease 2019 (COVID-19). While there is evidence for autoimmunity in severe COVID-19, the exact mechanisms remain unknown. Here, we established a prospective observational cohort to study lung specific autoantibodies (auto-Abs). Incubation of plasma from severe COVID-19 patients with healthy human lung tissue revealed the presence of IgA antibodies binding to surfactant-producing pneumocytes. Enzyme-linked immunosorbent assays (ELISA) and protein pull-downs using porcine surfactant confirmed the presence of auto-Abs binding to surfactant proteins in severe COVID-19 patients. Mass spectrometry and ELISAs with recombinant proteins identified IgA auto-Abs that target human surfactant proteins B and C. In line with these findings, lungs of deceased COVID-19 patients showed reduced pulmonary surfactant. Our data suggest that IgA-driven autoimmunity against surfactant may result in disease progression of COVID-19.
An open-label, single-arm, phase II trial of buparlisib in patients with melanoma brain metastases not eligible for surgery or radiosurgery—the BUMPER study
Neuro-Oncology Advances
Background Patients with melanoma brain metastasis (MBM) still carry a dismal prognosis. Preclini... more Background Patients with melanoma brain metastasis (MBM) still carry a dismal prognosis. Preclinical data originated in xenograft models showed that buparlisib therapy was highly effective in therapy-naïve MBM. Patients and Methods In this open-label, phase II trial, we investigate the safety and efficacy of monotherapy with buparlisib, a PI3K inhibitor, in patients with asymptomatic MBM who were not candidates for local therapy. These patients had also progressed under immunotherapy if BRAF wild-type or under targeted therapy with BRAF/MEK inhibitors if carrying a BRAFV600E/K mutation. The primary endpoint was the intracranial disease control rate assessed by the investigators. The secondary endpoints were overall response rate, duration of response (DOR) of intracranial disease, overall response, progression-free survival (PFS), overall survival (OS), safety, and tolerability of buparlisib. Results A total of 20 patients were screened and 17 patients were treated with buparlisib. ...
Cancers
Secreted factors play an important role in intercellular communication. Therefore, they are not o... more Secreted factors play an important role in intercellular communication. Therefore, they are not only indispensable for the regulation of various physiological processes but can also decisively advance the development and progression of tumours. In the context of inflammatory disease, Y-box binding protein 1 (YB-1) is actively secreted and the extracellular protein promotes cell proliferation and migration. In malignant melanoma, intracellular YB-1 expression increases during melanoma progression and represents an unfavourable prognostic marker. Here, we show active secretion of YB-1 from melanoma cells as opposed to benign cells of the skin. Intriguingly, YB-1 secretion correlates with the stage of melanoma progression and depends on a calcium- and ATP-dependent non-classical secretory pathway leading to the occurrence of YB-1 in the extracellular space as a free protein. Along with an elevated YB-1 secretion of melanoma cells in the metastatic growth phase, extracellular YB-1 exert...
OncoTargets and Therapy
Purpose: BRAF and MEK inhibitors significantly improved the prognosis of metastatic melanoma. Nev... more Purpose: BRAF and MEK inhibitors significantly improved the prognosis of metastatic melanoma. Nevertheless, initial treatment response may be only temporary. Liquid biopsies (LB) offer a possibility to monitor patients by measuring circulating tumor DNA (ctDNA). We sought to find out whether ctDNA can be used to reliably determine progressive disease under targeted therapy. In addition, we wanted to check whether ctDNA may represent a possible prognostic marker for survival. Patients and Methods: We included 19 melanoma patients with BRAF and MEK inhibitor therapy. For each patient, a 710 gene panel was analyzed on the latest available tumor tissue before the start of therapy. Repetitive LB were collected in which BRAF V600E/K mutations were monitored using digital droplet PCR (ddPCR). We correlated radiological staging results and overall survival with ctDNA results. Results: In 13 patients, ctDNA was detectable when starting targeted therapy, whereas in six patients, ddPCR was always negative, which we confirmed with ultra-deep sequencing. All patients with initially detectable ctDNA had ctDNA values declining to zero during followup, increasing again at the time of extracerebral progression or even slightly before detection by imaging. Survival was significantly worse for patients with elevated LDH (p=0.034) or detectable ctDNA (p=0.008) at the start of targeted therapy. Conclusion: Therapy monitoring by ctDNA seems to be a reliable method for detecting extracranial progression, even more sensitive and specific than LDH or S100B. However, due to the small number of cases in our study, further studies are necessary.
Cancers
The detection of somatic driver mutations by next-generation sequencing (NGS) is becoming increas... more The detection of somatic driver mutations by next-generation sequencing (NGS) is becoming increasingly important in the care of advanced melanoma patients. In our study, we evaluated the NGS results of 82 melanoma patients from clinical routine in 2017. Besides determining the tumor mutational burden (TMB) and annotation of all genetic driver alterations, we investigated their potential as a predictor for resistance to immune checkpoint inhibitors (ICI) and as a distinguishing feature between melanoma subtypes. Melanomas of unknown primary had a similar mutation pattern and TMB to cutaneous melanoma, which hints at its cutaneous origin. Besides the typical hotspot mutation in BRAF and NRAS, we frequently observed CDKN2A deletions. Acral and mucosal melanomas were dominated by CNV alterations affecting PDGFRA, KIT, CDK4, RICTOR, CCND2 and CHEK2. Uveal melanoma often had somatic SNVs in GNA11/Q and amplification of MYC in all cases. A significantly higher incidence of BRAF V600 mutati...
Cancers
Background: Combined immunotherapy has significantly improved survival of patients with advanced ... more Background: Combined immunotherapy has significantly improved survival of patients with advanced melanoma, but there are still patients that do not benefit from it. Early biomarkers that indicate potential resistance would be highly relevant for these patients. Methods: We comprehensively analyzed tumor and blood samples from patients with advanced melanoma, treated with combined immunotherapy and performed descriptive and survival analysis. Results: Fifty-nine patients with a median follow-up of 13 months (inter quartile range (IQR) 11–15) were included. Interestingly, nine patients were found to have pathogenic or likely pathogenic (P/LP) germline variants in one of these genes: BRCA2, POLE, WRN, FANCI, CDKN2A, BAP1, PALB2 and RAD54B. Most of them are involved in DNA repair mechanisms. Patients with P/LP germline variants had a significantly shorter progression-free survival (PFS) and melanoma specific survival (MSS) compared to patients without P/LP germline variants (HR = 2.16; ...
Cancers
Background: Mucosal and acral melanoma respond worse to immune checkpoint inhibitors (ICI) than c... more Background: Mucosal and acral melanoma respond worse to immune checkpoint inhibitors (ICI) than cutaneous melanoma. MDM2/4 as well as EGFR amplifications are supposed to be associated with hyperprogression on ICI in diverse cancers. We therefore investigated the response of metastatic acral and mucosal melanoma to ICI in regard to MDM2/4 or EGFR amplifications and melanoma type. Methods: We conducted a query of our melanoma registry, looking for patients with metastatic acral or mucosal melanoma treated by ICI. Whole exome sequencing, FISH and immunohistochemistry on melanoma tissue could be performed on 45 of the total cohort of 51 patients. Data were correlated with patients’ responses to ICI and survival. Results: 22 out of 51 patients had hyperprogressive disease (an increase in tumor load of >50% at the first staging). Hyperprogression occurred more often in case of MDM2/4 or EGFR amplification or <1% PD-L1 positive tumor cells. Nevertheless, this association was not sign...
Next-generation-sequencing of advanced melanoma: Which genetic alterations have an impact on systemic therapy response?
Journal of Clinical Oncology
European Journal of Cancer
Background: Adjuvant therapies have been approved for patients with AJCC (American Joint Committe... more Background: Adjuvant therapies have been approved for patients with AJCC (American Joint Committee on Cancer) stage III and stage IV cutaneous melanoma (CM) after complete resection. These therapies might also be indicated for patients with high-risk stage II CM. Material and methods: We included patients diagnosed with stage II melanoma between 2000 and 2016 and for which primary tumour tissue was available. The prognostic value of the 11gene expression profiling score (GEPS) was evaluated as a dichotomized parameter (GEPS 0 vs. >0). Endpoints of the analysis were melanoma specific survival (MSS), distant metastasis-free survival (DMFS) and relapse-free survival (RFS). Results: GEPS was determined in 245 patients ranging between À0.7 and 3.53. A total of 111 females and 134 males were included; the median follow-up was 41 months. Kaplan Meier analyses showed statistically significant survival differences between patients with high GEPS (n Z 154) and low GEPS (n Z 91) for MSS (p Z 0.018), DMFS (p Z 0.005) and RFS (p Z 0.009). The 5-year and 10-year MSS was 92% in the low-GEPS and 82% and 67% in
Biology Open
Despite recent progress in melanoma therapy via inhibition of activated oncogenes or immune stimu... more Despite recent progress in melanoma therapy via inhibition of activated oncogenes or immune stimulation, most stage IV melanoma patients still have limited survival times. Existing therapeutic approaches eventually fail to prevent further invasion and metastasis, which is driven by a morphological process termed epithelial-mesenchymal transition (EMT). We previously demonstrated that inhibition of EMT in melanoma cells via antagonizing the bone morphogenetic protein (BMP)-pathway abrogated EMT and neural crest migration of melanoma cells in chick embryos. Here, we show that BMP-2 is highly expressed in invasive melanoma cells and is elevated in the serum of stage IV melanoma patients compared to stage IB-IIC patients and healthy controls. Highly BMP-2-expressing melanoma cells display enhanced invasion in the rhombencephalon of the chick embryo. In addition to driving neural crest migration in the zebrafish embryo, the agonists BMP-2, BMP-7 and nodal induce EMT/invasion in radial growth phase melanoma cells and in human melanocytes in skin reconstructs. Blocking either BMP or nodal signaling by antagonists (noggin, lefty), or the Alk4/5/7-receptor inhibitor SB431542, decreases EMT and invasion of melanoma cells in human epidermal skin reconstructs. Together, our data suggest that inhibition of EMTinducing pathways in melanoma might be a therapeutic approach to attenuate melanoma cell invasiveness.
Cell Death & Disease
The efficacy of targeted MAPK signalling pathway inhibitors (MAPKi) in metastatic melanoma therap... more The efficacy of targeted MAPK signalling pathway inhibitors (MAPKi) in metastatic melanoma therapy is limited by the development of resistance mechanisms that results in disease relapse. This situation still requires treatment alternatives for melanoma patients with acquired resistance to targeted therapy. We found that melanoma cells, which developed resistance towards MAPKi show an enhanced susceptibility to platinum-based drugs, such as cisplatin and carboplatin. We found that this enhanced susceptibility inversely correlates with the expression level of the p53 family member TAp73. We show that the lower expression of the TAp73 isoform in MAPKi-resistant melanoma cells enhances accumulation of DNA double-strand breaks upon cisplatin and carboplatin treatment by reducing the efficiency of nucleotide excision repair. These data suggest that a subgroup of melanoma patients with acquired resistance to MAPKi treatment and low TAp73 expression can benefit from chemotherapy with platinum-based drugs as a secondline therapy.
Quantitative Proteomics Links the Intermediate Filament Nestin to Resistance to Targeted BRAF Inhibition in Melanoma Cells
Molecular & Cellular Proteomics
Clinical validation of a prognostic 11-gene assay in prospectively collected FFPE tissue of patients with AJCC v8 stage II cutaneous melanoma (CM)
Journal of Clinical Oncology
9518 Background: AJCC comprises two markers (Breslow thickness and ulceration) to subdivide stage... more 9518 Background: AJCC comprises two markers (Breslow thickness and ulceration) to subdivide stage II CM patients into groups with relatively low, average, or high risk of death. Recent updates of clinical guidelines (NCCN, AAD) suggest that patient management be further tailored to an individual prognosis, e.g. through gene expression profiling (GEP). The aim of this single center study was to clinically validate a prognostic GEP-based risk score (MelaGenix) for stage II CMs. Methods: All obtainable, formalin-fixed paraffin-embedded (FFPE) primaries of AJCC stage II CMs from the Central Malignant Melanoma Registry of Germany archived in Tuebingen were included. Study hypothesis and protocol were prospectively formulated. Tumors were analyzed blinded to clinical outcome (data exchange overseen by independent data clearing house) to determine GEP low- vs. high-score groups with a pre-specified GEP score cut-off (≤0.00 > ). Melanoma specific survival (MSS) was evaluated by Kaplan-Me...
Clinical Cancer Research
Kato and colleagues (1) reported 4 cancer patients with metastatic disease, hyperprogression unde... more Kato and colleagues (1) reported 4 cancer patients with metastatic disease, hyperprogression under treatment with anti-PD-1/ PD-L1 monotherapy, and a cooccurring MDM2/4 amplification in the cancer cells. They defined hyperprogression as time-totreatment failure <2 months, >50% increase in tumor burden and >2-fold increase in progression compared with baseline staging before immunotherapy. Hyperprogression under treatment with checkpoint inhibitors is discussed worldwide and occurs in about 9% of the patients, but the underlying mechanisms are not understood (2). The four reported patients suffered Clinical Cancer Research
Molecular Cancer
Background: During embryonic development Wnt family members and bone morphogenetic proteins (BMPs... more Background: During embryonic development Wnt family members and bone morphogenetic proteins (BMPs) cooperatively induce epithelial-mesenchymal transition (EMT) in the neural crest. Wnt and BMPs are reactivated during malignant transformation in melanoma. We previously demonstrated that the BMP-antagonist noggin blocked the EMT phenotype of melanoma cells in the neural crest and malignant invasion of melanoma cells in the chick embryo; vice-versa, malignant invasion was induced in human melanocytes in vivo by pre-treatment with BMP-2. Results: Although there are conflicting results in the literature about the role of β-catenin for invasion of melanoma cells, we found Wnt/β-catenin signaling to be analogously important for the EMT-like phenotype of human metastatic melanoma cells in the neural crest and during invasion: β-catenin was frequently expressed at the invasive front of human primary melanomas and Wnt3a expression was inversely correlated with survival of melanoma patients. Accordingly, cytoplasmic β-catenin levels were increased during invasion of melanoma cells in the rhombencephalon of the chick embryo. Fibroblast derived Wnt3a reduced melanoma cell adhesion and enhanced migration, while the β-catenin inhibitor PKF115-584 increased adhesion and reduced migration in vitro and in the chick embryonic neural crest environment in vivo. Similarly, knockdown of β-catenin impaired intradermal melanoma cell invasion and PKF115-584 efficiently reduced liver metastasis in a chick chorioallantoic membrane model. Our observations were accompanied by specific alterations in gene expression which are linked to overall survival of melanoma patients. Conclusion: We present a novel role for Wnt-signaling in neural crest like melanoma cell invasion and metastasis, stressing the crucial role of embryonic EMT-inducing neural crest signaling for the spreading of malignant melanoma.
Cellular Physiology and Biochemistry
Background/Aims: Prenylnaringenins are natural prenylflavonoids with anticancer properties. Howev... more Background/Aims: Prenylnaringenins are natural prenylflavonoids with anticancer properties. However, the underlying mechanisms have not been elucidated yet. Here we report a novel mode of action of 6- and 8-prenylnaringenin (PN) on human melanoma cells: Inhibition of cellular histone deacetylases (HDACs). Methods: We performed in silico and in vitro analyses using 6-PN or 8-PN to study a possible interaction of 6-PN or 8-PN with HDAC as well as Western blot and FACS analyses, real-time cell proliferation and cell viability assays to assess the impact of 6-PN and 8-PN on human metastatic melanoma cells. Results: In silico, 6-PN and 8-PN fit into the binding pocket of HDAC2, 4, 7 and 8, binding to the zinc ion of their catalytic center that is essential for enzymatic activity. In vitro, 100 µmol/L of 6-PN or 8-PN inhibited all 11 conserved human HDAC of class I, II and IV. In clinical oncology HDAC inhibitors are currently investigated as new anticancer compounds. In line, treatment o...
Molecular cancer research : MCR, 2018
Cutaneous melanoma represents one of the most aggressive human tumor entities possessing a high t... more Cutaneous melanoma represents one of the most aggressive human tumor entities possessing a high tendency to metastasize. Cancer cells frequently exploit a highly conserved developmental program, the epithelial-to-mesenchymal transition (EMT), to gain migratory and invasive properties promoting their metastatic spread. Cytoplasmic localization of the oncogenic transcription and translation factor Y-box binding protein 1 (YB-1) is a powerful inducer of EMT in breast carcinoma cells. Interestingly, EMT-like processes have also been observed in cutaneous melanoma despite its neural crest origin. Here, increased expression of YB-1 negatively affects patient survival in malignant melanoma and promotes melanoma cell tumorigenicity both and Intriguingly, this effect seems to be mainly mediated by cytoplasmic YB-1 that does not exhibit phosphorylation at serine-102 (S102). Moreover, S102 unphosphorylated YB-1 enhances the migratory and invasive potential of human melanoma cells in two-dimens...
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Papers by Tobias Sinnberg