Polyomavirus-positive Merkel cell carcinoma derived from a trichoblastoma suggests an epithelial origin of Merkel cell carcinoma
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ABSTRACT:
PROVIDER: EGAS00001003784 | EGA |
REPOSITORIES: EGA
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Project description:Differences in DNA-methylation between VP- and UV-MCCs mainly refer to heterogeneity in carcinogenesis rather than an origin in utterly different cell types. Indeed, a principal component derived scoring suggest an epithelial for UV-MCC as well as VP-MCC cell lines.
2022-03-02 | GSE178155 | GEO
Project description:Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor with high mortality rates. Merkel cell polyomavirus (MCPyV), identified in the majority of MCC, may drive tumorigenesis via viral T antigens. However, mechanisms underlying pathogenesis in MCPyV-negative MCC remain poorly understood. To nominate genes contributing to pathogenesis of MCPyV-negative MCC, we performed DNA microarray analysis on 30 MCCs. MCPyV status of MCCs was determined by PCR for viral DNA and RNA. 1593 probe-sets were differentially expressed between MCPyV-negative and -positive MCC, with significant differential expression defined as at least 2-fold change in either direction and p-value of ≤ 0.05. MCPyV-negative tumors showed decreased RB1 expression, whereas MCPyV-positive tumors were enriched for immune response genes. Validation studies included immunohistochemistry demonstration of decreased RB protein expression in MCPyV-negative tumors and increased peritumoral CD8+ T lymphocytes surrounding MCPyV-positive tumors. In conclusion, our data suggest that loss of RB1 expression may play an important role in tumorigenesis of MCPyV-negative MCC. Functional and clinical validation studies are needed to determine whether this tumor suppressor pathway represents an avenue for targeted therapy. We used microarrays to characterize global gene expression patterns related to Merkel cell polyomavirus status in Merkel cell carcinoma. Furthermore, we compared Merkel cell carcinoma to less aggressive primary cutaneous carcinomas. We utilized flash-frozen tumor tissue from primary Merkel cell carcinomas, metastatic Merkel cell carcinomas, primary cutaneous squamous cell carcinomas, and basal cell carcinomas. Merkel cell carcinoma cell lines, which represent a pure population of tumor cells, were also included. Merkel cell polyomavirus status was determined at the DNA and RNA level using multiple primers for viral T-antigen and capsid protein sequences. This Series represents two analyses - one with new Samples normalized together, and another with some of the new Samples re-normalized with Samples previously submitted under Series GSE13355. The latter group contain 'renormalized' in the titles.
2012-10-18 | E-GEOD-39612 | biostudies-arrayexpress
Project description:Co-expression of MCPyV TAgs and the Merkel cell lineage determinant ATOH1, in p53-deficient keratinocytes and their neuroendocrine progeny, yields tumors closely mimicking human MCC. Direct cellular reprogramming in vivo may provide a novel approach to generate tumors for which the cell of origin is uncertain.
2022-03-02 | GSE166751 | GEO
Project description:Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor with high mortality rates. Merkel cell polyomavirus (MCPyV), identified in the majority of MCC, may drive tumorigenesis via viral T antigens. However, mechanisms underlying pathogenesis in MCPyV-negative MCC remain poorly understood. To nominate genes contributing to pathogenesis of MCPyV-negative MCC, we performed DNA microarray analysis on 30 MCCs. MCPyV status of MCCs was determined by PCR for viral DNA and RNA. 1593 probe-sets were differentially expressed between MCPyV-negative and -positive MCC, with significant differential expression defined as at least 2-fold change in either direction and p-value of ≤ 0.05. MCPyV-negative tumors showed decreased RB1 expression, whereas MCPyV-positive tumors were enriched for immune response genes. Validation studies included immunohistochemistry demonstration of decreased RB protein expression in MCPyV-negative tumors and increased peritumoral CD8+ T lymphocytes surrounding MCPyV-positive tumors. In conclusion, our data suggest that loss of RB1 expression may play an important role in tumorigenesis of MCPyV-negative MCC. Functional and clinical validation studies are needed to determine whether this tumor suppressor pathway represents an avenue for targeted therapy. We used microarrays to characterize global gene expression patterns related to Merkel cell polyomavirus status in Merkel cell carcinoma. Furthermore, we compared Merkel cell carcinoma to less aggressive primary cutaneous carcinomas.
2012-10-18 | GSE39612 | GEO
Project description:MicroRNAs have been implicated in various skin cancers, including melanoma, squamous cell carcinoma, and basal cell carcinoma; however, the expression of microRNAs and their role in Merkel cell carcinoma (MCC) have yet to be explored in depth. To identify microRNAs specific to MCC (MCC-miRs), next-generation sequencing (NGS) of small RNA libraries was performed on different tissue samples including MCCs, other cutaneous tumors, and normal skin. Comparison of the profiles identified several microRNAs upregulated and downregulated in MCC. For validation, their expression was measured via qRT-PCR in a larger group of MCC and in a comparison group of non-MCC cutaneous tumors and normal skin. Eight microRNAs were upregulated in MCC: miR-502-3p, miR-9, miR-7, miR-340, miR-182, miR-190b, miR-873, and miR-183. Three microRNAs were downregulated: miR-3170, miR-125b, and miR-374c. Many of these MCC-miRs, with the miR-183/182/96a cistron in particular, have connections to tumorigenic pathways implicated in MCC pathogenesis. In situ hybridization confirmed that the highly expressed MCC-miR, miR-182, is localized within tumor cells. Furthermore, NGS and qRT-PCR reveals that several of these MCC-miRs are highly expressed in the patient-derived MCC cell line, MS-1. These data indicate that we have identified a set of MCC-miRs with high implications for MCC research. To identify microRNAs specific to Merkel cell carcinoma (MCC) next-generation sequencing (NGS) of small RNA libraries was performed on different tissue samples including MCCs, other cutaneous tumors, and normal skin
2014-03-20 | E-GEOD-53600 | biostudies-arrayexpress
Project description:Merkel cell carcinoma (MCC) is an aggressive neuroendocrine cancer of the skin, caused by either excessive UV damage or integration of the Merkel cell polyomavirus (MCV) genome. Here, we report that virally encoded MCV small T antigen (ST) establishes dependence on the LSD1 transcriptional repressor. Inhibition of LSD1 reduces growth of MCV-positive MCC and suppresses ST’s transformation capacity in vitro and in vivo. To define the mechanism of LSD1 inhibition in MCC, we performed a CRISPR loss-of-function library screen. We found that deletion of components of the non-canonical (ncBAF) chromatin remodeler complex confers resistance to LSD1 inhibitors and that LSD1 and ncBAF antagonistically regulate an overlapping set of genes involved in neuron differentiation. Our work provides mechanistic insight into the dependence of MCC on LSD1 and the role of ncBAF as a tumor suppressor in cancer.
2020-02-16 | GSE140505 | GEO
Project description:When using cell lines to study cancer, phenotypic similarity to the original tumor is paramount. Yet, little has been done to characterize how closely Merkel cell carcinoma (MCC) cell lines model native tumors. To determine their similarity to MCC tumor samples, we characterized MCC cell lines via gene expression microarrays. Using whole transcriptome gene expression signatures and a computational bioinformatic approach, we identified significant differences between variant cell lines (UISO, MCC13, and MCC26) and fresh frozen MCC tumors. Conversely, the classic WaGa and Mkl-1 cell lines more closely represented the global transcriptome of MCC tumors. When compared to publicly available cancer lines, WaGa and Mkl-1 cells were similar to other neuroendocrine tumors, but the variant cell lines were not. WaGa and Mkl-1 cells grown as xenografts in mice had histological and immunophenotypical features consistent with MCC, while UISO xenograft tumors were atypical for MCC. Spectral karyotyping and short tandem repeat analysis of the UISO cells matched the original cell line's description, ruling out contamination. Our results validate the use of transcriptome analysis to assess the cancer cell line representativeness and indicate that UISO, MCC13, and MCC26 cell lines are not representative of MCC tumors, whereas WaGa and Mkl-1 more closely model MCC. RNA was extracted from MCC cell lines and MCC and SCLC tumor samples and hybridized to Affymetrix microarrays for transcriptome profiling.
2014-12-23 | E-GEOD-50451 | biostudies-arrayexpress
Project description:Merkel cell carcinoma (MCC) is an aggressive neuroendocrine cancer of the skin, caused by either excessive UV damage or integration of the Merkel cell polyomavirus (MCV) genome. Here, we report that virally encoded MCV small T antigen (ST) establishes dependence on the LSD1 transcriptional repressor. Inhibition of LSD1 reduces growth of MCV-positive MCC and suppresses ST’s transformation capacity in vitro and in vivo. To define the mechanism of LSD1 inhibition in MCC, we performed a CRISPR loss-of-function library screen. We found that deletion of components of the non-canonical (ncBAF) chromatin remodeler complex confers resistance to LSD1 inhibitors and that LSD1 and ncBAF antagonistically regulate an overlapping set of genes involved in neuron differentiation. Our work provides mechanistic insight into the dependence of MCC on LSD1 and the role of ncBAF as a tumor suppressor in cancer.
2020-02-16 | GSE124857 | GEO
Project description:Merkel cell carcinoma (MCC) is a highly aggressive, neuroendocrine skin cancer that lacks actionable mutations, which could be utilized for targeted therapies. Epigenetic regulators governing cell identity may represent unexplored therapeutic entry points. Here, we targeted epigenetic regulators in a pharmacological screen and discovered that the lysine-specific histone demethylase 1A (LSD1/KDM1A) is required for MCC growth in vitro and in vivo. We show that LSD1 inhibition in MCC disrupts the LSD1-CoREST complex leading to displacement and degradation of HMG20B (BRAF35), a poorly characterized complex member that is essential for MCC proliferation. Inhibition of LSD1 causes derepression of transcriptional master regulators of the neuronal lineage, activates a gene expression signature resembling normal Merkel cells, and induces cell cycle arrest and cell death. Our study unveils the importance of LSD1 for proliferation and maintaining cell identity in MCC. There is growing evidence that cancer cells exploit cellular plasticity and dedifferentiation programs to evade destruction by the immune system. The combination of LSD1 inhibitors with checkpoint inhibitors may thus represent a promising treatment strategy for MCC patients.
2020-11-03 | PXD020590 | Pride
Project description:Merkel cell carcinoma (MCC) is an aggressive neuroendocrine cancer of the skin, caused by either excessive UV damage or integration of the Merkel cell polyomavirus (MCV) genome. Here, we report that virally encoded MCV small T antigen (ST) establishes dependence on the LSD1 transcriptional repressor. Inhibition of LSD1 reduces growth of MCV-positive MCC and suppresses ST’s transformation capacity in vitro and in vivo. To define the mechanism of LSD1 inhibition in MCC, we performed a CRISPR loss-of-function library screen. We found that deletion of components of the non-canonical (ncBAF) chromatin remodeler complex confers resistance to LSD1 inhibitors and that LSD1 and ncBAF antagonistically regulate an overlapping set of genes involved in neuron differentiation. Our work provides mechanistic insight into the dependence of MCC on LSD1 and the role of ncBAF as a tumor suppressor in cancer.
2020-02-16 | GSE124856 | GEO