Project description:Rhabdomyosarcomas (RMS) represent a family of aggressive soft tissue sarcomas that present in both the pediatric and adult setting. Pathologic risk stratification for RMS has been based on histologic subtype, with poor outcomes observed in alveolar rhabdomyosarcoma (ARMS) and adult-type pleomorphic rhabdomyosarcoma (PRMS) compared to embryonal rhabdomyosarcoma (ERMS). Recent genomic sequencing studies have expanded the spectrum of RMS, with several new molecularly defined entities, including fusion-driven spindle cell/sclerosing rhabdomyosarcoma (SC/SRMS) and MYOD1-mutant SC/SRMS. Comprehensive genomic analysis has previously defined the mutational and copy number spectrum for the more common ERMS and ARMS, as well as revealed corresponding methylation signatures. In contrast, genetic and epigenetic correlates have not been defined for the rare SC/SRMS or PRMS histologic subtypes. Herein, we present genomic sequencing, copy number analysis, and methylation profiling of the largest cohort of molecularly characterized RMS samples to date. We identified two novel methylation subtypes, one having SC/SRMS histology and defined by MYOD1 p. L122R mutations and the other matching adult type PRMS. Selected tumors from adolescent patients grouped with the PRMS methylation class, expanding the age range of these rare tumors. Pediatric patients in the MYOD1-mutant group, as well as those clustering with PRMS, appear to have poor overall survival.
Project description:Rhabdomyosarcomas (RMS) represent a family of aggressive soft tissue sarcomas that present in both children and adults. Pathologic risk stratification for RMS has been based on histologic subtype, with poor outcomes observed in alveolar rhabdomyosarcoma (ARMS) and the adult-type pleomorphic rhabdomyosarcoma (PRMS) compared to embryonal rhabdomyosarcoma (ERMS). Genomic sequencing studies have expanded the spectrum of RMS, with several new molecularly defined entities, including fusion-driven spindle cell/sclerosing rhabdomyosarcoma (SC/SRMS) and MYOD1-mutant SC/SRMS. Comprehensive genomic analysis has previously defined the mutational and copy number spectrum for the more common ERMS and ARMS and revealed corresponding methylation signatures. Comparatively, less is known about epigenetic correlates for the rare SC/SRMS or PRMS histologic subtypes. Herein, we present exome and RNA sequencing, copy number analysis, and methylation profiling of the largest cohort of molecularly characterized RMS samples to date. In addition to ARMS and ERMS, we identify two novel methylation subtypes, one having SC/SRMS histology and defined by MYOD1 p. L122R mutations and the other matching adult-type PRMS. Selected tumors from adolescent patients grouped with the PRMS methylation class, expanding the age range of these rare tumors. Limited follow-up data suggest that pediatric tumors with MYOD1-mutations are associated with an aggressive clinical course.
Project description:DNA methylation data of a novel group of mesenchymal tumors with DICER1 alteration which includes two novel classes designated “low-grade mesenchymal tumor with DICER1 alteration” (LGMT DICER1) and “high-grade sarcoma with DICER1 alteration” (HGS DICER1), as well as the recently described class of primary intracranial sarcoma, DICER1-mutant (PIS DICER1)
Project description:Purpose:Up to 80% of the human genome produces “dark matter” RNAs, most of which are noncapped RNAs (napRNAs). However, determining the functional impacts and metabolism of napRNAs requires the identification of their full-length sequences. Method:Here, by developing a novel method, NAP-seq, to globally profile the full-length sequences of napRNAs at single-nucleotide resolution, we revealed several novel classes of exceptionally structured noncoding RNAs (ncRNAs). Results:We discovered stably expressed linear intron RNAs (sliRNAs), a novel class of snoRNA-intron RNAs (snotrons), a new class of RNAs embedded in miRNA spacers (misRNAs) and thousands of new structured ncRNAs in humans and mice. These new napRNAs undergo dynamic changes in response to various stimuli and differentiation stages. Importantly, we showed that the novel napRNA DINAP interacts with dyskerin pseudouridine synthase 1 (DKC1) to promote cell proliferation by maintaining DKC1 protein stability. Conclusion:Our approach establishes a paradigm for discovering novel classes of ncRNAs with regulatory potency.
Project description:We have developed a new conditional genetically engineered mouse model of rhabdomyosarcoma (RMS) with homologous molecular signature to human RMS that provides valuable pre-clinical models for evaluating novel therapies
Project description:We have developed a new conditional genetically engineered mouse model of rhabdomyosarcoma (RMS) with homologous molecular signature to human RMS that provides valuable pre-clinical models for evaluating novel therapies
Project description:BACKGROUND & AIMS: Cholangiocarcinoma, the second most common liver cancer, can be classified as intrahepatic (ICC) or extrahepatic. We performed an integrative genomic analysis of ICC samples from a large series of patients. METHODS: We performed gene expression profile, high-density single nucleotide polymorphism array, and mutation analyses using formalin-fixed ICC samples from 149 patients. Associations with clinico-pathological traits and patient outcomes were examined for 119 cases. Class discovery was based on a non-negative matrix factorization algorithm and significant copy number variations (CNV) were identified by GISTIC analysis. Gene set enrichment analysis was used to identify signaling pathways activated in specific molecular classes of tumors, and to analyze their genomic overlap with hepatocellular carcinoma (HCC). RESULTS: We identified 2 main biological classes of ICC. The inflammation class (38% of ICCs) is characterized by activation of inflammatory signaling pathways, overexpression of cytokines, and STAT3 activation. The proliferation class (62%) is characterized by activation of oncogenic signaling pathways (including RAS, mitogen-activated protein kinase, and MET), DNA amplifications at 11q13.2, deletions at 14q22.1, mutations in KRAS and BRAF, and gene expression signatures previously associated with poor outcomes for patients with HCC. CNV-based clustering was able to further refine these molecular groups. We identified high-level amplifications in 5 regions, including 1p13 (9%) and 11q13.2 (4%), and several focal deletions, such as 9p21.3 (18%) and 14q22.1 (12% in coding regions for the SAV1 tumor suppressor). In a complementary approach, we identified a gene expression signature that was associated with reduced survival times of patients with ICC; this signature was enriched in the proliferation class (P<0.001). CONCLUSIONS: We used an integrative genomic analysis to identify 2 classes of ICC. The proliferation class has specific copy number alterations, many features of the poor-prognosis signatures for HCC, and is associated with worse outcome. Different classes of ICC, based on molecular features, might therefore require different treatment approaches. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
Project description:Many pediatric malignancies are embryonal in nature, and one hypothesis for the origin of embryonal tumors is that they arise from a defect in differentiation, either by an inability to terminally differentiate or a reversion to a pluripotent state. There is emerging evidence that epigenetic regulation plays an important role in the transition from embryonic stem cell to a more committed cell fate, utilizing both de novo DNA methylation and poised M-bM-^@M-^XbivalentM-bM-^@M-^Y chromatin domains (H3K27me3 and H3K4me3) to abolish pluripotency and gain lineage- and cell-type-specific characteristics as a cell differentiates. Thus inappropriate epigenetic silencing by aberrant DNA methylation of bivalent genes required for differentiation could lead to the uncontrolled cell growth observed in cancer. Our broad hypothesis is that aberrant DNA methylation in cancer is targeted to a non-random subset of critical pathways used in normal development. This dysregulation of the normal epigenetic program used in development promotes cellular proliferation and provides a mechanism to block differentiation in pediatric cancers, such as rhabdomyosarcoma. Examination of DNA methylation in fourteen human rhabdomyosarcoma patient samples using RRBS. In addition, RRBS was used to examine DNA methylation in one human rhabdomyosarcoma cell line (RD) forced to terminally differentiate by expression of the forced heterodimer MyoD~E12 (MDE). Lastly, RRBS was used to examine DNA methylation changes during normal differentiation in one primary human normal myoblast cell line