Project description:Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations, however the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). These contrasting roles for Sox9 correspond with protein interactions with histone deacetylating complexes in HGG, and association with the Rela oncofusion in EPN. Together, our studies demonstrate how epigenomic states are differentially regulated in distinct subtypes of brain tumors, while revealing divergent roles for Sox9 in HGG and EPN tumorigenesis.
Project description:Cancer-specific changes in DNA methylation can alter genetic stability, genomic structure, and gene expression. Promoter CpG island methylation can result in transcriptional silencing and plays an important role in the oncogenic process. We used genome-wide analysis to characterize the methylomes of breast cancers with diverse metastatic behavior. Here, we describe the identification of novel groups of breast tumors characterized by the presence or absence of coordinate hypermethylation at a large number of genes, demonstrating the existence of a breast-CpG island methylator phenotype (B-CIMP). B-CIMP imparts a distinct epigenomic profile and is a strong determinant of metastatic potential. Gene Expression Samples (GSM647057-GSM647077): Twenty-one breast cancer primary samples were analyzed. There are 10 CIMP positive and 11 CIMP negative samples. Methylation Profiling Samples (GSM651372-GSM651410): Thirty-nine breast cancer primary samples were analyzed. There are 17 CIMP positive and 22 CIMP negative samples.
Project description:Cancer-specific changes in DNA methylation can alter genetic stability, genomic structure, and gene expression. Promoter CpG island methylation can result in transcriptional silencing and plays an important role in the oncogenic process. We used genome-wide analysis to characterize the methylomes of breast cancers with diverse metastatic behavior. Here, we describe the identification of novel groups of breast tumors characterized by the presence or absence of coordinate hypermethylation at a large number of genes, demonstrating the existence of a breast-CpG island methylator phenotype (B-CIMP). B-CIMP imparts a distinct epigenomic profile and is a strong determinant of metastatic potential.
Project description:Epigenetic mechanisms contribute to the initiation and development of cancer, and epigenetic variation promotes dynamic gene expression patterns that facilitate tumor evolution and adaptation. While the NCI-60 panel represents a diverse set of human cancer cell lines that has been used to screen chemical compounds, a comprehensive epigenomic atlas of these cells has been lacking. Here, we report an integrative analysis of 60 human cancer epigenomes, representing a catalog of activating and repressive histone modifications. We identify genome-wide maps of canonical sharp and broad H3K4me3 domains at promoter regions of tumor suppressors, H3K27ac-marked conventional enhancers and super enhancers, and widespread inter-cancer and intra-cancer specific variability in H3K9me3 and H4K20me3-marked heterochromatin domains. Furthermore, we identify features of chromatin states, including chromatin state switching along chromosomes, correlation of histone modification density with genetic mutations, DNA methylation, enrichment of DNA binding motifs in regulatory regions, and gene activity and inactivity. These findings underscore the importance of integrating epigenomic maps with gene expression and genetic variation data to understand the molecular basis of human cancer. Our findings provide a resource for mining epigenomic maps of human cancer cells and for identifying epigenetic therapeutic targets.
Project description:This SuperSeries is composed of the following subset Series: GSE36204: Epigenomic enhancer profiling defines a signature of colon cancer [ChIP-seq] GSE36400: All exon array expression data in normal colon and primary colon cancer lines [expression] Refer to individual Series
Project description:The architecture of chromatin specifies eukaryotic cell identity by controlling transcription factor access to sites of gene regulation. Here we describe a dual transposase/peroxidase approach, integrative DNA And Protein Tagging (iDAPT), which detects both DNA (iDAPT-seq) and protein (iDAPT-MS) associated with accessible regions of chromatin. In addition to direct identification of bound transcription factors, iDAPT enables the inference of their gene regulatory networks, protein interactors, and regulation of chromatin accessibility. We applied iDAPT to profile the epigenomic consequences of granulocytic differentiation of acute promyelocytic leukemia, yielding previously undescribed mechanistic insights with potential therapeutic implications. Our findings demonstrate the power of iDAPT as a discovery platform for both the dynamic epigenomic landscapes and their transcription factor components associated with biological phenomena and disease.
Project description:While circulating tumor DNA (ctDNA) assays are increasingly used to inform clinical decisions in cancer care, they have limited ability to identify the transcriptional programs that govern cancer phenotypes and their dynamic changes during the course of disease. To address these limitations, we developed a method for comprehensive epigenomic profiling of cancer from 1mL of patient plasma. Using an immunoprecipitation-based approach targeting histone modifications and DNA methylation, we measured 1,268 epigenomic profiles in plasma from 433 individuals with one of 15 cancers. Our assay provided a robust proxy for transcriptional activity, allowing us to infer the expression levels of diagnostic markers and drug targets, measure the activity of therapeutically targetable transcription factors, and detect epigenetic mechanisms of resistance. This proof-of-concept study in advanced cancers shows how plasma epigenomic profiling could unlock clinically actionable information that is currently accessible only via direct tissue sampling.
Project description:Background: Cell-to-cell heterogeneity is a major driver of cancer evolution, progression, and emergence of drug resistance. Epigenomic variation at the single-cell level can rapidly create cancer heterogeneity, but is difficult to detect and assess functionally. Results: We develop a strategy to bridge the gap between measurement and function in single-cell epigenomics. Using single-cell chromatin accessibility and RNA-seq data in K562 leukemic cells, we identify the cell surface marker CD24 as co-varying with chromatin accessibility changes linked to GATA transcription factors in single cells. Fluorescence-activated cell sorting of CD24 high vs. low cells prospectively isolated GATA1 and GATA2 high vs. low cells. GATA high vs. low cells express differential gene regulatory networks, differential sensitivity to the drug imatinib mesylate, and differential self-renewal capacity. Lineage tracing experiments show that GATA/CD24hi cells have the capability to rapidly reconstitute the heterogeneity within the entire starting population, suggesting that GATA expression levels drive a phenotypically relevant source of epigenomic plasticity. Conclusion: Single-cell chromatin accessibility can guide prospective characterization of cancer heterogeneity. Epigenomic subpopulations in cancer impact drug sensitivity and the clonal dynamics of cancer evolution.