Predicting master transcription factors from pan-cancer expression data
Ontology highlight
ABSTRACT: Critical developmental “master transcription factors” (MTFs) can be subverted during tumorigenesis to control expression of oncogenic transcriptional programs. Current approaches to identify MTFs rely on chromatin immunoprecipitation-sequencing data, which is currently unavailable for many cancer types. We developed the CaCTS (Cancer Core Transcription factor Specificity) algorithm to prioritize candidate MTFs using pan-cancer RNA-sequencing data. CaCTS identified candidate MTFs across 34 tumor types and 140 subtypes, including known MTFs. We also made novel predictions, including for cancer types/subtypes for which MTFs are unknown. This included PAX8, SOX17, and MECOM as candidate MTFs in ovarian cancer (OV). In OV cells, these factors are required for viability, lie proximal to super-enhancers, co-occupy regulatory elements globally and co-bind at critical gene loci encoding OV biomarkers. Identification of tumor MTFs, especially for tumor types with limited understanding of transcriptional drivers, paves the way to therapeutic targeting of MTFs in a broad spectrum of cancers.
Project description:Critical developmental “master transcription factors” (MTFs) can be subverted during tumorigenesis to control expression of oncogenic transcriptional programs. Current approaches to identify MTFs rely on chromatin immunoprecipitation-sequencing data, which is currently unavailable for many cancer types. We developed the CaCTS (Cancer Core Transcription factor Specificity) algorithm to prioritize candidate MTFs using pan-cancer RNA-sequencing data. CaCTS identified candidate MTFs across 34 tumor types and 140 subtypes, including known MTFs. We also made novel predictions, including for cancer types/subtypes for which MTFs are unknown. This included PAX8, SOX17, and MECOM as candidate MTFs in ovarian cancer (OV). In OV cells, these factors are required for viability, lie proximal to super-enhancers, co-occupy regulatory elements globally and co-bind at critical gene loci encoding OV biomarkers. Identification of tumor MTFs, especially for tumor types with limited understanding of transcriptional drivers, paves the way to therapeutic targeting of MTFs in a broad spectrum of cancers.
Project description:The presence of noncanonical open reading frames within lncRNAs suggests their potential for translation, yielding various functional peptides or proteins. However, the existence and specific roles of these products in gastric cancer remain largely unexplored. Here we identify the HOXA10-HOXA9-derived small protein (HDSP) in gastric cancer through comprehensive analysis and experimental validation, including mass spectrometry and western blotting. HDSP exhibits high expression and oncogenic roles in gastric cancer. Mechanistically, HDSP blocks TRIM25-mediated ubiquitination and degradation by interacting with MECOM, leading to MECOM accumulation and enhanced SPINK1 transcription-a gene promoting cancer via the EGFR signaling pathway. Furthermore, MECOM fosters HOXA10-HOXA9 transcription, establishing a feedback loop activating SPINK1-EGFR signaling. HDSP knockdown inhibits tumor growth in a PDX model, and infusion of an artificially synthesized HDSP peptide as a neoantigen enhances immune cell-mediated anti-tumor efficacy against gastric cancer in vitro and in vivo. These findings propose HDSP as a potential therapeutic target or neoantigen candidate for gastric cancer treatment.
Project description:The abundance of noncanonical open reading frames present in long noncoding RNAs (lncRNAs) indicates the potential for translational capacity, thereby enabling the generation of multiple functional peptides or proteins. Nevertheless, the existence of peptide or protein products derived from lncRNAs and their specific roles in gastric cancer remain largely unexplored. In this study, we identified HOXA10-HOXA9-derived small protein (HDSP) in gastric cancer by conducting a comprehensive analysis and experimental validation with mass spectrometry and western blotting. HDSP is highly expressed and has oncogenic roles in gastric cancer. Mechanistically, HDSP blocked TRIM25-mediated ubiquitination and degradation by interacting with MECOM. This led to the accumulation of MECOM, which further enhanced the transcription of SPINK1, a gene that promotes cancer through the EGFR signaling pathway. In addition, MECOM promoted the transcription of HOXA10-HOXA9, creating a feedback regulatory loop that activated downstream SPINK1-EGFR signaling. Finally, we found that HDSP knockdown inhibited tumor growth in a patient-derived xenograft (PDX) model, and the infusion of an artificially synthesized HDSP peptide as a neoantigen improved the anti-tumor efficacy of immune cells against gastric cancer in vitro and in vivo. Our findings provide a potential therapeutic target or neoantigen candidate for the treatment of gastric cancer.
Project description:Most epithelial ovarian cancers are thought to arise from different cells in the ovarian or fallopian tube epithelium. We hypothesized that these distinct cells-of-origin may play a role in determining ovarian tumor phenotype and also could inform the molecular classification of ovarian cancer. To test this hypothesis, we developed new methods to isolate and culture paired normal human ovarian (OV) and fallopian tube (FT) epithelial cells from multiple donors without cancer and identified a cell-of-origin gene expression signature that distinguished these cell types within the same patient. Application of the OV versus FT cell-of-origin gene signature to gene expression profiles of primary ovarian cancers permitted identification of distinct OV and FT-like subgroups among these cancers. Importantly, the normal FT-like tumor classification correlated with a significantly worse disease-free survival. This work describes a new experimental method for culture of normal human OV and FT epithelial cells from the same patient. These findings provide new evidence that cell-of-origin is an important source of ovarian tumor heterogeneity and the associated differences in tumor phenotype. We analyzed 12 samples from two donor patients and established cultures of both ovarian epithelium and fallopian tube epithelium (hTERT immortalized), each with 3 replicates (different culture passages).
Project description:Most epithelial ovarian cancers are thought to arise from different cells in the ovarian or fallopian tube epithelium. We hypothesized that these distinct cells-of-origin may play a role in determining ovarian tumor phenotype and also could inform the molecular classification of ovarian cancer. To test this hypothesis, we developed new methods to isolate and culture paired normal human ovarian (OV) and fallopian tube (FT) epithelial cells from multiple donors without cancer and identified a cell-of-origin gene expression signature that distinguished these cell types within the same patient. Application of the OV versus FT cell-of-origin gene signature to gene expression profiles of primary ovarian cancers permitted identification of distinct OV and FT-like subgroups among these cancers. Importantly, the normal FT-like tumor classification correlated with a significantly worse disease-free survival. This work describes a new experimental method for culture of normal human OV and FT epithelial cells from the same patient. These findings provide new evidence that cell-of-origin is an important source of ovarian tumor heterogeneity and the associated differences in tumor phenotype.
Project description:Mass spectrometry imaging analysis of a clinical urothelial cancer cohort for their spatial tryptic peptide composition in two different tissue types, tumor and stroma, and two tumor subtypes, muscle-infiltrating and non muscle-infiltrating tumors.
Project description:Analysis of a clinical urothelial cancer cohort for their spatial tryptic peptide composition in two different tissue types, tumor and stroma, and two tumor subtypes, muscle-infiltrating and non muscle-infiltrating tumors.
Project description:The transcription factors MECOM, PAX8, SOX17 and WT1 are candidate master regulators of high-grade serous ‘ovarian’ cancer (HGSC), yet their cooperative role in the hypothesized tissue of origin, the fallopian tube secretory epithelium (FTSEC) is unknown. We generated 26 epigenome (CUT&TAG, CUT&RUN, ATAC-seq and HiC) data sets and 24 profiles of RNA-seq transcription factor knock-down followed by RNA sequencing in FTSEC and HGSC models to define binding sites and gene sets regulated by these factors in cis and trans. This revealed that MECOM, PAX8, SOX17 and WT1 are lineage-enriched, super-enhancer associated master regulators whose cooperative DNA-binding patterns and target genes are re-wired during tumor development. All four TFs were indispensable for HGSC clonogenicity and survival but only depletion of PAX8 and WT1 impaired FTSEC cell survival. These four TFs were pharmacologically inhibited by transcriptional inhibitors only in HGSCs but not in FTSECs. Collectively, our data highlights that tumor-specific epigenetic remodeling is tightly related to MECOM, PAX8, SOX17 and WT1 activity and these transcription factors are targetable in a tumor-specific manner through transcriptional inhibitors.
Project description:The transcription factors MECOM, PAX8, SOX17 and WT1 are candidate master regulators of high-grade serous ‘ovarian’ cancer (HGSC), yet their cooperative role in the hypothesized tissue of origin, the fallopian tube secretory epithelium (FTSEC) is unknown. We generated 26 epigenome (CUT&TAG, CUT&RUN, ATAC-seq and HiC) data sets and 24 profiles of RNA-seq transcription factor knock-down followed by RNA sequencing in FTSEC and HGSC models to define binding sites and gene sets regulated by these factors in cis and trans. This revealed that MECOM, PAX8, SOX17 and WT1 are lineage-enriched, super-enhancer associated master regulators whose cooperative DNA-binding patterns and target genes are re-wired during tumor development. All four TFs were indispensable for HGSC clonogenicity and survival but only depletion of PAX8 and WT1 impaired FTSEC cell survival. These four TFs were pharmacologically inhibited by transcriptional inhibitors only in HGSCs but not in FTSECs. Collectively, our data highlights that tumor-specific epigenetic remodeling is tightly related to MECOM, PAX8, SOX17 and WT1 activity and these transcription factors are targetable in a tumor-specific manner through transcriptional inhibitors.
Project description:Oncolytic viruses (OVs), known for their cancer-killing characteristics, overturn tumor-associated defects in antigen presentation through the MHC class I pathway and induce protective neo antitumor CD8 T cell responses. Nonetheless, whether OVs shape the tumor MHC-I ligandome remains unknown. Here, we investigated if an OV induces the presentation of novel MHC I-bound tumor antigens (termed tumor MHC-I ligands). Using comparative mass spectrometry (MS)-based MHC-I ligandomics, we determined differential tumor MHC-I ligand expression following treatment with oncolytic reovirus in a murine ovarian cancer model. In vitro we found that reovirus induces the presentation of tumor MHC-I ligands in cancer cells. Concurrent multiplexed quantitative proteomics revealed that the changes in tumor MHC-I ligand presentation were mostly independent of reovirus-induced alterations of their source proteins. In an in vivo model, tumor MHC-I ligands were induced by reovirus in tumors but also, more importantly, analysis of spleens (a source of antigen-presenting cells) showed exclusive induction of most MHC-I ligands occurred in tumor-bearing mice. Finally, IFNγ assays demonstrated immunogenicity of the reovirus-induced MHC-I ligands. OV-induced MHC-I responses may be exploited in combinatorial approaches to promote the efficacy of cancer immunotherapies.