Project description:ZNF322A, a C2H2 zinc finger transcription factor, is an oncoprotein in lung cancer. However, the transcription mechanisms of ZNF322A in lung cancer stemness remain elusive. By integrating our chromatin immunoprecipitation-sequencing and RNA-sequencing datasets, we identified and validated transcriptional targets of ZNF322A, which significantly enriched in developmental processes. Indeed, overexpression of ZNF322A promoted self-renewal ability and increased stemness-related gene expressions in vitro and in vivo. Importantly, ZNF322A bound directly to c-Myc promoter to transcriptionally suppress c-Myc expression, which in turn increased mitochondrial oxidative phosphorylation, promoted cell motility and thus maintained lung cancer stemness properties. Clinically, ZNF322AHigh/c-MycLow expression profile was revealed as an independent factor for poor outcome of lung cancer patients. Our study provides first evidence that ZNF322A-centered transcriptome promotes lung tumorigenesis and ZNF322A acts as a transcription suppressor of c-Myc to maintain lung cancer stemness by shifting metabolism phenotype to oxidative phosphorylation.
Project description:ZNF322A, a C2H2 zinc finger transcription factor, is an oncoprotein in lung cancer. However, the transcription mechanisms of ZNF322A in lung cancer stemness remain elusive. By integrating our chromatin immunoprecipitation-sequencing and RNA-sequencing datasets, we identified and validated transcriptional targets of ZNF322A, which significantly enriched in developmental processes. Indeed, overexpression of ZNF322A promoted self-renewal ability and increased stemness-related gene expressions in vitro and in vivo. Importantly, ZNF322A bound directly to c-Myc promoter to transcriptionally suppress c-Myc expression, which in turn increased mitochondrial oxidative phosphorylation, promoted cell motility and thus maintained lung cancer stemness properties. Clinically, ZNF322AHigh/c-MycLow expression profile was revealed as an independent factor for poor outcome of lung cancer patients. Our study provides first evidence that ZNF322A-centered transcriptome promotes lung tumorigenesis and ZNF322A acts as a transcription suppressor of c-Myc to maintain lung cancer stemness by shifting metabolism phenotype to oxidative phosphorylation.
Project description:WNT signaling promotes pancreatic ductal adenocarcinoma (PDAC) through diverse effects on proliferation, differentiation, survival, and stemness. A subset of PDAC with inactivating mutations in ring finger protein 43 (RNF43) have growth dependency on autocrine WNT ligand signaling, which renders them susceptible to porcupine inhibitors (PORCNi) that block WNT ligand acylation and secretion. For this study, non-targeted metabolomic analyses were performed to explore the therapeutic response of RNF43-mutant PDAC to the PORCNi LGK974. AsPC-1 (RNF43-mutant) PDAC cells were treated with 25 nM LGK974 to explore stable isotope-resolved metabolomics with uniform 1, D-glucose [U13-C6] labeling.
Project description:The transcription factor MYC is overexpressed in most cancers, where it drives multiple hallmarks of cancer progression. MYC is known to promote oncogenic transcription by binding to active promoters. In addition, MYC has also been shown to invade distal enhancers when expressed at oncogenic levels, but this enhancer binding has been proposed to have low gene-regulatory potential. Here, we demonstrate that MYC enhancer binding directly promotes cancer type-specific gene programs predictive of poor patient prognosis. MYC induces transcription of enhancer RNA through recruitment of RNAPII, rather than regulating RNAPII pause-release as is the case at promoters. This is mediated by MYC-induced H3K9 demethylation by KDM3A and acetylation by GCN5, leading to enhancer-specific BRD4 recruitment through its bromodomains, which facilitates RNAPII recruitment. Thus, we propose that MYC drives prognostic cancer type-specific gene programs by promoting RNAPII recruitment to enhancers through induction of an epigenetic switch.
Project description:The oncogenic transcription factor Myc is a pleiotropic regulator of RNA Polymerase II (RNAPII)-dependent transcription, DNA replication and DNA damage response pathways. Myc is stringently regulated by the ubiquitin system - for example, ubiquitination controls recruitment of the elongation factor Paf1c, which is critical for several Myc functions. Curiously, a key Myc-targeting deubiquitinase Usp28 also controls cellular response to DNA damage via the mediator protein 53bp1. Usp28 forms stable dimers, but the biological role of Usp28 dimerization is unknown. We show that dimerization limits Usp28 activity and restricts recruitment of Paf1c by Myc. Expression of monomeric Usp28 leads to ectopic Paf1c recruitment and resolution of transcription-replication conflicts, accelerating DNA synthesis. Strikingly, 53bp1 selectively interacts with and stabilizes dimeric Usp28 - depletion of 53bp1 favors formation of Usp28 monomers deregulating DNA replication. Genotoxic stress disrupts 53bp1-Usp28 complexes, promotes formation of Usp28 monomers and recruitment of Paf1 by Myc. This triggers ectopic DNA synthesis during early response to genotoxins, amplifying DNA damage. We propose that dimerization of Usp28 limits aberrant replication at transcriptionally active chromatin to maintain genome stability.
Project description:We report the distribution of binding sites of Myc-associated zinc finger (MAZ) transcription factor in primary human erythroid cells
