Project description:The recently described roles of vitamin C as an epigenetic regulator playsa crucial role in normal physiological development and pathological conditions.However, the epigenetic regulatory role of vitamin C in renal homeostasis andpathogenesis remains largely unknown. We aim to reveal that vitamin C deficiency promoted acute tubular necrosis,and provide a potential mechanism for epigenetic therapy in preventing the progression of chronic kidney disease.
Project description:Investigate the effect of jhdm1b on Oct4 mediated reprogramming Investigate the effect of vitamin C on the function of jhdm1b oct4 and jhdm1b infected MEF with or without vitamin C treatment
Project description:Cell state evolution underlies tumor development and response to therapy1, but mechanisms specifying cancer cell states and intratumor heterogeneity are incompletely understood. Schwannomas are the most common tumors of the peripheral nervous system and are treated with surgery and ionizing radiation2–5. Schwannomas can oscillate in size for many years after radiotherapy6,7, suggesting treatment may reprogram schwannoma cells or the tumor microenvironment. Here we show epigenetic reprogramming shapes the cellular landscape of schwannomas. We find schwannomas are comprised of 2 molecular groups distinguished by reactivation of neural crest development pathways or misactivation of nerve injury mechanisms that specify cancer cell states and the architecture of the tumor immune microenvironment. Schwannoma molecular groups can arise independently, but ionizing radiation is sufficient for epigenetic reprogramming of neural crest to immune-enriched schwannoma by remodeling chromatin accessibility, gene expression, and metabolism to drive schwannoma cell state evolution and immune cell infiltration. To define functional genomic mechanisms underlying epigenetic reprograming of schwannomas, we develop a technique for simultaneous interrogation of chromatin accessibility and gene expression coupled with genetic and therapeutic perturbations in single-nuclei. Our results elucidate a framework for understanding epigenetic drivers of cancer evolution and establish a paradigm of epigenetic reprograming of cancer in response to radiotherapy.
Project description:We found a small molecule-DKG, relative to Vitamin C, could replace the function of Viamin C during reprogramming. After comparing transcriptome profiling (RNA-seq) of this molecule to vitamin C, it could provide a framework for more mechanism.
Project description:The transcriptome of 3 cutaneous melanoma cell lines treated with Control (DMSO), CDK9 inhibitor (CDKI73), BET/bromodomain and extra terminal inhibitors IBET151, or combination of both drugs was assessed using RNAseq. Dysregulation of epigenetic modifiers is a frequent event in melanoma and underlies many aspects of melanoma biology including resistance to targeted and immunotherapies. Here we report that dual targeting of BET and CDK9 proteins have synergistic effects against melanoma cells in vitro and in vivo. The BET inhibitor (IBET151) and CDK9 inhibitor (CDKI73) synergistically killed melanoma cells in vitro independent of their BRAF or NRAS mutation status. The combination of drugs markedly inhibited the growth of human melanoma C002M cells in vitro in 3D spheroids and in vivo in NSG mice compared to vehicle control and the individual drugs (p<0.05). Cell death was associated with mitochondrial depolarisation and caspase dependent apoptosis with cleavage of PARP1 as well as downregulation of anti-apoptotic proteins BCL2, BCLXL and MCL1. GSEA revealed downregulation of hallmark gene-sets associated with E2F, G2M checkpoint and c-MYC. Survival analysis showed worse prognosis with high G2M, E2F or c-MYC gene signatures suggesting biomarkers of response of BET and CDK9 inhibitors in melanoma. This novel combination of epigenetic inhibitors targets multiple downstream genes leading to cell death of melanoma cells in vitro and in vivo and warrant further investigation for treatment of melanoma in patients not responding to current therapies.
Project description:The dynamic evolution of chromatin state patterns during metastasis, their relationship with bona fide genetic drivers and therapeutic vulnerabilities are not completely understood. Combinatorial chromatin state profiling of 46 melanoma samples reveals an association of NRAS-mutants with bivalent H3K27me3 and Polycomb Repressive Complex 2. Reprogramming of bivalent domains during metastasis occurs on master transcription factors of a mesenchymal phenotype, including ZEB1, TWIST1 and CDH1. Resolution of bivalency using pharmacological inhibition of EZH2 decreases invasive capacity of melanoma cells and markedly reduces tumor burden in vivo, specifically in NRAS-mutants. Coincident with bivalent reprogramming the increased expression of pro-metastatic and melanocyte-specific cell identity genes are associated with exceptionally wide H3K4me3 domains, suggesting a role for this epigenetic element. Overall, we demonstrate that reprogramming of bivalent and broad domains represents key epigenetic alterations in metastatic melanoma, and that EZH2 plus MEK inhibition may provide a promising therapeutic strategy for NRAS-mutant melanoma patients.