Project description:The expression of NRF2 was activated in human hepatocellular carcinoma. In current study, we observed that in hepatic carcinogen diethylnitrosamine induced liver tumor mouse model, NRF2 knockout mouse developed less liver tumor incidence than wild type mouse. To reveal the detailed mechanism, RNA-seq experiment was conducted to compare gene transcriptome profiles of NRF2 WT and KO mice during HCC progression.
Project description:Epigenetic and metabolic reprogrammings are implicated in cancer progression with unclear mechanisms. We report here that the histone methyltransferase NSD2 drives cancer cell and tumor resistance to therapeutics such as tamoxifen, doxorubicin, and radiation by reprogramming of glucose metabolism. NSD2 coordinately up-regulates expression of TIGAR, HK2 and G6PD and stimulates pentose phosphate pathway (PPP) production of NADPH for ROS reduction. We discover that elevated expression of TIGAR, previously characterized as a fructose-2,6-bisphosphatase, is localized in the nuclei of resistant tumor cells where it stimulates NSD2 expression and global H3K36me2 mark. Mechanistically, TIGAR interacts with the antioxidant regulator Nrf2 and facilitates chromatin assembly of Nrf2-H3K4me3 methylase MLL1 and elongating Pol-II, independent of its metabolic enzymatic activity. In human tumors, high levels of NSD2 correlate strongly with early recurrence and poor survival and are associated with nuclear-localized TIGAR. This study defines a nuclear TIGAR-mediated, epigenetic autoregulatory loop functioning in redox rebalance for resistance to tumor therapeutics. A total of 4 samples were analyzed in this study. The study included two cell lines, MCF7 and the tamoxifen-resistant subline TMR. Both were were cultured in medium containing vehicle control and/or 4-hydroxytamoxifen (Tam). The untreated MCF7 and TMR cell lines served as controls for the study.
Project description:Liver tumors had high levels of histone acetylation. Nrf2 knockout mice developed fewer tumors than Nrf2 wild-type mice. The mechanistic study found that Nrf2 knockout reduced the generation of acetyl CoA from impaired glycolysis, TCA cycle, and fatty acid metabolism. Acetyl CoA is the substrate for protein acetylation including histone acetylation. Here we determined the genome-wide distribution of AcH3K27. We found that Nrf2 through regulating acetyl CoA production affects histone acetylation (AcH3K27) to modulate the expression of genes, whose products were involved in the glycolysis, TCA cycle, fatty acid metabolism, and oncogenic Myc/mTor signaling. Our findings supported an Nrf2-integrated metabolic, epigenetic and oncogenic signaling in driving liver tumor development.
Project description:Epigenetic and metabolic reprogrammings are implicated in cancer progression with unclear mechanisms. We report here that the histone methyltransferase NSD2 drives cancer cell and tumor resistance to therapeutics such as tamoxifen, doxorubicin, and radiation by reprogramming of glucose metabolism. NSD2 coordinately up-regulates expression of TIGAR, HK2 and G6PD and stimulates pentose phosphate pathway (PPP) production of NADPH for ROS reduction. We discover that elevated expression of TIGAR, previously characterized as a fructose-2,6-bisphosphatase, is localized in the nuclei of resistant tumor cells where it stimulates NSD2 expression and global H3K36me2 mark. Mechanistically, TIGAR interacts with the antioxidant regulator Nrf2 and facilitates chromatin assembly of Nrf2-H3K4me3 methylase MLL1 and elongating Pol-II, independent of its metabolic enzymatic activity. In human tumors, high levels of NSD2 correlate strongly with early recurrence and poor survival and are associated with nuclear-localized TIGAR. This study defines a nuclear TIGAR-mediated, epigenetic autoregulatory loop functioning in redox rebalance for resistance to tumor therapeutics.