Project description:Folic acid is present in pre-natal vitamins, fortified cereal grains and multi-vitamin supplements. High intake of folic acid through these sources has resulted in populations with increased levels of serum folate and unmetabolized folic acid. Although the benefits of folic acid in the prevention of neural tube defects are undeniable, the impact of long-term consumption of folic acid on the prostate is not fully understood. In this study, we used a rodent model to test whether dietary folic acid (FA) supplementation changes prostate homeostasis and response to androgen deprivation. Although intact prostate weights do not differ between diet groups, we made the surprising observation that dietary folic acid supplementation confers partial resistance to castration-mediated prostate involution. More specifically, male mice that were fed a folic acid supplemented diet and then castrated had greater prostate wet weights, greater prostatic luminal epithelial cell heights, and more abundant RNAs encoding prostate secretory proteins compared to mice that were fed a control diet and castrated. We used RNA-seq to identify signaling pathways enriched in the castrated prostates from folic acid supplemented diet fed mice compared to control mice. We observed differential expression of genes involved in several metabolic pathways in the FA supplemented mice. Together, our results show that dietary FA supplementation can impact metabolism in the prostate and attenuate the prostate’s response to androgen deprivation. This has important implications for androgen deprivation therapies used in the treatment of prostate disease, as consumption of high levels of folic acid could reduce the efficacy of these treatments.
Project description:Deciphering the impact of metabolic intervention on response to anticancer therapy represents a path toward improved clinical responses. Here, we identify amino acid-related pathways connected to the folate cycle whose activation predicts sensitivity to MYC-targeting therapies in acute myeloid leukemia (AML). We establish that folate restriction and deficiency of the rate-limiting folate-cycle enzyme, MTHFR ― which exhibits reduced-function polymorphisms in about 10% of Caucasians ― enhance resistance to MYC targeting by BET and CDK7 inhibitors in cell lines, primary patient samples and syngeneic mouse models of AML. Further, this effect is abrogated by supplementation with the MTHFR enzymatic product, CH3-THF. Mechanistically, folate cycle disturbance reduces H3K27/K9 histone methylation, and activates a SPI1 transcriptional program counteracting the effect of BET inhibition. Our data provide a rationale for screening MTHFR polymorphisms and the folate cycle status to exclude patients least likely and nominate those most likely to benefit from MYC-targeting therapies.
Project description:The role of the histone methyltrasferase G9a (also known as Ehmt2) in the normal heart has not been studied extensively. To identify which genes were direct targets of G9a in hypertrophic cardiomyocytes, we performed ChIP-seq for G9a and H3K9me2 – the main histone methylation catalysed by the HMT – on cardiomyocytes isolated from normal mice (sham) and mice subject to transverse aortic constriction (TAC) for 1 wk, a surgical procedure that causes cardiac hypertrophy following the induction of pressure overload. We considered the best G9a-bound genomic regions as those in which G9a and H3K9me2 peaks overlapped. Since G9a contributes to trimethylation of H3K27 at a set of developmental genes through its interaction with PRC2, we also evaluated whether G9a had an effect on the distribution of this histone mark in hypertrophic cardiomyocytes. To this end, we performed ChIP-seq for H3K27me3 in CMs isolated from sham and TAC mice.
Project description:Using all three CpG DNA methyltransferases, Dnmt1, Dnmt3a and Dnmt3b deficient (TKO) mouse ES cells and TKO ntTS cells, we examined three histone modifications H3K4me2, H3K27me3 and H3K9me2, of promoter region in ES, TS and Flk1+ mesodermal cells with WT or TKO background by ChIP-chip analysis. Global profile analysis of gene expression and histone modification showed that the difference of profiles was mainly lineage dependent. Although the effects of DNA methylation loss in three lineages were modest, H3K27me3 is most sensitive to DNA methylation among three modifications. Interestingly, differentially expressed genes between WT and TKO cells were also lineage dependent and small number of genes was overlapped between lineages. Our further analysis showed that the profiles of H3K27me3 modifications were dynamically changed between lineages, especially in TS cells, and the pattern of H3K27me3 modification was defectively established by loss of DNA methylation. Our data suggest that DNA methylation contributes to lineage dependent expression regulation by collaborating with histone modification.
Project description:Chromatin immunoprecipitation and hybridization to a chromosome-wide DNA tiling array (ChIP-chip)was performed to identify the targets of the chromatin protein TERMINAL FLOWER 2/LIKE HETEROCHROMATIN PROTEIN 1. Epigenomic profiling was also carried out for three histone H3 modifications: H3K27me3, H3K9me2 and H3K9me3. Experiments were done using two independent biological replicates.
Project description:We report the high-throughput profiling of histone modifications, CTCF and HP1a binding sites in MCF7 breast cancer cells. ChIP-chip experiments were performed using the Agilent Human Genome CGH Microarray 1x1M. Regulatory markers H3K4Me1, H3K4Me3, H3K4Ac, H3K9Ac, CTCF are known to be positively correlated with gene expression, and H3K9Me2, H3K27Me3 and HP1a are negative markers. Together with MCF7 methylation data, we showed hypomethylated promoters are significantly enriched with positive regulatory elements, and lacks repressive markers.