Project description:The CpG island methylator phenotype (CIMP) is associated with prognosis and drug sensitivity in multiple cancer types. In gastric cancer, the CIMP is closely associated with Epstein-Barr virus (EBV) infection and AT-rich interactive domain 1A (ARID1A) mutations, a component of the SWI/SNF chromatin remodeling complex. However, the involvement of SWI/SNF defects in CIMP induction has been unclear. In this study, we demonstrate a causal role of ARID1A loss-of-function in CIMP induction. Mutations of SWI/SNF components, especially ARID1A, was associated with the CIMP, as well as EBV infection, in gastric cancers, and also in uterine endometrial and colorectal cancers, which are not affected by EBV infection. Genome-wide DNA methylation analysis showed that ARID1A knockout (KO) in cultured 293FT cells and gastric epithelial cells, GES1, induced aberrant DNA methylation of a substantial number of CpG sites. DNA methylation was induced at genomic regions with high levels of pre-existing histone H3 lysine 27 trimethylation (H3K27me3) and those with acquired H3K27me3 by ARID1A KO. These results showed that the ARID1A mutation induced aberrant DNA methylation, and this is likely to be one of the potential mechanisms of CIMP induction. (See GSE188293 for data of GES1 with ARID1A KO.)
Project description:Arid1a is the subunit of SWI/SNF complex, which was reported to guide SWI/SNF to DNA. Here, we found that loss of Arid1a in the liver results in improved liver regeneration after partial hepatectomy.Genome-wide analysis showed that after hepatectomy,loss of Arid1a reduces the recruitment and activity of E2F4 on target promoters, resulting in expression programs that favor regeneration during injury.RNAseq shows transcriptional profiling in WT and Arid1a LKO livers pre- and post-hepatectomy, which confirmed the E2F4 target genes and cell cycle genes were upregulated after hepatectomy. After partial hepatectomy, liver transcriptional profiling in WT and Arid1a liver specific KO mice were generated by RNA-seq analysis.
Project description:Arid1a is the subunit of SWI/SNF complex, which was reported to guide SWI/SNF to DNA. Here, we found that loss of Arid1a in the liver and other adult tissues results in improved organ regeneration. Within SWI/SNF complexes, Arid1a physically interacts with C/ebpα, a hepatocyte transcription factor that drives maturation and limits proliferation. Genome-wide analysis showed that loss of Arid1a reduces the recruitment and activity of C/ebpα on target promoters, resulting in expression programs that favor regeneration and cellular fitness during injury. Arid1a binding is enriched in promoters near transcriptional start sites (TSSs), and C/ebpα binds at precisely the same positions, indicating that Arid1a facilitates C/ebpα binding across the genome. Perfuse and isolate primary hepatocytes from mice livers, analysis of genomic occupancy of C/ebpα and H3K4me2 in hepatocytes from Arid1a WT and Arid1a liver specific KO mice by ChIP-seq. Analysis of genomic occupancy of Arid1a in the hepatocytes from V5-Arid1a transgenic mouse by ChIP-seq.
Project description:IDH3a KO in NHAs was demonstrated to exert global DNA methylation changes. These studies were followed by an Illumina EPIC methylation array to evaluate the location of differentially methylated CpGs