FIGURE 3 from Pharmacologic Targeting of Histone H3K27 Acetylation/BRD4-dependent Induction of ALDH1A3 for Early-phase Drug Tolerance of Gastric Cancer

Histone H3 lysine 27 acetylation marks ALDH1A3 and other DTP genes. A, ChIP-PCR analysis of histone modification in DTP cells in the ALDH1A3 promoter region. JSC15-3 cells were treated with 3 µmol/L 5-FU or DMSO for 5 days. Each bar represents the mean ± SD of three technical replicates. Experiments were performed at least three times, and representative data are shown. ***, P < 0.001, two-tailed t test. B, ChIP-seq analysis of histone modification in DTP cells in the ALDH1A3 promoter region. Cells were treated as described in A. Genome browser view of chromatin accessibility enrichment of H3K27ac and H3K27me3 at the ALDH1A3 locus is shown. C, Principal component analysis plot of H3K27ac and H3K27me3 peaks in parental and 5FU-TP (DTP) cells. Default profile plots of H3K27ac (D) and H3K27me3 (E) drawn using DiffBind package in R (version 3.8.4). Each sample was normalized to the input. F, Venn diagram of upregulated genes and H3K27ac peaks in DTP cells. Upregulated genes in DTP cells were identified by RNA-seq analysis of JSC15-3 cells treated with 3 µmol/L 5-FU and DMSO for 5 days. Genes with a read count of more than 10 (CPM > 2) and fold change (FC) of greater than 1.5 were extracted using EdgeR and csaw packages in R, among which 67 genes overlapped with genes exhibiting enhanced H3K27ac signals in DTP cells as determined by ChIP-seq analysis. G, Top 10 genes with upregulated expression and H3K27ac levels in DTP cells.