Inhibition of chronic signaling re-recruits polycomb to the PAX5 promoter. (A-E) ChIP-qPCR experiments measuring relative enrichment of the elongating form of the RNA Pol II complex as well as H3K27ac, H3K27me3, EZH2, and H2Aub1 at the PAX5 promoter hypersensitive sites in untreated Kasumi-1, DMSO-treated Kasumi-1, JNK, MEK, and p38 inhibitor-treated Kasumi-1 and HL-60 cells. (A,B) Relative enrichment shown is over the inactive IVL locus. (C-E) Enrichment is relative to (C) input, (D) TBP, and (E) Chr18. Each bar graph is a representative of 2 independent experiments and the error bars show variability between qPCR measurements. (F) Western blot showing BMI1 and phospho-BMI1 expression in untreated Kasumi-1, DMSO-treated Kasumi-1, JNK, MEK, and P38-treated Kasumi-1 cells and HL-60 cells. GAPDH expression in each of the above cell lines was used as a loading control. (G) The HDAC inhibitor TSA rescues the inhibition of signaling mediated downregulation of PAX5 expression. qRT-PCR experiment showing PAX5 expression in untreated, DMSO-treated, ethanol-treated, ethanol + DMSO treated, TSA-treated, JNK + MEK + P38 inhibitor–treated, and TSA + JNK + MEK + p38 inhibitor–treated Kasumi-1 cells. The y-axis shows PAX5 expression relative to GAPDH expression. The bar graph shows average values from 2 independent experiments measured in duplicate; error bars show the variability in qPCR measurements between the 2 experiments.