The JARID1 (Jumonji AT-Rich Interactive Domain 1) family of lysine demethylases is responsible for demethylation of trimethylated lysine 4 in histone H3 (H3K4me3). PBIT is a potent and selective inhibitor of JARID1 (IC50 = 3, 4.9 and 6 uM for JARID1B, 1A and 1C, respectively). It is selective for JARID1 over UTX and JMJD3. Treatment of cells with PBIT inhibits the demethylation of H3K4me3. PBIT inhibits proliferation of breast cancer cell lines expressing high levels of JARID1B.
