BIX-01294 inhibits oncoproteins NSD1, NSD2 and NSD3

NSD1, NSD2/MMSET/WHSC1, and NSD3/WHSC1L1 make up the nuclear receptor-binding Su(var)3-9, Enhancer-of-zeste and Trithorax domain family of histone methyltransferases, which are essential for regulating the chromatin. Abnormalities in histone methyltransferases function are increasingly being found to be associated with numerous pathological conditions, including carcinogenesis and tumor progression. NSD1, NSD2, and NSD3 are oncoproteins aberrantly expressed in numerous cancers in which selective inhibition may offer therapeutic opportunities, especially in cases of conditions with poor prognoses such as multiple myeloma. Histone methyltransferase inhibitors are scarce and selective inhibitors are being explored. NSD inhibitors are urgently needed. BIX-01294 is a G9a-like protein/G9a histone methyltransferase inhibitor commonly used to modulate H3K9 methylation in the context of cell reprogramming and cancer biology with in vitro IC50 values of 0.7 and 1.9 μM, respectively. Since the catalytic Su(var)3-9, Enhancer-of-zeste and Trithorax domain of the NSDs is highly related to that of G9a-like protein and G9a, we investigated the potentially differential NSDs inhibition by BIX-01294. In this study, we identified BIX-01294 as an NSD in vitro hit compound that differentially inhibits H3K36 methylation by NSD1, NSD2, and NSD3 with IC50 values of 40 ~ 112 μM. Furthermore, we investigated the molecular basis of inhibition by BIX-01294 on the NSDs and discuss the prospects of BIX-01294 derivatives for selective NSD inhibition.