MM-102 TFA (HMTase Inhibitor IX TFA) is a potent WDR5/MLL interaction inhibitor with an IC50 of 2.4 nM. This compound prevents the interaction between mixed lineage leukemia 1 (MLL1) and WD Trp-Asp repeat domain 5 (WDR5), inhibiting MLL1 H3K4 histone methyltransferase (HMT) activity and down-regulating H3K4me3, which facilitates the epigenetic reprogramming of porcine somatic cell nuclear transfer embryos.

MLL1:0.4 μM

MM-102, in bone marrow cells transduced with MLL1-AF9 fusion construct shows that the compound effectively decreases the expression of HoxA9 and Meis-1, two critical MLL1 target genes in MLL1 fusion protein mediated leukemogenesis.?MM-102 also specifically inhibits cell growth and induces apoptosis in leukemia cells harboring MLL1 fusion proteins.

In Vitro Histone Methyltransferase (HMT) Assay: The HMT assay is performed in 50 mM HEPES pH 7.8, 100 mM NaCl, 1.0 mM EDTA, and 5% glycerol at 22 °C. Each reaction contains 1.5 μCi of the co-factor, 3H-S-adenosylmethionine. H3 10-residue peptide is used as the substrate at 50 μM. Compounds are added at concentrations ranging from 0.125 to 128 μM and incubated with the pre-assembled WDR5/RbBP5/ASH2L complex at a final concentration of 0.5 μM for each protein for 2–5 min. Reactions are initiated by addition of the MLL1 protein at a final concentration of 0.5 μM and allowed to proceed for 30 min before preparing scintillation counting. To count samples, reactions are spotted on separate squares of P81 filter paper and precipitated by submerging in freshly prepared 50 mM sodium bicarbonate buffer with pH 9.0. After washing and drying, samples are vortexed in Ultima Gold scintillation fluid and counted. As a negative control, assays are performed using 0.5 μM MLL1/WDR5/RbBP5/ASH2L complex assembled with the non-interacting mutant, WDR5D107A.