KDM5-C70 (KDOAM-21) corresponds to the ethyl ester precursor of a selective αKG-competitive KDM5 histone demethylase inhibitor KDM5-C49 (KDOAM-21; KDM5A/B/C/D Ki = 2/1/6.1/3.4 nM vs. KDM4C/6B/3A/2A Ki = 0.51/4.55/2.59/4.4 μM; KDM5A/B/C/D IC50 = 1.1/0.8/3.2/2.7 μM by FDH assay with [αKG] = 1 mM & [E]/[S] = 0.5/15 μM; KDM5A/B/C IC50 = 25/30/59 nM by alphaLISA with [αKG] = 25 μM & [E]/[S] = 10/100 nM). KDM5-C70 treatment selectively upregulates cellular histone H3 trimethylation on Lys4 (H3K4me3), but not on Lys9/7/36 (5 μM, 3d), and inhibits KDM5-dependent cancer growth (by 85%/MCF7/11d, 97%/BT474/24d, and 70%/ZR-75-1/24d; 5 μM).
