Nanaomycin A is a selective inhibitor of DNA methyltransferase 3B (DNMT3B) with IC50 value of 500 nM [1].
In the biochemical in vitro methylation assay, Nanaomycin A showed selective inhibition of DNMT3B but not DNMT1 although it was docked to the catalytic domain of human DNMT1 in a multi-step docking approach. Nanaomycin A showed cell viability inhibition in HCT116, A549 and HL60 cells with IC50 values of 400 nM, 4100 nM and 800 nM, respectively. It decreased the genomic methylation level of these cells significantly. Besides that, Nanaomycin A treatment resulted in demethylation of the RASSF1A promoter in A549 cells. The demethylation caused by Nanaomycin A reactivated the transcription and expression of a silenced tumor suppressor gene [1].
References:
[1] Kuck D, Caulfield T, Lyko F, et al. Nanaomycin A selectively inhibits DNMT3B and reactivates silenced tumor suppressor genes in human cancer cells. Molecular cancer therapeutics, 2010, 9(11): 3015-3023.