Human mutT homolog (MTH1) is a nucleotide pool sanitizing enzyme that cleaves oxidized nucleotides (dNTPs) to prevent incorporation of damaged bases during DNA replication. Cancer cells rely on MTH1 activity in order to avoid cell death. TH287 is an MTH1 inhibitor (IC50 = 0.8 nM) that selectively kills cancer cell lines (IC50s = 0.8-3.06 μM) without significant cytotoxicity towards primary or immortalized cells (IC50s = ≥20 μM). At up to 100 μM it does not show significant effect towards the related nudix hydrolase protein family members MTH2, NUDT5, NUDT12, NUDT14, and NUDT16, as well as other proteins with known nucleoside triphosphate pyrophosphatase activity (dCTPase, dUTPase, and ITPA).
