The presumed MTH1-inhibitor TH588 sensitizes colorectal carcinoma cells to ionizing radiation in hypoxia.

TH588 has cytotoxic effects on transformed and untransformed cells and synergizes with IR in normoxia and in hypoxia. TH588 toxicity is not fully explained by MTH1 inhibition as HCT116 were unaffected by lentiviral suppression of MTH1 expression. TH588 should be explored further because it has radiosensitizing effects in hypoxia.