[The selective toxicity of 5-hydroxymethyldeoxyuridine for the cells of human adenocarcinoma of the large intestine].

Comparing the toxicities of potential anticancer agents for tumorous and normal cells derived from human intestinal epithelium may be a preferred approach for in vitro testing of compounds directed against colon carcinoma. 5-Hydroxymethyldeoxyuridine, a thymidine analog, was preferentially cytotoxic for two lines of human colon adenocarcinoma cells compared to a cell line derived from normal human fetal intestine. Unlike deoxyuridine and deoxycytydine, thymidine protected HT-29 human adenocarcinoma against 5-hydroxymethyldeoxyuridine toxicity, suggesting that thymidilate synthetase is the probable target enzyme of this thymidine analog. 5-Hydroxymethyldeoxyuridine may hold promise as an agent with specific activity against human adenocarcinoma cells.