Deoxynucleoside triphosphate pool perturbation is not a general feature in mutagen-treated mammalian cells

Abstract

Deoxynucleoside triphosphate (dNTP) and ribonucleoside triphosphate (rNTP) pools were analyzed in 4 mammalian cell lines following treatment with UV-C (254 nm), UV-A (365 nm) or the carcinogen, 1-methyl-3-nitro-1-nitrosoguanidine (MNNG). No substantial alterations in dNTP pool levels were observed in any treatment group. However, the cellular conversions of exogenously added deoxycytidine and deoxyguanosine to the corresponding triphosphates were inhibited 30-97% by UV-C and MNNG treatment. In addition, the conversion of dGuo to GTP and deoxyadenosine to ATP were inhibited 25-50% in CHO cells by mutagen treatment. The data do not support the notion that modulation of specific dNTP pools is a general feature of mutagen treatment in mammalian cells, but so suggest a mutagen-sensitivity of deoxynucleoside metabolism.