Modification of Gamma Radiation and 4-Nitroquinoline 1-Oxide Induced Genotoxicity by Tumour Promoter Iodoacetate

Abstract

Modifying effects of tumour promoter Iodoacetic Acid -sodium salt (IA) was studied on 60 Co gamma radiation and 4-Nitroquinoline 1-oxide (4-NQO) induced recombination (gene conversion), back mutation and aberrant colony formation (ACF) using eukaryotic model system, yeast. Cells were exposed to 0-400 Gy of radiation or were treated with 0.15-1.5 mM 4-NQO and grown on the media containing 0-200 µg IA/ml. The results indicated that IA reduced the frequencies of spontaneous; gamma radiation as well as 4-NQO induced back mutation and ACF significantly. Further, it had no effect on spontaneous, radiation or 4-NQO induced recombination (gene conversion) frequency. These observations suggest that IA does not act like other tumour promoters, which enhance the frequency of genetic events induced by carcinogens in vitro.