Effect of caffeine on cell killing, mutation induction, DNA repair, and DNA synthesis after treatment with ethylnitrosourea
- 1 January 1981
- journal article
- research article
- Published by Oxford University Press (OUP) in Carcinogenesis: Integrative Cancer Research
- Vol. 2 (12) , 1267-1271
- https://doi.org/10.1093/carcin/2.12.1267
Abstract
The effect of caffeine on cell killing, mutation induction, DNA repair and inhibition of DNA synthesis was investigated in a clonal derivative of M3-1 Chinese hamster cells after treatment with N-ethyl-N-nitrosourea (ENU). Caffeine enhanced cell killing but had no effect on the mutation frequency/viable cells for the 2 genetic markers, 6-thioguanine resistance and ouabain resistance. The removal of ethylated purine bases from DNA was as follows: most of the 3-ethyladenine was lost in 20 h (> 85%) and .apprx. 45% of the 7-ethylguanine was lost in 45 h; 75-93% of the O6-ethylguanine was still present at this time. Caffeine did not seem to influence these rates significantly. The ENU-induced inhibition of DNA synthesis was reversed by caffeine. The potentiation of ENU-induced cell killing by caffeine is caused by the increased frequency of DNA replication past damaged sites in parental DNA.This publication has 1 reference indexed in Scilit: