Nucleotide pools and mutagenic effects of alkylating agents in wild-type and APRT-deficient Friend erythroleukaemia cells.
Wild-type Friend mouse erythroleukaemia cells (clone 707) were compared with adenine phosphoribosyltransferase (APRT)-deficient mutant subclones (707DAP8 and 707DAP10) for sensitivity to cell killing and mutagenesis by ethyl methanesulphonate (EMS) and methyl methanesulphonate (MMS). Cells were exposed to 0-300 micrograms/ml EMS and to 0-20 micrograms/ml MMS for a period of 16 h. A slight difference was found between wild-type cells and the two APRT-deficient subclones in terms of sensitivity to cell killing by both mutagens. The APRT-deficient subclones were, however, significantly more sensitive than wild-type cells to mutagenesis to 5-bromo-2-deoxyuridine resistance and 6-thioguanine resistance by EMS and MMS. The APRT-deficient subclones were found to have significantly decreased levels of dATP and dTTP nucleotides and decreased levels of all four ribonucleoside triphosphates (ATP, GTP, CTP and UTP) relative to wild-type cells. Wild-type Friend cells were found to have insignificant levels O6-methylguanine-DNA methyl transferase and it is suggested that the increased mutagen sensitivity of APRT-deficient cells may be due to imbalance of deoxyribonucleoside triphosphate pools during DNA excision-repair processes, or more probably due to deficiency of ATP for ATP-dependent DNA excision-repair enzymes.
Amara
F M
FM
Department of Biological and Biomedical Sciences, University of Ulster, Coleraine Northern Ireland.
Wilkinson
Y A
YA
Ward
P E
PE
Thompson
C C
CC
McKenna
P G
PG
D000477:Alkylating Agents / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D003854:Deoxyribonucleotides / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005622:Friend murine leukemia virus; D066298:In Vitro Techniques; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics*; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008780:Methyltransferases / Q000032:analysis; D051379:Mice; D016296:Mutagenesis / Q000187:drug effects*; D009711:Nucleotides / Q000032:analysis*; D012263:Ribonucleosides / Q000032:analysis
D000477:Alkylating Agents; D003854:Deoxyribonucleotides; D009711:Nucleotides; D012263:Ribonucleosides; D005020:Ethyl Methanesulfonate; D008741:Methyl Methanesulfonate; D008780:Methyltransferases