Differential sensitivities of transformed and untransformed murine cell lines to DNA cross-linking agents relative to repair of O6-methylguanine.
Sensitivities of several murine cell strains to killing by the DNA cross-linking agents 1-(2-chloroethyl)-1-nitrosourea (CNU), cis-diamminedichloroplatinum (II) (Cis-Pt) and mitomycin C (MMC) were measured by post-treatment colony-formation. Virally-transformed murine cells were usually more sensitive to cell killing by these agents than were the parental 3T3 cell strains. The hypersensitivity to CNU of some virally-transformed murine cell strains correlated well with the reduced ability to repair O6-methylguanine (O6mGua), a phenomenon similar to that in human cells. The loss of ability to repair O6mGua, as well as the increased sensitivity of transformed strains to cell killing, may not be due to a mutation but rather due to a change of gene expression associated with transformation by viruses or activation of oncogenes.
Yagi
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Nucleic Acids Section, NCI, Bethesda, MD 20892.
Day
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RS
D000818:Animals; D002455:Cell Division; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D003432:Cross-Linking Reagents; D004260:DNA Repair; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D008780:Methyltransferases / Q000378:metabolism; D051379:Mice; D019853:O(6)-Methylguanine-DNA Methyltransferase
D003432:Cross-Linking Reagents; D006147:Guanine; C008449:O-(6)-methylguanine; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase