Lack of direct correlation among repair, oncogenesis, and lethality in cultured synchronized mouse fibroblasts treated with N-methyl-N'-nitro-N-nitrosoguanidine.
The repair of single-strand breaks induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in mouse embryo fibroblast DNA was studied using an alkaline sucrose sedimentation procedure with cells synchronized by arginine deprivation. Parallel studies in synchronized cells examined the effects of MNNG on malignant transformation and cell death. Cells in late G1 were maximally transformed, while cells in S-phase were maximally killed; by contrast, the repair capacity in both cases was similarly rapid. Arginine-deprived cells showed a low level of DNA repair, but the extent of cell death and transformation was comparable to that in rapidly repairing cells in G1 and S, respectively. Thus, in this system there is no direct correlation among DNA repair, cell transformation, and lethality.
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D004247:DNA / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D051379:Mice; D008970:Molecular Weight; D009604:Nitrosoguanidines / Q000494:pharmacology*
D009604:Nitrosoguanidines; D008769:Methylnitronitrosoguanidine; D004247:DNA