6533b832fe1ef96bd129a35f

RESEARCH PRODUCT

Apoptosis induced by MNNG in human TK6 lymphoblastoid cells is p53 and Fas/CD95/Apo-1 related.

Bernd KainaTorsten R DunkernWynand P. Roos

subject

MethylnitronitrosoguanidineCell SurvivalHealth Toxicology and MutagenesisApoptosisCHO CellsBiologyCell LineBcl-2-associated X proteinCricetinaeProto-Oncogene ProteinsGeneticsCytotoxic T cellAnimalsHumansfas Receptorbcl-2-Associated X ProteinMitogen-Activated Protein Kinase 1Cell growthLymphoblastFas receptorMolecular biologyKineticsCell killingProto-Oncogene Proteins c-bcl-2Cell cultureApoptosisbiology.proteinTumor Suppressor Protein p53DNA Damage

description

Agents inducing O(6)-methylguanine (O(6)MeG) in DNA, such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), are not only highly mutagenic and carcinogenic but also cytotoxic because of the induction of apoptosis. In CHO fibroblasts, apoptosis triggered by O(6)MeG requires cell proliferation and MutSalpha-dependent mismatch repair and is related to the induction of DNA double-strand breaks (DSBs). Furthermore, it is mediated by Bcl-2 degradation and does not require p53 for which the cells were mutated [Cancer Res. 60 (2000) 5815]. Here we studied cytotoxicity and apoptosis induced by MNNG in a pair of human lymphoblastoid cells expressing wild-type p53 (TK6) and mutant p53 (WTK1) and show that TK6 cells are more sensitive than WTK1 cells to cell killing (determined by a metabolic assay) and apoptosis. Apoptosis was a late response observed <24h after treatment and was related to accumulation of p53 and upregulation of Fas/CD95/Apo-1 receptor as well as Bax. The data indicate that MNNG induces apoptosis in lymphoblastoid cells by activating the p53-dependent Fas receptor-driven pathway. This is in contrast to CHO fibroblasts in which, in response to O(6)MeG, the mitochondrial damage pathway becomes activated.

yearjournalcountryeditionlanguage
2003-12-04Mutation research
10.1016/j.mrrev.2003.06.005https://pubmed.ncbi.nlm.nih.gov/14644318