Morris S M, Domon O E, McGarrity L J, Chen J J, Casciano D A
Department of Health and Human Services, US Public Health Service, Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR 72079, USA.
Mutat Res. 1995 Jun;329(1):79-96. doi: 10.1016/0027-5107(95)00020-j.
One role of programmed cell death (apoptosis) is the removal of cells with DNA damage from the population. Certain cells, however, are able to suppress the signals for apoptotic cell death and maintain viability. This suggests that the susceptibility of a cell to either undergo apoptosis or escape from the apoptotic death pathways may be an important factor in chemical mutagenesis. In order to provide insight into the role of apoptosis in the recovery of chemically induced mutants, AHH-1 cells were exposed to the chromosomal mutagen, m-amsa, and the percentage of cells undergoing apoptosis or necrosis quantified by flow cytometry. Logistic regression analysis revealed that the primary manner of cell death was by apoptosis. Two specific-locus mutations assays, the tk and the hprt, were utilized as markers for cells with DNA damage and that retained clonogenicity under conditions known to induce apoptosis. Analysis of variance indicated that the concentration-dependent increase in the mutant fraction at the tk locus was significant and the result of the recovery of clones with the slow-growth phenotype. Because this phenotype is thought to reflect chromosomal mutations, these results are consistent with the survival and clonogenicity of damaged cells. This suggests that the ability to recover mutant cells may be influenced by the suppression of or an escape from the apoptotic death pathways.
程序性细胞死亡（凋亡）的一个作用是从细胞群体中清除具有DNA损伤的细胞。然而，某些细胞能够抑制凋亡性细胞死亡的信号并维持生存能力。这表明细胞对经历凋亡或逃避凋亡死亡途径的敏感性可能是化学诱变中的一个重要因素。为了深入了解凋亡在化学诱导突变体恢复中的作用，将AHH-1细胞暴露于染色体诱变剂m-amsa，并通过流式细胞术对经历凋亡或坏死的细胞百分比进行定量。逻辑回归分析表明细胞死亡的主要方式是凋亡。两种特定基因座突变检测方法，即tk和hprt，被用作具有DNA损伤且在已知诱导凋亡的条件下仍保持克隆形成能力的细胞的标志物。方差分析表明，tk基因座处突变分数的浓度依赖性增加是显著的，并且是具有缓慢生长表型的克隆恢复的结果。由于这种表型被认为反映了染色体突变，这些结果与受损细胞的存活和克隆形成能力一致。这表明恢复突变细胞的能力可能受到凋亡死亡途径的抑制或逃避的影响。
