Limoli Charles L, Giedzinski Erich
Department of Radiation Oncology, University of California, San Francisco, CA 94103-0806, USA.
Neoplasia. 2003 Jul-Aug;5(4):339-46. doi: 10.1016/S1476-5586(03)80027-1.
Earlier studies using GM10115 cells analyzed the capability of different DNA-damaging agents to induce genomic instability and found that acute oxidative stress was relatively inefficient at eliciting a persistent destabilization of chromosomes. To determine whether this situation would change under chronic exposure conditions, the human-hamster hybrid line GM10115 was cultured under conditions of oxidative stress. Chronic treatments consisted of 1-hour incubations using a range of hydrogen peroxide (25-200 microM) or glucose oxidase (GO; 5-50 mU/ml) concentrations that were administered once daily over 10 to 30 consecutive days. The toxicity of chronic treatments was modest (- one log kill) and consistent with the low yield of first division aberrations (<5%). However, analysis of over 180 clones and 36,000 metaphases indicated that chronic oxidative stress led to a high incidence of chromosomal instability. Treatment of cells with 100 and 200 microM hydrogen peroxide or 50 mU/ml GO was found to elicit chromosomal instability in 11%, 22%, and 19% of the clones analyzed, respectively. In contrast, control clones isolated after mock treatment did not show signs of chromosomal destabilization. These data suggest that chronic oxidative stress constitutes a biochemical mechanism capable of disrupting the genomic integrity of cells.
早期使用GM10115细胞的研究分析了不同DNA损伤剂诱导基因组不稳定的能力，发现急性氧化应激在引发染色体持续不稳定方面相对效率较低。为了确定在慢性暴露条件下这种情况是否会改变，将人-仓鼠杂交细胞系GM10115在氧化应激条件下培养。慢性处理包括使用一系列过氧化氢（25 - 200微摩尔）或葡萄糖氧化酶（GO；5 - 50毫单位/毫升）浓度进行1小时孵育，每天给药一次，连续10至30天。慢性处理的毒性适中（- 一个对数杀伤），且与首次分裂畸变的低发生率（<5%）一致。然而，对超过180个克隆和36000个中期细胞的分析表明，慢性氧化应激导致染色体不稳定的发生率很高。用100和200微摩尔过氧化氢或50毫单位/毫升GO处理细胞，分别在分析的克隆中引发染色体不稳定的比例为11%、22%和19%。相比之下，模拟处理后分离的对照克隆未显示染色体不稳定的迹象。这些数据表明，慢性氧化应激构成了一种能够破坏细胞基因组完整性的生化机制。
