羟基喜树碱诱导膀胱癌T24细胞凋亡的研究

Apoptosis induced in bladder cancer cell line T24 by hydroxycamptothecin

目的探讨羟基喜树碱(HCPT)诱导膀胱癌T24细胞凋亡与氧化应激的关系。方法体外培养人膀胱癌T24细胞,以0.10～100.00 mg/L的羟基喜树碱处理6～48 h后,MTT法测定细胞抑制率,得出HCPT的IC50和最佳作用时间,DNA琼脂糖凝胶电泳、流式细胞仪检测细胞凋亡情况。HCPT 10.00 mg/L作用细胞24 h后,采用生物化学方法检测SOD、MDA、LDH、总抗氧化能力(total antioxidant capacity,T-AOC)、活性氧以及谷胱甘肽(glutathione,GSH)与谷胱甘肽还原酶(glutathione reductase,GR)的水平并与正常值对照,分析HCPT对T24细胞氧化与抗氧化系统的影响。结果0.10～100.00 mg/L的HCPT均能抑制T24细胞增殖并诱导调亡,其作用具有时间及浓度依赖性。细胞生化指标分析HCPT明显提高了培养上清液LDH的活力,降低了细胞内LDH的活力;细胞内SOD、T-AOC、GSH及GR的水平明显减少(P<0.05),MDA、活性氧的水平显著升高(P<0.05)。结论通过诱导激活氧化应激致使凋亡抑制细胞增殖可能是HCPT抗肿瘤作用机制之一。

Objective To study the relationship between apoptosis induced by hydroxycamptothecin（HCPT） and oxidative stress. Methods Human bladder cancer cells T24 cultured in vitro were exposed to a variety of concentrations of HCPT for different lengths of time,the inhibitory effect of HCPT on cell T24 proliferation was measured by MTT assay.FACScan flow cytometry and DNA agarose gel electrophoresis were used to determine the induction of apoptosis;the IC50 and optimal length of time were received.After the cells were exposed to HCPT（10 mg/L） for 24hours,biochemical assays were used to test the level of active oxygen,LDH,SOD,MDA,T-AOC,GSH and GR.These reflected the influence of HCPT on T24 cellular oxidation and anti-oxidizing system. Results HCPT could inhibit the growth of T24 cells and induce apoptosis in vitro and present the dependent relationship of time and concentration.Biochemical index analysis showed that HCPT could significantly increase LDH＇s activity in supernatant fluid,decrease LDH＇s activity in endocelluar,increase out leakage of LDH;decrease the activity of succinct acid dehydrogenase in chondriosome;SOD、T-AOC、GSH and Gred decreased while MDA and active oxygen increased. Conclusions Oxidative stress inducing apoptosis may be as a very important mechanism of treating urinary bladder cancer.