As2O3诱导肿瘤细胞凋亡依赖H2O2途径

目的：探讨三氧化二砷（arsenic trioxide，As₂O₃）对人乳头瘤病毒（HPV）阳性宫颈癌HeLa细胞和HPV阴性胰腺癌AsPC-1细胞的 凋亡诱导作用与细胞内H₂O₂水平的关系。方法：采用不同浓度的As 2O3处理HeLa细胞和AsPC-1细胞不同时段，显微镜下观察细胞的凋亡，噻唑蓝（MTT）法 测定细胞生长抑制情况；不同浓度的As₂O₃处理细胞2、5、8、12、24 h后，用DCFH-DA 标记检测细胞内的H₂O₂水平。结果：2 μmol/L As₂O₃处理HeLa 细胞48 h后细胞的生长受到明显抑制，表现出细胞凋亡的特征，随着As₂O₃浓度的增加 和作用时间的延长效果更加明显。而 1 μmol/L As₂O₃处理AsPC-1细胞24 h 即呈 现明显 的生长抑制和凋亡特征。As₂O₃处理HeLa细胞2 h细胞内H₂O₂的水平比对照组升高(1 0 μmol/L组达51.30%)，持续到8 h达到高峰（升高84.19%），12 h后下降，24 h水平与 对照组接近，并有明显的剂量依赖性。As₂O₃处理AsPC-1细胞2 h后，细胞内H₂O₂的 水平也明显升高（10 μmol/L组达79%），持续到5 h达到高峰（增高169%），且该细胞内H₂O₂水平升高比HeLa细胞更明显，12 h之后的变化情况与HeLa细胞类似。结论:As₂O₃诱导HeLa细胞和AsPC-1细胞凋亡与细胞内的H₂O₂水平改变有关,而与HPV的感染无明显相关性。H₂O₂积累是As₂O₃诱导细胞凋亡途径中的早期事件,H₂O₂可能在As₂O₃诱导肿瘤细胞凋亡途径中扮演类似第二信使的作用。

Solid tumor cell apoptosis induced by arsenic trioxide is relat ed to generation of reactive oxygen species

AIM:To study the effects of As₂O₃ on t he growth of human cervical carcinoma cell line,HeLa cells,human pancreatic ca rcinoma cell line,AsPC-1 cells,and the generation of reactive oxygen species ( ROS) in the cells.METHODS:HeLa cells and AsPC-1 cells were treated with various c oncentrations of As₂O₃.The effects of As₂O₃ on HeLa cells and AsPC-1 ce lls survival and apoptosis were determined by MTT assay and light microscope,an d cellular ROS was also measured by fluorometer.RESULTS:After being treated with 2 μmol/L As₂O₃ for 48 h,the survival of HeLa cells was decreased,a marked apoptosis characteristic was observed in time- and dose-dependent manner.However,the survival of AsPC-1 cel ls markedly decreased after being treated with even 1μmol/L As₂O₃ for 24 h.When we measured the cellular hydrogen peroxide (H₂O₂) level,we found that the H₂O₂ level in HeLa cells started to rise after being incubated with As₂O₃ for 2 h,and sustained increased,reached the peak of H₂O₂ level at 8 h,then it began to decrease.While the H₂O₂ level in AsPC-1 cells started to rise at 2 h,reached the highest point at 5 h,after which it began to desce nd.At 12 h,the H₂O₂ level in HeLa cells and AsPC-1 cells were similar to t hat of the control group.CONCLUSION:The molecular mechanisms underlying As₂O₃ -induc ed apoptosis in cells derived from the solid tumors may be related to the cellul ar ROS level.