重楼皂苷Ⅰ对胰腺癌PANC-1细胞体外放射敏感性的影响

目的]探讨重楼皂苷IfPSI）对胰腺癌PANC-1细胞的放射增敏作用及可能机制。方法]MTT法检测PS I对PANC．1细胞的增殖抑制作用。克隆形成实验检测PS Ⅰ对PANC．1细胞的放射增敏效应。流式细胞仪检测细胞周期变化。AnnexinV-PI双染法检测细胞凋亡。WesternBlot法检测caspase-3、Bax、Bcl-2蛋白表达改变。结果]不同浓度PSI对PANC．1细胞有不同程度的体外抑制作用。1μg/ml PSⅠ联合放射线明显降低PANC．1细胞克隆形成率。增敏组凋亡率及G2／M期细胞比例较对照组明显增多（P〈0．01）。PSⅠ作用后细胞caspase．3、Bax蛋白表达增加，Bcl-2蛋白表达降低。结论]PSI对胰腺癌PANC-1细胞具有放射增敏作用，其机制可能与诱导caspase．3、Bax蛋白表达增加，Bcl-2蛋白表达降低，引起细胞G2/M期阻滞，促进细胞凋亡有关。

Radiosensitivity of Paris Saponin I on Pancreatic Carcinoma Cell Line PANC-1 in Vitro

Purpose] To investigate the radiosensitization of paris saponin I （ PSI ） on pancreatic carcinoma cell line PANC-1 and its possible mechanism. Methods] MTF assay was used to measure the effect of PSⅠ on PANC-1 cell proliferation. Clonogenic assay was performed to determine the radiosensitizing effect of PS I on PANC-1 cell line. The cell cycle was measured by flow cytometry and apoptosis was measured by Annexin V-PI. Caspase-3, Bax and Bcl-2 protein expression were detected by Western Blot. Results]PS I inhibited PANC-1 cell line proliferation. Radiation with PS I （1μg/ml） decreased cloning efficiency significantly. The radiosensitization group had a higher apoptosis rate and G2/M phase cells than control group （P〈 0.01）. Western Blot showed easpase-3 and Bax protein expression increased after the treatment of PSI , but Bcl-2 protein expression decreased. Conclusion] PSI could enhance the radiosentivity, of pancreatic carcinoma cell line PANC-1 ,which might induce caspase-3, Bax proteins increasing, Bcl-2 protein expression decreasing, and cause G2/M phase arrest and promote cell apoptosis.