【作者】 徐龙江；

【导师】 冯一中； 顾振纶； 周文轩； 郭次仪；

【作者基本信息】 苏州大学 ， 病理学与病理生理学， 2009， 硕士

【摘要】 目的:研究熊果酸(ursolic acid,UA)对人胰腺癌细胞SW1990的生长抑制作用,并探讨其作用机制。方法:用不同浓度的UA处理人胰腺癌细胞SW1990,采用MTT法测定UA对SW1990细胞的生长抑制作用、流式细胞术分析细胞周期改变和细胞凋亡;Hoechst 33258荧光染色、透射电镜等方法观察给药前后细胞的形态变化;RT-PCR检测UA处理SW1990细胞前后的基因表达水平变化;同时引入p53的抑制剂PFT-α(pifithrin alpha,PFT-α)做对照研究。应用免疫组织化学染色方法检测胰腺癌中P53和Bcl-2的表达情况。结果:UA对SW1990细胞生长具有显著的抑制作用,且此作用呈明显的时间、剂量依赖趋势。流式细胞术分析显示,UA可以诱导人胰腺癌SW1990细胞凋亡,引起细胞发生S期阻滞;Hoechst 33258荧光染色、透射电镜观察证实UA可以诱导SW1990细胞发生凋亡。RT-PCR分析结果显示UA(40μmol/L)作用于胰腺癌SW1990细胞,可以调节细胞凋亡相关基因的表达,上调p53、cytochrome C、caspase-3的表达,下调Bcl-2表达。用p53的抑制剂PFT-α预处理SW1990细胞后再给予UA处理,细胞凋亡现象受到抑制,RT-PCR结果显示下调p53、cytochrome C、caspase-3的表达,上调Bcl-2表达。免疫组织化学染色检测结果显示胰腺癌中存在着高频率的p53突变。结论:UA能明显抑制人胰腺癌SW1990细胞的生长,并诱导其凋亡,这种作用可能与p53、cytochrome C、caspase-3、Bcl-2基因的表达变化相关。更多还原

【Abstract】 Objective: To study the effects and mechanisms of ursolic acid on human pancr- eastic carcinoma cell line SW1990.Metheods: After UA treatment, the growth inhibition of SW1990 cells were assessed by MTT assay. Cells were evaluated with flow cytometric analysis, Hoechst 33258 staining and transmission electron microscope after it was induced by UA;It’s mechanisms was determined by RT-PCR analysis. The inhibitor of p53-pifithrin alpha (PFT-a) was applied to investigate the effect of p53 in the study. The p53 and Bcl-2 expression in SW1990 was examined by immunocytochemistry method.Results: The proliferation of SW1990 cells was significantly inhibited in a dose-and time-dependent manner after UA treatment. Cell apoptosis ratio and cell cycle arrest was examined by FCM; UA-induced apoptosis was confirmed by Hoechst 33258 staining and transmission electron microscope. After cells were treated by UA(40μmol/L), the expressions of p53, cytochrome C, caspase-3 increased whereas bcl-2 decreased. After the pretreatment of PFT-a on the SW1990 cell , the ratio of cell apoptosis became weakly.The immunocytochemistrical examination showed the expression of p53 mutated.Conclusions: It is significant that the growth of human pancreatic carcinoma cell line SW1990 could be inhibitated when treated by UA. UA can induce cell apoptosis. These effects might be related with the expressions of p53, Bcl-2, cytochrome C, caspase-3.更多还原