紫杉醇诱导的胰腺癌SW1990细胞凋亡过程中转录激活因子5和Bax表达水平的变化

Expression of activating transcription factor 5 and Bax in the apoptosis of pancreatic cancer cells SW1990 induced by paclitaxel

目的转录激活因子5(Activating transcription factor 5,ATF5)是一个新的与肿瘤细胞分化、增殖及凋亡密切相关的因子。文中检测胰腺癌SW1990细胞中ATF5的表达,并进一步研究紫杉醇(Paclitaxel,PTX)诱导的人胰腺癌SW1990细胞凋亡的水平,及其与ATF5、Bax表达水平的相关性。方法 RT-PCR检测未经药物处理的SW1990细胞中ATF5 mRNA表达水平;以不同浓度的紫杉醇(0、6.25、12.5、25、50、100、200 nmol/L)作用SW1990细胞不同时间(0、6、12、24、48 h),噻唑蓝(MTT)比色法检测细胞增殖情况;用100 nmol/L紫杉醇作用SW1990细胞不同时间(0、12、24、48 h)后,观察形态学变化并用Annexin V/7-AAD双染法,流式细胞仪检测细胞凋亡情况;采用RT-PCR检测紫杉醇作用不同时间后ATF5、Bax的mRNA表达变化。结果胰腺癌SW1990细胞中表达ATF5。紫杉醇抑制胰腺癌SW1990细胞的增殖,并在一定范围内呈剂量、时间相关性。随着紫杉醇作用时间的增加,流式细胞仪检测凋亡率显著提高。半定量RT-PCR检测结果显示:ATF5、Bax mRNA表达均明显增强,且两者之间存在相关性(r=0.916,P<0.05)。结论 ATF5在胰腺癌SW1990细胞中高表达,并且在紫杉醇诱导的细胞凋亡过程中,表达量进一步上升,其变化趋势与Bax基因相似。提示ATF5参与紫杉醇诱导的细胞凋亡,并可能与Bax的凋亡途径存在相关性。

Objective Activating transcription factor 5（ATF5） is a new regulator closely associated with the differentiation,proliferation and apoptosis of tumor cells.We detected the expression of ATF5 in human pancreatic cancer cells SW1990,and determined the correlation of ATF5 and Bax expressions with the apoptosis of the cells induced by paclitaxel（PTX）.Methods The mRNA expression of ATF5 in the untreated human pancreatic cancer cell line SW1990 was detected by RT-PCR.The proliferation of the cells was determined by MTT assay after exposed to PTX at the concentrations of 0,6.25,12.5,25,50,100 and 200 nmol/L for 0,6,12,24 and 48 hours,respectively.Their morphological changes were observed by inverted microscopy and their apoptosis by flow cytometry with Annexin V/7-AAD double staining.Changes in the mRNA expressions of ATF5 and Bax were analyzed by RT-PCR.Results PTX inhibited the proliferation of the human pancreatic cancer cells SW1990 in a dose-and time-dependent manner.Flow cytometry showed an obviously increased apoptosis of the cells.RT-PCR revealed a marked rise in the mRNA expressions of ATF5 and Bax,and there was a significant correlation between them（r=0.916,P0.05）.Conclusion ATF5 is highly expressed in human pancreatic cancer cells SW1990,and its expression increases when treated with PTX,similar to that of the Bax gene.This indicates that ATF5 is involved in the cell apoptosis induced by PTX,which may be associated with Bax.