TPX2通过p38 MAPK信号通路诱导直肠癌HR-8348细胞凋亡

TPX2 induces apoptosis of rectal cancer HR-8348 cells through p38 MAPK signaling pathway

目的:研究下调非洲爪蟾驱动蛋白样蛋白2靶蛋白(TPX2)对直肠癌细胞凋亡的影响及机制。方法:用TPX2小干扰RNA(si RNA)转染直肠癌HR-8348细胞,记为TPX2 si RNA组;以不做转染的细胞作为正常对照(control)组;以转染si RNA阴性对照(si RNA-NC)的细胞作为si RNA-NC组;用p38 MAPK抑制剂处理敲减TPX2表达后的直肠癌HR-8348细胞记为TPX2 si RNA+SB203580组。RT-qPCR和Western blot测定TPX2的表达水平,MTT法测定细胞存活率,流式细胞术测定细胞凋亡,Western blot测定细胞中p38 MAPK、p-p38 MAPK、cleaved caspase-3和Bcl-2的蛋白水平。结果:TPX2 si RNA转染后HR-8348细胞中TPX2的m RNA和蛋白表达水平显著下降(P <0. 05),而转染si RNA-NC对HR-8348细胞中TPX2的m RNA和蛋白水平没有影响。敲减TPX2表达后的直肠癌HR-8348细胞存活率降低,凋亡率升高,细胞中的cleaved caspase-3、p-p38 MAPK/p38 MAPK蛋白水平明显升高,Bcl-2水平水平降低,与control组比较,差异有统计学意义(P <0. 05)。与TPX2 si RNA组相比,TPX2 si RNA+SB203580组的HR-8348细胞凋亡率、cleaved caspase-3水平和p-p38 MAPK/p38 MAPK蛋白水平明显降低,存活率明显升高(P <0. 05)。结论:TPX2表达下调可以通过激活p38 MAPK促进直肠癌HR-8348细胞凋亡。

AIM:To study the effect of targeting protein for Xenopus kinesin-like protein 2(TPX2)expression knockdown on the apoptosis of rectal cancer HR-8348 cells.METHODS:The HR-8348 cells transfected with TPX2 small interfering RNA(siRNA)served as TPX2 siRNA group.The non-transfected cells were used as control group.The cells transfected with siRNA negative control(siRNA-NC)were used as siRNA-NC group.The TPX2 siRNA-transfected cells exposed to p38 MAPK inhibitor SB203580 served as TPX2 siRNA+SB203580 group.The expression of TPX2 at mRNA and protein levels was determined by RT-qPCR and Western blot.The cell viability was measured by MTT assay,the apoptosis was analyzed by flow cytometry.The protein levels of p38 MAPK,p-p38 MAPK,cleaved caspase-3 and Bcl-2 in the HR-8348 cells were determined by Western blot.RESULTS:After transfection,the expression of TPX2 at mRNA and protein levels was decreased in TPX2 siRNA-transfected cells(P<0.05).Transfection with siRNA-NC had no effect on TPX2 mRNA and protein levels in the cells.After knockdown of TPX2 expression,the viability of rectal cancer HR-8348 cells and the expression of Bcl-2 were decreased,while the apoptotic rate and the protein levels of cleaved caspase-3 and p-p38 MAPK/p38 MAPK were increased significantly reduced(P<0.05).Compared with TPX2 siRNA group,the apoptotic rate and the protein levels of cleaved caspase-3 and p-p38 MAPK/p38 MAPK in TPX2 siRNA+SB203580 group were significantly decreased,while the viability was significantly increased(P<0.05).CONCLUSION:Knockdown of TPX2 expression promotes apoptosis of rectal cancer HR-8348 cells by activating p38 MAPK signaling pathway.