Effect of Smac on TRAIL-induced Apoptosis of Prostate Cancer Cell Line PC-3 and the Molecular Mechanism  

作　　者：王淼 黄韬 曾甫清 蒋国松 汪良 郑丽端 童强松 

机构地区：[1]Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology [2]Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology

出　　处：《Journal of Huazhong University of Science and Technology(Medical Sciences)》2012年第2期233-236,共4页华中科技大学学报（医学英德文版）

基　　金：supported by grants from the National Natural Sciences Foundation of China(No.81001132);Special Scientific Research Foundation for the Doctoral Program of Higher Education from Ministry of Education(No.200804871105);Hubei Natural Science Foundation of China(No.2010CDB07601)

摘　　要：The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was assayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin Ⅴ-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly increased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100–200 ng/mL TRAIL for 12–36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Accordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 subunit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was assayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin Ⅴ-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly increased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100–200 ng/mL TRAIL for 12–36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Accordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 subunit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.

关 键 词：Smac gene prostate carcinoma TRAIL apoptosis 

分 类 号：R737.25[医药卫生—肿瘤]