摘要
AIM: To investigate the role of TR3 in induction of apoptosis in gastric cancer cells. METHODS: Human gastric cancer cell line, MGC80-3, was used. Expression of TR3 mRNA and its protein was detected by Northern blot and Western blot. Localization of TR3 protein was showed by immunofluorescence analysis under laser-scanning confocal microscope. Apoptotic morphology was observed by DAPI fluorescence staining, and apoptotic index was counted among 1000 cells randomly. Stable transfection assay was carried out by Lipofectamine. RESULTS: Treatment of MGC80-3 cells with TPA and VP-16 resulted in apoptosis, accompanied by the repression of Bcl-2 protein in a time-dependent manner. At the same time, TPA and VP-16 also up-regulated expression level of TR3 mRNA in MGC80-3 cells that expressed TR3 mRNA. When antisense-TR3 expression vector was transfected into the cells, expression of TR3 protein was repressed. In this case, TPA and VP-16 did not induce apoptosis. In addition, TPA and VP-16-induced apoptosis involved in translocation of TR3. In MGC80-3 cells, TR3 localized concentrative in nucleus, after treatment of cells with TPA and VP-16, TR3 translocated from nucleus to cytosol obviously. However, when this nuclear translocation was blocked by LMB, apoptosis was not occurred in MGC80-3 cells even in the presence of TPA and VP-16. CONCLUSION: Induction of apoptosis by TPA and VP-16 is through induction of TR3 expression and translocation of TR3 from nucleus to cytosol, which may be a novel signal pathway for TR3, and represent the new biological function of TR3 to exert its effect on apoptosis in gastric cancer cells.
AIM: To investigate the role of TR3 in induction of apoptosisin gastric cancer cells.METHODS: Human gastric cancer cell line, MGC80-3, wasused. Expression of TR3 mRNA and its protein was detectedby Northern blot and Westem blot. Localization of TR3protein was showed by immunofluorescence analysis underlaser-scanning confocal microscope. Apoptotic morphologywas observed by DAPI fluorescence staining, and apoptoticindex was counted among 1000 cells randomly. Stabletransfection assay was carried out by Lipofectamine.RESULTS: Treatment of MGC80-3 cells with TPA and VP-16resulted in apoptosis, accompanied by the repression ofBcl-2 protein in a time-dependent manner. At the sametime, TPA and VP-16 also up-regulated expression level ofTR3 mRNA in MGC80-3 cells that expressed TR3 mRNA.When antisense-TR3 expression vector was transfected intothe cells, expression of TR3 protein was repressed. In thiscase, TPA and VP-16 did not induce apoptosis. In addition,TPA and VP-16-induced apoptosis involved in translocationof TR3. In MGC80-3 cells, TR3 localized concentrative innucleus, after treatment of cells with TPA and VP-16, TR3translocated from nucleus to cytosol obviously. However,when this nuclear translocation was blocked by LMB,apoptosis was not occurred in MGC80-3 cells even in thepresence of TPA and VP-16.CONCLUSION: Induction of apoptosis by TPA and VP-16 isthrough induction of TR3 expression and translocation of TR3from nucleus to cytosol, which may be a novel signalpathway for TR3, and represent the new biological function ofTR3 to exert its effect on apoptosis in gastric cancer cells.
基金
the National Outstanding Youth Science foundation of China (B type,39825502)
the National Natural Science Foundation of China (39880015,30170477)
the Natural Science Foundation of Fujian Province (C0110004).
