全反式维甲酸对Rb细胞的生长及Cx43蛋白分子表达的影响

目的研究全反式维甲酸（ATRA）对视网膜母细胞瘤（Rb）细胞的生长及细胞间隙连接蛋白（Cx）43分子表达的影响，探讨其作用机制。方法设立3种浓度（10^-3mol／L、10^-6mol／L和10^-7mol／L）ATRA分别作用于Rb细胞，采用四甲基偶氮唑蓝（methyl thiazolyl tetrazolium，MTT）比色法检测细胞生长抑制率，流式细胞术检测细胞周期改变及凋亡率，免疫组织化学方法检测细胞Cx43蛋白的表达。结果经ATRA作用后，Rb细胞增生率下降，G0／G1期细胞比例增高而S期比例相对下降，细胞凋亡率升高，Cx43蛋白表达上调。上述效应均呈药物浓度及作用时间依赖性。结论ATRA通过将Rb细胞生长周期阻滞于G0／G1期并促进凋亡而抑制其生长，同时可诱导细胞Cx43分子表达上调。

Effects of all trans retinoic acid on cell growth and Cx43 expression in human retinoblatoma cells

ObjectiveIn many tumors,the connexins(Cx) play important roles in cellular growth control and carcinogenesis.Studies have shown that all trans retinoic acid(ATRA) can inhibit the growth of tumor cells by inducing the expression of connexins.However,there is few date showing the effects of RA on the growth of human retinoblatoma(Rb) cells as well as the relationship between pharmacodynamics and connexins.The aim of present paper was to investigate the mechanism of ATRA on the inhibition of cell proliferation and the expression of junction protein Cx43.MethodsRb cells from fatal corpse eye were cultured in RPIM-1640 containing 10% FBS medium and were treated by ATRA in three different concentrations (10-5mol/L,10-6mol/L and 10-7mol/L,or C,D,E group) respectively.Rb cells alone were cultured for blank control group (A group),and 0.1% alcohol was used for the B group.The proliferation of Rb cells was detected by methyl thiazolyl tetrazolium(MTT)colorimetric assay,and cell cycle was analyzed by flow cytometry.The expression of Cx43 protein was detected by immunohistochemistry.ResultsAfter treatment with ATRA,the proliferation rate of Rb cells was decreased.The proportion of the cells at G0/G1 phase was increased but those at S phase were decreased.The apoptosis rates of cells in C,D,E groups(OR cells treated by ATRA) were also increased;expression of Cx43 protein was enhanced.The effect indexes of ATRA were dose and time dependant.ConclusionATRA can inhibit the growth of Rb cells by sustaining cell cycle in G0/G1 phase and induce Rb cells to express Cx43 protein.