黏附分子T-cadherin表达诱导C6胶质母细胞瘤细胞G2期阻滞

目的 研究T-cadherin分子表达抑制胶质母细胞瘤C6细胞增殖的机制。方法 利用脂质体转染pcDNA3和pcDNA3-T-cadherin质粒后获得的表达和不表达T-cadherin的C6细胞克隆，以流式细胞仪检测两种克隆细胞的细胞周期的变化，同时分析其细胞周期与细胞分裂指数的关系。结果 转染后表达T-cadherin的C6细胞在去血清培养48h使细胞周期同步后，分别用血清刺激培养12h后行流式细胞仪检测，与转染空载体的1、2克隆相比，转染T-cadherin基因后表达T-cadherin的3、4克隆于G2／M期的细胞比例显著增加（3、4克隆为52．60％和51．84％，1、2克隆为16．17％和13．47％），而G1期的细胞比例显著下降（3、4克隆为0．66％和0．39％，1、2克隆为50．6％和57．9％）。在血清刺激0、4、8、12、24和48h时，空载体克隆1在各时间点的分裂指数与其G2／M期的细胞比例一致，而表达T．cadherin的克隆3在各时间点的分裂指数显著低于其G2／M期的细胞比例数。结论 T．cadherin分子表达能诱导C6细胞G2期细胞阻滞，该机制可能是T-cadherin抑制C6细胞增殖的主要机制。

T- cadherin gene expression induces G2 arrest in C6 glioma cells

Objective To study the mechanism by which T-cadherin gene expression suppresses cell growth in C6 glioma cells. Methods C6 cells were transfected with pcDNA3 and pCDNA3.T-cadherin using lipofectin,the vector-transfected C6 clone 1,2 and T-cadherin-expressing C6 clone 3,4 were analyzed by cell cycle analysis and mitotic index analysis. Results After synchronization by serum starvation for 48 h followed by the serum stimulation for 12 h,cell cycle analysis indicated that the percentages of cells in G_2/M phase in clone 3 and 4 were significantly increased (52.67% and 51.84% vs 16.17% and 13.47%),but the percentages of cells in G_1 phase in clone 3 and 4 were profoundly decreased (0.66% and 0.39% vs 50.6% and 57.9%) as compared with vector-transfected clone 1,2.At the time points 0,4,8,12,24 and 48 h with serum stimulation,the percentages of cells in G_2/M in vector-transfected clone 1 were comparable to their mitotic indexes,however,the mitotic indexes of T-cadherin-expressing clone 3 at different time points were significantly lower than those of cells in G_2/M phase. Conclusion T-cadherin gene expression induces G_2 arrest in C6 cells,and this could be the main mechanism by which T-cadherin expression results in cell growth suppression in C6 cells.