皮质肌动蛋白在不同转移潜能乳腺癌细胞中的表达及意义

目的筛选不同转移潜能的乳腺癌细胞亚系,并探讨皮质肌动蛋白(cortactin)在乳腺癌细胞增殖和侵袭过程中的作用。方法经过连续人工基质膜侵袭实验后获得高、低转移潜能的乳腺癌细胞亚系,通过透射电镜观察比较两系细胞的超微结构,四甲基偶氮唑盐(MTT)法检测两系细胞增殖能力,流式细胞仪检测两系细胞周期,Transwell侵袭小室模型比较两系的迁移能力。应用免疫细胞化学法、反转录聚合酶链反应(RT-PCR)和蛋白质印迹分析法检测cortactin蛋白在两系细胞中的表达。结果利用人工基质膜侵袭实验筛选出高、低转移潜能乳腺癌细胞亚系,并且两系细胞形态上无明显差异。MTT实验显示高转移潜能细胞体外生长速度显著快于低转移潜能细胞(P0.05)。流式细胞仪检测结果显示,高转移潜能细胞亚系与低转移潜能细胞亚系相比,G0/G1期细胞前者比后者少(52.67±3.69)%vs(64.46±2.79)%],而S期细胞前者比后者多(30.53±6.19)%vs(24.63±2.04)%]。高转移潜能细胞亚系增殖指数(PI)高于低转移细胞亚系(47.32±3.69)%vs(35.53±2.80)%,P0.05],侵袭能力显著强于低转移潜能细胞亚系(61.46±7.08)vs(25.32±4.87)个/视野,P0.05]。免疫组化、RT-PCR和蛋白质印迹分析均显示在高转移潜能细胞亚系中cortactin在基因和蛋白水平的表达均高于低转移潜能细胞亚系(P0.05)。结论 Cortactin的过表达与乳腺癌的增殖和转移过程密切相关。

Expression of cortactin in human breast cancer cell lines with different metastasis potentials

Objective To screen for human breast cancer sub-cell lines with different metastasis potentials, and to investigate the role of cortactin in proliferation and metastasis of human breast cancer cells. Methods Human breast cancer sub-cell lines with different metastasis potentials were screened by continuous in vitro invasion assays. Ultra-microstructures of sub-cell lines were observed under transmission electron microscope. The proliferation of sub-cell lines was detected by MTT; the cell cycle was observed by flow cytometry; and the migration ability of sub-cell lines was observed by Transwell assay. The mRNA and protein expression of cortactin was examined by immunofluorescence, RT-PCR and Western blotting assay. Results Two sub-cell lines with different potentials of metastasis were obtained through continuous in vitro invasion assay, and they showed essentially identical morphology under the transmission electron microscope. The MTT results showed that proliferation of high metastasis cells was faster than that of low metastasis cells (P<0.05). Flow cytometry demonstrated that the proportion of high metastasis cells in G0/G1 phase was less (\52.67±3.69\]% vs \64.46±2.79\]%), and that in S phase was more than that of low metastasis cells (\30.53±6.19\]% vs \24.63±2.04\]%). The proliferation index (PI) of high metastasis cells was higher than that of low metastasis cells (\47.32±3.69\]% vs \35.53±2.80\]%, P<0.05). Compared with low metastasis cells, the number of high metastasis cells passing through the membrane was significantly more (\61.46±7.08\] vs \25.32±4.87\] cells/field, P<0.05). The expression levels of mRNA and protein of cortactin in high metastasis cells was higher than that in low metastasis cells (P<0.05). Conclusion Over-expression of cortactin is closely related to the proliferation and metastasis of human breast cancer cells.