乳腺癌干细胞上皮-间质转化标志物表达变化及意义

The Significance and Expression of Markers of Epithelial-mesenchymal Transition in Breast Cancer Stem Cells

目的探讨乳腺癌干细胞上皮-间质转化标志物表达变化及其临床意义。方法采用无血清悬浮培养法,从MCF-7细胞培养乳腺癌微球体细胞,应用流式细胞仪检测微球体细胞中CD44和CD24的表达,采用Western blot方法检测微球体细胞中E-钙黏素、N-钙黏素、纤维连接蛋白、波形蛋白的表达水平,体外穿膜实验检测肿瘤细胞的迁移、侵袭能力。结果乳腺微球体富集了CD44+CD24-的乳腺癌干细胞,并能在含血清培养基中增殖分化。该微球体细胞的上皮标志物E-钙黏素表达水平下调,而间质标志物N-钙黏素、纤维连接蛋白、波形蛋白的表达水平上调,同时乳腺癌干细胞的迁移、侵袭能力显著增强。结论乳腺癌干细胞具有上皮-间质转化的特征,具有显著增强的迁移、侵袭能力。

Objective To study the expressions of markers of epithelial-mesenchymal transition and potential of migration and invasion in human breast cancer stem cell. Methods MCF-7 cells were seeded in serum-free medium supplemented with bFGF and EGF to form spheres. After the MCF-7 breast cancer spheres formed, they were dissociated and passaged periodically and were also induced to differentiate in the medium with FBS supplemented. The expressions of CD24 and CD44 were detected with the flow-cytometric analysis and the expressions of E-cadherin, N-cadherin, Fibrenectin and Vimentin were detected with Western blot in these ceils. Ceil migration and invasion were also detected with Transwell assays. Results The breast cancer spheres were generated in serum-free medium and MCF-7 spheres can also be induced to differentiate in medium with FBS supplemented. There were 74.6% CD44＋ CD24^ - cells in MCF-7 spheres ceils. The expression of E-cadherin in spheres cells was significantly higher than in MCF-7 cell but the expression of N-cadherin, Fibronectin and Vimentin in spheres cells was significantly lower than in MCF-7 cell. Meanwhile, the potential of migration and invasion in spheres cells increased significantly. Conclusion Human breast cancer stem cells got characteristics of epithelial-mesenchymal transition and an increase in cell migration and invasion.