膜突蛋白促进乳腺癌细胞侵袭转移的机制研究

 目的 探讨膜突蛋白与乳腺癌细胞侵袭转移的关系。方法 应用免疫组织化学法、RT-PCR和Western blot等技术,检测转移与非转移性乳腺癌组织以及不同转移潜能人乳腺癌细胞系中膜突蛋白的定位及表达；应用RNAi技术结合体外侵袭运动实验，探讨膜突蛋白缺失对乳腺癌细胞侵袭运动能力的影响及相关分子机制。结果 免疫组织化学结果显示，膜突蛋白定位于细胞膜与细胞质，且在转移组中的表达高于非转移组，差异具有统计学意义(P=0.001，χ²=17.536)。Western blot结果显示，膜突蛋白的表达与乳腺癌细胞转移潜能呈正相关。此外，Transwell实验结果显示，膜突蛋白表达缺失显著抑制了乳腺癌细胞的侵袭和迁移能力，且对侵袭潜能高的乳腺癌细胞的抑制更为显著。膜突蛋白缺失后，细胞中MTDH mRNA与nm-23 mRNA水平明显降低；vimentin蛋白表达增加、E-cadherin和MMP-9蛋白表达降低，差异具有统计学意义(P<0.05)。结论 膜突蛋白高表达与乳腺癌转移潜能增强呈正相关，可能通过影响MTDH和nm-23表达、增强上皮间质转化、增加MMP-9分泌等来增强乳腺癌细胞的侵袭转移能力。

Relationship between moesin expression and breast cancer metastasis

Objective To explore the internal relationship between moesin expression and breast cancer metastasis. Methods Immunohistochemistry (IHC), RT-PCR and Western blot were used to identify moesin expression in breast cancer tissue samples and a series of human breast cancer cell lines with different metastatic potentials. RNAi technique combined with invasion and motility assay in vitro were also used to reveal the interrelationship between moesin deficiency and invasion and motility ability of breast cancer cells. Results IHC analysis showed that moesin were mainly distributed on the cell membrane and cytoplasm.Its expression was higher in metastatic breast cancer tissue samples than in non-metastatic ones (P=0.001, χ²=17.536).  Western blot results revealed positive correlation between moesin expression and metastatic potential of breast cancer cells.The results of Transwell experiment displayed that moesin expression silencing remarkably inhibited invasion and motility ability of breast cancer cells, especially the cells with high metastatic potential. After moesin expression, the levels of MTDH mRNA and nm-23 mRNA in breast cancer cells (P<0.05) significantly decreased, while vimentin expression increased, and the expressions of E-cadherin and MMP-9 decreased. Conclusions Moesin over-expression presents a positive correlation to breast cancer metastatic potential. Moesin may participate in the process of invasion and metastasis of breast cancer cells through influencing MTDH and nm-23, enhancing epithelial mesenchymal transition and increasing MMP-9 secretion.