【摘要】 目的研究RhoC在不同转移能力乳腺癌细胞系中的表达及其与乳腺癌侵袭行为的相关性。方法利用逆转录-聚合酶链反应、Western blot、细胞爬片免疫组织化学和免疫荧光组织化学染色检测乳腺癌低转移细胞系MCF-7和高转移细胞系MDA-MB-231中RhoC mRNA和蛋白表达水平。构建RhoC真核表达载体,并转染乳腺癌低转移细胞系MCF-7;利用Matrigel穿膜侵袭实验检测转染后细胞的体外侵袭能力,划痕修复实验检测运动迁移能力,组织化学染色检测微丝骨架结构的变化,并利用Western blot检测Akt磷酸化水平变化。结果RhoC在不同转移能力的乳腺癌细胞系中呈不同程度表达,在高转移细胞系MDA-MB-231中高表达,在低转移细胞系MCF-7中低表达,差异有统计学意义(P<0.01)。基因转染过表达RhoC后,乳腺癌细胞的体外侵袭能力明显增强,正义转染组穿膜细胞数(56.88±4.18)与其相应空载体组(23.77±3.64)、反义组(23.12±3.22)和未转染对照组(28.44±2.48)比较,明显增多(P<0.01);运动迁移能力明显增强,正义转染组24 h划痕修复率(58.28%±2.14%)明显高于转染空载体组(28.23%±2.62%)、反义组(22.36%±2.73%)和未转染对照组(30.18%±2.86%),差异有统计学意义(P<0.01);组织化学染色显示,正义转染组细胞内肌动蛋白多聚体减少,微丝骨架重构;此外,RhoC正义转染组细胞p-Akt水平升高。结论RhoC过表达促进乳腺癌细胞的体外侵袭能力,并与乳腺癌细胞系转移潜能正相关,有望成为阻断乳腺癌转移的新靶点。更多还原

【Abstract】 Objective To investigate the expression of RhoC in breast cancer cells with different metastatic potential and its correlation with invasiveness. Methods Expression of RhoC mRNA and protein in human breast cancer cells MCF-7 with low metastatic potential and MDA-MB-231 with high metastatic potential was detected by RT-PCR, Western blot, immunohistochemistry and immunofluorescence staining. Eukaryotic expression plasmids of RhoC were constructed and transfected into MCF-7 cells. The biological effects were observed, including in vitro invasion by Boyden charmber assay, motility by would healing assay, alteration of microfilament network by TRTIC-phalloidin staining and expression of p-Akt by Western blot assay. Results The expression levels of RhoC mRNA and protein varied in the two different metastatic breast cancer cell lines. RhoC was significantly up-regulated in the highly metastatic cells in comparison to the weakly metastatic counterpart ( P < 0.01). As shown by Boyden charmber assay, the invasive capacity of transfected cells overexpressing RhoC was significantly promoted as reflected by more penetrating cells (56. 88±4.18) than that of the antisense transcripts (23. 12±3. 22), the negative (23. 77±3. 64) and blank controls (28.44±2.48). Further study by would healing assay indicated that cells overexpressing RhoC were more motile in actin-based active movement. The wound healing ratio after 24 h of the sense transcripts, antisense transcripts, negative controls and blank controls was 58. 28%±2. 14% , 22. 36%±2.73% , 28.23%±2.62% , 30. 18%±2.86% , respectively. The TRITC-phalloidin staining revealed less actin filament bundles and a reorganized cytoskeleton within the sense transcripts. In addition, p-Akt expression level was upregulated in the sense transcripts. Conclusion RhoC overexpression may promote the invasive capacity of human breast cancer cells in vitro and its expression level is positively correlated with the metastatic capacity of those cells. So RhoC may be a potential target in the development of a novel strategy for treating metastasis of breast cancer.更多还原