膜型基质金属蛋白酶-1增强乳腺癌细胞系MCF-7的恶性表型

Enhancement of membrane type-1 matrix metalloproteinase on malignant phenotype of breast carcinoma MCF-7 cells

目的:探讨膜型基质金属蛋白酶-1(MT1-MMP)蛋白酶-1表达对人乳腺癌细胞系MCF-7细胞生物学行为的影响及MT1-MMP催化亚单位在其中的作用。方法:应用脂质体转染法将携带MT1-MMP及其突变体基因MT1-MMP-E240A的pcDNA3.1载体分别稳定导入MCF-7细胞,通过超微结构观察及体外生长、迁移实验检测MCF-7细胞生物学行为的变化。结果:转染后的细胞经RT-PCR证实MT1-MMPmRNA的表达与对照组比较明显增强;免疫荧光细胞化学染色显示MT1-MMP蛋白呈强阳性表达,阳性颗粒分布于肿瘤细胞的胞浆和胞膜。透射电子显微镜观察显示pcDNA3.1组和MCF-7组细胞未见异常,而MT1-MMP组与MT1-MMP-E240A组细胞与对照组相比出现较多处于分裂期的细胞和瘤巨细胞,部分细胞胞浆内出现糖原池和髓样小体样溶酶体。细胞增殖周期、细胞生长曲线测定结果显示,MT1-MMP组与MT1-MMP-E240A组处于G2M期的细胞比率明显高于对照组(P<0.01),提示转染组细胞的增殖能力增强。转染组细胞在Matrigel和FN上的迁移能力较对照组明显增强(P<0.05)。结论:MT1-MMP能够促进肿瘤细胞的增殖、迁移,在一定程度上增加其恶性表型;MT1-MMP催化亚单位在其中不发挥主要作用。

Objective To investigate the effects of membrane type-1 matrix metalloproteinase （MT1-MMP） on the biological behavior of breast carcinoma MCF-7 cells. Methods A eukaryotic expression vector peDNA3.1 containing MT1-MMP and MT1-MMP-E240A was stably transfeeted into MCF-7 cells liposome transfection method. The expression level of MT1-MMP was detected by RT-PCR and immunofluorescenee cytochemistry. The test of the growth in vitro, proliferation ability and migration in the extracellular matrix （ECM）, as well as electron microscope observation were used to detect the biological behavior of MCF-7 ceils after transfection. Results The expression of MT1-MMP mRNA of MCF7 cells after transfection was increased compared with control group proved by RT PCR, the expression of MT1-MMP protein was positive detected by immunofluorescenee cytoehemistry, the positive staining localized in the cytoplasm and cell membrane. Compared with control group, a lot of cells at division phase and tumor giant cells were found in MT1-MMP group and MT1-MMP-E240A group, glucogen pools and marrow body like lysosomes appeared in part of the cytoplasms observed under transmission electron microscope, The percentage of cells at G2M phase was increased in MT1-MMP group and MT1-MMP- E240A group compared with control group （P〈0.01）. The migration ability of transfected ceils was also increased on the Matrigel and Fibronectin compared with control group （P〈0.05）. Conclusion MT1 MMP can promote the proliferation, migration of MCF-7 cells and increase their malignant phenotype. MT1-MMP catalytic domain does not play prominent role in the proliferation, migration and malignant phenotype of MCF-7 cells.