关键词: 乳腺肿瘤, MCF-7, 恶性表型, 迁移

Abstract: 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 pcDNA3.1 containing MT1-MMP and MT1-MMP-E240A was stably transfected into MCF-7 cells liposome transfection method.The expression level of MT1-MMP was detected by RT-PCR and immunofluorescence 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 cells after transfection.Results The expression of MT1-MMP mRNA of MCF-7 cells after transfection was increased compared with control group proved by RT-PCR,the expression of MT1-MMP protein was positive detected by immunofluorescence cytochemistry, 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 cells 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.

Key words: breast neoplasms, MCF-7, malignant phenotype, migration