Abstract: ObjectiveTo investigate the difference in invasion ability in vitro of different breast cancer cell lines and to screen genes associated with the difference.MethodsTwo common breast cancer cell lines (MDA-MB-231high metastatic potential and MCF-7low metastatic potential) were used in the study.The invasion ability of the two cell lines was evaluated with wound healing assay,cell adhesion assay,and transwell assay;real-time fluorescence quantitative PCR was used to identify gene expressions associated with the invasion ability and cellular immunohistochemistry method was adopted to confirm primary identifications.ResultsThe average migration distance of MDA-MB-231 cells at 24 and 48 hours were 218.75±20.16 μm and 211.50±16.54 μm,and significantly higher than those of MCF-7 cells (130±29.62 μm and 119.50±25.65 μm:both P<0.01).Cell adhesion assay revealed that the adhesion ability of MDA-MB-231 cells were higher than that of MCF-7 cells.The average number of MDA-MB-231 cells migrating through the membrane at 24 hours was higher than that of MCF-7 cells (57.75±4.19 vs.35.50±4.20,P<0.01).The results of real-time fluorescent quantitative PCR showed that the expression levels of intercellular adhesion molecule 1 (ICAM-1) and breast cancer suppressor candidate 1 (BCSC-1) in MDA-MB-231 cells were 0.09±0.01 and 0.15±0.03,significantly lower than those in MCF-7 cells (both P<0.01);but the matrix metalloproteinase 14 (MMP-14) expression level in MDA-MB-231 cells was 14.43±1.01,higher than that in MCF-7 cells (P<0.01).The results of cell immunohistochemistry also demonstrated that ICAM-1 and BCSC-1 were lower expressed and MMP-14 was highly expressed in MDA-MB-231 cells compared to those in MCF-7 cells.ConclusionThe invasion ability of MDA-MB-231 cells in vitro is higher significantly than that of MCF-7 cells,and the ability may be associated with low expression of ICAM-1 and BCSC-1 and high expression of MMP-14.