ObjectiveTo investigate the inhibitory effect of short hairpin RNA (shRNA) mediated contactin-1 (CNTN1) gene silencing on growth of human breast cancer cell line MDA-MB-468 transplanted tumors in nude mice.MethodsEighteen nude mice (4-week-old male BALB/c) were randomly equally divided into three groups: blank control group, empty vector group, and silencing group. The MDA-MB-468 cells (blank control group), MDA-MB-468 cells transfected by nonsense shRNA (empty vector group), and MDA-MB-468 cells transfected by shRNA (silencing group) were collected in the logarithmic growth period, respectively. The subcutaneous tumor models of nude mice were prepared by the subcutaneous injection of the different group cells. The tumor growth was observed and the expressions of CNTN1 and Ki-67 proteins in the transplanted tumor were detected by the immunohistochemistry.ResultsThe xenograft models of human breast cancer cells were established successfully. The tumor growth in the silencing group was significantly slower than that of the other two groups at every 3 d point (P<0.05). The tumor volume and the tumor weight in the silencing group were significantly smaller or slighter than those of the other two groups at day 18 (P<0.05). The positive rates of CNTN1 and Ki-67 protein expressions in the tumor tissues of the silencing group were lower than those of the other two groups (P<0.05), respectively.ConclusionSilencing expression of CNTN1 gene might inhibit growth of breast cancer cell line MDA-MB-468 transplanted tumors in mude mice.