Abstract:

Objective To investigate the effect of CCN5 gene knockdown on the proliferation of human breast cancer cells， to explore the mechanism of CCN5 in the proliferation of these cancer cells， and to explore the association of CCN5 with the occurrence and development of breast cancer. Methods CCN5siRNA transfection group， lentivirus empty vector transfection group and blank control group were set up by different treatment methods. CCN5siRNA transfection group （hereinafter referred to as transfection group）： transfection of human breast cancer cells MCF?7 with CCN5siRNA mediated by lentiviral vector， lentivirus empty vector transfection group （hereinafter referred to as no?load group）： transfection of cells MCF?7 with empty lentivirus vector. No transfection was performed in the blank control group. MTT assay was used to detect the changes in cell proliferation capacity in each group， so were RT?PCR and Western blotting to detect the mRNA and protein expressions of CCN5， Skp2 and p27Kip1. Results MTT assay showed that proliferation ability of MCF?7 in transfection group was higher than that in empty vector group and control group. The results of RT?PCR and Western blotting showed that the mRNA and protein levels of CCN5 in transfection group were lower than those in empty vector group and control group （P < 0.05）， the mRNA and protein levels of Skp2 in transfection group were higher than those in empty vector group and control group （P < 0.05）， while the mRNA and protein levels of p27Kip1 in transfection group were lower than those in empty vector group and control group （P < 0.05）. Conclusions CCN5siRNA inhibits the mRNA and protein expression of CCN5， promotes and induces the proliferation of breast cancer cells by up?regulating Skp2 and down?regulating P27Kip1.

Key words: breast cancer, CCN5, Skp2, P27Kip1, siRNA, lentivirus