[Effects of ubiquitin-specific proteases 2-69 on proliferation of breast cancer cells].

ABSTRACT

Objective: To investigate the expression and significance of ubiquitin-specific proteases 2-69(USP2-69) in invasive ductal carcinoma of breast. Methods: Twenty-four cases of human breast tissue with invasive ductal carcinoma diagnosed at Huanshan Hospital, Fudan University from 2013 to 2015 were collected, and the expression of USP2-69 mRNA and protein was detected by molecular hybridization, Western blot and immunohistochemistry. USP2-69 was over-expressed in cultured human breast cancer cell line MCF-7 by USP2-69 plasmid transfection. The cellular proliferative activity was investigated in vitro. Results: The USP2-69 mRNA and protein were highly expressed in breast invasive ductal carcinoma, compared to adjacent normal tissues (P<0.01). Ki-67 protein expression was also increased in cases with high USP2-69 protein level. Western blot showed significantly higher USP2-69 protein level in cancer tissue compared to the adjacent normal tissue. In the cultured tumor cells, there was increased S phase fraction, cellular proliferation rate, flat positive clones, cyclin D1 expression and decreased p27 expression in USP2-69-transfected MCF-7 cells. Conclusions: USP2-69 is over-expressed in breast invasive ductal carcinoma, and is closely related to proliferation promoting effects. The data provide an important experimental basis for further study on the molecular mechanism of breast cancer cell proliferation.