Effect of oncoprotein HBXIP on the proliferation of ovarian cancer cells

Objective　To investigate the effect of hepatitis B X-interacting protein (HBXIP) on the proliferation of ovarian cancer cells and its underlying mechanism. Methods　Ovarian cancer cells transfected with plasmid encoding pCMV-HBXIP were taken as experimental group, and those transfected with pCMV-Tag 2B vector served as control group. The proliferation of ovarian cancer cells was detected by colony formation assay and MTT assay. The Skp2 promoter activity in pCMV-HBXIP-transfected ovarian cancer cells was identified by luciferase report gene assay. The expression of HBXIP in ovarian cancer cells was detected by PCR. The expressions of HBXIP and Skp2 protein in ovarian cancer cells were assessed by Western blotting. Results　Colony formation assay revealed that the formed colonies were significantly higher in the ovarian cancer cells of the experimental group than in control group (P<0.01). MTT assay indicated that the survival number was also significantly higher in the ovarian cancer cells of experimental group than in control group (P<0.05). Luciferase report gene assay showed that the Skp2 promoter activity was significantly increased in experimental group (P<0.01). The expression of HBXIP in ovarian cancer cells was detected with PCR, but none in control group. Western blotting revealed that the expression levels of HBXIP and Skp2 proteins were significantly increased in experimental group than in control group (P<0.05). Conclusion　HBXIP may promote the proliferation of ovarian cancer cells by activating Skp2 promoter and up-regulating the expression of Skp2.