| Objectives:To detect the expression of Bmi1 in the tissues of HCC and HCC cell line HepG2.And to investigate the expression of Bmi1 and its relationship with cell proliferation and apoptosis in HCC.In oder to provide a new idea for the diagnosis, condition assessment,treatment and prognosis of HCC.Methods: The expression of Bmi1 and Ki67 in 54 cases of HCC tissues and paraneoplastic hepatic tissues and 10 normal liver tissues were detected by EnVision immunohistochemical. Apoptosis of these specimens were detected by TUNEL methods. The HCC cell line HepG2 were transfected with the constructed pCMV6-Bmi1 vector, then the expression was identified by Western blot and real-time PCR after 48h. Apoptosis and cell cycle were analyzed by flow cytometry.Results: Immunohistochemical and TUNEL showed that the increased Bmi1 expression in HCC was not correlated with gender,age,tumor size,tumor number,portal involvement,TNM stage,liver cirrhosis and HBsAg status(P>0.05). However, the expression of Bmi1 in HCC was associated with the histological differentiation,of which well and moderately differentiated HCCs were higher than that in poor differentiated HCCs (P<0.05).The average value of proliferative index(PI) in Bmi1 positive cases in HCC (50.3±21.4)% was significantly higher than that in Bmi1 negative cases (17.3±7.1)%(P<0. 05).The average value of apoptosis index(AI) was no significant difference (P>0.05). Western blot and real-time PCR showed that the Bmi1 protein and Bmi1 mRNA were overexpression in HepG2 cell lines.Drawing the growth curve, which showed that pCMV6-Bmi1 transfected group cells growed much faster than the non-transfected group and pCMV6-entry vector transfected group cells. Apoptosis and cell cycle were analyzed by flow cytometry showed that compared to pCMV6-entry vector transfected group cells, G2%+S% and DNA synthesis increased significantly in pCMV6-Bmi1 transfected group cells.24h after adding 5-FU,the apoptosis rate of pCMV6-Bmi1 transfected group cells was significantly lower than pCMV6-entry vector transfected group cells.Conclusion: The above experiments suggested that the Bmi1 involved in the regulation of HCC cell proliferation, and promote tumorigenesis of HCC and cell proliferation.But the relationship between Bmi1 and apoptosis was not confirmed. We concluded that the study sample size may be less or there is not a direct regulation relationship between them.There are many factors involved in the process. |
