Studies On The Correlation Between BAG-1and Human Hepatocellular Carcinoma

Objective1. To investigate the expression of BAG-1in human hepatocellular carcinoma (HCC) and its correlation with the development and prognosis of HCC.2. To explore the expression of BAG-1in HCC cell lines, the mechanism by which BAG-1mediates drug risistance to doxorubicin and the ablity of BAG-1to affect the cell cycle and proliferation.Methods1. In tissue level,8tumoral and peritumoralal tissues were chosen to show the expression of BAG-1by Westernblot analysis.65tissue slices were chosen for immunohistochemical analysis to detect the expression of BAG-1and the data was analyzed by SPASS13.0.2. In cell level, the expression of BAG-1in different HCC cell lines and normal hepatocyte cell line, the alteration of BAG-1and NF-κB acivity upon doxorubicin stimulation, the change of NF-κB acivity as well as proliferation ability and drug resistance after BAG-1knocking down were studied by Westernblot, CCK-8, siRNA, immunofluorescence, luciferase reporter gene, serum starvation, flow cytometry and Tunel techniques.Results1. In tissue level, Westernblot analysis showed nuclear BAG-1expression was significantly high expressed in tumor tissues compared with peritumoralal tissues. Immunohistochemical analysis showed nuclear BAG-1was variablely expressed in different histologic grade tissues with low expression of nuclear BAG-1in high grade tissues (P<0.001), and HCC patients with high nuclear BAG-1expression were significantly associated with poor overall survival (P=0.004), indicating that BAG-1is an independent prognosis factor for HCC.2. In cell level, the results showed that BAG-1was high expressed in HCC cell lines compared to normal hepatocyte cell lin. The cell line which showed high expression of BAG-1was more resistant to doxorubicin. BAG-1was degraded upon stimulation of doxorubicin which was not modulated by ubiquitin-proteasome dependent degradation. Doxorubicin could activate NF-κB which might be modulated by BAG-1. The resistance of HCC cell line to doxorubicin decreased by knocking down BAG-1expression or NF-κB inhibition. The cell cycle was significantly inhibited by BAG-1knocking down.Conclusions1. BAG-1was dysregulated in HCC patients. Nuclear expression of BAG-1was correlated with poor prognosis of HCC and BAG-1may be a new prognostic marker for HCC. 2. BAG-1could increase the resistance of HCC cells to doxorubicin which was mediated by potentiating the activity of NF-κB, indicating that BAG-1may be a potential target for treating HCC.