Increased expression of the insulin-like growth factor I (IGF-I) receptor gene in hepatocellular carcinoma cell lines: implications of IGF-I receptor gene activation by hepatitis B virus X gene product.

摘要: Hepatitis B virus infection is associated with acute and chronic liver disease the development of hepatocellular carcinoma (hcc). Several lines evidence have suggested that hepatitis X protein (HBx), which a transcriptional trans-activator, plays role in process carcinogenesis. We investigated expression insulin-like growth factor I (IGF-I) receptor human cell using SNU368 cells containing HBx SNU387 cells, lack gene transcript (J-G. Park et al., Int. J. Cancer, 62: 276-282, 1995), an attempt to understand its possible relationship HBx-induced hcc. The binding 125I-labeled IGF-I was 5-fold higher than cells. Scatchard analysis data revealed single class site for Kd 7.6 8.8 nM maximum capacities 169 33 fmol/10(5) respectively. Therefore, difference observed between due increase number sites no change affinity receptor. An enhanced level receptors also by fluorescence-activated sorting monoclonal antibody against receptor, alpha IR3. RNA basal promoter activity were 5 10 times those To substantiate further could transactivate endogenous gene, Hep G2 transiently transfected vector. transfection vector resulted increased levels RNA, activity, 2.6-, 2.8-, 2-fold, As result mitogenic effect IGFs (IGF-I IGF-II) on 6 These results suggest may play hcc activating expression.