Figure 3. HBx up-regulates ErbB3 expression at both mRNA and protein levels.

A. The expression of ErbB family and downstream signaling in Hep3B and HepG2 cells and their HBx-derivatives were determined by Western blot. B. The mRNA expression of ErbB family in Hep3B and Hep3Bx cells were examined by RT-qPCR analysis. The mRNA levels of ErbB family were normalized to GAPDH expression. C–D. Hep3B and HepG2 cells were transiently transfected or infected with HBx at different dose for 2 days. The protein expression and mRNA level of ErbB3 were detected by Western blot and RT-qPCR analysis, respectively. E–F. Hep3B cells were transfected with control vector, HBV-whole genome, and HBx-deleted HBV mutant for 2 days (E) Hep3Bx cells were transiently transfected with si-HBx for 3 days (F) The protein expression and mRNA level of ErbB3 were detected by Western blot and RT-qPCR analysis, respectively. G. The ErbB3 mRNA level of HCC patients were examined by RT-qPCR. The fold changes of ErbB3 mRNA were normalized to its adjacent normal tissue. H. The protein expression level of ErbB3 examined by Western blot and quantified by image J system. The expression level of ErbB3 was normalized to β-actin. I. Total lysates from HBV-associated HCC tumor liver tissue were prepared and subjected to Western blot with anti-ErbB3, HBx and ERK antibodies. The coefficient of determination (R²) between ErbB3 and HBx expression level was analyzed by simple regression, p < 0.001.