Figure 2.

Effects of HBx expression on p53-mediated apoptosis and on p53 localization in normal human hepatocytes. Primary hepatocytes were microinjected with a p53 expression vector or coinjected with p53 and HBx (adr and ayw subtypes for donor 1; adr subtype for donor 2) expression vectors. (A) After 24 h, cells were immunostained for p53 and scored for apoptosis as described in Materials and Methods. Bar values represent the percentage of apoptotic hepatocytes from one to three individual experiments. The total number of p53 immunopositive cells scored for donors 1 and 2 were 108 and 119, respectively. ND, not determined. ∗, Fisher’s exact test comparing the levels of p53-mediated apoptosis in the absence versus presence of HBx expression, P ≤ 0.036. In the case of p53 ± HBx (adr) with donor 2, a χ² test was performed because greater than 100 cells were analyzed, P ≤ 0.046. (B) Twenty-four hours after microinjection with p53 expression vector alone (Upper Left) or coinjection with p53 and full-length HBx expression vectors (Upper Right and Lower), hepatocytes were simultaneously immunostained for p53 (Texas red) and HBx (FITC) as described in Materials and Methods. Yellow regions (Lower Right) reflect overlapping areas of p53 and HBx immunostaining in a single hepatocyte also shown (Upper Right and Lower Left).