IMMUNOHISTOCHEMICAL EXPRESSION OF P53 PROTEIN AND PROLIFERATING CELL NUCLEAR ANTIGEN IN HEPATOCELLULAR-CARCINOMA

There is an increased prevalence of p53 mutations in hepatocellular ca rcinomas (HCCs). A total of 62 HCC samples with adjacent liver tissue were analyzed immunohistochemically for the presence of p53 by two dif ferent commercial sources of Pab 1801. Polyclonal antibodies anti-HbsA g and anti-HbcAg were employed for the detection of HBV in the adjacen t tissue and PC-10 for the defection of proliferating cell nuclear ant igen (PCNA). Positive staining for p53 runs identified In 42% and 55% of the HCC cases using each monoclonal antibody. p53 teas found in 42% of the low grade and 43% of the high grade HCC. In 32% of the HCC cas es, p53 was found in the adjacent liver tissue. In 52.6% of the cases with evidence of HBV infection, p53 positive expression was observed. PCNA was detected in 56% of the HCC cases (69% low grade, 57% high gra de HCC). Eighty-one percent of the p53 positive tumours expressed PCNA , mostly with a high index. p53 and PCNA were not related to histologi c grade. A trend for positive correlation was observed between p53 exp ression and HBV infection. The defection of p53 in non neoplastic tiss ue and the absence of a significant correlation between p53 expression and degree of differentiation support the hypothesis that the p53 gen e mutation is involved in early stages of hepatocellular carcinogenesi s.