IMMUNOHISTOCHEMICAL DETECTION OF ABERRANT P53 EXPRESSION IN HEPATOCELLULAR-CARCINOMA - CORRELATION WITH CELL PROLIFERATIVE ACTIVITY INDEXES, INCLUDING MITOTIC INDEX AND MIB-1 IMMUNOSTAINING

We analyzed the p53 expression immunohistochemically in 50 specimens o f hepatocellular carcinoma (HCC) using two monoclonal antibodies (DO7 and PAb1801) and one polyclonal antibody (CM1), which recognize both w ild and mutant type p53 proteins and can be used for paraffin-embedded sections. Fifteen of the 50 HCC specimens (30%) showed p53 expression localized at tumor nuclei, and this expression was significantly more frequent in HCCs with histologically lower differentiation. Except fo r serum titers of alpha-fetoprotein, the p53 expression had no statist ically significant correlation with clinicopathological parameters, in cluding hepatitis virus infection, tumor size, and background liver di seases. Conversely, the cell proliferative activities of tumor cells a s assessed by mitotic index and immunostaining for MIB-1 were well cor related with the grade of histological differentiation. Moreover, MIB- 1 immunostaining was shown to be useful in distinguishing well differe ntiated HCC from hepatocytes in chronic liver diseases. It also was sh own that p53 expression was strongly associated with cell proliferativ e activity. Our results indicate that p53 expression takes place in th e late stage of tumor progression and is related to the high malignant potential of HCCs. Copyright (C) 1995 by W.B. Saunders Company