Apoptosis and cell proliferation: correlation with BCL-2 and P53 oncoprotein expression in human hepatocellular...

Occurrence and biological characteristics of tumors are related not only to over-proliferation of carcinoma cells but also to decrease of apoptosis. The present study was suggested to evaluate the correlation between P53 and Bcl-2 oncoprotein expression with apoptosis and cell proliferative activity in HCC patients.

P53 and Bcl-2 protein expression were estimated in the sera and in liver tissues of 45 HCC cases using ELISA and immunohistochemistry. Apoptosis was estimated as apoptotic index (AI) and cell proliferative activity was detected using AgNORs.

Serum p53 antigen in HCC patients (0.46±0.331ng/ml) showed significant elevation than healthy individuals (0.24±0.11ng/ml, p<0.05). P53 protein was immunostained in 41% of HCC; 37.5% of these positive cases were in diffuse pattern representing the mutant p53. Serum Bcl-2 was elevated in HCC cases (50.28±25.83u/ ml) than healthy individuals (26.65±8.63u/ml, p<0.05). Bcl-2 was immunohistochemically localized in 35.9% of HCC and the positivity was inversely proportional with the histological grade (47.4%, 25%, 25% in grade I,II,III respectively). Bcl-2 showed a positive linear correlation with p53 in the sera of carcinoma patients (p<0.05).

Bcl-2 may play a role in hepatocarcinogenesis as an inhibitor of apoptosis. However, a positive linear correlation was found between bcl-2 and p53 suggesting that bcl-2/p53 co-expression pattern may be of value in the development of more effective medical therapies in HCC.