Immunohistochemical Expression of p53 and Factor VIII-Related Antigen for Determination of Tumour Angiogenesis in Hepatocellular Carcinoma

Hepatocellular carcinoma, is reported as the second most common cancer of the digestive tract in Egypt. Angiogenesis is an essential step in tumour growth and metastases. p53 a cancer suppressor gene exerts an important role in the control of normal cell proliferation. p53 mutations have been found in a variety of human malignancies including liver carcinogenesis. In addition, it has also been suggested that p53 is involved in the control of tumour angiogenesis. The aim of this study is to assess the expression of mutant p53 protein in HCC and to analyze the possible association between p53 immunostaining and microvessel density to determine the role of p53 in the regulation of angiogenesis in HCC. This study consisted of 20 cases of hepatocellular carcinoma. The paraffin blocks of the cases were stained with p53 monoclonal antibody and factor VHI - related monoclonal antibody. In tissue sections, p53 positive nuclear immunoreactivity was observed in 35% of cases. The prevalence of p53 expression was found to correlate significantly with high grade HCCs. The microvascular density was counted per x 250 magnification on the three chosen fields of the highest density. It was found that 55% of the cases showed low microvessel count (MVC). A direct relation was found between the microvessel density (MVD) and tumour grade as evidenced by the increase in MVD with the increase of tumour grade in most of the cases. Analysis of the association between p53 expression and microvessel density revealed a statistically significant association between these two variables. p53 immunoreactivity was significantly more intense in tumours with high MVC (57.1%)than in those with low MVC (42.9%) thus supporting the association between p53 mutation and angiogenesis in human HCC.