EXPRESSION AND SIGNIFICANCE OF p21~(WAF1) AND p53 IN HEPATIC CELL CARCINOMA

Objective To explore the expression and significance of p21 WAF1 and p53 in HCC. Methods Immunohistochemical method (IHC) was used to localize and semi quantitate the proteins of p21 WAF1 and p53 and to observe the relationship between the expression of p21 WAF1 and the different histopathologic characters in 38 patients of HCC and their peri cancer tissue as well as 5 normal liver tissue. Results Of all 38 cases, both p21 WAF1 and p53 expression were significantly higher in tumor than that in corresponding non tumors liver tissue; 14 (36 8 %) of 38 cases showed p21 WAF1 positive staining, 28 cases (73 7 %) were p53 positive, p21 WAF1 +/p53+ or p21 WAF1 /p53- were observed in 18, while 20 cases showed p53+/p21 WAF1 - or p53-/p21 WAF1 +. p21 WAF1 + was seen in 1 of 38 (2 6 %) corresponding non cancerous tissue and 2 of 5 normal liver tissue. p53 protein was not detected neither in the non tumorous tissue nor in normal liver. No significant association was found between the expressions of p21 WAF1 and p53( P 0 05) in HCC. Their was no significant correlation between p21 WAF1 or p53 expression and the different histopathologic characters of tumor (differentiating grades, intrahepatic metastasis and/or cancerous thrombi within portal veins). Conclusion Both p21 WAF1 and p53 proteins are over expressed in HCC than that in corresponding non tumorous liver tissue, but there is no relationship between them. Both p53 independent and p53 dependent mechanism may play a role in regulating p21 WAF1 expression in HCC. p21 WAF1 immunostaining cannot be used to assess the status of p53 in any given cell or tissue.