Expression of p53 and bcl-2 in Renal Cell Carcinoma

Abstract

Background. Renal cell carcinoma (RCC) is often resistant to conventional chemotherapy and irradiation, which suggests that RCC cells are unable to undergo apoptosis. Both p53 and bcl-2 are involved in the regulation of apoptosis. The aims of this study were 1) to determine the relationship between p53 and bcl-2 statuses in RCC during the pathologic stage, and 2) to evaluate the roles of p53and bcl-2 in RCC metastasis. Methods. Immunohistochemical stains of p53and bcl-2 protein were performed on 34 paraffinembedded RCC specimens, from 16 patients (stage I: 8, stage II: 5and stage III: 3) who did not develop metastasis and 18 patients (stage I: 2, stage II: 6, stage Ill: 6 and stage IV: 4) who developed metastasis during follow-up. Results. Staining results positive for p53were detected in 10 (29%) of 34 RCCs and staining results positive for bcl-2 were seen in 12 (35%) of 34 RCCs. No correlations between p53frequency and disease stage or between p53 frequency and pathologic grade were detected. The metastatic group had higher incidence in p53expression than the non-metastatic group (p = 0.063), especially for clear cell type of RCCs (ρ= 0.017). The bcl-2 expression showed a significant correlation with tumor grade (p = 0.048) but not with pathological stage or metastatic potential. Staining results positive for both p53 and bcl-2 were detected in six (18%) of 34 RCCs, but there were no significant correlations between the status of tumor stage, tumor grade or metastasis. Conclusions. From our limited number of cases we concluded that patients with welldifferentiated RCC had a higher incidence of bcl-2 expression than those with moderately or poorly differentiated RCCs. For clear cell type RCCs, the metastatic group had a higher incidence of positive staining results for p53than the non-metastatic group.