Emerging role of p53, bcl-2 and telomerase activity in Egyptian breast cancer patients

Apoptotic cell death represents an important mechanism for the precise regulation of cell numbers, and a defense mechanism against tumor cells. Both bcl-2 and mutant p53 gene products have been involved in apoptotic pathways. On the other hand, cell proliferation capacity and tumorgenesis have been controlled by telomerase. The purpose of our study is to assess the prognostic significance of additional markers implicated in apoptosis and tumorgenesis. Fifty-one fresh tissue samples of primary breast carcinoma and 26 tissue samples of benign breast lesions were included in this study. Expression of bcl-2 in cell lysates and mutant p53 protein in nuclear fraction were measured by Oncogene Science EIA procedures. Telomerase activity was analyzed using the Telomerase-PCR-ELISA based on the TRAP (telomerase repeat amplification protocol) method. On the same specimens, steroid hormone receptors (ER and PgR) were measured in cytosol fraction using Abbott EIA assays. In addition, information regarding surgical-pathological features of the tumor was obtained. Univariate and Multivariate analysis was done to identify variables predictive of poor prognosis. Significant expression of bcl-2, mutant p53 proteins and relative telomerase activity were observed in malignant cases when compared to benign ones. Univariate analysis revealed significant association in the level of both mutant p53 and relative telomerase activity with tumor size and disease recurrence. Moreover, telomerase activity was significantly expressed in late stages than early ones. Multivariate analysis revealed that bcl-2, mutant p53, telomerase activity, PgR and age were independent prognostic factors. Among a panel of molecular genetic factors investigated, mutant p53 and relative telomerase activity were strongly associated with disease recurrence; hence they exert a significant prognostic role in breast cancer.