Analyses of telomerase activity and apoptosis in invasive ductal carcinoma of the breast by using immunohistochemical and western blot methods

Invasive breast cancer is the most common carcinoma in women. Invasive ductal carcinoma comprises the largest group of invasive breast cancers. In this study, it is aimed to investigate telomerase activity and apoptosis by using immunohistochemical and western blot methods.Seventy five cases which diagnosed as invasive ductal carcinoma and six cases which underwent frozen procedure in Pathology Department of Medical School of Firat University are included in our study. The acquired sections are stained with Bax, Bcl-2, hTERT and BNIP3. Age of patient, tumor size and grade, estrogen, progesteron and c-erbB2 status are evaluated as well as the staining characteristics of the antibodies in question.A decrease of Bcl-2 positivity and an increase of Bax positivity were found with increasing tumor grade in immunohistochemical method. Although, these results were not statistically significant, the data obtained by western blot method showed that Bcl-2 was highest in grade 1 tumor. The relationship between the Bcl-2 and estrogen receptor positivity and progesteron receptor positivity was statistically significant, suggesting that there is hormonal control in the apoptosis. Also BNIP3 which effects hypoxic cell death, was found to be decreased with increasing tumor grade. Similarly, BNIP3 was found to have the lowest value in grade 3 tumors by western blot method. hTERT, which regulates telomerase activity and provide continuance of cell proliferation was found to be increased with increasing tumor grade. In western blot method, hTERT increased nearly four-fold compared to control.hTERT, which has very high levels in tumor, may be a helpful cancer marker. Both hTERT and BNIP3 are important markers which can provide information about the prognosis. Positive staining in the DCIS areas with these markers shows that telomerase and apoptosis have an effect on the first stages of tumor development. There will be a big improvement in tumor progression control with the new treatment modalities that stop telomerase activity and hypoxic cell death.Key words: Breast, carcinoma, apoptosis, telomerase.