Investigation of PTEN gene expression levels in patients with different stages and grades of breast cancer

Breast cancer is the most common malignancy in women that causes death. Although new approaches and methods are being developed today, the increase in the incidence of the disease has made breast cancer a very important health problem. Genetic and environmental factors affect the development of breast cancer. In many studies, it has been determined that PTEN is an important tumor suppressor gene for breast cancers and its loss induces carcinogenesis in the breast. In our study, mRNA expression levels of PTEN gene were determined in tumor tissues and peripheral blood samples of 31 cases diagnosed with breast cancer, and breast tissues and peripheral blood samples of 5 healthy individuals. Real-Time Polymerase Chain Reaction method was used for the analysis. The results were evaluated with the REST 2009 software program. In our study, when PTEN gene expression changes were evaluated in tumor tissues and peripheral blood samples of breast cancer patients, down regulation was observed in 15 of 31 patients and up regulation was observed in 16 of 31 patients. 32.3% of these changes are statistically significant. 30% of these significant changes are down regulation and 70% is up regulation. When PTEN gene expression changes in peripheral blood samples of breast cancer patients were evaluated, 23 of 31 patients were down-regulated and 8 were upregulated. 58.1% of these changes are statistically significant. 83.3% of these significant changes are down regulation and 16.7% are up regulation. There is a contrast between PTEN gene expression behavior between blood and tissue. In addition, the down regulation in PTEN gene expression, which was analyzed in peripheral blood samples of patients with breast cancer stage IIA, attracts attention with 92.9%. When PTEN gene expression is evaluated in patients with breast cancer found in Grad I-II-III, it appears that PTEN gene is regulated up in tumor tissue in every histological grade while down regulated in peripheral blood. In general, when our results are evaluated, we think that the decrease in the mRNA levels of the PTEN gene (down regulation) in the peripheral blood of breast cancer cases may be a potential finding in early stage diagnosis. These data will shed light on new comprehensive studies.