A cohort study investigating the role of Bisphenol A in the molecular pathogenesis of breast cancer

Background Breast cancer is an abnormal division of breast cells. Bisphenol A (BPA), an environmental toxicant, is identified as an emerging risk factor for breast cancer development. However, to the best of our knowledge, no previous study has investigated the BPA levels in breast cancer patients in Pakistan. The present study sought to explore the role of BPA in tumor growth among the Pakistani population. Methods The levels of BPA were analyzed in the serum samples of breast cancer patients and controls by using HPLC. To elucidate the role of BPA to initiate tumorigenic events in breast tissue different biochemical assays along with expression analysis of tumor markers were performed. Results The level of BPA in the serum samples of breast cancer patients was significantly higher than control. Histological analysis of breast cancer tissue samples revealed distinct subtypes of tumor, such as ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). There was a significant increase in ROS level while a significant decrease in the levels of superoxide dismutase (SOD) and catalase (CAT) enzymes in malignant breast tissue samples as compared to control tissue samples. We found upregulated expression of p53, ZEB1 and WNT1 genes at mRNA level in malignant breast tissue samples by 17 folds, 328 folds and 35 folds, respectively. p53 protein expression in malignant breast tissue samples was also enhanced at the translational level. Conclusion Current findings suggest a relationship between BPA and the progression of breast cancer among the Pakistani population.