E-cadherin, Snail, ZEB-1, DNMT1, DNMT3A and DNMT3B expression in normal and breast cancer tissues*

Breast cancer is known as one of very important cancers among females, given that a variety of external (i.e., environmental risk factors) and internal factors (i.e., genetics, and epigenetics) are related to the emergence and progression of breast cancer. Among genetic and epigenetic factors, DNA methyltransferase and EMT related genes have critical roles in breast cancer pathogenesis. In the study presented here, we investigated expression of DNA methyltransferases (e.g., DNMT1, DNMT3A and DNMT3B) and EMT related genes (e.g., E-cadherin, Snail, ZEB-1).Tissue samples were collected from 18 cancer and 24 normal breast tissues. We evaluated the expression levels of DNA methyltransferases and EMT related genes using Quantitative real-time PCR (qRT-PCR).Our results indicated that the expression levels of ZEB-1, Snail, and DNMT3B were increased in breast cancer subjects in comparison to the control group. On the other hand, there was a significant decrease in E-cadherin expression in breast cancer tissues in comparison to the normal tissues. Moreover, there were no significant changes for DNMT1 and DNMT3A expression in breast cancer tissues when compared to the normal tissues.Taken together, our finding show that up regulation of ZEB-1 and Snail could be associated with down regulation of E-cadherin and results in promotion of cancer cell invasion. Moreover, down regulation of E-cadherin may be related to deterioration of DNMT3B inpatients with breast cancer.