Methyl CpG binding protein MBD2 has a regulatory role on the BRCA1 gene expression in ER+, PR+ & triple-negative breast cancer cells

Abstract

Abstract Background It has been shown that Resveratrol regulate BRCA1 gene expression in breast cancer cells and that MBD proteins bind to the BRCA1 gene promoter regions, the molecular link or mechanism has yet to be established. In This study aimed to evaluate the effect of MBD proteins in the regulation of BRCA1, BRCA2, and p16, genes as well as their impacts on breast cancer cells. Methods Efficacy of resveratrol was calculated by MTT assay. The binding assay was performed by EMSA, ChIP, & MeIP assay. MBD genes & proteins expression were analyzed by qRT-PCR & western blotting. Clonogenic, migratory, and sphere formation assays were used to assess cancer cells' colony-forming, metastatic, and tumor-forming abilities. The cytotoxicity of resveratrol on cancer cells was also tested using an apoptosis assay. Results This study found that IC50 of resveratrol was 30µM. MBD proteins bind to the BRCA1 gene promoter. Resveratrol regulates MBD genes expression, which in turn adversely influences BRCA1 gene expression and protein expression. A high concentration of Resveratrol reduced the colony & sphere formation as well as migration of cancer cells. It also increases no. of apoptotic cells in breast cancer cells. Conclusions In conclusion MBD2 protein interact to the BRCA1 gene promoter, and resveratrol modulates MBD2 gene expression, which in turn regulates BRCA1 gene expression, and inhibits cell proliferation, migration, and induces apoptosis in ER+, PR+ & Triple negative breast cancer cells. Impact Identification of MBD2-BRCA1 axis indicates their significant role in the induction of apoptosis and reduction of metastasis and proliferation in Breast cancer cells. Further therapy can be designed to target these MBD proteins and resveratrol could be used along with other anticancer drugs to target breast cancer.