The loss of miR-200 family, through DNA methylation, results in cancer cells undergoing an epithelial to mesenchymal transition (EMT), and metastasis. In this study, we established that the transcriptional repressor Kaiso directly binds methylated regions of the miR-200 family, and this is reversed with 5-aza treatment. sh-Kaiso PC-3 cells display increased miR-200-a/b/c, miR-141, and miR-429 expression, with miR-200c demonstrating the most significant increase. Interestingly, overexpression of EGFR or treatment with EGF decreases miR-200c expression and this is reversed after treatment with EGFR specific kinase inhibitor PD153035. However, EGF did not have a significant effect on miR-200c in sh-Kaiso DU-145 or PC-3 cell lines, suggesting Kaiso silences miR-200c through the activation of EGFR signaling. Overexpression of Kaiso in LNCaP cells results in decreased expression of miR-200-a/b/c, miR-141, and miR-429, along with increased expression of ZEB1, p-EGFR and total EGFR levels. Overexpression of miR200c in PC-3 cells results in decreased expression of EGFR, ZEB1, ERK1/2 and Kaiso. Additionally, sh-Kaiso PC-3 demonstrates reduced in vivo tumor formation and metastasis. Thus, our data suggests that EGFR signaling regulates the silencing of miR-200 family through Kaiso binding to methylated regions in the promoter.
Cancer letters. 2018 May 08 [Epub ahead of print]
Abisola Abisoye-Ogunniyan, Huxian Lin, Anghesom Ghebremedhin, Ahmad Salam, Balasubramanyam Karanam, Shaniece Theodore, Jacqueline Jones-Trich, Melissa Davis, William Grizzle, Honghe Wang, Clayton Yates
Department of Biology and Center for Cancer Research, Tuskegee University, Tuskegee, AL 36088, USA., Department of Biology and Environmental Sciences, Troy University, Troy, AL 36082, USA., Department of Surgery, Henry Ford Medical Center, Detroit MI, USA., Department of Pathology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA., Department of Biology and Center for Cancer Research, Tuskegee University, Tuskegee, AL 36088, USA. Electronic address: .