Inhibition of miR-20a-5p Suppresses Epithelial-Mesenchymal Transition of Colorectal Cancer Cells Through GJA1

Abstract

This study was designed to clarify the role of GJA1 in colorectal cancer. qPCR was adopted to detect the GJA1 and miR-20a-5p expression levels in tumor tissues and cells; and EdU, Transwell assay, Scratch test to examine the migration, invasion, and proliferation of colorectal cancer cells. The EMT-related protein expression was measured by immunofluorescence and western Blot. The binding relationship between GJA1 and miR-20a-5p was examined using dual luciferase reporting subsystem. In situ hybridization was utilized to examine the miR-20a-5p expression in tumor tissues and metastases. Rescue experiments were performed by simultaneous transfection of sh-GJA1 inhibitor and miR-20a-5p inhibitor. The miR-20a-5p expression was high and the GJA1 expression was low in colorectal cancer tissues and cells. A targeting relationship was found in GJA1 and miR-20a-5p targets. The invasion, migration, and proliferation of colorectal cancer cells can be inhibited by overexpression of GJA1. Meanwhile, overexpression of GJA1 markedly elevated the e-cadherin expression, but reduced the levels of vimentin, α-SMA and n-cadherin expression. miR-20a-5p inhibitor + sh-GJA1 promoted the invasion, migration, and proliferation of colon cancer cells and EMT process. Overall, miR-20a-5p could target GJA1 to down-regulate the GJA1 expression, thereby regulating the EMT response, and ultimately promoting the progression of colorectal cancer.

Keywords: Colorectal cancer; EMT; GJA1; Invasion; Metastasis; MiR-20a-5p.