Inhibition of MicroRNA-302c on Stemness of Colon Cancer Stem Cells via the CARF/Wnt/β-Catenin Axis.

Abstract

Even though the relevance of microRNA (miR)-302c has been studied, little is known about its involvement in colon cancer (CC). Our aim here was to investigate the role of miR-302c in the cancer stem cells (CSCs) of CC. Firstly, the CSCs were screened out from cultured SW1116 and SW480 cells by flow cytometry, and the differentially expressed miRNAs in cell were obtained by microarray analysis. The expression of miR-302c, collaborator of ARF (CARF), and Wnt/β-catenin-related genes in CSCs was determined by means of RT-qPCR and Western blot. A dual-luciferase reporter assay was conducted to authenticate the binding relationship between miR-302c and CARF. Proliferation, migration, invasion, sphere formation as well as apoptosis of CSCs were assessed by cell counting kit-8, Transwell assay, sphere formation assay as well as flow cytometric analysis, respectively. The roles of miR-302c and CARF in tumor growth were determined in vivo. The expression of miR-302c in CC cells was reduced versus that in normal cells. The overexpression of miR-302c weakened the stemness, proliferation, invasion, and migration abilities while induced apoptosis of CSCs in CC. Also, miR-302c reduced tumor size and weight in mice, accompanied with lowered CARF expression. The mechanistic analysis manifested that miR-302c bound to CARF and suppressed its expression and disrupted the Wnt/β-catenin signaling. This study offers a novel characterization of miR-302c function in CSCs in CC, which may be beneficial to the development of capable therapeutic options for CC.