Colorectal cancer is a common gastrointestinal cancer ranking in third place of all cancers. Downregulation of miR-148a has been observed in many tumors, and miR-148a was found to be an oncogene in colorectal cancer. The aim of our study was to investigate the molecular mechanisms by which miR-148a and ErbB3 proliferate and migrate in colorectal cancer. The expression of miR-148a and ErbB3 were measured by western blot analysis and RT-qPCR. MTT and transwell assays were performed to analyze the proliferative and migratory abilities. The dual luciferase reporter assay was employed to confirm miR-148a regulated the expression of ErbB3 in colorectal cancer. It was discovered that miR-148a was overexpressed while ErbB3 expression was low in colorectal cancer, and the mRNA level of miR-148a had a negative correlation with the expression of ErbB3. Upregulation of miR-148a suppressed the proliferation and migration in colorectal cancer cells. Furthermore, ErbB3 was identified as a direct target of miR-148a, which suppressed the proliferation and migration through directly binding to the 3'UTR of ErbB3 mRNA. This study established that miR-148a inhibited the proliferative and migratory abilities through mediating the expression of ErbB3. The newly identified miR-148a/ErbB3 axis provides novel insight into the pathogenesis of colorectal cancer, and represents a potential target for treatment of colorectal cancer.
Keywords: ErbB3; colorectal cancer; miR-148a; migration; proliferation.