Interaction between linc01615 and miR-491-5p regulates the survival and metastasis of colorectal cancer cells

BACKGROUND: The 5-year survival of colorectal cancer (CRC) has had no obvious improvement during the past decades, although a significant progress in treatments has been established. The molecular mechanisms that drive the progression of CRC are still unclear. This study aims to determine the biological activities of linc01615 and its regulatory microRNAs in CRC cells. METHODS: The expression of linc016150 and miR-491-5p was measured in six CRC cell lines and one normal colon mucosal epithelial cell line. Their effects on cell proliferation, apoptosis, invasion, and migration were tested in Caco-2 cells. RESULTS: Linc01615 mRNA expression was upregulated in six colorectal cancer cell lines compared to the normal colon mucosal epithelial cell line, which was negatively regulated by miR-491-5p in Caco-2 cells. Silencing of linc01615 gene expression significantly decreased cell proliferation, increased apoptosis, and inhibited invasion and migration in Caco-2 cells. Overexpression of linc01615 exhibited an opposite effect on silencing of linc01615 expression. Transfection with miR-491-5p mimics downregulated linc01615 expression and inhibited the biological activities of linc01615. In contrast, the inhibitor of miR-491-5p up-regulated linc01615 expression and subsequently enhanced the biological activities of linco1615. Also, overexpression of linc01615 can block the effects of miR-491-5p mimics in Caco-2 cells. CONCLUSIONS: Linc01615 functions as an oncogene while miR-491-5p functions as a tumor suppressor in colorectal cancer cells through negatively regulating each other; both are involved in cell proliferation, apoptosis, invasion, and migration in colorectal cancer cells.