MicroRNA-188-5p targeting Forkhead Box L1 promotes colorectal cancer progression via activating Wnt/β-catenin signaling.

MicroRNA-188-5p (miR-188) enhances oncologic progression in various human malignancies. This study aimed to explore its role in colorectal cancer (CRC). Human CRC tissues paired with normal tissues, and several CRC cell lines were utilized. Real-time quantitative PCR was applied to measure the expression of miR-188. Overexpression and knockdown were used to access the function of miR-188 and to investigate whether FOXL1/Wnt signaling mediates such function. The proliferation, migration and invasion of cancer cells were evaluated by CCK8, wound-healing and transwell assays, respectively. Whether FOXL1 acted as a direct target of miR-188 was verified by dual-luciferase reporter assays. Levels of miR-188 were upregulated in CRC tissues than in paired-normal tissues, as well as in various CRC cell lines. High expression of miR-188 was strongly associated with advanced tumor stage, accompanied with significant tumor cell proliferation, invasion and migration. It was confirmed that FOXL1 played positive crosstalk between miR-188 regulation and downstream Wnt/β-catenin signaling activation. All findings indicate that miR-188 promotes CRC cell proliferation and invasion through targeting FOXL1/Wnt signaling and could be served as a potential therapeutic target for human CRC in the future.