MiRNA-212 acts as a tumor-suppressor in colorectal carcinoma through targeting SOX4.

OBJECTIVE: Colorectal cancer is a common gastrointestinal cancer, with mortality ranking the third all over the world. MicroRNA-212 (miR-212), located on chromosome 17p13.3, was lowly expressed in a variety of tumors. The purpose of our study was to explore the effects of miR-212 on colorectal cancer (CRC) cells. PATIENTS AND METHODS: Quantitative Real Time-Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and Western blot were employed to evaluate the levels of mRNAs and proteins. The transwell assay was performed to calculate the abilities of migration and invasion. The Luciferase reporter assay was utilized to verify miR-212 targeting to the 3'-UTR of SOX4 mRNA. Statistical analysis was applied to analyze the experimental data. RESULTS: MiR-212 was lowly expressed in CRC tissues and cell lines, while the expression of SRY-box 4 (SOX4) was overexpressed. Exogenous increasing of miR-212 or knockdown of SOX4 inhibited the migration, invasion and epithelial-mesenchymal transition (EMT) in CRC cells. Moreover, the expression of miR-212 had a negative connection with SOX4 expression, and miR-212 mediated the expression of SOX4 by directly binding to the 3'-UTR of SOX4 mRNA. In addition, low expression of miR-212 or overexpression of SOX4 was associated with poor prognosis of colorectal cancer patients. CONCLUSIONS: MiR-212 inhibited the migration, invasion and EMT by direct targeting to the 3'-UTR of SOX4 mRNA in colorectal cancer. The newly identified miR-212/SOX4 axis provides novel insight for colorectal treatment.