regulates cell proliferation, migration, and apoptosis by targeting SOX9 in human colorectal cancer cells.

The human microRNA 133A () was identified as a CRC-associated miRNA. It was down-regulated in human CRC tissues. We identified the putative and target genes by comparing the transcriptome analysis data of and knock-in cells with the candidate target genes predicted by bioinformatics tools. We identified 29 and 33 putative and direct target genes, respectively. Among them, we focused on the master transcription regulator gene SRY-box transcription factor 9 (), which exhibits a pleiotropic role in cancer. We confirmed that is a direct target gene of by luciferase reporter assay, quantitative RT-PCR, and western blot analysis. Overexpression of in CRC cell lines significantly decreased SOX9 and its downstream PIK3CA-AKT1-GSK3B-CTNNB1 and KRAS-BRAF-MAP2K1-MAPK1/3 pathways and increased apoptosis. Furthermore, functional studies reveal that cell proliferation, colony formation, and migration ability were significantly decreased by -overexpressed CRC cell lines. Knockdown of SOX9 in CRC cell lines by gene silencing showed similar results. We also used a xenograft model to show that overexpression suppresses tumor growth and proliferation. Our results suggest that regulates cell proliferation, migration, and apoptosis by targeting in human colorectal cancer.