MicroRNA 133A Regulates Cell Proliferation, Cell Migration, and Apoptosis in Colorectal Cancer by Suppressing CDH3 Expression

MicroRNAs are endogenous, non-coding RNA that play an essential role in colorectal carcinoma (CRC) pathogenesis by targeting specific genes. This research aimed to determine and validate the target genes of the MIR133A associated with CRC. We verified that cadherin 3 (CDH3) is the direct target gene of MIR133A using a luciferase reporter assay, quantitative RT-PCR, and western blot analyses. CDH3 mRNA and protein expression were reduced significantly in CRC cells after transfection with MIR133A or siCDH3. We also verified that MIR133A regulated CDH3-mediated catenin, matrix metalloproteinase, apoptosis, and the epithelial-mesenchymal transition (EMT) pathway. Knockdown of CDH3 in CRC cell lines by siCDH3 produced similar results. Compared with adjacent non-tumor tissues, CDH3 protein expression was upregulated in CRC tissues, which is further confirmed by immunohistochemistry. Additionally, molecular and functional studies revealed that cell viability, migration, and colony formation were significantly reduced, and apoptosis was increased in CRC cell lines transfected with MIR133A or siCDH3. Our results suggest that MIR133A regulates CDH3 expression in human CRC.