MicroRNA-214 suppresses the viability, migration and invasion of human colorectal carcinoma cells via targeting transglutaminase 2

Colorectal carcinoma (CRC) is a common malignancy of the digestive tract. MicroRNA (miR)-214 is considered a key hub that controls tumor networks; therefore, the effects of miR-214 on CRC were examined and its target gene was investigated in this study. The expression levels of transglutaminase 2 (TGM2) and miR-214 were detected in CRC and adjacent normal tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting, and luciferase activity was analyzed by dual luciferase reporter analysis. In addition, cell viability, invasion and migration were measured by Cell Counting kit-8 and Transwell assays, respectively. The expression levels of epithelial-mesenchymal transition-related proteins, and phosphoinositide-3 kinase (PI3K)/protein kinase B (Akt) signaling-associated factors were detected using RT-qPCR and western blotting. The results demonstrated that miR-214 expression was downregulated in CRC tissue, whereas TGM2 expression was upregulated. According to TargetScan prediction, miR-214 possesses a binding site to TGM2. In addition, transfection with miR-214 mimics markedly suppressed the viability of LoVo cells. miR-214 overexpression also inhibited cell invasion and migration by increasing E-cadherin and tissue inhibitor of metalloproteinases-2 expression, and decreasing matrix metalloproteinase (MMP)-2 and MMP-9 expression. Furthermore, miR-214 downregulated phosphorylation of PI3K and Akt; however, the expression levels of total PI3K and Akt were not affected by miR-214. In conclusion, this study indicated that TGM2 was a target gene of miR-214, and a negative correlation between miR-214 and TGM2 expression was determined in CRC. Notably, miR-214 markedly suppressed the viability, invasion and migration of CRC cells, which may be associated with a downregulation in PI3K/Akt signaling. These findings suggested that miR-214 may be considered a novel target for the treatment of CRC.