MicroRNA-92a Promotes Colorectal Cancer Cell Growth and Migration by Inhibiting KLF4

Colorectal cancer (CRC) is the third most common malignancy with high mortality around the world. However, the biological mechanism of CRC carcinogenesis is not completely known. In the present study, we determined the role of miR-92a in the regulation of CRC cell motility. Expression of miR-92a is aberrantly upregulated in human CRC tissues and cultured cells, as shown by RT-PCR analysis. The effects of miR-92a on the proliferation and migration of human CRC SW620 and LoVo cells were measured by CCK-8 and Transwell assay, respectively. Results showed that the proliferation and migration capacity of both SW620 and LoVo cells were significantly increased by miR-92a mimic transfection but reduced by miR-92a inhibition. Additionally, KLF4 was identified as a direct target of miR-92a in CRC cells through bioinformatics and luciferase reporter analysis. KLF4 overexpression attenuated the effects of miR-92a on the regulation of CRC cell motility. Further studies suggested that the cell cycle inhibitor p21 was aberrantly downregulated in CRC cells, whereas this inhibition was reversed by miR-92a inhibitor. In conclusion, our data demonstrated that miR-92a may play a positive role in the colorectal carcinogenesis by promoting the proliferation and migration of CRC cells through targeting KLF4 as well as downstream p21. This could be an alternative therapeutic target for CRC.