miR-145-5p suppresses proliferation, metastasis and EMT of colorectal cancer by targeting CDCA3.

MicroRNAs play a critical role in regulating the carcinogenesis of colorectal cancer (CRC). Even though its role is unclear in CRC, miR-145-5p has been reported to have anti-oncogene properties in several tumors. Our research examined the function of miR-145-5p in CRC and the potential underlying mechanism. From the bioinformatics and qRT-PCR analysis, miR-145-5p levels were lower in CRC samples and cell lines. LoVo and SW480 cells were treated with miR-145-5p mimics and inhibitor, respectively. Cell cycle, CCK-8 and EdU assays revealed that overexpression of miR-145-5p suppressed cell viability and G1/S phase transition. Conversely, miR-145-5p inhibitor promoted cell growth and cell cycle transition. Elevated miR-145-5p expression also suppressed the migration, invasion and EMT of CRC cells, while miR-145-5p reduction had a reverse effect. CDCA3 was identified as a downstream effector of miR-145-5p and had a negative correlation with the miR-145-5p expression in CRC. In addition, co-transfection of miR-145-5p inhibitor and si-CDCA3 showed that CDCA3 in SW480 cells could reverse the effect caused by miR-145-5p. In conclusion, our findings demonstrated that miR-145-5p could act as a tumor suppressor in CRC by targeting CDCA3, and serve as a diagnostic and therapeutic biomarker of CRC.