Circulating microRNA-762 upregulates colorectal cancer might through Wnt-1/b-catenin signaling

BackgroundA number of microRNAs (miRNAs) have been demonstrated to be correlated with the diagnosis, progression and prognosis of colorectal cancer (CRC). However, the key miRNAs and the associated signaling pathways that regulate the growth and metastasis of CRC remain unclear. MethodsThe circulating miRNAs from BALB/c mice with CRC CT26 cell implantation were assayed by microarray. Then, mmu-miR-762 mimic and inhibitor were transfected to CT26 cells for analysis of cell viability, invasion, and epithelial-mesenchymal transition (EMT), cell cycle, and regulatory molecule expression. Human subjects were included for comparison the circulating has-miR-762 levels in CRC patients and control donors, as well as the patients with and without distant metastasis. ResultsThe miRNA levels in mice with CRC cell implantation indicated that plasma mmu-miR-762 was upregulated. Transfection of mmu-miR-762 mimic to CT26 cells increased cell viability, invasion, and EMT, whereas transfection of mmu-miR-762 inhibitor decreased the above abilities. Cells treated with high-concentration mmu-miR-762 inhibitor induced cell cycle arrest at G0/G1 phase. Western blot analysis showed that mmu-miR-762 mimic transfection upregulated the expression of Wnt-1 and {beta}-catenin. Further analysis was performed to demonstrate the correlation of has-miR-762 with CRC patients. The results showed that serum has-miR-762 levels in CRC patients were higher than in control donors. Among the CRC patients, patients with distant metastasis showed higher serum has-miR-762 levels than patients without distant metastasis. ConclusionsThe present study demonstrated that circulating miR-762 might be a biomarker with upregulation of CRC cell growth and invasion through the Wnt/{beta}-catenin signaling.