Abstract 4834: Circulating microRNA-762 promotes colorectal cancer proliferation and invasion by upregulating the Wnt-1/β-catenin pathway

Background: A number of microRNAs (miRNAs) have been demonstrated to be associated with the diagnosis, progression and prognosis of colorectal cancer (CRC). However, the function of miRNA-762 (miR-762) in CRC remains unclear, and the molecular mechanisms underlying the effects of miR-762 in CRC require further investigation. Methods: The circulating miRNAs from BALB/c mice with CRC CT26 cell implantation were assayed by microarray. Then, 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 miR-762 levels in CRC patients and control donors, as well as the patients with and without distant metastasis. Results: The screening for miRNA levels in mice with CRC cell implantation indicated that plasma miR-762 was upregulated. Transfection of miR-762 mimic to CT26 cells increased cell viability, invasion, and EMT, whereas transfection of miR-762 inhibitor decreased the above abilities. Western blot analysis showed that miR-762 mimic transfection upregulated the expression of Wnt-1 and β-catenin, as well as increased the nuclear translocation of β-catenin. Further analysis showed that serum miR-762 levels in CRC patients were higher than in control donors. Among the CRC patients (n = 20), six patients with distant metastasis showed higher serum miR-762 levels than the patients without distant metastasis. Conclusions: Circulating miR-762 could promote CRC disease development and progression through the Wnt/β-catenin signaling. miR-762 might be used as a biomarker for CRC diagnosis and targeted therapy. Citation Format: Ying-Yin Chen, Peng-Sheng Lai, Chung-Yu Chen, Hui-Fen Liao. Circulating microRNA-762 promotes colorectal cancer proliferation and invasion by upregulating the Wnt-1/β-catenin pathway [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4834.