Back to Journals » OncoTargets and Therapy » Volume 13

MicroRNA-126 Inhibit Viability of Colorectal Cancer Cell by Repressing mTOR Induced Apoptosis and Autophagy

Authors Wei L, Chen Z, Cheng N, Li X, Chen J, Wu D, Dong M, Wu X

Received 12 November 2019

Accepted for publication 19 January 2020

Published 24 March 2020 Volume 2020:13 Pages 2459—2468


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 2

Editor who approved publication: Dr Sanjeev Srivastava

Li Wei,1,* Zhanhong Chen,1,* Na Cheng,2,* Xing Li,1 Jie Chen,1 Donghao Wu,1 Min Dong,1 Xiangyuan Wu1

1Medical Oncology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, People’s Republic of China; 2Pathology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510630, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xiangyuan Wu; Min Dong
Medical Oncology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600, Tianhe Road, Guangzhou 510630, Guangdong, People’s Republic of China
Tel +86-20-85252272

Objective: Colorectal cancer (CRC) is a fatal disease, and tumor development is a complex cellular event involving a multistep cascade process involving proliferation, invasion, and migration. In recent years, it has been shown that microRNA-126 (miR-126) plays a key role in the tumorigenesis of CRC, but further studies are required to investigate the regulatory mechanisms through which this miRNA affects cell viability, autophagy, and apoptosis in CRC. We aimed to study the effect of miR-126 in gene regulation in CRC HCT116 cells.
Methods: CRC biopsy samples and normal colorectal tissue samples were used for miRNA profiling. Real-time quantitative PCR and WB were utilized to detect RNA and protein levels. MTT and colony formation assays were performed to examine cell viability. Furthermore, an immunofluorescence assay and Annexin V/PI flow cytometry were performed to detect autophagy and apoptosis, respectively.
Results: The expression of miR-126 was downregulated in CRC biopsies and cell lines compared with that in normal cells and tissues. The upregulation of miR-126 resulted in impaired viability and growth of CRC cells. Furthermore, with the overexpression of miR-126, cell autophagy was increased, as evidenced by LC3-I/II transformation and p62 degradation. Meanwhile, apoptosis induction was also observed because of the increased miR-126 levels. The autophagy inhibitor Bafilomycin A1 (BafA1) repressed both autophagy and apoptosis, indicating that miR-126 induced autophagy was responsible for the induction of apoptosis. A dual-luciferase reporter assay (DLRA) and bioinformatics prediction revealed that miR-126 silenced the mTOR gene by targeting the 3′-UTR. mTOR mRNA levels in CRC biopsy tissues and cell lines were upregulated to a greater extent than that in normal cells and tissues. Furthermore, HCT116 cells transfected with an miR-126 mimic showed a decreased expression of mTOR. In addition, the overexpression of mTOR counteracted miR-126 on autophagy and apoptosis.
Conclusion: Our study demonstrated that miR-126-induced can regulate the activity of CRC cells via autophagy and apoptosis and suggested a new mechanism of miR-126–mTOR interaction in CRC pathogenesis.

Keywords: CRC, miR-126, mTOR, apoptosis, autophagy

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]