lncRNA NORAD Contributes to Colorectal Cancer Progression by Inhibition of miR-202-5p

Oncol Res. 2018 Oct 17;26(9):1411-1418. doi: 10.3727/096504018X15190844870055. Epub 2018 Feb 22.

Abstract

Previous study indicates that long noncoding RNA NORAD could serve as a competing endogenous RNA to pancreatic cancer metastasis. However, its role in colorectal cancer (CRC) needs to be investigated. In the present study, we found that the expression of NORAD was significantly upregulated in CRC tissues. Furthermore, the expression of NORAD was positively related with CRC metastasis and patients' poor prognosis. Knockdown of NORAD markedly inhibited CRC cell proliferation, migration, and invasion but induced cell apoptosis in vitro. In vivo experiments also indicated an inhibitory effect of NORAD on tumor growth. Mechanistically, we found that NORAD served as a competing endogenous RNA for miR-202-5p. We found that there was an inverse relationship between the expression of NORAD and miR-202-5p in CRC tissues. Moreover, overexpression of miR-202-5p in SW480 and HCT116 cells significantly inhibited cellular proliferation, migration, and invasion. Taken together, our study demonstrated that the NORAD/miR-202-5p axis plays a pivotal function on CRC progression.