Long noncoding RNA NORAD promotes epithelial mesenchymal transition progression in lung adenocarcinoma

Non-Coding RNA Activated By DNA Damage (NORAD, also known as LINC00657) is a newly discovered long noncoding RNA and emerging evidences have reported that NORAD had an essential role in various cancers. However, it is not clear about its role in lung adenocarcinoma (LUAD). This study mainly aims to explore the role of NORAD in the occurrence and development of LUAD. In our study, an obvious high expression of NORAD in LUAD was exhibited and we found a strongly positive association between NORAD and epithelial mesenchymal transition (EMT) progression. Moreover, we further predicted that NORAD might upregulate GEMIN2 expression to induce EMT progression in LUAD by acting as a ceRNA to sponge four microRNAs including miR-7-1, miR-33a, miR-590 and miR-4668. In sum, our study demonstrated that NORAD was overexpressed in LUAD and could promote the progression of EMT. To reveal the mechanism of NORAD promoting EMT in lung adenocarcinoma, we performed genetic silence of NORAD in A549 cell line using si-NORAD and examined the effects of NORAD silence on invasion and migration of A549 cells. mRNA profiles of control and si-NORAD cells were generated by deep sequencing, using Illumina HiSeq 4000. In total, six samples were sequenced.