lncRNA NORAD promotes lung cancer progression by competitively binding to miR-28-3p with E2F2.

Lung cancer (LC) is a prevailing primary tumor in the lung. lncRNA non-coding RNA activated by DNA damage (NORAD) is a popular target in human cancers. This experiment is designed to probe the mechanism of lncRNA in LC progression. NORAD expression in normal lung epithelial cells and LC cells was examined and then silenced to assess its effect on LC cell proliferation, invasion, and migration. Subcellular localization of NORAD was analyzed through online databases and then corroborated by fractionation of nuclear and cytoplasmic RNA assay. The target binding relations between NORAD and miR-28-3p and between miR-28-3p and E2F2 were verified. Eventually, LC cells with NORAD silencing were transfected with miR-28-3p inhibitor or pcDNA3.1-E2F2 to measure LC cell proliferation, invasion, and migration. NORAD was overexpressed in LC cells and NORAD knockout led to suppressed LC cell proliferation, invasion, and migration. Besides, NORAD targeted miR-28-3p and miR-28-3p targeted E2F2 transcription. Inhibiting miR-28-3p or overexpressing E2F2 could both annul the inhibitory role of si-NORAD in LC cell proliferation, invasion, and migration. Generally, our findings demonstrated that NORAD competitively bound to miR-28-3p with E2F2, to promote LC cell progression.