Long non-coding RNA FENDRR attenuates the stemness of non-small cell lung cancer cells via decreasing multidrug resistance gene 1 (MDR1) expression through competitively binding with RNA binding protein HuR

The roles of long non-coding RNA (lncRNA) FENDRR in non-small cell lung cancer (NSCLC) cells progression have never been revealed. As cancer stem cells (CSCs) act important roles in tumor progression, here, we focused on FENDRR roles in NSCLC cell stemness. We found that lncRNA FENDRR expression was significantly decreased in lung cancer tissues and cells, especially in NSCLC cells. Then we constructed NSCLC cells with FENDRR stable overexpression and revealed that FENDRR overexpression attenuated the stemness of NSCLC cells, evident by decreased stemness markers expression and capacity of cell spheroid formation. Mechanistically, we found that FENDRR could directly and specifically bind to the 3′ untranslated region (3′UTR) of multidrug resistance gene 1 (MDR1), hinder the binding of RNA binding protein HuR to MDR1 3′UTR and thus decrease MDR1 expression. Finally, we demonstrated that FENDRR exerted its effects on NSCLC cell stemness through the HuR/MDR1 axis. Our results suggest that FENDRR attenuates NSCLC cell stemness through inhibiting the HuR/MDR1 axis.