Fig. 4

miR-30a-5p expression is decreased in NSCLC, and miR-30a-5p directly targets the 3′-UTR of CD73 to decrease CD73 expression. a Relative miR-30a-5p levels in 59 NSCLC tissues (T) and paired noncancerous lung tissues (N). b Scatter diagram showing relative CD73 mRNA expression in NSCLC tumors and adjacent normal lung tissues from a public data set (GSE36681). c qRT-PCR analysis of relative miR-30a-5p expression in human NSCLC cell lines. d Schematic diagram showing the subcloning of the predicted miR-30a-5p binding site at two positions (328–355 and 1442–1449) of the CD73 3′-UTR into a psiCHECK-2 luciferase construct. Predicted duplex formation between miR-30a-5p and the wild-type or mutant miR-30a-5p binding site is indicated. e–g Luciferase activity of the construct containing the wild-type or mutant CD73 3′-UTR reporter gene in A549 and H226 cells co-transfected with the negative control (NC) or miR-30a-5p. Scrambled sequences were used as the NC. Relative Renilla luciferase activity was determined and normalized against firefly luciferase activity. h–j and k–m Expression of miR-30a-5p and CD73 in NSCLC cells transfected with miR-30a-5p mimics or inhibitor was detected by qRT-PCR and western blot analysis respectively. ^* P < 0.05; ^** P < 0.01; ^*** P < 0.001