circ-PVT1 negatively regulates the expression of miR-429. (A) It was predicted that miR-429 may target the 3′UTR of circ-PVT1. (B) The relationship between circ-PVT1 and miR-429 was measured via a dual-luciferase reporter assay. ***P<0.001 vs. miR-429 mimic + circ-PVT1 MUT group. (C) The mRNA levels of miR-429 in human normal lung epithelial cells (BEAS-2B) and human lung adenocarcinoma cells (HCC827, H1299, PC-9, A549) were measured via reverse transcription-quantitative PCR. ***P<0.001 vs. BEAS-2B group. (D) The correlation between circ-PVT1 and miR-429 was determined using Pearson's correlation coefficient in human normal lung epithelial cells and human lung ADC cells. (E) The mRNA expression of miR-429 after knockdown of circ-PVT1 was determined. ***P<0.001 vs. Control group; ###P<0.001 vs. shRNA-NC group. (F) Proof of transfection for miR-429 mimic and inhibitor transfections. ***P<0.001 vs. Control group; ###P<0.001 vs. mimic-NC group; $P<0.05 vs. NC inhibitor group. circ-PVT1, circular RNA plasmacytoma variant translocation 1; miR, microRNA; shRNA, short hairpin RNA; NC, negative control; Oe, overexpression; WT, wild-type; MUT, mutant.