Abstract:

Objective  To investigate the expression of microRNA-582-5p （miR-582-5p） in non-small cell lung cancer （NSCLC） and its effect on proliferation and invasion of A549 cells， as well as the targeting regulation of Rab27a gene. Methods  The expression of miR-582-5p in 33 NSCLC tissues and adjacent tissues， A549 cell line and human normal bronchopulmonary epithelial cell line BEAS-2B was detected by real-time fluorescence quantitative polymerase chain reaction （QPCR）. MiR-582-5p inhibitor （anti-miR-582-5p） and miR-582-5p mimics （mim-miR-582-5p） transfected into A549 cells， and anti-NC and mim-NC were used as negative control. The relationship between Rab27a and miR-582-5p was validated by double luciferase reporter assay. MTT assay and Transwell chamber assay were used to detect the proliferation and invasion ability of A549 cells， QPCR and Western blotting were used to detect the expression of Rab27a gene and protein. Results  The expression of miR-582-5p in NSCLC tissues and adjacent tissues were 0.26±0.09 and 0.83±0.10， respectively. The expression of miR-582-5p in A549 cell lines and BEAS-2B cell lines were 0.63±0.08 and 1.17±0.09， respectively， with statistical significance （P＜0.05）. The proliferation rates of A549 cells in anti-miR-582-5p group after 24， 48， 72 and 96 hours were （115.68±4.34）％， （130.48±5.48）％， （138.95±5.55）％， （147.03±5.69）％， respectively， which were significantly higher than those in anti-NC group （P＜0.05）. The proliferation rates of A549 cells in mim-miR-582-5p group after 24， 48， 72 and 96 hours were （91.31±4.18）％， （86.74±3.23）％， （79.45±3.20）％， （75.22±4.09）％ respectively， which were significantly lower than those in mim-NC group （P＜0.05）. Transwell chamber results showed that the invasion number of A549 cells in anti-miR-582-5p group was 189±19， which was significantly higher than that in anti-NC group； the invasion number of A549 cells in mim-miR-582-5p group was 55±8， which was significantly lower than that in mim-NC group （P＜0.05）. MiR-582-5p inhibited the luciferase activity of wild type Rab27a 3’-UTR reporter gene vector， but had no effect on mutant Rab27a 3’-UTR luciferase activity. The expression of Rab27a mRNA and protein in anti-miR-582-5p group were （2.01±0.29） and （0.85±0.12）， which were higher than anti-NC group （P＜0.05）. The expression of Rab27a mRNA and protein in mim-miR-582-5p group were （0.35±0.08） and （0.21±0.05）， which were lower than mim-NC group （P＜0.05）. Conclusion  Up-regulation of the expression of miR-582-5p can inhibit the expression of Rab27a， thus inhibiting the proliferation and invasive activity of lung cancer A549 cells. MicroRNA-582-5p is expected to become a new therapeutic target for lung cancer.

Key words: Non-small cell lung cancer（NSCLC）, microRNAs, miR-582-5p, Rab27a, Proliferation, Invision