Abstract: Background and purpose: miRNA is supposed to be involved in the occurrence and progression of tumors. However, studies are still inadequate. This study aimed to investigate whether miR-933 can inhibit cell proliferation, migration and invasion and induce apoptosis of lung cancer cell lines A549 and H460 by regulating Kruppel-like zinc finger transcription factor 6 (KLF6). Methods: Expression of miR-933 in lung cancer cell lines (A549, H460) and bronchial epithelial cells (BEAS-2B) was detected using real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). Lung cancer cells were transfected with miR-933 mimic and mimic NC, respectively. RTFQ-PCR and Western blot were performed to detect expression of KLF6 in A549 and H460. Cell proliferation was detected by cell counting kit-8 (CCK-8) assay and EdU assay, migration and invasion were detected by transwell assay, and apoptosis was detected by Annexin Ⅴ-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. Results: Results of RTFQ-PCR showed that the expression of KLF6 in lung cancer cell lines transfected with miR-933 mimic was obviously upregulated (P<0.05). Western blot assay displayed that expression of KLF6 protein increased in A549 and H460 transfected with miR-933 mimic separately (P<0.05). Compared with negative control, the abilities of cell proliferation, migration and invasion in both A549 and H460 cells were significantly inhibited by overexpression of miR-933 (P<0.05). Annexin Ⅴ-FITC/PI staining results showed that apoptotic rates were 48.3%±1.0% and 6.1%±0.2% respectively in A549 and H460 cells after transfection of miR-933 mimic, compared with negative control (37.6%±0.9%, 2.7%±0.01% (P<0.001). Conclusion: By regulating KLF6, miR-933 induces apoptosis, inhibits cell proliferation, reduces abilities of migration and invasion of lung cancer cells and delays the occurrence and development of lung cancer.

Key words: miRNA, Non-small cell lung cancer, Cell proliferation, Cell apoptosis, Kruppel-like zinc finger transcription factor 6