Targeted regulation of microRNA?708 on FOXO3 expression and its effect on proliferation, invasion and migration of non?small cell lung cancer cells

GAO Yan; XIN Wenyan; WANG Bei; LU Xianling; LIU Dong; CAO Yuwen; LI Jing

Abstract：investigate the effect of microRNA?708 ( miR?708) on the expression of Fork head transcription factor 3 (FOXO3), and proliferation, invasion and migration of non?small cell lung cancer(NSCLC) cells. Methods MiR?708 inhib?itor (inhibitor group) and negative control (NC group) were transfected into NSCLC cell A549 by liposome method, and blank control group was set. The level of miR?708 was detected by real?time quantitative PCR ( QPCR) to evaluate the transfection efficiency. The proliferation, migration and invasion of A549 cells were detected by MTT assay, scratch assay and invasion assay, respectively. The targeting regulation of miR?708 on FOXO3 was validated by double luciferase reporter gene experiment.The mRNA level of FOXO3 was detected by QPCR. Results The miR?708 level in inhibitor group was 0. 241±0. 057, lower than 1. 027±0. 121 in blank control group and 1. 186±0. 254 in NC group (P＜0. 05). Compared with blank control group and NC group, the cell proliferation activity in inhibitor group decreased at 24?48 h after transfection (P＜0. 05). The scratch healing rate and number of proliferating cells in inhibitor group were (33. 24±1. 98)% and 202. 9 ± 8. 4, lower than ( 54. 23 ± 2. 16)% and 352. 7 ± 12. 5 of blank control group, and ( 55. 63 ± 2. 78)% and 361. 2± 13. 7 of NC group ( P＜0. 05). Double luciferase reporter gene experiment showed that the mimics of miR?708 could inhibit the luciferase activity of wild?type 3’ untranslated region of FOXO3 without affecting the mutant. QPCR results showed that FOXO3 gene level in inhibitor group was higher than those in blank control group and NC group (P＜0. 05). Conclusion Down?regulation of miR?708 can inhibit the proliferation, migration and invasion of A549 cells, which may play a role in promoting cancer by targeting FOXO3 and become a potential target for NSCLC prevention and treatment.