OBJECTIVETo investigate the function and mechanism of miR-610 in lung cancer cell proliferation and invasion.

METHODSThe expression of miR-610 was detected by real-time PCR in lung cancer cell lines 95D and 95C with different metastatic ability. miR-610 mimics and inhibitor were transfected into 95D and 95C cells, respectively, and CCK-8 kit and BrdU incorporation assay were used to detect the effect of miR-610 on lung cancer cell proliferation. Cell scratch test and Transwell test were used to detect the effect of miR-610 on lung cancer cell invasion. Bioinformatics software was used to predict the potential target genes of miR-610. Dual-luciferase reporter gene system and Western blot were applied to test whether miR-610 regulates GJA3 expression directly.

RESULTSThe expression of miR-610 in the weakly metastatic lung cancer 95C cells was (8.75 ± 0.21) times higher than that in the highly metastatic lung cancer 95D cells (P < 0.01). BrdU incorporation assay showed that the number of proliferating 95C cells was (37.41 ± 2.39)% in the control group and (59.63 ± 4.57)% in the miR-610 mimics transfection group (P < 0.01). The number of proliferating 95D cells was (68.75 ± 4.28)% in the control group and (46.13 ± 3.27)% in the miR-610 mimics transfection group (P < 0.01). Cell scratch test showed that at 24 and 48 hours after scratching, the scratch width of 95C cells in the miR-610 inhibitor group was reduced to (58.74 ± 4.62)% and (34.63 ± 2.73)%, respectively, of the initial scratch width, both were significantly lower than that of blank control group and miR-610 inhibitor control group (P < 0.01 for both). The scratch width of 95D cells in the miR-610 inhibitor group was (88.59 ± 6.92)% and (72.24 ± 5.46)%, respectively, of the initial scratch width, and both were significantly higher than that of the blank control group and miR-610 inhibitor control group (P < 0.01 for both). Transwell assay showed that the numbers of invading 95C cells after transfection with miR-610 inhibitor was (112.4 ± 10.6) cells/square in the miR-610 inhibitor control group and (161.8 ± 12.5) cells/square in the miR-610 inhibitor group, indicating a significantly increased invasion ability of 95C cells in the miR-610 inhibitor transfection group (P < 0.01). The numbers of invading 95D cells after transfection with miR-610 mimics was (178.4 ± 12.3) cells/square in the miR-610 mimics control group and (76.7 ± 5.8) cells/square in the miR-610 mimics group, indicating a significantly decreased invasion ability of 95D cells in the miR-610 mimics transfection group (P < 0.01). These data indicated that miR-610 can suppress the invasion of lung cancer cells.

CONCLUSIONmiR-610 suppresses lung cancer cell proliferation and invasion by targeting GJA3 expression.