OBJECTIVETo explore the role of fatty acid binding protein 4 (FABP4) in regulating lung cancer cell metastasis and identify miRNAs that target FABP4.

METHODSThe expression of FABP4 in lung cancer cells with different metastatic potentials was detected using enzyme-linked immunosorbent assay (ELISA) and Western blotting. The effects of FABP4 knockdown or overexpression by shRNA or a recombinant lentivirus, respectively, on lung cancer cells metastasis were assessed. The miRNAs that targeted FABP4 were screened using target prediction algorithms and the results were verified with Q-PCR.

RESULTSFABP4 expression was significantly higher in lung cancer cell lines with high metastatic potentials (NL9980, H661, and 95C) than in those with low metastatic potentials (L9981, A549, and PC13) (P<0.05). FABP4 knockdown in NL9980 cells resulted in significantly inhibited metastasis of the cells (P<0.05), while FABP4 overexpression obviously promoted the metastasis of A549 cells (P<0.05). The expressions of miR-203, miR-361 and miR-539 were significantly higher in highly metastatic lung cancer cells than in the cells with low metastatic potentials (P<0.05). In NL9980 cells, FABP4 expression was most obviously suppressed by miR-203 (P<0.05), and target site mutational FABP4 overexpression significantly attenuated the inhibitory effect of miR-203 on NL9980 metastasis (P<0.05).

CONCLUSIONFABP4 can promote lung cancer metastasis, and by targeting FABP4 to inhibit its expression, miR-203 can suppress the metastasis of lung cancer cells.