Micro ribonucleic acid (RNA)-101 inhibits cell proliferation and invasion of lung cancer by regulating cyclooxygenase-2

BACKGROUND Micro ribonucleic acid (miR-101) can regulate the expression of cyclooxygenase-2 (COX-2) and participate in the pathogenesis of malignant tumors. This study investigates the effects of miRNA-101 and COX-2 in lung cancer and the impact of miR-101 on the proliferation and invasion of human lung cancer A549 cell line. METHODS The expression of miR-101 in 20 separate lung cancer tissues was detected by real time polymerase chain reaction; COX-2 expression was also detected. A549 cells were transfected with miR-101 or negative control oligonucleotide duplex mimic (miR-NC). In vivo tumorigenesis abilities were detected in localized human lung cancer xeno-transplant models in BALB/c nude mice. RESULTS MiR-101 expression was significantly lower and the level of COX-2 significantly higher in lung cancer tissues than in adjacent parenchyma (2.918 ± 1.006 vs. 5.953 ± 1.976, P = 0.001; 0.887 ± 0.260 vs. 0.355 ± 0.156, P = 0.001, respectively). Correlation analysis revealed that miR-101 negatively correlated with COX-2 in lung cancer tissues (R = -0.596, P = 0.002). Compared with A549-miR-NC cells, the expression of COX-2 was significantly decreased in A549 cells transfected with miR-101 (P < 0.001). The proliferation of A549 cells was markedly inhibited after transfection of miR-101. The in vivo tumor growth of A549 cells transfected with miR-101 was significantly slower than wide type A549 cells. CONCLUSION MiR-101 expression is decreased in lung cancer, inducing an increase in COX-2 level. Enforced expression of miR-101 can remarkably reduce the cell proliferation and invasion ability of lung cancer cells.