Correspondence

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 oligonucle-otide 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 signifi-cantly 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).Cor-relation 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-2was significantly decreased in A549 cells transfected withmiR-101 (P < 0.001). The proliferation of A549 cells was markedly inhibited after trans-fection 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 pro-liferation and invasion ability of lung cancer cells