MicroRNA-130b promotes lung cancer progression via PPARγ/VEGF-A/BCL-2-mediated suppression of apoptosis

BACKGROUND The prognosis of non-small-cell lung cancer (NSCLC) is poor yet mechanistic understanding and therapeutic options remain limited. We investigated the biological and clinical significance of microRNA-130b and its relationship with apoptosis in NSCLC. METHODS The level of microRNA-130b in relationship with the expression of PPARγ, VEGF-A, BCL-2 and apoptosis were analyzed in 91 lung cancer patient samples using immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay on tissue microarrays. Gain and loss-of-function studies were performed to investigate the effects of microRNA-130b, peroxisome proliferator-activated receptor γ (PPARγ) or vascular endothelial growth factor-A (VEGF-A) on biological functions of lung cancer cells using in vitro and in vivo approaches. RESULTS MicroRNA-130b up-regulation conferred unfavorable prognosis of lung cancer patients. Notably, microRNA-130b targeted PPARγ and inhibiting microRNA-130b markedly repressed proliferation, invasion and metastasis of lung cancer cells, leading to increased apoptosis. MicroRNA-130b-dependent biologic effects were due to suppression of PPARγ that in turn activated BCL-2, the key mediator of anti-apoptosis. Administration of microRNA-130b mimic to mouse xenografts promoted tumor growth. In vitro and in vivo, miR-130b enrichment associated with down-regulation of PPARγ, up-regulation of VEGF-A and BCL-2, and decreased apoptosis. CONCLUSIONS The present study demonstrates that microRNA-130b promotes lung cancer progression via PPARγ/VEGF-A/BCL-2-mediated suppression of apoptosis. Targeting microRNA-130b might have remarkable therapeutic potential for lung cancer therapy.