MicroRNAs associated with tumour migration, invasion and angiogenic properties in A549 and SK-Lu1 human lung adenocarcinoma cells

Objectives: Dysregulation in miRNA expression contributes towards the initiation and progression of metastasis by regulating multiple target genes. In this study, variations in miRNA expression profiles were investigated between high and low invasive NSCLC cell lines followed by identification of miRNAs with targets governing NSCLC's metastatic potential. Materials and methods: Two NSCLC sub-cell lines possessing opposing migration and invasion properties were established using serial transwell invasion assays. Global miRNA expression profiles were obtained using microarray followed by RT-qPCR validation. Target prediction and pathway enrichment analyses were conducted on dysregulated miRNAs using DIANA-mirPath, DIANA-microT 4.0 and TargetScan 52 softwares. Metastatic effects of dysregulated miRNAs were evaluated using wound healing assay, invasion assay and HUVEC angiogenesis assay following transfection with mimics and inhibitors. Results: A total of eleven differentially expressed miRNAs were revealed from microarray analyses, with four miRNAs validated through RT-qPCR. Three of these miRNAs were further selected for biological function validations, with only two modulating metastasis. A pathway model describing interactions between miRNAs and metastasis highlighted four major pathways: non-canonical Wnt/PCP, TGF-beta, MAPK and integrin-FAK-Src signalling cascade. Conclusion: These results provide a list of potential candidate metastatic markers during the classification of NSCLCs and a platform for the development of bio-therapeutics targeting these miRNA control elements. (C) 2013 Elsevier Ireland Ltd. All rights reserved.