Serum level of microRNA-147 as diagnostic biomarker in human non-small cell lung cancer

Objectives In this study, we intended to examine the gene expression level and the clinical significance of microRNA-147 (miR-147) in cancer tissues and sera of patients with non-small cell lung cancer (NSCLC). Methods Quantitative real-time PCR (qRT-PCR) was used to investigate the expression levels of miR-147 in 32 paired NSCLC tissues and their adjacent normal lung tissues, sera of 122 control and 87 NSCLC patients. The correlation of serum miR-147 expression level with clinicopathological characteristics, and the prognosis of NSCLC patients was statistically evaluated. Results MiR-147 was significantly down-regulated in NSCLC tissues than in paired adjacent normal tissues, and in sera of NSCLC patients than in sera of control patients. In addition, serum miR-147 was markedly down-regulated in advanced NSCLC patients and the patients with lymph node metastasis (LNM). Low serum miR-147 expression level was found to be significantly correlated with tumor, lymph node, metastasis stage, LNM, and tumor size. Statistical analysis showed that patients with low serum miR-147 had much worse overall survival, and low serum miR-147 expression level was an independent prognostic factor for poor prognosis for NSCLC. Conclusion Low serum miR-147 expression level may be a useful biomarker for patients with NSCLC.