Clinical significance of circulating miRNA detection in lung cancer

Lung cancer is the most common cancer in the world and the leading cause of tumor death among males. MicroRNAs (miRNAs) are single-stranded RNAs of approximately 22 nucleotides and constituted a new class of gene regulators in humans. As a novel class of emerging biomarkers, the aberrant expression of miRNA has been detected in various tumors. miRNAs are secreted into circulation by microvesicles from the broken tumor cells and act as either oncogenes or tumor suppressors in tumor tissues. In this review, we summarized different circulating miRNAs and their expression level as well as predictable values in lung cancer patients which were investigated in recent 5 years. Circulating miRNAs are found to be dysregulated and have association with clinicopathological parameters and overall survival in lung cancer patients. In conclusion, circulating miRNAs have the potential for distinguishing lung cancer patients from healthy individuals, with the advantages of stabilities, noninvasiveness and cost-effectiveness.