miRNA expression profiles associated with diagnosis and prognosis in lung cancer.

miRNAs, which are small single-stranded RNA molecules composed of 18-23 nts, act as oncogenes or tumor suppressor genes playing important roles in the processes of tumor formation, infiltration and metastasis. Lung cancer currently has the highest morbidity and mortality among all malignant tumors; yet, lack of early specific diagnostic markers and effective treatments hinders its proper management. In lung cancer, about 40-45 abnormal expression patterns of miRNAs have been discovered and are involved in lung cancer development. miRNAs have functions together with oncogenes and tumor suppressor genes of lung cancer. miRNAs-based tests can be used for early clinical diagnosis and prediction of clinical outcomes of lung cancer. Studying the role of miRNAs in lung cancer development and its relationship with diagnostic and prognostic parameters might help to improve the sensitivity of diagnosis and the efficacy of lung cancer treatment.