Increased expression of microRNA-301a in nonsmall-cell lung cancer and its clinical significance.

Aims: Recently, accumulating evidence indicates that dysregulation of microRNAs is associated with the initiation and progression of cancer. Oncogenic miR-301a has been reported upregulation and associated with tumorigenesis and progression in various types of cancer. The aim of this study was to investigate the expression of miR-301a in nonsmall-cell lung cancer. (NSCLC), and to assess its association with malignancy, metastasis and prognosis. Subjects and Methods: total of 88 NSCLC patients (females = 21 and males = 67), aged 15-81 years were included in the study. miR-301a expression in tumor tissue was estimated by real-time quantitative reverse transcription polymerase chain reaction. Results: miR-301a was significantly upregulated in NSCLC tissues compared with their paired adjacent nontumor tissues. (P 0.001). Increased expression of miR-301a was detected in tumors with lymph node metastases. (P =0.003). In addition, high miR-301a expression was significantly associated with poorly differentiation. (P =0.015), lymph node metastasis. (P =0.013) and advanced tumor-node-metastasis. (TNM) stage. (P =0.018). A. comparison of survival curves of low versus high expressers of miR-301a revealed a highly significant difference in NSCLC, which suggests that overexpression of miR-301a is associated with a poorer disease-free survival (DFS) (P =0.002). Moreover, multivariate Cox proportional hazard regression analyses revealed that the miR-301a overexpression was an unfavorable prognostic factor for disease-free survival in addition to TNM stage. Conclusions: miR-301a may represent a novel prognostic indicator, a biomarker for the early detection of lymph node metastasis and a therapeutic target in NSCLC.