Аннотация
Lung cancer is one of the leading causes of cancer deaths worldwide. Presently for lung cancer patients various treatments are available, such as surgery, chemotherapy and radiotherapy. Nevertheless the 5 year overall survival remains still low. As many modern studies show, microRNAs can be novel and reliable biomarkers to predict the prognosis of lung cancer. Therefore, the aim of this study was to investigate the expression levels of hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-155b-5p in plasma of patients with non-small cell lung cancer (NSCLC) to clarify the relationships of free-circulating microRNAs expression with clinical factors and prognosis of NSCLC patients. Total RNA was extracted from blood samples of 49 NSCLC patients before treatment, 37 NSCLC patients after platinum-based chemotherapy and 50 healthy controls. The relative expression levels of microRNAs were evaluated by real time-polymerase chain reaction (RT-PCR). Kaplan-Meier method was used to analyze the survival curve. Plasma hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-155b-5p expression levels in NSCLC patients were significantly upregulated compared with those in healthy individuals (all P <= 0.01). In plasma of NSCLC patients the expression level of hsa-miR-155b-5p significantly decreased in response to chemotherapy (P <0.01). NSCLC patients with high plasma hsa-miR-19b-3p and hsa-miR-155b-5p expression levels had a shorter overall survival than patients with low expression levels of these microRNAs (P =0.005). Thus, the freecirculating hsa-miR-19b-3p and hsa-miR-155b-5p levels may serve as promising prognostic biomarkers in patients with NSCLC and hsa-miR-155b-5p can be used as biomarker for monitoring of effectiveness of antitumor therapy.