Abstract
Circulating microRNAs have been recognized as promising biomarkers for the detection of lung cancer. The objective of this study was to evaluate miR-10b, miR-1 and, miR-30a in the plasma samples of lung cancer patients to confirm any possible relevance in the early detection of lung cancer. Plasma samples from 47 non-small-cell lung cancer patients and 41 cancer-free subjects were evaluated for selected microRNAs using the real-time PCR method. To evaluate the tobacco smoking effects on microRNAs expression, the studied groups were categorized into two subgroups: never-smokers and smokers. MiR-1/miR-30a expression levels were significantly reduced in lung cancer, while the miR-10b level was significantly elevated. We found that smoking had significant effects on the levels of circulating microRNAs in the smokers of the cancer-free group (a significant up-regulation of miR-10b and significant down-regulation of miR-1/miR-30a), and lung cancer patients (a significant elevation of miR-10b). Receiver operating characteristic curve analysis showed that miR-10b with an area under the curve of 0.861, and miR-1/miR-30a with values of0.905 and 0.889 for the same parameter, could distinguish non-small-cell lung cancer patients from cancer-free subjects. Our findings demonstrated significant differences in the expression of microRNAs in lung cancer and the considerable effects of smoking on microRNAs levels. Area under curve analysis showed that miR-10b with 78% sensitivity/78% specificity, miR-1 with 95% sensitivity/80% specificity and miR-30a with 87% sensitivity/83% specificity,might be good (miR-10b/miR-30a) and excellent (miR-1) markers for lung cancer detection.