Diagnostic value of plasma expression of microRNAs complementary to Drosha and Dicer in lung cancer patients

Lung cancer (LC) is diagnosed mostly in advanced, non-operable stage, with poor prognosis. The analysis of microRNAs may be a useful tool for early and non-invasive detection of cancer. Dicer and Drosha are enzymes with an essential role for microRNA biogenesis. The aim of our study was to analyze the expression of miRNA-27a-3p, miRNA-31, miRNA-182, miRNA-195 with the ability to reciprocal regulation of Dicer and Drosha expression in lung cancer patients.

The relative expression of microRNAs was detected by qPCR in plasma of 160 LC patients. The U-Mann Whitney test was used to compare the relative expression between particular groups of lung cancer patients and healthy individuals. The diagnostic value of microRNAs examination was analyzed using a receiver operating curve.

We demonstrated that the plasma levels of miRNA-27, miRNA-31 and miRNA-182 were significantly higher and miRNA-195 significantly lower in the whole group of LC patients and in patients with early stages of NSCLC, in comparison with healthy donors. ROC analysis showed that four studied microRNAs have a potential diagnostic value for early stages of NSCLC with AUC=0.95 for miRNA-27a (94% sensitivity and 81% specificity, p=0.0001), 0.71 for miRNA-31 (73% sensitivity and 61% specificity, p=0.001) 0.77 for miRNA-182 (70% sensitivity and 79% specificity, p=0.0001) and 0.82 for miRNA-195 (74% sensitivity and 80% specificity, p=0.0001).

We have proved that the expression of miRNA-27a-3p, miRNA-31, miRNA-182, and miRNA-195 in patients with LC is different from the expression of these molecules in healthy people. The examination of these microRNAs in plasma could be used in non-invasive lung cancer diagnosis.