Potential circulating miRNA signature for early detection of NSCLC.

Circulating microRNAs (c-miRNAs) are promising biomarkers for screening, early detection and prognosis of cancer. The purpose of this investigation was to identify a panel of c-miRNAs in plasma that could contribute to early detection of non-small cell lung cancer (NSCLC). We profiled the expression of 44 unique plasma miRNAs in training set of 34 NSCLC patients and 20 matched healthy individuals by miRCURY LNA™ Universal RT microRNA PCR Panel and calculated dysregulation fold changes using the 2-ΔΔCt equation. Selected plasma miRNAs were then validated by SYBR green q-RT PCR using an independent validation set of plasma samples from NSCLC patients (n: 72) and NC (n: 50). In the validation set, the receiver operating characteristic (ROC) curves were generated for four miRNAs. In the training set, 17 miRNAs were significantly up-regulated and nine were down-regulated in the plasma from NSCLC patients versus matched normal controls. Four miRNAs (miR-21, miR-328, miR-375 and miR-141) were selected for validating their diagnostic value in the testing set. ROC plot analysis showed that a high specificity (98%) and sensitivity (82.7%) in miR-141 in comparing early NSCLC patient and controls. So among these four plasma miRNAs only miR-141 could be promising biomarkers for early detection of NSCLC. In addition to, we found a significant positive correlation between stage and miR-21 expression level (95% CI: 0.687-0.863; p-value < 0.0001). Considering the accessibility and stability of circulating miRNAs, plasma miR-141 is a useful biomarker early detection of NSCLC as a supplement in future screening studies.