Exosomal miR-21/Let-7a ratio distinguishes non-small cell lung cancer from benign pulmonary diseases

To assess the exosomal miR-21/Let-7a ratio, a noninvasive method, in distinguishing non-small cell lung cancer (NSCLC) from benign pulmonary diseases.

The exosomes were extracted from the peripheral blood serum using serum exosomal extraction kit. miR-21 and Let-7a levels were evaluated by quantitative reverse transcription polymerase chain reaction.

We found that miR-21/Let-7a ratio of NSCLC patients was significantly higher than that of healthy people, patients with pulmonary inflammation diseases, and benign pulmonary nodules, respectively. Receiver-operating characteristic analysis revealed that as compared with healthy controls, miR-21/Let-7a produced the area under the curve (AUC) at 0.8029 in patients with NSCLC, which helped to distinguish NSCLC from healthy controls with 81.33% sensitivity and 69.57% specificity. In addition, the AUC of miR-21/Let-7a in NSCLC patients was 0.8196 in comparison to patients with pulmonary inflammation diseases. Meanwhile, the sensitivity and specificity were 56.00% and 100%, respectively. Furthermore, compared with patients with benign pulmonary nodules, the AUC of miR-21/Let-7a in NSCLC patients was 0.7539. The sensitivity and specificity were 56.00% and 82.61%, respectively.

In the present study, our findings revealed that exosomal miR-21/Let-7a ratio holds considerable promise as a noninvasive biomarker for the diagnosis of NSCLC from benign pulmonary diseases.