Serum miR-210-3p as a Potential Noninvasive Biomarker of Lung Adenocarcinoma: A Preliminary Study

Background: Development of noninvasive biomarkers could potentially contribute to extending the 5-year overall survival rate of nonsmall cell lung cancer (NSCLC) patients. Circulating microRNAs (miRNAs), due to their high stability, have the potential to become valuable cancer biomarkers. Methods: Using reverse transcription-quantitative polymerase chain reaction and testing three methods for data normalization, the expression levels of six miRNAs were evaluated in serum samples obtained from 50 NSCLC patients. Subsequently, the clinical significance of tested miRNAs was determined. Results: Significant downregulation of miR-21-5p, miR-30a-5p, and miR-126-3p and upregulation of miR-210-3p and miR-486-5p in serum samples of NSCLC patients were identified in comparison to healthy controls. miR-205-5p appeared to be undetectable in all tested samples. Furthermore, miR-210-3p was differentially expressed between two subtypes of NSCLC. Receiver operating characteristic analysis for miR-210-3p revealed the area under the curve of 0.842 (95% confidence interval, 0.72-0.96; p = 0.0003) and demonstrated that miR-210-3p displayed considerable accuracy in discriminating serum of lung adenocarcinoma (AC) patients from serum of healthy controls. Conclusions: Findings from this preliminary study indicate that five of six tested miRNAs were deregulated in serum of NSCLC patients. Moreover, miR-210-3p appears to be a promising biomarker for diagnosis of lung AC.