Circulating long non-coding RNA GAS5 and SOX2OT as potential biomarkers for diagnosis and prognosis of non-small cell lung cancer.

Early diagnosis of non-small cell lung cancer (NSCLC) is essential for patient treatment and prognosis. Long noncoding RNA (lncRNA) have potential roles in tumor initiation and differentiation. The objective of this study was to investigate whether the circulating lncRNA, growth arrest-specific transcript 5 (GAS5) and SOX2 overlapping transcript (SOX2OT), could be used as noninvasive biomarkers for NSCLC diagnosis. Moreover, we aimed at evaluating the association between lncRNA and the clinicopathological features of NSCLC in order to predict the cancer prognosis. The results showed significant downregulation of GAS5 expression and upregulation of SOX2OT in NSCLC patients compared with controls (P < 0.001). Furthermore, the expression level of GAS5 was declined in stage IV of NSCLC, but SOX2OT expression was increased sharply in stages III and IV. The expression levels of lncRNAs were used to distinguish NSCLC patients from control with an area under curve of 0.81 (sensitivity 82.5% and specificity 80%) for GAS5 and 0.73 (sensitivity 76.3% and specificity 78.6%) for SOX2OT. The combination of GAS5 and SOX2OT showed differentiation NSCLC patients from controls with increased sensitivity (83.8) and specificity (81.4). In conclusion, the newly developed diagnostic panel involving of circulating GAS5 and SOX2OT could be perfect biomarker for diagnosis and prognosis of NSCLC.