Identification of an Exosomal Long Noncoding RNA SOX2-OT in Plasma as a Promising Biomarker for Lung Squamous Cell Carcinoma

Aims: Evaluation of nucleic acids in plasma exosomes is a noninvasive method that can be used to detect different types of cancer. The aim of this study was to determine the value of exosomal long noncoding RNAs (lncRNAs) in detecting lung squamous cell carcinoma (LSCC). Materials and Methods: A total of 75 LSCC patients and 79 negative control subjects were enrolled in the study. Twenty differentially expressed lncRNAs were evaluated as potential candidates. Exosomes were isolated by ultracentrifugation, and lncRNA levels in exosomes were determined using real-time polymerase chain reaction. Receiver Operating Characteristic (ROC) curves were used to determine specificity and sensitivity. Results: Exosomal SOX2-OT was significantly upregulated in LSCC patients and showed the strongest power in detecting LSCC. The area under the ROC curve was 0.815, and the sensitivity and specificity were 76% and 73.17%, respectively. Moreover, exosomal SOX2-OT levels were significantly correlated with tumor size, TNM stage, and lymph node metastasis. Exosomal SOX2-OT levels were significantly decreased in the postoperative plasma of LSCC patients. Conclusion: SOX2-OT may serve as a promising noninvasive plasma-based tumor biomarker for LSCC.