circIARS: a potential plasma biomarker for diagnosing non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is one of the most prevalent cancers in the world, and early diagnosis can effectively improve patient survival. Here, differentially expressed circIARS genes are screened from the sequencing results, and their molecular characteristics are examined by Sanger sequencing, RNase R assay, agarose gel electrophoresis (AGE), and fluorescence in situ hybridization (FISH). Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) is performed to detect the expression level of circIARS. The diagnostic value of the signature is analyzed using a subject operating characteristic (ROC) curve. Moreover, plasma is collected from postsurgical, chemotherapy, and relapse patients to investigate the prognostic value of circIARS in NSCLC. The expression of circIARS is greater in both the plasma and tissues of NSCLC patients than in those of healthy individuals, and could be used to distinguish NSCLC patients from patients with benign pulmonary disease (BPD), small cell lung cancer (SCLC) patients, and healthy individuals. The expression level of circIARS relatively decreases after antitumor therapy, such as chemotherapy, and relatively increases after recurrence. ROC analysis reveals that circIARS has better detection efficiency than traditional markers. In addition, circIARS expression level is strongly correlated with several clinicopathological parameters. Finally, we tentatively predict the downstream miRNAs or RBP that might bind to circIARS. Plasma circIARS is significantly greater in NSCLC patients and has good stability and specificity as a diagnostic marker, which could aid in the adjuvant diagnosis and dynamic monitoring of NSCLC.