Tumor-educated platelet SNORD55 as a potential biomarker for the early diagnosis of non-small cell lung cancer

Background: Despite the emerging insights into many snoRNAs (small nucleolar RNAs) which are detectable in body fluids and serve as noninvasive biomarkers, few studies have previously discussed the role of snoRNAs in tumor-educated platelets (TEPs). Herein, we systematically estimated dysregulation of snoRNAs in non-small cell lung cancer (NSCLC) and clarified the biomarker potential of SNORD55 in platelets. Methods: We compared expression of snoRNAs between NSCLC and normal tissues using SNORic datasets. Platelets were isolated from plasma using low-speed centrifugation and subjected to quantitative polymerase chain reaction (qPCR) for SNORD55 detection. Results: SNORD55 was significantly decreased in TEPs from NSCLC patients especially in early-stage patients compared with healthy controls. Importantly, we validated that TEP SNORD55 was capable of acting as a promising biomarker for NSCLC. It exerted diagnostic performance for NSCLC diagnosis, possessing an AUC of 0.803, as well as for early NSCLC diagnosis, possessing an AUC of 0.784. Moreover, the combination of TEP SNORD55 and carcinoembryonic antigen (CEA) improved the diagnostic efficiency of cancer progression. In addition, TEP SNORD55 also potentially acts as a noninvasive early biomarker for lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) with favorable diagnostic efficiencies. Conclusions: In summary, TEP SNORD55 could potentially serve as a noninvasive biomarker for NSCLC diagnosis and early diagnosis. Key points: SNORD55 was significantly decreased in TEPs from NSCLC patients compared to healthy controls and acted as a novel biomarker for early NSCLC.