Expression of CD91 in extracellular vesicles: A potential biomarker for the diagnosis of non-small cell lung cancer

Abstract

Lung cancer is the leading cause of death; by the time it is diagnosed, the patient is usually in late-stage grade IV. Late-stage lung cancer is mainly associated with metastasis in the liver, brain, and lymphoid tissues; as a result, a localized lung cancer treatment remains meaningless. Early diagnosis of non-small cell lung cancer (NSCLC) may be curable or will improve the survival rate. Although with advanced developments to screen high-risk patients by LDCT scan, false-positive rates and limited resolution necessitated the development of advanced diagnostic techniques for NSCLC. Extracellular vesicles (EVs) released from cells freely circulate in the blood and contain various transmembrane proteins, and they may be a non-invasive biomarker for cancer diagnosis and prognosis. Current studies predict that the CD91 marker in EVs may be a potential biomarker of NSCLC; however, the expression of CD91 in lung cancer tissues is not fully known. Here, this study determines the differential expression of CD91 in lung cancer cells and in circulating EVs in blood as a potential biomarker of NSCLC patients. Our results confirmed the expression of CD91 in NCI–H1975 cultured cells and NSCLC lung biopsy tissues. Furthermore, biophysical characterization of EVs from lung cancer cells determines the substantial expression of CD91, which the Transmission Electron Microscope confirms. Thus, this study suggests EVs containing CD91 could be an asset to studying the development of diagnostic and prognostic biomarkers in NSCLC disease.