Circulating CD15+ LOX-1+ PMN-MDSCs are a potential biomarker for the early diagnosis of non-small-cell lung cancer.

Abstract

Non-small-cell lung cancer (NSCLC) is the most common clinical lung cancer. Polymorphonuclear-myeloid derived suppressor cells (PMN-MDSCs), which are the major population of MDSCs, are involved in NSCLC progression. Recently, it was found that lectin-type oxidized LDL receptor 1 (LOX-1) could identify human PMN-MDSCs. However, the role of CD15+ LOX-1+ PMN-MDSCs in NSCLC early diagnosis has not been revealed. Here, we tried to confirm the application of the newly identified CD15+ LOX-1+ PMN-MDSCs in the early diagnosis of NSCLC. Flow cytometry (FCM) was used to detect the proportion of CD15+ LOX-1+ PMN-MDSCs in the peripheral blood (PB) of healthy controls (HC) and NSCLC patients. The correlation of CD15+ LOX-1+ PMN-MDSC frequency with levels of cytokeratin 19-fragments (CYFRA21-1), carcinoembryonic antigen (CEA), and carbohydrate antigen 125 (CA125) was analysed. Receiver operating characteristic (ROC) curve was used to estimate the diagnostic efficacy of CD15+ LOX-1+ PMN-MDSCs for NSCLC. Additionally, the association of CD15+ LOX-1+ PMN-MDSC frequency with NSCLC prognosis/recurrence after surgery was explored. The proportion of CD15+ LOX-1+ PMN-MDSCs increased in PB of NSCLC patients. CD15+ LOX-1+ PMN-MDSC proportion was positively correlated with levels of CEA, CA125 and CYFRA21-1. Detection of PMN-MDSC percentage in PB owed high sensitivity and specificity for NSCLC diagnosis. The proportion of CD15+ LOX-1+ PMN-MDSCs decreased in patients after surgery. The frequency of CD15+ LOX-1+ PMN-MDSCs was lower in NSCLC patients without recurrence compared to those with recurrence after surgery. Circulating CD15+ LOX-1+ PMN-MDSCs are a potential diagnostic marker for NSCLC, and are associated with NSCLC prognosis and recurrence after surgery.