Increased levels of N6-methyladenosine in peripheral blood RNA: a perspective diagnostic biomarker and therapeutic target for non-small cell lung cancer

Abstract Objectives Due to lack of effective biomarkers for non-small cell lung cancer (NSCLC), many patients are diagnosed at an advanced stage, which leads to poor prognosis. Dysregulation of N6-methyladenosine (m 6 A) RNA contributes significantly to tumorigenesis and tumor progression. However, the diagnostic value of m 6 A RNA status in peripheral blood to screen NSCLC remains unclear. Methods Peripheral blood samples from 152 NSCLC patients and 64 normal controls (NCs) were applied to assess the m 6 A RNA levels. Bioinformatics and qRT-PCR analysis were performed to identify the specific immune cells in peripheral blood cells and investigate the mechanism of the alteration of m 6 A RNA levels. Results Robust elevation of m 6 A RNA levels of peripheral blood cells was exhibited in the NSCLC group. Moreover, the m 6 A levels increased as NSCLC progressed, and reduced after treatment. The m 6 A levels contained area under the curve (AUC) was 0.912, which was remarkably greater than the AUCs for CEA (0.740), CA125 (0.743), SCC (0.654), and Cyfra21-1 (0.730). Furthermore, the combination of these traditional biomarkers with m 6 A levels elevated the AUC to 0.970. Further analysis established that the expression of m 6 A erasers FTO and ALKBH5 were both markedly reduced and negatively correlated with m 6 A levels in peripheral blood of NSCLC. Additionally, GEO database and flow cytometry analysis implied that FTO and ALKBH5 attributes to peripheral CD4 + T cells proportion and activated the immune functions of T cells. Conclusions These findings unraveled that m 6 A RNA of peripheral blood immune cells was a prospective biomarker for the diagnosis of NSCLC.