Abstract
PURPOSE: An effective biomarker for the diagnosis of breast cancer (BC) and benign breast diseases (BBD) is crucial for improving the prognosis. We investigated whether N6-methyladenosine (m6A) can be a diagnostic biomarker of BC. MATERIALS AND METHODS: We detected the contents of peripheral blood m6A in 62 patients with BC, 41 patients with BBD, and 41 normal controls (NCs) using the colorimetric method. The relative expression of the m6A regulated genes methyltransferase-like 14 (METTL14) and fat mass and obesity-associated (FTO) was analyzed using quantitative real-time polymerase chain reaction. RESULTS: m6A in peripheral blood RNA was significantly higher in patients with BC than that in patients with BBD (p < 0.001) or the NCs (p < 0.001). m6A was closely associated with the disease stage (from stage 0 to stage I-IV, p=0.003). The receiver operating characteristic curve of m6A contained an area under the curve (AUC) value of 0.887 in BC, which was greater than that of carcinoembryonic antigen (CEA) or carbohydrate antigen 153 (CA153). The combination of m6A, CEA, and CA153 improved the AUC to 0.914. The upregulated and downregulated mRNA expression of METTL14 and FTO, respectively, might contribute to the increase of m6A in patients with BC. m6A combined with METTL14 and FTO improved the AUC to 0.929 with a specificity of 97.4% in the peripheral blood of patients with BC. CONCLUSION: The peripheral blood RNA of m6A might be a valuable biomarker for the diagnosis of BC.