Fig. 1

METTL3 high expression is associated with poor prognosis of HNSCC patients. A Dot blot assay was conducted with mRNA extracted from HNSCC tissues and paired paracancerous normal tissues using an anti-m6A antibody, and MB (methylene blue) staining served as the loading control (representative images in left panel). The relative m6A contents on mRNA in HNSCC tissues and paired normal normal tissues were calculated (right panel, n = 7). B TCGA data showed that METTL3 expression was significantly upregulated in HNSCC (n = 520) than normal tissue (n = 44). C Disease-free survival (RFS) of HNSCC patients based on METTL3 expression obtained from GEPIA website (http://gepia.cancer-pku.cn/). D The levels of METTL3 expression in HNSCC and paired normal tissues were measured by qRT-PCR (n = 10). E METTL3 protein levels were measured in HNSCC tissues and paired normal tissues by western blotting (n = 7). F METTL3 expression was significantly upregulated in HNSCC compared with the paired paracancerous normal tissue by IHC staining (n = 5, scale bars = 100 μm). G Kaplan–Meier OS analysis of HNSCC patients based on METTL3 expression measured by IHC of tissue microarray (n = 100). H Univariate Cox regression analysis was conducted in HNSCC patients (n = 100). All bars correspond to 95% confidence intervals. I Multivariate Cox regression analysis was conducted in HNSCC patients (n = 100). J The time-dependent receiver operating characteristic (ROC) analysis for the clinical risk score (TNM stage), the METTL3 risk score, and the combined METTL3 and clinical risk scores in HNSCC cohort