Upregulation of METTL3 Expression Predicts Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND: The N(6)-methyladenosine (m(6)A) RNA modification of mRNA mediates various cellular functions and cancer progression. However, the roles of m(6)A RNA modification in the regulation of esophageal squamous cell carcinoma (ESCC), the dominant subtype of esophageal cancer in Asia, were unclear. MATERIALS AND METHODS: Here, we analyzed the mRNA expression level of methyltransferase like 3 (METTL3) in the public available datasets of ESCC tissues and matched adjacent normal tissues. We also performed immunohistochemistry (IHC) assays to detect the protein expression of METTL3 in human ESCC tissue specimen. In our study, we also analyzed the association between METTL3 expression and prognosis using Cox proportional hazard regression in 207 ESCC patients. RESULTS: The results of public available datasets and IHC assays showed that METTL3 was upregulated in tumor compared with adjacent nonmalignant esophageal mucosal tissues. The IHC results indicated that higher expression level of METTL3 was associated with worse survival. We also found that METTL3 expression level was an independent predictor for disease-free survival and overall survival of ESCC patients. CONCLUSION: Our results revealed that the METTL3 expression level could be used as an independent prognostic biomarker for ESCC prognosis.