Methyltransferase-like 1 regulates lung adenocarcinoma A549 cell proliferation and autophagy via the AKT/mTORC1 signaling pathway.

Methyltransferase-like 1 (METTL1) is a transfer RNA and microRNA modifying enzyme. However, its role in lung adenocarcinoma (LUAD) remains unknown. The present study aimed to investigate the effect of METTL1 in LUAD and determine the association between METTL1 expression and prognosis of patients with LUAD. The expression profile of METTL1 in LUAD tissues was downloaded from public cancer databases and analyzed using the Gene Expression Profiling Interactive Analysis database and UALCAN online software. In addition, the association between METTL1 expression and prognosis of patients with LUAD was assessed using the Kaplan-Meier Plotter software. The effect of METTL1 in the A549 cell line was determined in vitro via overexpression and knockdown experiments. The results demonstrated that METTL1 was upregulated in LUAD tissues, and its increased expression was associated with unfavorable prognosis. Furthermore, METTL1 promoted proliferation and colony formation of A549 cells, and inhibited autophagy via the AKT/mechanistic target of rapamycin complex 1 signaling pathway. Taken together, the results of the present study suggest that METTL1 acts as an oncogene in LUAD, thus may be a potential prognostic predictor and therapeutic target for LUAD.