m6A hypermethylation of TCF-1 regulated by METTL16 promotes acute myeloid leukemia

Methyltransferase 16 (METTL16) functions as an oncogene in various cancer, including leukemia. However, the role of METTL16 in acute myeloid leukemia (AML) is scarcely reported. The present study aimed to investigate the potential of METTL16 in AML.

RT-qPCR was used to METTL16 expression in AML patients and healthy control. m6A levels was determined using m6A assay. Methylated RNA immunoprecipitation (MeRIP) assay applied for determining m6A hypermethylation of T cell factor 1 (TCF-1) transcripts in AML cells. Chimeric antigen receptor (CAR)-T-cell functions were analyzed using flow cytometry.

METTL16 is upregulated in AML patients. High levels of METTL16 were associated with poor prognosis of AML patients. Functionally, METTL16 deficiency promoted the persistence and tumor-killing ability of CAR-T cells. Moreover, METTL16 deficiency promoted the differentiation of CAR-T cells into TCF-1 precursor exhausted T cells (T_PEX). METTL16 mediated the m6A modification of TCF-1 and inhibited its mRNA expression and stability. TCF-1 deficiency promoted the exhaustion and inhibited the self-renewal ability of T cells.

Collectively, METTL16 deficiency promoted the persistence of CAR-T cells and memory formation in AML. Therefore, targeting METTL16 may stimulate the anti-tumor immunity in AML.