METTL3 regulates Ambra1 expression in an m6A-YTHDF2-dependent manner to promote mantle cell lymphoma progression.

BACKGROUND: Ambra1 has recently been identified as a key regulatory factor in the progression of mantle cell lymphoma (MCL). The objective of this study was to investigate the biological role and molecular mechanism of Ambra1 in MCL. METHODS: The m6A modification level of Ambra1 was detected by MeRIP-qPCR. Wild-type and mutant Ambra1 plasmids were constructed to verify the direct regulation of Ambra1 by METTL3-mediated m6A modification. The influence of METTL3/m6A/YTHDF2/Ambra1 on the viability, proliferation, migration, apoptosis, and cell cycle of MCL cells was evaluated by standard in vitro assays. RIP and RNA pull-down assays were performed to validate Ambra1 as a downstream target of YTHDF2. Xenograft tumor models were established using BALB/c nude mice to confirm the in vivo phenotype of METTL3 and Ambra1 silencing. RESULTS: Ambra1 was downregulated in MCL cells by METTL3-mediated m6A modification. Furthermore, knocking down METTL3 in the MCL cells inhibited their proliferation, migration, and invasion through the upregulation of Ambra1, while METTL3 overexpression had the opposite effect. The m6A reader protein YTHDF2 downregulated Ambra1 expression by binding to Ambra1-m6A. YTHDF2 knockdown inhibited the growth of MCL cells through Ambra1, while YTHDF2 overexpression had the opposite effect. Mechanistically, METTL3 downregulated Ambra1 in the MCL cells in an m6A-YTHDF2-dependent manner to inhibit apoptosis. Finally, METTL3 knockdown inhibited MCL progression in vivo by inducing Ambra1 expression. CONCLUSION: METTL3 promotes MCL progression through YTHDF2-mediated degradation of Ambra1 mRNA, suggesting that the METTL3/YTHDF2/Ambra1 may serve as a potential therapeutic target for MCL.