Fig. 4. METTL3-dependent m⁶A upregulation on APC mRNA suppresses APC expression.

a Luciferase vectors with the WT or mutated m⁶A nucleotides in the APC gene were transfected into KYSE180 cells with or without METTL3 depletion or METTL3 overexpression. Relative luciferase activity was measured. Data represent means ± SD of triplicate samples. ***p = 2.93E − 06 (left), 5.88E − 06 (right). Two-tailed t-test; ns, not significant. b, c The relative mRNA and protein expression levels of APC in KYSE450 cells with or without METTL3 depletion (b), or with reconstituted expression of Flag-rMETTL3 (c) were determined by qPCR and immunoblotting analyses with the indicated antibodies, respectively. Data represent means ± SD of triplicate samples. b **p = 0.0088 (left), 0.0074 (right). c ***p = 0.0004. Two-tailed t-test; ns, not significant. d–g KYSE450 cells were transfected with or without a plasmid expressing METTL3 (d). KYSE450 cells expressing the METTL3 expression-inducible Tet-on lentiviral vector were treated with or without the indicated dosages of tetracycline e. KYSE450 cells were transfected with or without plasmids expressing WT METTL3, an inactive METTL3 mutant (f), WT METTL3 or METTL3 and METTL14 shRNA (g). Immunoblotting analyses were performed for three times with similar results. Source data are provided as a Source Data file.