Fig. 1: Helicobacter pylori infection downregulates METTL14 in GC cells.

a–d METTL14 mRNA was measured by qRT‒PCR in AGS cells treated with Hp26695 and Hp11637 at different time points and different MOIs. e, f METTL14 protein in AGS cells treated with Hp26695 and Hp11637 at different time points and MOIs was detected by Western blot. g Western blotting was used to detect METTL14 expression levels in AGS cells treated with H. pylori, H. pylori broth culture supernatants and heat-killed H. pylori at MOI = 100 for 12 h. h METTL14 protein levels in AGS cells treated with Hp26695-CagA+ strain and Hp26695-CagA- strain at MOI = 100 for 12 h were detected by Western blot. i Venn diagram showing that HumanTFDB and JASPAR have five overlapping transcription factors for METTL14. j, k qRT‒PCR and Western blot analyses of ATF3 in AGS cells treated with Hp26695 and Hp11637 at MOI = 100 for 12 h. l, m METTL14 mRNA and protein levels were measured by qRT‒PCR and Western blot in ATF3-knockdown AGS cells. n, o METTL14 mRNA and protein were measured by qRT‒PCR and Western blot in ATF3-overexpression AGS cells. p ChIP assays were used to determine the binding of ATF3 to the METTL14 promoter in HGC27 cells. q, r A dual-luciferase reporter assay was used to determine the activity of the METTL14 promoter (1000 bp) in AGS and HGC27 cells with ATF3 overexpression or knockdown. *p < 0.05, **p < 0.01, ***p < 0.001.