Fig. 1

The m⁶A-induced upregulation of RPRD1B is involved in the lymph node metastasis of GCs. A Venn diagram showing eight genes putatively related to lymph node metastasis predicted by RNA sequencing of our GC cohort and TCGA database. B RT–qPCR showing that RPRD1B was overexpressed in both primary GC tissues (n = 36) and metastatic lymph nodes (n = 12) from our cohort. C Representative images of RPRD1B IHC staining of the TMA. Scale bar, 50 μm. D RPRD1B was overexpressed in both GC primary tumors (n = 191) and metastatic lymph nodes (n = 94) in the TMA. E Plasma invasion, vascular invasion and lymph node metastasis occurred more frequently in patients with high RPRD1B expression. F The Kaplan–Meier analysis revealed that high RPRD1B expression in tumors (n = 191) and metastatic lymph nodes (n = 93) was related to the shorter overall survival of patients with GC in our cohort. G RIP-qPCR analysis showing the stronger enrichment of m⁶A-modified RPRD1B in GC cells than in GES1 cells. H Positive correlation between RPRD1B expression and Mettl3 expression in TCGA data. I, J Levels of the RPRD1B and Mettl3 proteins and mRNAs after Mettl3 knockdown or overexpression in AGS cells. K RIP-qPCR showing the enrichment of m⁶A in AGS after Mettl3 depletion. L The decay rate of the RPRD1B mRNA after treatment with 2.5 μM actinomycin D for the indicated times in AGS cells with Mettl3 knockdown or overexpression. Data are presented as the means ± SD of three independent experiments. (*, P < 0.05; ***, P < 0.001)