Helicobacter pylori CagA effector protein drives gastric cancer progression via m6A/DUSP6-mediated regulation of tumor glycolysis

Infection with Helicobacter pylori (Hp) is associated with various gastric disorders, and its virulence factor cytotoxin-associated protein A (CagA) drives cytopathological changes, cellular transformation, and tumor progression. N6-methyladenosine (m6A) mRNA modification plays a key role in carcinogenesis, including gastric cancer (GC). However, whether Hp promotes GC malignancy by regulating m6A modification remains poorly understood. The expression levels of CagA and related genes were detected by RT-qPCR and Western blotting. Functional validation of CagA-mediated malignant phenotypes in GC cells was performed using CCK-8, colony formation, wound healing, and Transwell assays. Global m6A modification levels were evaluated by RNA dot blot analysis. The expression and distribution of METTL3 and other target genes in cells and tissues were assessed by immunofluorescence and immunohistochemistry. Co-immunoprecipitation (Co-IP) and ubiquitination assays were used to examine the interaction between METTL3 and USP7, as well as the ubiquitin-dependent degradation of METTL3. CagA promoted GC cell proliferation, metastasis, and glycolysis both in vitro and in vivo. Omics data analysis, RT-qPCR, and Western blotting results demonstrated that CagA increased METTL3 expression and global m6A levels in GC cells. Mechanistically, CagA enhanced the interaction between USP7 and METTL3, thereby inhibiting METTL3 ubiquitination and proteasomal degradation. CagA upregulates m6A modification of DUSP6 to boost glycolysis and accelerate GC progression.