H. pylori infection induces WEE1 to promote drug resistance in gastric adenocarcinoma

Background: Gastric cancer (GC) is the 5 th leading cause of cancer-related mortality worldwide, with a poor prognosis and frequent resistance to therapy. Identifying key molecular drivers of this resistance and novel therapeutic vulnerabilities is urgently needed. This study investigates the non-canonical role of the nuclear kinase WEE1 in GC progression and drug resistance, particularly in the context of Helicobacter pylori (H. pylori) infection. Methods: Integrative analyses of over 2,000 gastric cancer patient samples from various datasets, cell line models, and patient-derived xenografts (PDXs) were employed to elucidate WEE1-associated signaling pathways. Gene set enrichment analysis (GSEA) was conducted to identify transcriptional programs associated with high WEE1 expression. Functional validation was performed using siRNA knockdown, overexpression, Western blot, RT-qPCR, immunofluorescence, and in vivo xenograft models. A high-throughput screen of 892 FDA-approved drugs was conducted to identify effective drug combinations with the WEE1 inhibitor MK1775. Results: WEE1 was found to be aberrantly overexpressed and mis-localized to the cytoplasm in gastric cancer cells. GSEA across 14 datasets consistently showed enrichment of MYC and E2F target genes in WEE1-high tumors. Mechanistically, WEE1 activated E2F1 through the phosphorylation of RB, leading to the transcriptional upregulation of MYC. MYC, in turn, enhanced expression of WEE1 and E2F1, forming a feedforward oncogenic loop. Notably, H. pylori infection robustly induced WEE1 and MYC expression, as well as their downstream effectors, linking microbial etiology to transcriptional reprogramming and tumor progression. Targeting WEE1 with MK1775 suppressed MYC-driven transcriptional activity, reduced anti-apoptotic gene expression (BCL2, BCL2L1), and sensitized GC cells to DNA-damaging agents. A high-throughput screen identified Afatinib, an EGFR/HER2 inhibitor, as a potent synergistic partner with MK1775. Combination therapy demonstrated enhanced anti-tumor efficacy in vitro , in PDX models, and in 3D organoid systems derived from GC patients. Conclusions: This study identifies a novel H. pylori -WEE1-E2F1-MYC signaling axis that contributes to GC pathogenesis and resistance. Given the lack of clinically available MYC inhibitors, targeting WEE1 provides a promising alternative approach. The discovery of synergistic efficacy with Afatinib supports a new therapeutic strategy for overcoming resistance in MYC-driven gastric cancer.