The "Hit-and-Run" legacy: epigenetic locking and the survival switch in H. pylori-associated gastric cancer.

Abstract

The mortality associated with gastric cancer (GC) is mostly attributed to metastasis that is resistant to therapy, presenting a therapeutic challenge that frequently continues even after effective eradication of Helicobacter pylori (H. pylori). This paper addresses the "eradication paradox" by introducing a novel conceptual framework, the "Survival Switch" hypothesis: H. pylori infection not only induces a temporary epithelial-mesenchymal transition (EMT) but also stabilizes gastric epithelial cells in a persistent, drug-resistant "Hybrid Epithelial/Mesenchymal (Hybrid E/M) state." We systematically outline this evolutionary trajectory through three distinct phases: (1) The Igniter: The virulence factor Cytotoxin-associated gene A (CagA) compromises junctional integrity and commandeers YAP/ZEB1 signaling to initiate plasticity; (2) The Lock: A "Hit-and-Run" mechanism establishes "epigenetic scarring," specifically methyltransferase-like 3 (METTL3)-mediated N⁶-methyladenosine (m⁶A) modifications, that perpetuates the mesenchymal phenotype independently of the bacterial stimulus; and (3) The Niche: An inflammatory ecosystem comprising CAFs and TAMs functions as an extrinsic amplifier, creating a "fail-safe" network that reinforces the hybrid state through paracrine feedback loops. We propose a theoretical paradigm shift in clinical practice from broad-spectrum cytotoxicity to a "Wake-up and Kill" sequential strategy, employing EMT-reversing drugs to activate the survival switch and re-sensitize tumors before chemotherapy. This review presents a precise strategy for overcoming the epigenetic and stromal barriers of refractory GC by incorporating upcoming technologies like liquid biopsy for dynamic stratification and nanocarrier-based RNA delivery.