Hydrogen Sulfide Inhibits H. pylori-Induced Gastric Fibroblast Activation: Implications for Cancer Prevention.

Early prevention of pathological changes underlying gastric cancer (GC) development is a critical strategy, offering the most effective opportunity to limit malignant progression and improve patient outcomes. We have previously demonstrated that Helicobacter pylori (Hp) (cagA+vacA+) contributes to GC development by activating gastric fibroblasts toward CAF-like phenotype, eliciting aggressive, cancer stem cells (CSCs)-related malignant transformation of LGR5+ normal epithelial cells. A key mediator of these processes appears to be the NF-κB/STAT3 axis. Therefore, our aim was to investigate the protective role of hydrogen sulfide (H2S) as a potential novel strategy for counteracting Hp-induced fibroblast reprogramming. Human fibroblasts were infected with Hp (cagA+vacA+) for 120 h. The fast-releasing H2S donor NaHS (50, 100, 200 and 400 µM) was added every 24 h. Activation markers, corresponding signaling pathways, H2S release and activities of H2S-metabolizing enzymes were determined. NaHS reduced Hp-induced fibroblast activation and their pro-inflammatory, pro-tumorigenic markers, which was associated with the inhibition of NF-κB/STAT3 axis and Twist expression. Additionally, it modulated sulfur metabolism while preserving sulfur-enzyme homeostasis. NaHS limited Hp adhesion (high doses), reduced reinfection-induced activation and increased sensitivity of Hp to metronidazole. These findings suggest that H2S signaling may represent a modulatory factor of NF-κB/STAT3-driven inflammatory responses during Hp infection and warrant further investigation.