Constitutive STAT3 Serine Phosphorylation Promotes Helicobacter-Mediated Gastric Disease

Jesse J. Balic, Mohamed I. Saad, Ruby Dawson, Alice J. West, Louise McLeod, Alison C. West, Kimberley D'Costa, Virginie Deswaerte, Anouk Dev, William Sievert, Daniel J. Gough, Prithi S. Bhathal, Richard L. Ferrero, Brendan J. Jenkins

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15 Citations (Scopus)


Gastric cancer is associated with chronic inflammation (gastritis) triggered by persistent Helicobacter pylori (H. pylori) infection. Elevated tyrosine phosphorylation of the latent transcription factor STAT3 is a feature of gastric cancer, including H. pylori–infected tissues, and aligns with nuclear transcriptional activity. However, the transcriptional role of STAT3 serine phosphorylation, which promotes STAT3-driven mitochondrial activities, is unclear. Here, by coupling serine-phosphorylated (pS)-STAT3–deficient Stat3SA/SA mice with chronic H. felis infection, which mimics human H. pylori infection in mice, we reveal a key role for pS-STAT3 in promoting Helicobacter-induced gastric pathology. Immunohistochemical staining for infiltrating immune cells and expression analyses of inflammatory genes revealed that gastritis was markedly suppressed in infected Stat3SA/SA mice compared with wild-type mice. Stomach weight and gastric mucosal thickness were also reduced in infected Stat3SA/SA mice, which was associated with reduced proliferative potential of infected Stat3SA/SA gastric mucosa. The suppressed H. felis–induced gastric phenotype of Stat3SA/SA mice was phenocopied upon genetic ablation of signaling by the cytokine IL-11, which promotes gastric tumorigenesis via STAT3. pS-STAT3 dependency by Helicobacter coincided with transcriptional activity on STAT3-regulated genes, rather than mitochondrial and metabolic genes. In the gastric mucosa of mice and patients with gastritis, pS-STAT3 was constitutively expressed irrespective of Helicobacter infection. Collectively, these findings suggest an obligate requirement for IL-11 signaling via constitutive pS-STAT3 in Helicobacter-induced gastric carcinogenesis.

Original languageEnglish
Pages (from-to)1256-1270
Number of pages15
JournalAmerican Journal of Pathology
Issue number6
Publication statusPublished - Jun 2020

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