Hypoxia-inducible factor-1α mediates reflux-induced epithelial-mesenchymal plasticity in Barrett's oesophagus patients

Gut. 2024 Jul 11;73(8):1269-1279. doi: 10.1136/gutjnl-2023-331467.

Abstract

Introduction: Epithelial-mesenchymal plasticity (EMP), the process through which epithelial cells acquire mesenchymal features, is needed for wound repair but also might contribute to cancer initiation. Earlier, in vitro studies showed that Barrett's cells exposed to acidic bile salt solutions (ABS) develop EMP. Now, we have (1) induced reflux oesophagitis in Barrett's oesophagus (BO) patients by stopping proton pump inhibitors (PPIs), (2) assessed their biopsies for EMP and (3) explored molecular pathways underlying reflux-induced EMP in BO cells and spheroids.

Methods: 15 BO patients had endoscopy with biopsies of Barrett's metaplasia while on PPIs, and 1 and 2 weeks after stopping PPIs; RNA-seq data were assessed for enrichments in hypoxia-inducible factors (HIFs), angiogenesis and EMP pathways. In BO biopsies, cell lines and spheroids, EMP features (motility) and markers (vascular endothelial growth factor (VEGF), ZEB1, miR-200a&b) were evaluated by morphology, migration assays, immunostaining and qPCR; HIF-1α was knocked down with siRNA or shRNA.

Results: At 1 and/or 2 weeks off PPIs, BO biopsies exhibited EMP features and markers, with significant enrichment for HIF-1α, angiogenesis and EMP pathways. In BO cells, ABS induced HIF-1α activation, which decreased miR-200a&b while increasing VEGF, ZEB1 and motility; HIF-1α knockdown blocked these effects. After ABS treatment, BO spheroids exhibited migratory protrusions showing nuclear HIF-1α, increased VEGF and decreased miR-200a&b.

Conclusions: In BO patients, reflux oesophagitis induces EMP changes associated with increased HIF-1α signalling in Barrett's metaplasia. In Barrett's cells, ABS trigger EMP via HIF-1α signalling. Thus, HIF-1α appears to play a key role in mediating reflux-induced EMP that might contribute to cancer in BO.

Trial registration number: NCT02579460.

Keywords: BARRETT'S METAPLASIA; CANCER; CELL MIGRATION; GASTROESOPHAGEAL REFLUX DISEASE.

Publication types

  • Clinical Study
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Barrett Esophagus* / genetics
  • Barrett Esophagus* / metabolism
  • Barrett Esophagus* / pathology
  • Cell Movement
  • Epithelial-Mesenchymal Transition*
  • Esophagitis, Peptic / etiology
  • Esophagitis, Peptic / metabolism
  • Esophagitis, Peptic / pathology
  • Female
  • Gastroesophageal Reflux / complications
  • Gastroesophageal Reflux / metabolism
  • Gastroesophageal Reflux / pathology
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit* / metabolism
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Middle Aged
  • Proton Pump Inhibitors* / pharmacology
  • Vascular Endothelial Growth Factor A / metabolism
  • Zinc Finger E-box-Binding Homeobox 1 / genetics
  • Zinc Finger E-box-Binding Homeobox 1 / metabolism

Substances

  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • MicroRNAs
  • MIRN200 microRNA, human
  • Proton Pump Inhibitors
  • Vascular Endothelial Growth Factor A
  • ZEB1 protein, human
  • Zinc Finger E-box-Binding Homeobox 1

Associated data

  • ClinicalTrials.gov/NCT02579460