Journal of Gastroenterology

, Volume 49, Issue 7, pp 1121–1134

Toll-like receptor 4 activation in Barrett’s esophagus results in a strong increase in COX-2 expression

  • Romy E. Verbeek
  • Peter D. Siersema
  • Fiebo J. Ten Kate
  • Kees Fluiter
  • Rhonda F. Souza
  • Frank P. Vleggaar
  • Pauline Bus
  • Jantine W. P. M. van Baal
Original Article—Alimentary Tract

DOI: 10.1007/s00535-013-0862-6

Cite this article as:
Verbeek, R.E., Siersema, P.D., Ten Kate, F.J. et al. J Gastroenterol (2014) 49: 1121. doi:10.1007/s00535-013-0862-6

Abstract

Background

Barrett’s esophagus (BE) is known to progress to esophageal adenocarcinoma in a setting of chronic inflammation. Toll-like receptor (TLR) 4 has been linked to inflammation-associated carcinogenesis. We aimed to determine the expression and functional activity of TLR4 in the esophagus and whether TLR4 activation in BE could promote carcinogenesis by inducing COX-2 expression.

Methods

TLR4 expression in esophageal adenocarcinoma, BE, duodenum, reflux esophagitis and normal squamous esophagus biopsies was assessed using real-time PCR and validated by in situ hybridization and immunohistochemistry. Ex vivo cultures of BE, duodenum and normal squamous esophagus biopsies and a BE cell line (BAR-T) were stimulated with the TLR4 agonist lipopolysaccharide (LPS). To evaluate the effect of TLR4 activation, NF-κB activation, IL8 secretion and expression and COX-2 expression were determined.

Results

TLR4 expression was significantly increased in esophageal adenocarcinoma, BE, duodenum and reflux esophagitis compared to normal squamous esophagus. LPS stimulation resulted in NF-κB activation and a dose-dependent increase of IL8 secretion and mRNA expression. The induction of IL8 was more evident in BE compared to normal squamous esophagus. Upon LPS stimulation, COX-2 expression increased significantly in ex vivo cultured BE biopsies, which was observed in both epithelium and lamina propria cells. However, no effect was found in duodenum and normal squamous esophagus biopsies.

Conclusion

TLR4 activation in BE results in a strong increase in COX-2 and may contribute to malignant transformation.

Keywords

Barrett’s esophagus Toll-like receptor 4 Cyclooxygenase-2 Esophageal adenocarcinoma 

Abbreviations

BE

Barrett’s esophagus

COX-2

Cyclooxygenase-2

EAC

Esophageal adenocarcinoma

ELISA

Enzyme-linked immunosorbent assay

HGD

High-grade dysplasia

IL8

Interleukin 8

IHC

Immunohistochemistry

ISH

In situ hybridization

FBS

Fetal bovin serum

IBD

Inflammatory bowel diseases

MAPK

Mitogen-activated protein kinases

MSK

Mitogen- and stress-activated protein kinase

LGD

Low-grade dysplasia

LPS

Lipopolysaccharide

NF-κB

Nuclear factor–κB

PBS

Phosphate buffered saline

PGE2

Prostaglandin E2

PPIs

Proton pump inhibitors

Q-RT-PCR

Quantitative reverse transcriptase polymerase chain reaction

RE

Reflux esophagitis

SQ

Normal squamous esophagus

TLR

Toll-like receptor

TNFα

Tumor necrosis factor alpha

Tollip

Toll interacting protein

Copyright information

© Springer Japan 2013

Authors and Affiliations

  • Romy E. Verbeek
    • 1
  • Peter D. Siersema
    • 1
  • Fiebo J. Ten Kate
    • 2
  • Kees Fluiter
    • 3
  • Rhonda F. Souza
    • 4
  • Frank P. Vleggaar
    • 1
  • Pauline Bus
    • 1
  • Jantine W. P. M. van Baal
    • 1
  1. 1.Department of Gastroenterology and Hepatology (F02.618)University Medical Center UtrechtUtrechtThe Netherlands
  2. 2.Department of PathologyUniversity Medical Center UtrechtUtrechtThe Netherlands
  3. 3.Department of Neurogenetics, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
  4. 4.Department of MedicineUniversity of Texas Southwestern Medical Center, VA North Texas Health Care SystemDallasUSA

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