Article Text

Download PDFPDF

Activated neutrophils induce an hMSH2-dependent G2/M checkpoint arrest and replication errors at a (CA)13-repeat in colon epithelial cells
  1. C Campregher,
  2. M G Luciani,
  3. C Gasche
  1. Medical University of Vienna, Department of Internal Medicine III, Division of Gastroenterology and Hepatology and Christian Doppler Laboratory on Molecular Cancer Chemoprevention, Vienna, Austria
  1. Professor Christoph Gasche, AKH Wien, Division of Gastroenterology and Hepatology, Währinger Gürtel 18, A-1090 Vienna, Austria; christoph.gasche{at}meduniwien.ac.at

Abstract

Objective: Chronic inflammation in ulcerative colitis is associated with increased risk for colorectal cancer. Its molecular pathway of cancer development is poorly understood. We investigated the role of neutrophil-derived cellular stress in an in vitro model of neutrophils as effectors and colon epithelial cells as targets, and tested for changes in cell cycle distribution and the appearance of replication errors.

Design: Colon epithelial cells with different mismatch repair phenotypes were co-cultured with activated neutrophils. Target cells were analysed for cell cycle distribution and replication errors by flow cytometry. Changes in nuclear and DNA-bound levels of mismatch repair- and checkpoint-related proteins were analysed by western blotting.

Results: Activated neutrophils cause an accumulation of target cells in G2/M, consistent with the installation of a DNA-damage checkpoint. Cells that do not express hMSH2, p53 or p21waf1/cip1 failed to undergo the G2/M arrest. Phosphorylation of p53 at site Ser15 and Chk1 at Ser317, as well as accumulation of p21waf1/cip1, was observed within 8–24 h. Superoxide dismutase and catalase were unable to overcome this G2/M arrest, possibly indicating that neutrophil products other than superoxide or H2O2 are involved in this cellular response. Finally, exposure to activated neutrophils increased the number of replication errors.

Conclusions: By using an in vitro co-culture model that mimics intestinal inflammation in ulcerative colitis, we provide molecular evidence for an hMSH2-dependent G2/M checkpoint arrest and for the presence of replication errors.

View Full Text

Statistics from Altmetric.com

Footnotes

  • Funding: This study was supported by the Austrian Science Fund (FWF grant P18270).

  • Competing interests: None.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.