Biased competition between Lgr5 intestinal stem cells driven by oncogenic mutation induces clonal expansion

EMBO Rep. 2014 Jan;15(1):62-9. doi: 10.1002/embr.201337799. Epub 2013 Dec 15.

Abstract

The concept of 'field cancerization' describes the clonal expansion of genetically altered, but morphologically normal cells that predisposes a tissue to cancer development. Here, we demonstrate that biased stem cell competition in the mouse small intestine can initiate the expansion of such clones. We quantitatively analyze how the activation of oncogenic K-ras in individual Lgr5(+) stem cells accelerates their cell division rate and creates a biased drift towards crypt clonality. K-ras mutant crypts then clonally expand within the epithelium through enhanced crypt fission, which distributes the existing Paneth cell niche over the two new crypts. Thus, an unequal competition between wild-type and mutant intestinal stem cells initiates a biased drift that leads to the clonal expansion of crypts carrying oncogenic mutations.

MeSH terms

  • Adult Stem Cells / physiology*
  • Animals
  • Cell Cycle
  • Cell Proliferation
  • Cell Transformation, Neoplastic
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / pathology*
  • Intestinal Mucosa / pathology
  • Intestine, Small / pathology
  • Mice
  • Mice, Transgenic
  • Mutation, Missense
  • Oncogenes
  • Proto-Oncogene Proteins p21(ras) / genetics*
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism*
  • Stem Cell Niche

Substances

  • Lgr5 protein, mouse
  • Receptors, G-Protein-Coupled
  • Hras protein, mouse
  • Proto-Oncogene Proteins p21(ras)