Loss of adiponectin promotes intestinal carcinogenesis in Min and wild-type mice

Gastroenterology. 2011 Jun;140(7):2000-8, 2008.e1-2. doi: 10.1053/j.gastro.2011.02.019. Epub 2011 Feb 18.

Abstract

Background & aims: Metabolic syndrome- and obesity-associated cancers, including colon cancer, are common in Western countries. Visceral fat accumulation and decreased levels of plasma adiponectin (APN) have been associated with development of human colorectal adenoma. We investigated the function of APN in intestinal carcinogenesis.

Methods: APN+/+, APN+/-, or APN-/- mice (C57BL/6J) were given injections of azoxymethane (AOM), which led to development of intestinal tumors; these strains of mice were also crossed with Min mice to assess polyp formation. Adipocytokine levels and phosphorylation/activation of AMP-activated protein kinase (AMPK) were evaluated to investigate the mechanisms of APN in tumor growth.

Results: The total number of polyps in the intestines of male APN+/-Min and APN-/-Min mice increased 2.4- and 3.2-fold, respectively, by the age of 9 weeks and 3.2- and 3.4-fold, respectively, by 12 weeks, compared with those of APN+/+Min mice. Similar results were obtained from female mice. AOM induced colon tumor formation in 40% of APN+/+, 50% of APN+/-, and 71% of APN-/- (P<.05) mice, respectively; mean values for tumor multiplicity of each genotype were 0.5, 0.6, and 1.1 (P<.05), respectively. Phosphorylation of AMPK decreased in intestinal epithelial cells of APN-/- mice compared with APN+/+ mice. Among serum adipocytokines, plasminogen activator inhibitor-1 levels increased in APN-/-Min mice and APN-/- mice that received injections of AOM. Activation of AMPK suppressed expression of plasminogen activator inhibitor-1 in Min mice.

Conclusions: Mice with disruptions in APN develop more intestinal tumors and have decreased activation (phosphorylation) of AMPK and increased levels of plasminogen activator inhibitor-1, compared with wild-type mice. APN and its receptor might be developed as targets for cancer chemopreventive agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Adenomatous Polyposis Coli / chemically induced
  • Adenomatous Polyposis Coli / genetics
  • Adenomatous Polyposis Coli / metabolism*
  • Adenomatous Polyposis Coli / pathology
  • Adiponectin / deficiency
  • Adiponectin / genetics
  • Animals
  • Azoxymethane
  • Cells, Cultured
  • Chi-Square Distribution
  • Colon / metabolism*
  • Colon / pathology
  • Colonic Polyps / chemically induced
  • Colonic Polyps / genetics
  • Colonic Polyps / metabolism*
  • Colonic Polyps / pathology
  • Disease Models, Animal
  • Down-Regulation
  • Enzyme Activation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Genes, APC*
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Phosphorylation
  • Plasminogen Activator Inhibitor 1 / blood
  • Signal Transduction
  • Time Factors
  • Tumor Burden
  • Up-Regulation

Substances

  • Adiponectin
  • Adipoq protein, mouse
  • Plasminogen Activator Inhibitor 1
  • AMP-Activated Protein Kinases
  • Azoxymethane