Microarray analysis reveals that leptin induces autocrine/paracrine cascades to promote survival and proliferation of colon epithelial cells in an Apc genotype-dependent fashion

Mol Carcinog. 2008 Jan;47(1):9-21. doi: 10.1002/mc.20357.

Abstract

The imbalance in systemic mediators of inflammation, such as leptin, is thought to be involved in obesity-associated cancers. In addition, systemic endocrine signals can influence the local autocrine/paracrine factors produced within this microenvironment to influence epithelial cell fate. We previously demonstrated that leptin preferentially promotes the survival and proliferation of colon epithelial cells possessing an Apc mutation (IMCE) but not model normal cells (YAMC). Therefore, the purpose of this study was to identify leptin-induced functional gene family changes which characterize the response of colon epithelial cells possessing an Apc mutation but not normal cells. Consistent with our knowledge of colon carcinogenesis, genes regulating the Wnt/beta-catenin-mediated pathway including Mdm2, Pik3r1, and Rb1 were upregulated by leptin. Importantly, leptin induced IGF-mediated pathway gene expression changes and their protein products in IMCE cells. In the IMCE cells IGFBP-6, IGF-1, and Crim1 expression was upregulated, while IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-5, and Nov expression was downregulated by leptin treatment. These data establish a biologically plausible mechanistic link between the elevated levels of growth factors and the increased risk of colon cancer associated with obesity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Division / drug effects
  • Cell Division / genetics*
  • Cell Survival / drug effects
  • Cell Survival / physiology*
  • Colon / cytology
  • Colon / physiology*
  • Gene Expression Regulation
  • Genes, APC*
  • Genotype
  • Humans
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / physiology*
  • Leptin / pharmacology*
  • Mice
  • Mice, Transgenic
  • Oligonucleotide Array Sequence Analysis*
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics

Substances

  • Leptin
  • RNA, Messenger