The molecular contribution of TNF-α in the link between obesity and breast cancer

Oncol Rep. 2011 Feb;25(2):477-83. doi: 10.3892/or.2010.1099. Epub 2010 Dec 10.

Abstract

Obesity is a growing worldwide medical problem, as it pre-disposes the affected hosts to a number of severe diseases, including postmenopausal breast cancer. Obesity development is characterised, amongst others, by aberrant secretion of adipokines. White fat tissue infiltrating macrophages secrete tumour necrosis factor-α (TNF-α) so that its circulating levels correlate positively with body mass index (BMI). In the study presented here, the effect of TNF-α on cell proliferation, cell signalling pathway activation and cell cycle in two breast cancer cell lines and one breast epithelial cell lines was assessed to determine the contribution of TNF-α on breast cancer progression and aetiology, respectively. TNF-α acted differently on all three cell lines. In MDA-MB-231 breast cancer cells, cell proliferation and PI3-kinase activation were not affected, while MAP-kinase activation and cell cycle progression were decreased, with indications of increased apoptosis. This suggests a growth inhibitory function of TNF-α in these cells. In SK-BR-3 breast cancer cells, cell proliferation and cell signalling pathway activation increased, while cell cycle progression decreased, which contradictorily suggests both growth promoting and growth inhibiting properties of TNF-α on these cells. This makes TNF-α an unlikely candidate for a general contribution to the link between obesity and breast cancer progression, however, individual tumours may be responsive to a proliferative signal of TNF-α. In MCF-10A breast epithelial cells, cell proliferation and MAP-kinase activation increased, while cell cycle progression was unaffected. This suggests a strong proliferative response in these cells, suggesting the possibility that TNF-α may contribute to breast cancer aetiology as a novel link between obesity and increased risk of breast cancer development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / etiology*
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology
  • Breast Neoplasms / blood
  • Breast Neoplasms / etiology*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Cell Cycle / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Disease Progression
  • Disease Susceptibility
  • Female
  • Humans
  • Obesity / blood
  • Obesity / complications*
  • Obesity / metabolism
  • Risk Factors
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Time Factors
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / pharmacology
  • Tumor Necrosis Factor-alpha / physiology*

Substances

  • Tumor Necrosis Factor-alpha