Effect of Diet and Exercise on Serum Insulin, IGF-I, and IGFBP-1 Levels and Growth of LNCaP Cells in Vitro (United States)

Cancer Causes Control. 2002 Dec;13(10):929-35. doi: 10.1023/a:1021911517010.

Abstract

Objective: Accumulating evidence indicates that prostate cancer is associated with high levels of serum IGF-I. This study was conducted to determine whether a low-fat diet and exercise (DE) intervention may modulate the IGF axis and reduce prostate cancer cell growth in vitro.

Methods: Fasting serum was obtained from 14 men (age 60 +/- 3 years) participating in an 11-day DE program and from eight similarly aged men who had followed the DE program for 14.2 +/- 1.7 years (long-term). Insulin, IGF-I, IGFBP-1, and IGFBP-3 were measured by ELISA, and serum was used to stimulate LNCaP cell growth in vitro.

Results: Serum IGF-I levels decreased by 20% while IGFBP-1 increased by 53% after 11-day DE. In the long-term group, IGF-I was 55% lower, while IGFBP-1 was 150% higher relative to baseline. Serum insulin decreased by 25% after 11-day DE and was 68% lower in the long-term group, relative to baseline. No changes in serum IGFBP-3 were observed. Serum-stimulated LNCaP cell growth was reduced by 30% in post-11-day serum and by 44% in long-term serum relative to baseline. LNCaP cells incubated with post-DE serum showed increased apoptosis/ necrosis, compared to baseline.

Conclusions: A low-fat diet and exercise intervention induces in-vivo changes in the circulating IGF axis and is associated with reduced growth and enhanced apoptosis/necrosis of LNCaP tumor cells in vitro.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Apoptosis
  • Diet, Fat-Restricted*
  • Enzyme-Linked Immunosorbent Assay
  • Exercise*
  • Humans
  • In Vitro Techniques
  • Insulin / blood*
  • Insulin-Like Growth Factor Binding Protein 1 / blood*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Middle Aged
  • Prostatic Neoplasms / pathology*
  • Prostatic Neoplasms / prevention & control*
  • Tumor Cells, Cultured

Substances

  • Insulin
  • Insulin-Like Growth Factor Binding Protein 1
  • Insulin-Like Growth Factor I