Surgical removal of the parametrial fat pads stimulates apoptosis and inhibits UVB-induced carcinogenesis in mice fed a high-fat diet

Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):9065-70. doi: 10.1073/pnas.1205810109. Epub 2012 May 21.

Abstract

Removal of the parametrial fat pads (partial lipectomy) from female SKH-1 mice fed a high-fat diet inhibited UVB-induced carcinogenesis, but this was not observed in mice fed a low-fat chow diet. Partial lipectomy in high-fat-fed mice decreased the number of keratoacanthomas and squamous cell carcinomas per mouse by 76 and 79%, respectively, compared with sham-operated control mice irradiated with UVB for 33 wk. Immunohistochemical analysis indicated that partial lipectomy increased caspase 3 (active form) positive cells by 48% in precancerous epidermis away from tumors, by 68% in keratoacanthomas, and by 224% in squamous cell carcinomas compared with sham-operated control mice. In addition, partial lipectomy decreased cell proliferation away from tumors and in tumors. RT-PCR analysis for adipokines revealed that mRNAs for TIMP1, MCP1, and SerpinE1 (proinflammatory/antiapoptotic cytokines) in the parametrial fat pads of sham-operated control mice were 54- to 83-fold higher than levels in compensatory fat that returned after surgery in partially lipectomized mice at the end of the tumor study. Feeding mice high-fat diets for 2 wk increased levels of TIMP1 and other adipokines in serum and epidermis, and these increases were inhibited by removal of the parametrial fat pads. Our results are a unique demonstration that surgical removal of a specific tissue fat results in inhibition of carcinogenesis in obese mice. This inhibition was associated with an increase in apoptosis and a decrease in proliferation in tumors and in precancerous areas away from tumors.

Publication types

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

MeSH terms

  • Absorptiometry, Photon
  • Adipose Tissue / surgery*
  • Animals
  • Apoptosis / physiology*
  • Bromodeoxyuridine
  • Carcinoma, Squamous Cell / prevention & control*
  • Carcinoma, Squamous Cell / surgery
  • Caspase 3
  • Diet, High-Fat
  • Female
  • Immunohistochemistry
  • Keratoacanthoma / prevention & control*
  • Keratoacanthoma / surgery
  • Lipectomy / methods*
  • Mice
  • Neoplasms, Radiation-Induced / prevention & control*
  • Neoplasms, Radiation-Induced / surgery
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ultraviolet Rays*

Substances

  • Caspase 3
  • Bromodeoxyuridine