title: Exercise does not counteract the effects of a "westernized" diet on prostate cancer xenografts.
abstract: BACKGROUND
  The relationships between diet, exercise, and prostate cancer (PCa) remain unclear. We have previously reported that a "Western" diet promotes PCa tumor growth in vivo. Presently, we report the effects of sustained aerobic exercise on PCa progression in animals fed a high-fat diet versus a standard diet.
  
  
  METHODS
  Athymic mice (n = 43) were inoculated subcutaneously with human PCa (LNCaP) cells, fed ad libitum with either a high-fat or a standard diet, and randomized into forced exercising and non-exercising groups. Body weight, tumor volume, and food consumption were recorded tri-weekly. Terminal serum samples and tumor biopsies were obtained for analysis.
  
  
  RESULTS
  Body weight differences were not observed between the groups over time. The high-fat diet with exercise (HF-Ex) group showed significantly increased tumor growth rate compared to all other groups (P < 0.0007). Tumor growth rate of the standard diet with exercise (Std-Ex) group was reduced significantly compared to the high-fat diet without exercise (HF-No Ex) group (P = 0.0008). Significant differences (P ≤ 0.012) were observed in energy consumption (kcal) between the groups over time. Exercising mice consumed significantly more kcal than non-exercising mice, and the HF-Ex group consumed significantly more than each of the other three groups (P < 0.0007). The expression levels of p27 and p21 were increased in exercising animals, while AR expression was elevated in the HF-Ex group versus the Std-Ex and HF-No Ex groups.
  
  
  CONCLUSIONS
  Sustained aerobic exercise did not counteract the tumor-promotional effect of increased consumption of a high-fat diet, suggesting that diet is more influential in PCa progression than exercise. Combining exercise with a healthy diet reduced the rate of PCa progression in this model. This study may have implications for PCa risk reduction in humans.
authors: Division of Urology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors: Avi D
authors: AD
authors: Vandersluis
authors: Natalie A
authors: NA
authors: Venier
authors: Alexandra J
authors: AJ
authors: Colquhoun
authors: Linda
authors: L
authors: Sugar
authors: Michael
authors: M
authors: Pollak
authors: Alex
authors: A
authors: Kiss
authors: Neil E
authors: NE
authors: Fleshner
authors: Laurence H
authors: LH
authors: Klotz
authors: Vasundara
authors: V
authors: Venkateswaran
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D000075202:Contraindications; D059305:Diet, High-Fat / Q000009:adverse effects* / Q000379:methods; D002149:Energy Intake / Q000502:physiology; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010805:Physical Conditioning, Animal / Q000379:methods / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000517:prevention & control*; D012307:Risk Factors; D023041:Xenograft Model Antitumor Assays / Q000379:methods