The effect of physical training on the N-methyl-N-nitrosourea-induced mammary carcinogenesis of Sprague-Dawley rats.

Abstract

The impact of physical activity on carcinogenesis has been demonstrated in many studies. Taking into account the discrepant results of physical exercise on the cell proliferation and apoptosis of breast cancer, we aimed to examine the impact of physical training on N-methyl-N-nitrosourea-(MNU)-induced mammary carcinogenesis. Fifty female rats were divided into four groups according to the intensity of physical activity they undertook. The number of developed tumors, tumor volume, and histopathological diagnoses were noted. Apoptosis and cell proliferation were studied by the number of TUNEL-positive and Ki-67-expressing cells. We demonstrated a statistically significant decrease in the tumor number between all trained groups and the control group. The results were most pronounced in the group with a moderate intensity of training. Moreover, we showed a decrease in tumor volume as training intensity increased, though the differences were not statistically significant. The mean number of TUNEL-positive cancer cells was significantly higher in the training groups than in the control group. These data suggest that physical training, especially of moderate intensity, may alleviate MNU-induced mammary carcinogenesis. The results could suggest that physical exercise-induced apoptosis may be a protective mechanism.

• Authors: Iwona Malicka, Katarzyna Siewierska, Bartosz Pula, Christopher Kobierzycki, Dominik Haus, Urszula Paslawska, Marek Cegielski, Piotr Dziegiel, Marzena Podhorska-Okolow, Marek Wozniewski
• Journal: Experimental biology and medicine (Maywood, N.J.) (Exp Biol Med (Maywood)) Vol. 240 Issue 11 Pg. 1408-15 (Nov 2015) ISSN: 1535-3699 [Electronic] England
• PMID: 25990440 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 by the Society for Experimental Biology and Medicine.

Chemical References

• Carcinogens
• Ki-67 Antigen
• Methylnitrosourea

Topics

• Animals
• Apoptosis
• Carcinogens
• Cell Proliferation
• Female
• Immunohistochemistry
• In Situ Nick-End Labeling
• Ki-67 Antigen (metabolism)
• Mammary Neoplasms, Experimental (chemically induced, drug therapy, prevention & control)
• Methylnitrosourea
• Microarray Analysis
• Physical Conditioning, Animal
• Rats
• Rats, Sprague-Dawley