Effects of Moderate Exercise Training on Cancer-Induced Muscle Wasting

• Published in: Healthcare (Basel) Vol. 11; no. 19; p. 2652
• Main Authors: Figueira, Ana Cristina Corrêa, Pereira, Ana, Leitão, Luís, Ferreira, Rita, Oliveira, Paula A, Duarte, José Alberto
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 29.09.2023; MDPI
• Subjects: Animals; Breast cancer; breast tumor; Cancer; cancer-induced muscle wasting; Collagen; Complications and side effects; Diagnosis; Disease; Exercise; exercise training; Fitness equipment; Fitness training programs; gastrocnemius; Health aspects; Metabolism; Mortality; Musculoskeletal system; Physical fitness; Physiological aspects; Protein synthesis; Proteins; Running; soleus; Portugal; Germany; Spain
• ISSN: 2227-9032; 2227-9032
• DOI: 10.3390/healthcare11192652

Background: Muscle wasting is a common phenomenon in oncology and seems to be attenuated by exercise training. The aim of this study is to determine the degree of aggressiveness of cancer-induced muscle wasting in two different phenotypic muscles. It will also determine whether exercise training can attenuate this muscle dysfunction. Methods: Fifty Sprague Dawley rats were randomly assigned to four experimental groups: two breast cancer model groups (sedentary and exercise) and two control groups (sedentary and exercise). Breast cancer was induced by 1-methyl-1-nitrosoureia (MNU). After 35 weeks of endurance training, animals were sacrificed, and gastrocnemius and soleus muscles harvested for morphometric analysis. Results: In sedentary tumor-bearing animals, a significant reduction in cross-sectional area was found in both muscles (p < 0.05). Interstitial fibrosis was significantly higher in the gastrocnemius muscle of the sedentary tumor-bearing animals (p < 0.05), but not in the soleus muscle. In the gastrocnemius of sedentary tumor-bearing animals, a shift from large to small fibers was observed. This cancer-related muscle dysfunction was prevented by long-term exercise training. Conclusions: In sedentary animals with tumors, the gastrocnemius muscle showed a very pronounced reduction in cross-sectional area and a marked degree of interstitial fibrosis. There was no difference in collagen deposition between tumor groups, and the soleus muscle showed a less pronounced but significant reduction in cross-sectional area. These contrasting results confirm that cancer-induced muscle wasting can affect specific types of fibers and specific muscles, namely fast glycolytic muscles, and that exercise training can be used to improve it.