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Protective Effects of Preconditioning Exercise on Skeletal Muscle Strength and Tumor Growth in the Female Tumor‐Bearing Mouse
Author(s) -
Tichy Louisa,
Brantley T. J.,
Blackburn George,
Parry Traci
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.05483
Subject(s) - cachexia , medicine , wasting , cancer , treadmill , sed , skeletal muscle , cancer related fatigue , disease , oncology
Background Cancer cachexia, a complex metabolic wasting disease, occurs in up to 80% of cancer patients and results in death in up to one‐third of cancer patients. While research in this field is growing, cancer cachexia remains an untreated condition with irreversible effects as there are no clear diagnostic criteria. Therefore, a great need exists to better understand this disease and possible preventative methods. Research has shown that exercise interventions have a positive impact on inhibiting tumor growth and preserving muscle mass. Many questions remain regarding the most effective timing and extent of exercise as a protective measure. Therefore, the purpose of this study was to examine the effects of preconditioning exercise as a protective measure for cancer cachexia. Methods Female LC3 Tg+ and WT mice were randomly separated into four groups, sedentary non‐tumor bearing (SED+NT), sedentary tumor bearing (SED+T), treadmill exercise non‐tumor bearing (TM+NT), and treadmill exercise tumor bearing (TM+T). Mice underwent an 8‐week treadmill exercise training protocol (TM) or remained sedentary (SED). Next, mice were implanted with tumor cells (T group; 1x10 5 LLC cells in flank) or remained non‐tumor (NT) for 4 weeks. To examine the protective effects of exercise on tumor growth and muscle wasting during cancer cachexia, grip strength and tumor growth evaluations were taken at baseline, 8‐week, and 12‐week time points. At the end of the 12‐week study, muscle and tumor tissue was collected and weighed. Results While no differences existed between groups at baseline, exercise trained (TM) mice exhibited modest gains in grip strength compared to SED mice. Following tumor bearing, SED+T mice exhibited a significant (P < 0.05) decline in grip strength compared to SED+NT animals. Additionally, SED+T skeletal muscle mass (gastrocnemius, mixed fiber) was significantly (P < 0.05) less compared to TM+T. Interestingly, TM resulted in a 20‐fold decrease in estimated tumor volume (P < 0.05) and a 60% decrease in tumor mass (P < 0.05) compared to SED tumors. Conclusion The analyzed data indicate that preconditioning exercise appears to play an important role in protecting the musculature during cancer cachexia. This is evidenced by exercise's ability to guard against cancer cachexia‐mediated declines in both muscle strength and mass. Furthermore, exercise preconditioning significantly stunted tumor growth even when animals did not exercise during the tumor bearing. This information is crucial in understanding the significance of exercise in cancer patients and in elucidating the importance of timing of exercise as a protective measure against the detrimental effects of cancer cachexia.