DOES PHYSICAL EXERCISE ADAPTIVE-RESPONSE AND CANCER-RELATED CACHEXIA SHARE COMPONENTS OF THE UBIQUITIN PROTEASOME SYSTEM?

Resumo

Cachexia is a multifactorial syndrome characterized by a progressive loss of body mass, primarily in the skeletal muscle tissue and secondarily in the unilocular adipose tissue, resulting in patients’ physical deterioration. The incidence of cachexia might be associated with a pathological pro-inflammatory state, common amongst cancer patients. The loss of mass and skeletal muscle function is promoted by the activation of the proteolytic ubiquitin-proteasome system (UPS) in the muscle fibers. Usually, pharmacological and nutritional treatments are mostly ineffective, despite the possible attenuation protein catabolism in skeletal muscle fiber in individuals with cancer-associated cachexia. However, it has been shown that the experience of regular physical exercises can reverse the skeletal muscle catabolic state in the cancer-associated cachexia. Intriguingly, the mechanisms related to exercise-induced adaptation might be shared with those triggered by cancer-related cachexia. Therefore, there are gaps in research regarding these shared mechanisms, especially when considering the effect of physical exercise in cachectic cancer individual. The present study addresses the known biological mechanisms of physical exercise regulating protein synthesis and hypothesizes a possible modulation of UPS in the cachexia associated with the various diseases.