Cancer cachexia and the effects of physical activity

Abstract

Physical activity is, among other things, characterized by an increased quality of life and several physiological positive results such as hypertrophy and counteracting atrophy. Cachexia has been proven to degradate muscle proteins and seems to be a death contributing factor during cancer.Cachectic muscles are resistant to anabolic effects, and this knowledge combined with the many proven positive outcomes on muscle hypertrophy by exercise led this study to investigate the previous studies conducted on this subject further. The Ubiquitin-Proteasome System (UPS) plays a significant role in protein degradation, more specifically the E3 ubiquitin ligases MuRF-1 (Muscle RING Finger protein-1) and MaFbx (Muscle atrophy F-box), which are FoxO (forkhead box-O) transcription factors. The UPS can be inhibited by substrates upregulated by physical activity, such as IGF-1 (Insulin-like Growth Factor-1) and PGC-1α (Peroxisome proliferator-activated receptor gamma coactivator 1-alpha). In conclusion, there are a lot of pathways in both cancer cachexia and physical activity that border on each other, but the molecular mechanisms are complex and not always clear