Figure 2.

Exosome regulation of muscle and adipose wasting in cancer cachexia. Tumor cells secrete a range of exosomes which differ based on the tumor type. Nevertheless, common features of exosomes include a tumor regulated inflammatory environment which stimulates cytokine and E3 ligase activation in skeletal muscle along with an upregulation of signaling for apoptosis, reduced myocyte protein synthesis, and increased muscle protein degradation. Furthermore, tumor derived exosomes stimulate a dysregulated metabolic phenotype in skeletal muscle. Similarly, tumor derived exosomes decrease adipogenesis, increase browning of adipose cells and increase lipolysis, which contributes to overall loss of adipose stores. The resultant loss of skeletal muscle and adipose tissue is defined as cancer cachexia.