The roles and mechanism of tumor-derived factors in the development of cancer cachexia

Syndrome of cachexia,which is a common feature of many types of cancer,characterized by loss of adipose tissue and skeletal muscle,is responsible not only for a poor quality of life and poor response to chemotherapy,but also a decreased survival time.It can not be fully explained by the accompanying anorexia,because increasing nutrient support is unable to reverse the wasting syndrome.Although patients with cachexia frequently show an elevated resting energy expenditure,cachexia can occur with a normal energy expenditure.Lipid mobilizing factor and proteolysis inducing factor,two tumor-derived factors,can directly mobilize fatty acids and amino acids from adipose tissue and skeletal muscle respectively.It is important of the knowledge about the roles and mechanism of LMF and PIF in the development of cancer cachexia,which should lead to the development of new therapeutic methods.