Characterization of a Cancer-Induced Bone Pain Model for Use as a Model of Cancer Cachexia.

Cancer cachexia is a debilitating syndrome characterized by progressive weight loss, muscle wasting, and systemic inflammation. Despite the prevalence and severe consequences of cancer cachexia, effective treatments for this syndrome remain elusive. Therefore, there is a greater need for well-characterized animal models to identify novel therapeutic targets. Certain manifestations of cachexia, such as pain and depression, have been extensively studied using animal models of cancer-induced bone pain (CIBP). In contrast, other aspects of cachexia have received less attention in these models. To address this issue, we established the CIBP model by injecting Lewis lung carcinoma into the intramedullary cavity of the femur, observed cachexia-related symptoms, and demonstrated the utility of this model as a preclinical platform to study cancer cachexia. This model accurately recapitulates key features of cancer cachexia, including weight loss, muscle atrophy, adipose tissue depletion, CIBP, and anxiety. These findings suggest that psychological factors, in addition to physiological and metabolic factors, play significant roles in cancer cachexia development. Our model offers a valuable resource for investigating the underlying mechanisms of cancer cachexia and for developing innovative therapeutic strategies that target physical and psychological components.