Fatigue like behavior in different tumor-bearing mice metastasis model for the study of colorectal cancer

Abstract

Background: Fatigue is a usual occurrence in tumor patients during illness and treatment, patients with cancer related fatigue (CRF) showed signs of fatigue after tumor development, and not only in patients with advanced process, and still a evidently subjective fatigue even after effective symptomatic treatment. Methods: In this study, two metastasis models of BALB/c mice were established by subcutaneous and intraperitoneal inoculation of tumor cells, and a series of quantitative description and qualitative prediction techniques were adopted to investigate the effects of subcutaneous and intraperitoneal tumorigenesis on the life of mice, After 21 days periods, all mice were tested for several aspects of CRF: (1) size of tumor volume; (2) behavioral detection of fatigue; (3) liver, kidney function and lipid levels; (4) organ indices; (5) pathological and electron microscopic observation of gastrocnemius and quadriceps muscles; and (6) determination of oxidative stress indices in gastrocnemius.Results: Compared with normal mice, the fatigue level significantly increased in both models mice, and tumor growth was accompanied by significant fatigue in the organism and might be related to decrease of skeletal muscle mass, destruction of muscle structure, and disorders of skeletal muscle metabolism. Different analyses were performed on the two models, and it was found that the fatigue level was more severe in the abdominal transfer model compared with the subcutaneous transplantation tumor model. HGB and HCT decreased significantly, liver and kidney function were more severely impaired, gastrocnemius muscle area was more reduced, and oxidative damage of gastrocnemius muscle was higher. Conclusion: This study provides a comprehensive description of the main processes that cause fatigue due to tumor itself and provides a standard and reliable animal model for further pharmacological or pharmacodynamic studies.