Abstract
Objective: Obesity has been linked to esophageal adenocarcinoma (EAC). We hypothesize that adipokines, which are altered by obesity, could affect EAC growth rates and potentially serve as biomarkers of disease and targets for treatment. We have developed a potential murine model to investigate the effects of obesity-altered adipokines on EAC in vivo.
Methods: Severe combined immune-deficient mice were fed either a high-fat diet (HFD) containing 60% animal fat, or a control diet with 10% animal fat, and monitored for weight gain for 5 weeks. All mice were subcutaneously implanted with EAC cells (OE33), and tumor volume was monitored for an additional 4 weeks by direct measurement and uptake of fluorescently labeled 2-D-deoxyglucose. At sacrifice, serum triglyceride levels and abdominal fat-pad weight were measured to assess obesity state. Adipokine levels were measured within abdominal fat of tumor-bearing mice.
Results: Mice fed the HFD displayed increased body weight, visceral fat, and serum leptin and triglycerides. All mice developed tumors; OE33 EAC cells in HFD mice displayed increased growth rates, proliferation, and metabolic activity relative to tumors of EAC in control diet mice. Adipokine expression in the abdominal fat revealed distinct changes associated with the HFD and increased body weight.
Conclusions: Ad libitum feeding of the HFD was correlated with more-proliferative EAC tumors in vivo. This phenotype was associated with alterations to secreted adipokines, representing a potential mechanism for our observations. Further studies are necessary to explore findings, as they have potential to improve treatment of EAC.