Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract only
Publication Acceptance Date: 11/11/2010
Publication Date: 3/17/2011
Citation: Yan, L., Demars, L.C. 2011. Effects of diet-induced obesity on secondary tumor development and plasma cytokine expression in mice. Federation of American Societies for Experimental Biology Conference. 25:977.11 Interpretive Summary:
Technical Abstract: The present study investigated the effects of diet-induced obesity on secondary tumor development and expression of plasma cytokines in mice. Three-wk old male C57BL/6 mice were fed the AIN-93G diet or a 45% fat diet (kcal %; n=25/group) for 7 wks before they were subcutaneously injected with 2.5 x 105 Lewis lung carcinoma cells into the lower dorsal region. The primary tumor was resected 2 wks later, and mice were maintained on their respective diets for an additional 2 wks. The high-fat diet significantly increased body weight and abdominal adipose content compared to the AIN-93G diet. There was an approximately 2-fold increase in the number of tumors formed in the lungs in the high-fat diet-fed mice compared to the AIN-93G-fed mice (30±4 vs. 18±4, mean±SEM; P<0.05). Results of angiogenesis and obesity proteomic arrays showed that feeding tumor-bearing mice the high-fat diet resulted in 50% or greater increases in expression of 16 plasma cytokines, and an approximately 50% decrease in adiponectin, compared to the AIN-93G-fed tumor-bearing mice. These cytokines were amphiregulin, angiogenin, FGF acidic, FGF-21, HGF, IL-1ß, IL-10, IL-11, IP-10, leptin, MCP-1, SDF-1, serpin E1, RANTES, TIMP-1, and VEGF. Results of ELISA assays showed that were no differences in plasma concentrations of TIMP-1, IL-1ß, VEGF and MCP-1 in non-tumor-bearing mice fed the AIN-93G or the high-fat diet, but significant increases in these cytokines in tumor-bearing mice fed the AIN-93G diet compared to the non-tumor-bearing mice fed the same diet.Further significant increases in these cytokines in tumor-bearing mice fed the 45% fat diet compared to the same tumor-bearing mice fed the AIN-93G diet. The present study demonstrated that diet-induced obesity enhanced secondary tumor development and growth in the lungs of tumor-bearing mice and that this aggressiveness was accompanied with increases in expression of angiogenic cytokines in plasma, suggesting that the diet-induced obesity affects secondary tumor development and growth by promoting angiogenic processes.