Abstract C33: Effects of monocyte chemotactic protein-1 deficiency on spontaneous metastasis of Lewis lung carcinoma in mice fed a high-fat diet

Abstract

Abstract Obesity is a risk factor for cancer. Adipose tissue is considered an endocrine organ that produces pro-inflammatory adipokines, e.g. monocyte chemotactic protein-1 (MCP-1), that may contribute to obesity-related malignant progression. This study investigated effects of MCP-1 deficiency on pulmonary metastasis of Lewis lung carcinoma (LLC) in male C57BL/6 mice using a spontaneous metastasis model. The high-fat diet (45% of energy from fat) significantly increased the number and size (cross-sectional area and volume) of lung metastases compared to the AIN93G control diet (16% of energy from fat). Deficiency of MCP-1 reduced the number of lung metastases by 37% (p < 0.05) in high-fat diet-fed mice; it reduced metastatic cross-sectional area by 46% (p < 0.05) and volume by 69% (p < 0.05) compared to wild-type mice. Adipose and plasma concentrations of MCP-1 were significantly higher in high-fat diet-fed wild-type mice than in their AIN93G-fed counterparts, but they were not detectable in MCP-1 deficient mice regardless of diets. Plasma concentrations of plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were significantly higher in MCP-1 deficient mice than in wild-type mice. We conclude that adipose-produced MCP-1, at least partly, contributes to high-fat diet-enhanced metastasis and suggest that the overproduction of inflammatory cytokines (PAI-1, TNF-α) and angiogenic factors (VEGF, TIMP-1) in the absence of MCP-1 may support the metastatic development and growth of LLC in MCP-1 deficient mice. Citation Format: Lin Yan, Sneha Sundaram. Effects of monocyte chemotactic protein-1 deficiency on spontaneous metastasis of Lewis lung carcinoma in mice fed a high-fat diet. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C33.