Medicine and Health Sciences Commons^™

High Fat Diet-Induced Obesity Increases The Formation Of Colon Polyps Induced By Azoxymethane In Mice, Jiezhong Chen, Xu-Feng Huang

Illawarra Health and Medical Research Institute

Background: Obesity has been found to be associated with colon cancer. However, the mechanism of this relationship is unclear and thus a good animal model is required. Our previous research showed that some mice developed diet-induced obesity (DIO) whilst others were diet-resistant (DR) when fed a high-fat diet. Methods: In the present study, we have tested the effects of a high-fat diet on the formation of colon polyps induced by azoxymethane (AOM) in both DIO and DR mice. Results: We found that the DIO mice have developed 2.5 times of polyps compared to the DR mice (P<0.05) and 3.4 times of polyps compared to the low fat fed mice (P<0.05). Although the DR mice tended to have more polyps than the low-fat diet fed mice, this was not statistically significant. The DIO mice could have an increased polyp formation due to obesity-related cancer risk factors and different gene expression from DR mice. Conclusions: DIO mice could be used as an appropriate model for studying obesity-associated colon cancer; however DR mice are not suitable because they don't show any significant weight gains to indicate obesity. Keywords: Obesity-associated colon cancer; high-fat diet; diet-induced obesity (DIO); diet resistant (DR); polyp; animal model