Abstract
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.