TLR4 and NOD2/CARD15 Polymorphisms and Their Association with Dietary Factors in Colorectal Cancer

Abstract

Epigenetic and genetic factors affect the incidence of colorectal cancer. Intestinal bacteria have been implicated in diet-induced obesity and inflammation. TLR4 and NOD2/CARD15 that play a crucial role in immunity have been implicated in signal transduction events induced by bacterial antigens. Here, we investigated the combined effect of epigenetic and genetic factors with occurrence of colorectal cancer in Tunisian population. We aimed to investigate interaction between polymorphisms in innate immunity genes TLR4 D299G/T399I and NOD2/CARD15 3020insC and dietary factors in colorectal cancer. Methods: This study involved 101 patients with colorectal cancer and 140 healthy controls. The association was analyzed by statistical tools. We observed a protective effect between a low consumption of cheese and butter and TLR4 T399I polymorphism on colorectal cancer incidence. We also showed that TLR4 D299G polymorphism associate to a higher consumption of tea and cheese and to low consumption of fruits increases the occurrence of CRC. We found no significant association between NOD2/CAR15 polymorphism and dietary products on CRC risk. Finally, we found a positive interaction between TLR4 mutated genotypes and a higher consumption of cheese and butter in patients with colorectal cancer. These results suggest interactions between dietary factors and innate immunity genes polymorphisms are involved in colorectal cancer risk.