Association Between Toll-like Receptor-4 Gene Polymorphism And Inflammatory Bowel Disease And Colorectal Cancer

Background and aims: Previous pathophysiological studies have shown that signaling by TNF and NF-kB in mononuclear cells play a key role in inflammatory bowel disease (IBD). therefore genetic variants that would lead to increase or persistent NF-kB activation are particularly interest. Toll-like receptor-4 (TLR4) is a member of NF-kB activators that is known to bind LPS through their LRR domain. So we genotype the polymorphism of TLR4 to study the distribution of TLR4 gene Asp299Gly polymorphism and to define whether mutation of TLR4 gene was involved in IBD and colorectal cancer in Chinese population with Han nationality in Hubei province.Methods: Sixty-two patients with IBD (47 patients with ulcerative colitis, 15 patients with Crohn's disease), 104 patients with colorectal cancer (41 patients with colon cancer, 63 patients with rectal cancer) and 110 healthy controls were genotyped for TLR4 gene Asp299Gly polymorphism by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP).Results: (1) No mutation of TLR4 gene Asp299Gly allele was detected in all 276 DNA samples. The distributions of the genotype and allele frequencies of three groups have no significant differences. (2) Comparing the genotype and allele frequencies of the TLR4 Asp299Gly polymorphism, the distributions of the TLR4 Asp299Gly polymorphism were quite different between Asia and western populations.Conclusion: The non-synonymous single nucleotide polymorphism Asp299Gly in TLR4 gene was rare and was not associated with inflammatory bowel disease and colorectal cancer in Chinese population with Han nationality in Hubei province.