Expression of IL-1α and TNF-α modified by Toll-like receptor 4 genetic polymorphism is associated with colorectal carcinoma

AIM: To investigate the association of D299G, T399I and A896G polymorphisms of Toll-like receptor 4 (TLR4) and colorectal carcinoma (CRC). METHODS:
The genotypes of these 3 loci among 268 patients with CRC and 268 healthy controls were determined by polymerase chain reaction-restriction fragment lengthy polymorphism (PCR-RFLP). The protein levels of IL-1α, IL-8, TGF-β and TNF-α in the homogenate of CRC biopsies were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: No significant difference of the genotype frequencies of TLR4 A896G and D299G between the cases and the controls was observed. CT combined TT genotype of T399I was significantly associated with increased CRC risk. The individuals with the T allele of T399I showed a 1.843-fold increase in CRC risk as compared with the C allele. The concentrations of IL-1α and TNF-α in CRC biopsies were significantly elevated in the individuals with the genotype of T399I CT combined with TT as compared with the genotype of CC. CONCLUSION: TLR4 T399I promotes the development of CRC by modifying the expression of IL-1α and TNF-α in CRC tissues.