TNFalpha promoter SNPs in Croatian population, association with colon cancer

The immune system is a complex network of cells that are involved in the protection of humans against infectious agents and tumor growth. Inherited polymorphisms in immuno-modulatory genes may contribute to variation in immune function and genetic susceptibility for complex disease, including cancer. TNFalpha is a cytokine produced by activated monocytes and macrophages, which play a key role in the inflammatory response. Increased serum TNFalpha levels have been described in cancer patients, and are associated with an adverse disease outcome. TNFalpha gene is mapped to chromosome 6p21.3 and a large number of polymorphisms of its promoter, called "high-production" polymorphisms, have been described. The aim of our study was to estimate allelic frequency for four promoter SNPs in TNFalpha gene, -238, -308, -857 and -1031 in the Croatian population and in patients with colon cancer. DNAs obtained from 150 colon cancer patients and 150 unrelated healthy volunteers were genotyped for the TNFalpha -238, -308, -857 and -1031 SNPs using real-time PCR TaqMan® ; ; ; ; SNP genotyping assays. The frequency of alleles associated with altered TNFalpha production was: 3%, 4%, 18.8% and 18.8% for -238A, -308A, -857T and -1031C, respectively. "High-production" allele variant -308A was more common in the population with colon cancer in the comparison to healthy volunteers. The association between these polymorphism and colon cancer has to be investigated in the future studies.