Association between the 308 G>A variant of the TNF-α gene and risk of colorectal cancer

Abstract

Genetic polymorphisms of cytokine genes may lead to variations in immunological response and genetic susceptibility to complex diseases that include cancer. Tumor necrosis factor-a (TNF-a) is an inflammatory cytokine that performs a crucial function in the immune reaction and may be involved in the development of colorectal cancer (CRC). There is evidence that genetic variations of the TNF-α gene increase susceptibility to CRC. We aimed to investigate the relationship between the TNF-α 308 G > A polymorphism, located in the TNF-α promoter region, and the risk of CRC. One hundred and eleven patients with CRC and 234 controls were recruited. DNA genotyping was undertaken using a Taqman® based assay. The frequency of the minor allele was approximately 0.2. The TNF-α-308G/A polymorphism was associated with an increased risk of CRC (Allele model (A vs. G), OR = 0.43, 95%CI = 0.26–0.71, p = 0.001; recessive model (AA+AG vs. GG), OR = 2.81, 95%CI = 1.60–4.93, p = 0.003; co-dominant model (AG vs. AA+GG), OR = 2.87, 95%CI = 1.60–5.14, p = 0.0004). Further investigations are required in more diverse populations to determine the value of this polymorphism as a risk stratification biomarker for CRC.