Genetic variants in the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and death receptor (DR4) genes contribute to susceptibility to colorectal cancer in pakistani population

Abstract

TRAIL mediated signaling in cancer cells has emerged as one amongst the most deeply studied molecular phenomenon. Data obtained through genetic studies has highlighted highly polymorphic nature of DR4 and in accordance with this concept, we aimed to investigate the association between Colorectal cancer and polymorphisms in TRAIL and DR4 gene. We selected 100 patients with colorectal cancer and 100 healthy, sex and age matched volunteers randomly. C626G and A1322G in DR4 gene were analyzed using Polymerase Change Reaction (PCR), Restriction Fragment Length Polymorphism (RFLP) and Amplification Refractory Mutation System (ARMS) techniques. PCR-RFLP was used to study TRAIL 1595 C>T. TRAIL gene 1595 C>T genotypes percentage in colorectal cancer patients was statistically non-significant. CC was 43% in patients and 50% in controls. CT was 45% in patients and 43% in controls. TT was 12% in patients and 7% in controls. C allele was 0.655% in cancer patients and 0.715% in controls. T allele was 0.345% in patients and 0.285% in controls. DR4 gene 626 C>G genotypes percentage analysis indicated that CC was 28% in patients and 2% in controls. GC was 42% in patients and 40% in controls. GG was 30% in patients and 58% in controls. CC was statistically significant (p=0.00000207) in cancer patients. C allele was 0.49% in patients and 0.22% in controls. G allele was 0.51% in patients and 0.78% in controls. For DR4 A1322G, homozygous GG genotype was 36% in the patients and in controls. There was statistically insignificant difference (p> 0.05). The heterozygous GT genotype was 30% in patients and 29% in controls. This difference was statistically insignificant (p value > 0.05). Similarly, the homozygous genotype TT of the minor allele was (35%) in controls and patients (34 %). This difference was also statistically insignificant (p value > 0.05). C allele was 0.51% in patients and 0.5% in controls. T allele was 0.49% in patients and 0.495% in controls. Future studies must converge on a larger sample size, sporadic mutations of DR4 and TRAIL and expression profiling.