The effect of 5'untranslated region polymorphism in EGF gene, rs4444903, on colorectal cancer

Abstract

Aim: The purpose of this study was to determine the relationship of rs4444903 (EGF+61A/G) SNP genotype with colorectal cancer and tumor stage in an Iranian population.

Background: Epidermal growth factor (EGF) is one of the important proteins that determine survival of cells. EGF binds to its receptor on the cell surface and then activates some of the cell signaling pathway networks within cells that lead to activation or deactivation of factors which are responsible for growth and apoptosis of cells. In this study we assessed the association in EGF polymorphism rs4444903 with colorectal cancer (CRC) in Iranian population.

Patients and methods: We conducted case-control study to investigate the association of polymorphism rs4444903 in EGF, with colorectal cancer risk in Iranian population. Analyzed Polymorphism of EGF rs4444903 with restriction fragment length polymorphisms (RFLP) among two groups of subjects consisting of including 220 cases with colorectal cancer and 220 healthy individuals as controls. Mutations were confirmed in 10% of the samples by direct sequencing.

Results: The frequencies of AA, AG and GG genotypes among cases with colorectal cancer were 28.2, 46.8, and 25.0 % respectively and in controls genotype frequencies were 23.2, 56.4, and 20.5 %, respectively. Frequency of A allele among case group was 51.6% and for control group was 51.4%. The frequency of G allele in case and control was, respectively 48.4% and 48.6% (OR= 1.009, 95% CI= 0.775-1.315; P= 0.946). The percentage of Stage 0, I, II, III, IV were 5%, 9.35%, 38.84%, 30.21% and 16.54%, respectively, among the cases. However, no significant association between this polymorphism and CRC stage was observed (p=0.626).

Conclusion: Our data suggest a SNP rs4444903 may not represent a risk factor in the development and progression of CRC among Iranian population.

Keywords: Colorectal cancer; EGF+61A/G; Epidermal growth factor; Single nucleotide polymorphism; rs4444903.

Figure 1

Electrophoresis digested products with AluI restricted enzyme on agarose gel showed different bonds. The marker (M) that used was 100 base pairs

Figure 2

Direct DNA sequencing results for the EGF rs4444903, genotype GG and genotype AA were observed from the electropherogram.