AbstractBackground and Aim:
Interleukin (IL)-18 level and association of its two promoter gene polymorphisms at −607C/A and −137G/C positions were investigated in Iranian patients with gastrointestinal (GI) cancers.Methods:
232 cases of GI cancers and 312 healthy controls were enrolled. Serum level of IL-18 was measured by enzyme linked immunosorbent assay (ELISA) and genotyping of IL-18 gene polymorphisms were assessed by allele-specific polymerase chain reaction (PCR).Results:
There was a significant difference in the frequency of −137 G/C genotype between patients with stomach or colorectal cancers and control group. In patients with colorectal cancer, the frequency of the −607AA/−137GC genotype combination in unwell-differentiated cases was more than those with well-differentiated cancer. Haplotype analysis showed that in patients with stomach cancer −607C/−137C and −607A/−137G and in patients with colorectal cancer −607C/−137C were decreased compared with control group, and this difference reached statistical significance. Serum analysis revealed that the mean IL-18 serum level in stomach and colorectal cancer before and after surgical operation was significantly higher than healthy volunteers. Postoperative IL-18 level for all patients with colorectal cancer was significantly decreased compared with the levels before surgery.Conclusion:
Results of this investigation suggests that Single Nucleotide Polymorphism (SNP) at position −137 G/C and haplotype frequency may play a role in predisposition of Iranian patients to stomach and colorectal cancers. In addition, increasing serum IL-18 level may have clinical importance as a diagnostic marker in patients with stomach and colorectal cancer.