title: IL-18 serum level and IL-18 promoter gene polymorphism in Iranian patients with gastrointestinal cancers.
abstract: OBJECTIVE
  Interleukin (IL)-18 level and association of its two promoter gene polymorphisms at -607 C/A and -137 G/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 -607 AA/-137 GC genotype combination in unwell-differentiated cases was more than those with well-differentiated cancer. Haplotype analysis showed that in patients with stomach cancer -607 C/-137 C and -607 A/-137 G and in patients with colorectal cancer -607 C/-137 C 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Haghshenas
authors.forename: Seyed Vahid
authors.initials: SV
authors.lastname: Hosseini
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Mahmoudi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Saberi-Firozi
authors.forename: Shirin
authors.initials: S
authors.lastname: Farjadian
authors.forename: Abbas
authors.initials: A
authors.lastname: Ghaderi
mesh_terms: D000483:Alleles; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000097:blood* / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D020382:Interleukin-18 / Q000097:blood* / Q000235:genetics*; D007492:Iran; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic
chemical_list: D015415:Biomarkers; D020382:Interleukin-18