IL-18 serum level and IL-18 promoter gene polymorphism in Iranian patients with gastrointestinal cancers.
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.
Haghshenas
Mohammad Reza
MR
Shiraz Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran.
Hosseini
Seyed Vahid
SV
Mahmoudi
Mahmoud
M
Saberi-Firozi
Mehdi
M
Farjadian
Shirin
S
Ghaderi
Abbas
A
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
D015415:Biomarkers; D020382:Interleukin-18