Functional IL-18 promoter gene polymorphisms in Tunisian nasopharyngeal carcinoma patients.
OBJECTIVE
There is growing evidence suggesting that IL-18 levels may affect individual to virus-associated neoplasia and that single nucleotide polymorphisms (SNPs) within the gene may influence its production. In this study we wanted to know whether IL-18 polymorphisms at positions -607 C/A and -137 G/A are associated with susceptibility and/or are markers of nasopharyngeal carcinoma (NPC) prognosis.


METHODS
Using the restriction fragment length polymerase chain reaction (RFLP-PCR), 163 Tunisian patients and 164 healthy controls were genotyped.


RESULTS
No significant association was found between each studied polymorphism and NPC. However, we noted that the -607 A allele, which is associated with lower IL-18 production, increased the risk of advanced tumor stages (OR=3.59; P=0.017) and that this risk was more pronounced among the older patient's age at onset (OR=3.85; P=0.012). Moreover, the significant difference in CA/GG haplotype frequency distribution between young and older patients supported the idea that NPC disease has biologically different features between age sub-groups.


CONCLUSIONS
Functional IL-18 gene polymorphisms do not influence the susceptibility to NPC in Tunisians but may contribute to disease onset and aggressiveness.
Laboratory of Molecular Immuno-Oncology, Faculty of Medicine of Monastir, Monastir 5019, Tunisia.
Karim
K
Farhat
Elham
E
Hassen
Nadia
N
Bouzgarrou
Sallouha
S
Gabbouj
Noureddine
N
Bouaouina
Lotfi
L
Chouchane
D000328:Adult; D004247:DNA / Q000235:genetics; D005260:Female; D015894:Genome, Human / Q000235:genetics; D005838:Genotype; D006262:Health; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014416:Tunisia / Q000453:epidemiology
D020382:Interleukin-18; D004247:DNA