Sex-specific functional effect of IL-12 gene polymorphisms in brain tumours

Abstract

The role of the IL-12 family cytokines in brain tumourigenesis is an active area of research, but only a few studies have explored the impact of the functional IL12B polymorphisms on brain tumour (BT) risk. The present study aimed to evaluate the possible impact and functional effect of IL12B rs3212227 and rs17860508 on BT susceptibility in adults. We observed a lower frequency of the C-allele variant of the rs3212227 polymorphism among cases with primary BT compared to those with brain metastasis (BrM) and individuals with no benign or malignant tumours under allelic and dominant genetic models. The frequency of the C-allele of rs3212227 was significantly lower in primary BT cases than in controls (16% vs. 26.5% with OR = 0.529, 95%CI: 0.3–0.94, p = .029; ORadjusted=0.442; 95%CI: 0.23–0.87; p = .018). There was no significant association between rs17860508 and BT risk under all analysed genetic models after age and sex adjustment. A significantly higher IL-12p40 serum level in men with primary BT than in women (p = .0007) was found. We observed a sex-specific effect of rs3212227 polymorphism on serum IL-12p40 levels in cases with primary BT in contrast to BrM. The C-allele carriership was associated with higher IL-12p40 in women with primary BT. Serum levels of IL-23 were similar across the patients’ subgroups. The obtained results suggest that the IL12B rs3212227 polymorphism influences the risk for primary BT in contrast to rs17860508 polymorphism and shows a sex-specific functional effect on IL-12p40 levels. Also, the male gender was associated with higher IL-12p40 in cases with primary BT.