The Contribution of Interleukin-12A and Interleukin-12B Genotypes to Colorectal Cancer in Taiwan

Background/Aim: Interleukin-12 (IL12) plays a crucial role in immune regulation and inflammation and is critical in developing colorectal cancer (CRC). This study investigated the association between IL12A rs568408, IL12A rs2243115, and IL12B rs3212227 polymorphisms and CRC susceptibility in a Taiwanese population.

Materials and Methods: Genotypic and allelic distributions were analyzed in 362 non-cancer controls and patients with CRC via restriction fragment length polymorphism methods.

Results: All three polymorphisms fit well to the Hardy–Weinberg equilibrium (p>0.05). The frequencies of IL12A rs568408 GG, AG and AA genotypes were 73.5%, 22.9% and 3.6% in CRC cases, compared to 76.8%, 20.7%, and 2.5% in controls (p for trend=0.4973). No significant associations were observed for AG [odds ratio (OR)=1.16, 95% confidence interval (CI)=0.81-1.65, p=0.4752] or AA (OR=1.51, 95% CI=0.63-3.59, p=0.4715) genotypes. Dominant and recessive models showed no significant correlation (OR=1.22, 95% CI=0.87-1.71, p=0.2845; and OR=1.46, 95% CI=0.62-3.46, p=0.5160, respectively). Similarly, IL12A rs2243115 and IL12B rs3212227 genotypic distributions were comparable between cases and controls (p for trend=0.7209 and 0.5997, respectively). Allelic analysis further confirmed the lack of significant association: IL12A rs568408 A allele: OR=1.20, 95% CI=0.89-1.62, p=0.2552; IL12A rs2243115 G allele: OR=0.91, 95% CI=0.63-1.33, p=0.7019; and IL12B rs3212227 C allele: OR=0.90, 95% CI=0.73-1.10, p=0.3174.

Conclusion: These findings suggest that IL12A and IL12B polymorphisms are not significantly associated with CRC susceptibility in the Taiwanese population. Future research should explore other IL12A and IL12B polymorphisms, gene–gene and gene–phenotype interactions, and the role of IL12’ in immune regulation, which may offer insights for clinical applications and therapies.