PD-1 Gene Polymorphisms in Iranian Patients With Colorectal Cancer

Objective: Programmed cell death protein 1 (PD-1) gene encodes an inhibitory cell surface receptor involved in the regulation of T-cell function during immunity and tolerance. This study investigates PD-1 gene polymorphism in patients with colorectal cancer (CRC). Methods: Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), this polymorphism was genotyped in 190 Iranian subjects (80 patients with CRC and 110 healthy controls). Results: Comparing CRC patients with healthy controls, the frequencies of the G/A genotype (40.9% vs. 33.75%, OR=1.36, P=0.32) were not significantly different. However, G/G and A/A genotype frequencies between the CRC patients and healthy controls were significantly different (P=0.015, P=0.0004, respectively). Also, allele frequencies of this polymorphism were significantly different (P=0.0001) in CRC patients compared to healthy controls. Conclusion: These results suggest a correlation between PD-1 gene polymorphism and CRC susceptibility in our study group.