Investigation of pd-1 gene polymorphism (PD-1.5 C/T) in Turkish patients with colorectal cancer

Programmed death-1 (PD-1), expressed by activated T cells, is an inhibitory cell surface receptor concerned in the regulation of T cell task during immunity and tolerance. The associations of the immune response-related genes with cancer have been established. This study investigates PD-1.5 (C/T) polymorphism in patients with colorectal cancer (CRC). PD-1.5 (C/T) polymorphism was investigated in 249 Turkish subjects (99 patients with CRC and 150 healthy individuals as controls) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The distribution of PD-1.5 (C/T) genotypes between the patients with CRC and healthy controls were significantly different (p=0.003). The patients who have distance metastasis have increased C allele and heterozygous CT genotypes than those with negative metastatic {p=0.016, odds odds ratio (OR), 1.248; 95% confidence interval (CI), 1.063-1.465; p<0.001, odds oranı (OR), 1.732; 95% confidence interval (CI), 1.291-2.322). Moreover, the patients who have angiolymphatic invasion have increased frequency of CC genotype than those with the absence of angiolymphatic invasion (p=0.043, OR: 2.25; 95% CI: 1.063-4.763). The patients who have mucineous component have increased frequency of T allele than those with the absence of mucineous component (p=0.023, OR: 1.284; 95% CI: 1.066-1.546). Our results have shown significant associations between PD-1.5 (C/T) polymorphism and CRC susceptibility and progression of the disease. Further researches comprising more patients are required to clarify whether a particular genotype of the PD-1.5 polymorphism is associated with colorectal cancer and clarify the association of PD-1.5(C/T) polymorphism and clincopathological characteristics.