Investigation of Programmed Cell Death-۱ (PD-۱) Gene Variations at Positions PD۱.۳ and PD۱.۵ in Iranian Patients with Non-small Cell Lung Cancer

Background: Tumor cells express PD-۱ ligands to bind PD-۱ on immune cells and escape immune responses. In the present study, we aimed to investigate whether single nucleotide polymorphisms at positions PD۱.۳ (+۷۱۴۶, rs۱۱۵۶۸۸۲۱) G/A, and PD۱.۵ (+۷۷۸۵ C/T, rs۲۲۲۷۹۸۱) may be considered risk factors for susceptibility to nonsmall cell lung cancer in the Iranian population. Methods: This study enrolled ۲۰۶ histopathologically confirmed lung cancer patients and ۱۷۳ age/sex matched healthy controls. We performed PCR-RFLP to determine the genotypes of the extracted genomic DNA.Results: The frequencies of PD۱.۳ GG, GA and AA genotypes were ۱۷۱ (۸۳%), ۳۱ (۱۵%) and ۴ (۱.۹%) out of ۲۰۶ patients, and ۱۴۴ (۸۳.۲%), ۲۶ (۱۵%), and ۳ (۱.۷%) out of ۱۷۳ controls, respectively. The frequencies of PD۱.۵ CC, CT and TT genotypes were ۷۸ (۳۷.۹%), ۱۰۰ (۴۸.۵%), and ۲۸ (۱۳.۶%) in patients, and ۶۰ (۳۴.۷%), ۸۹ (۵۱.۴%), and ۲۴ (۱۳.۹%) in controls. There were no significant differences in genotype analysis between patients and controls at positions PD۱.۳ (P=۰.۹۸) or PD۱.۵ (P=۰.۸۰). No significant differences existed in the frequencies of alleles and haplotypes between the two groups (P>۰.۰۵).Conclusion: Our data have indicated no association between PD۱.۳ (+۷۱۴۶) G/A and PD۱.۵ (+۷۷۸۵) C/T with susceptibility to non-small cell lung cancer. Investigation of other PD۱ genetic variations and emerged haplotypes are required to completely define the role of PD۱ genetic variations in susceptibility to lung cancer.