Seyyed Saeed Shams - Student Research Committee, Islamic Azad University, Mashhad Branch, Mashhad, Iran
Mohammad Reza Tabasiyan - Student Research Committee, Islamic Azad University, Mashhad Branch, Mashhad, Iran.
Mohammad Reza Khakzad - Innovative Medical Research Center and Department of Immunology, Mashhad Branch Islamic Azad University, Mashhad, Iran

Gastric cancer is the fifth most common malignancies worldwide. One proposed mechanism has been used by cancer cells for immune evasion is the suppression of immunity via the expression of programmed cell death protein ۱ (PD-۱) and its ligands (PDL-۱). This study was conductedto evaluate the correlation between PD۱ and PDL-۱ expression and prognosis in patients with gastric cancer.Methods: In this case-control study, ۲۰ RNA samples from gastric adenocarcinoma patients and ۱۳ RNA samples from healthy subjects who were admitted to Razavi Hospital and ۲۲ Bahman Hospital, Mashhad, Iran between ۲۰۱۴ and ۲۰۱۸ were analyzed. the gastric adenocarcinoma patients who diagnosed according to ۷th edition of American Joint Committee on Cancer (AJCC) and ۷th edition the Union for International Cancer Control (UICC)criteria. Total RNA was extracted from homogenized tissues specimens using TRIzol reagent .then, for detection of the expression of the human PD۱, PD-L۱ and glyceraldehyde ۳-phosphate dehydrogenase (GAPDH( the Real-Time PCR system (Corbett, Germany) was used. Data were analyzed by SPSS version ۲۲ using one-way ANOVA. The significance level in this study was <۰.۰۵. Findings: Totally ۳۳ specimens from ۲۰ male and ۱۳ female participants were analyzed. The mean age ofpatients and healthy controls were ۶۲.۲۵±۱۰.۲۳ and ۵۸.۲±۷.۶۲ years, respectively. our results showed that the expression of PD-۱ was significantly higher in patients with gastric adenocarcinoma in comparison with healthy controls(p<۰.۰۵). Also, we observed that the PD-۱ and the PDL-۱ expression were significantly correlated with the patient’s age and gender, respectively.Conclusion: The result of this study showed the PD-۱ expression pattern in tumor tissues is an appropriateprognosis factor for gastric adenocarcinoma cancer.

Gastric cancer, Adenocarcinoma, Immune Checkpoint Inhibitors, PD-۱, PDL-۱