Association Of PD-1 SNPs With Esophagogastric Junction Adenocarcinoma Risk And The Functional Study

(PART 1)Programmed Death-1 Polymorphisms and Risk of Esophagogastric Junction Adenocarcinoma: A large sample size case-control studyBackground: Esophagogastric junction adenocarcinoma?EGJA?is increasing in North America and Europe and the similar phenomenon was found in Eastern Asian.In our country,EGJA is a highly fatal form of carcinoma.The findings of epidemiological studies indicated that foods preserved by salting,smoking and obesity et al.might contribute the major risk to EGJA.While these environmental risk factors could not explain the all etiology.The individual's genetic background may confer risk to EGJA.Objective: The aim of this study is to investigate the possible relationship of single nucleotide polymorphisms?SNPs?in Programmed cell death 1?PD-1?with the susceptibility of EGJA.Methods: In this case-control study,we enrolled 2,740 participants.Among them,1,063 were patients with EGJA and 1,677 were controls.SNPscan genotyping assay was used to determine the genotyping of PD-1 rs7421861 A>G,rs10204525 T>C,rs2227982 A>G and rs36084323 T>C polymorphisms.We used the SAS 9.4 version software to analyze all data.An online software,SHESIS,was used to construct the haplotypes.The definition of statistical significance was defined as P < 0.05?two-tailed?.Results: PD-1 rs7421861 A>G?PD-1.7?polymorphism was correlated with an increased risk of EGJA.However,PD-1 rs2227982 A>G?PD-1.9?polymorphism might be a protective factor for EGJA.PD-1 rs36084323?PD-1.1?CC genotype might confer a borderline decreased risk to EGJA.After a subgroup analysis,in never drinking and never smoking subgroups,the decreased susceptibility of EGJA was found.The findings of haplotypes constructing suggested that PD-1 T_rs10204525G_rs2227982C_36084323A_rs7421861 may be a protective factor for EGJA.However,PD-1 T_rs10204525G_rs2227982C_36084323G_rs7421861 haplotype may confer an increased risk to EGJA.Conclusion: Our results highlight PD-1 polymorphisms and haplotypes are significantly associated with the risk of EGJA.?PART 2?Effect of PD-1 Polymorphisms on the Level of Cytokines in PlasmaBackground: The previous studies have reported that cytotoxic T lymphocyte antigen-4?CTLA-4?polymorphisms can regulate the secretion of IL-2.PD-1 is very similar to CTLA-4.Thus,we supposed that polymorphisms in PD-1 gene might affect the level of Cytokines in Plasma.Objective: We intend to explore the potential relationship between PD-1 SNPs and the Level of Cytokines in plasma.Methods: Eighty five EGJA patients without any treatment and 93 healthy controls were included.We measured the level of IL-2,IL-4,IL-6 and IL-17 A in plasma.And then,we analyzed the relationship between PD-1 polymorphisms and these cytokines.Results: Firstly,PD-1 rs2227982 A>G polymorphism lead to a higher tendency for IL-2 level in plasma in the positive group of lymph node metastasis and stage III/IV group.PD-1 rs2227982 A>G polymorphism was associated with the increased plasma levels of IL-6 in controls.Secondly,PD-1 rs7421861 A>G polymorphism might be correlated with the decrease IL-4 level in plasma.Finally,we found that PD-1 rs36084323 T>C polymorphism lead to a higher tendency for IL-6 level in controls.Conclusion: PD-1 polymorphisms may alter the plasma level of multiple cytokines.?PART 3?Effect of PD-1 Polymorphisms on PD-1 Expression in Tumor Infiltrating LymphocytesBackground: Results of a number of studies demonstrate PD-1 expresses on the surface of tumor-infiltrating lymphocytes?TILs?.The findings of previous studies suggested that PD-1 expression was associated with low differentiation,lymph node metastasis and advanced stage status and confered poor prognosis to carcinoma.Objective: We intend to assess the relationship between PD-1 polymorphisms and the level of PD-1 expressed on TILs in EGJA patients.Methods: In this study,we enrolled 84 EGJA patients who underwent surgical treatment.The expression of PD-1 on TILs was assessed by immunohistochemical staining.The expression of PD-1 on TILs in EGJA patients was also compared by different PD-1 genetype to determine the effect of PD-1 polymorphisms on the expression of PD-1 on TILs.Results: The scores of PD-1 expression on TILs was significantly higher in low differentiated EGJA group than it was in the well/moderately differentiated EGJA group.The results showed that PD-1 rs36084323 T>C and PD-1 rs2227982 A>G polymorphisms were associated with the decreased score of PD-1 expression on TILs.The PD-1 rs7421861 A>G polymorphism was not correlated with the expression of PD-1 on TILs.Conclusion: These findings indicate that PD-1 rs36084323 T>C and PD-1 rs2227982 A>G polymorphisms may decrease the level of PD-1expression on TILs.