Associations of HLA-G 3’UTR polymorphisms and increased HLA-G expression with gastric cancer susceptibility and prognosis

Background: Gastric cancer (GC) remains a serious health concern and is characterized by a multifactorial etiology involving both genetic and epigenetic factors. The aim of the current study was to examine the relationship between Human leukocyte antigen (HLA)-G 3’UTR polymorphisms and the expression of HLA-G in both tumor tissues and plasma samples from patients with GC in the Tunisian population. Methods: HLA-G 3’UTR polymorphisms (14pb Insertion/deletion and + 3142C/G) were identified by polymerase chain reaction (PCR) or Sanger sequencing. Plasma levels of sHLA-G (total sHLA-G, shed HLA-G1 and HLA-G5) were determined. Immunohistochemistry was used to evaluate the expression of HLA-G in tumor tissues. Results: The Del/Del genotype and Del allele frequencies were different between GC patients and healthy donors (HD) (OR [95 % CI] = 2.483 [1.070–5.410], p = 0.025 vs. OR [95 % CI] = 1.537 [0.924–2.584], p = 0.099; respectively). The C/C genotype and C allele frequencies were significan...