Association of Tumor Necrosis Factor Receptor 1 Promoter Gene Polymorphisms (-580 A/G and -609 G/T) and TNFR1 Serum Levels with the Susceptibility to Gastric Precancerous Lesions and Gastric Cancer Related to H. pylori Infection in a Moroccan Population

Abstract

Chronic inflammation due to H. pylori infection is the risk factor of gastric cancer (GC). Through its receptor (TNFR1), TNF-α plays a fundamental role in inflammatory, infectious, and tumor processes. Dysregulation of TNFR1 gene expression could impact many biological processes that can lead to cancer. This study is aimed at evaluating the association of TNFR1 promoter gene polymorphisms (-580 A/G and -609 G/T) and TNFR1 serum levels with GC and precancerous lesion susceptibility. Patients suffering from gastric lesions (65 chronic gastritis, 50 precancerous lesions, and 40 GC) related to H. pylori infection and 63 healthy controls (HC) were involved in this study. Individuals are genotyped by TNFR1 gene promoter sequencing, and TNFR1 serum levels were measured by the ELISA quantitative method. Concerning TNFR1 -609 G/T locus, we noticed that the T allele was associated with an attenuated susceptibility to GC (OR=0.4; p value = 0.02). At the genotypic level and under the recessive model, the TNFR1 -609 TT genotype showed a decreased risk of GC (OR=0.3, p value = 0.03) compared to the combined (GG/GT) genotypes. TNFR1 serum levels have been increased together with gastric lesion severity (p value < 0.05). The TNFR1 -609 TT genotype seemed linked to a low level of sTNFR1 compared to GT and GG genotypes (p value = 0.07). Concerning TNFR1 -580 A/G locus, no significant relation was noticed between this polymorphism and GC susceptibility, as well as with the TNFR1 serum level. Our results suggest that the TNFR1 -609 T allele appears to have a protective effect against GC. High levels of TNFR1 serum levels seemed to be associated with the aggressiveness of gastric lesions. Therefore, our results suggest that TNFR1 -609 T/G polymorphism and the TNFR1 serum levels may be related to GC susceptibility.