Gastric cancer (GC) is one of the most common cancer types in the world with a high mortality rate. Hereditary predisposition for GC is not fully elucidated so far. The aim of this study was identification of possible new candidate genes, associated with the increased risk of gastric cancer development. Whole exome sequencing (WES) was performed on 18 DNA samples from adenocarcinoma specimens and non-tumor-bearing healthy stomach tissue from the same patient. Three pathogenic variants were identified: c.1320+1G>A in the CDH1 gene and c.27_28insCCCAGCCCCAGCTACCA (p.Ala9fs) of the VEGFA gene were found only in the tumor tissue, whereas c.G1874C (p.Cys625Ser) in the FANCA gene was found in both the tumor and normal tissue. These changes were found only in patients with diffuse gastric cancer and were absent in the DNA of healthy donors.

The main function of matrix metalloproteinases is the degradation of the extracellular matrix and participation in signal transduction. In addition, it is known that they are involved in all stages of the progression of the tumor process. The activity of metalloproteinases can be regulated by interactions with specific inhibitors of matrix metalloproteinases, so the latter are also able to participate in tumor growth. The genes of matrix metalloproteinases and their inhibitors, as well as many other genes, are characterized by polymorphism. We have analyzed the frequency distribution of the alleles and genotypes of the polymorphic loci rs1799750 and rs494379 of the MMP1 gene, rs2285053 of the MMP2 gene, rs3025058 of the MMP3 gene, rs3918242 and rs17576 of the MMP9 gene, rs2276109 of the MMP12 gene, rs8179090 of the TIMP2 gene, and rs9619311 of the TIMP3 gene in 314 patients with gastric cancer, as well as in 339 unrelated healthy individuals from the Republic of Bashkortostan. It was shown that the markers of the increased risk of developing gastric cancer are the genotypes rs1799750*1G/2G of the MMP1 gene and rs2276109*A/A of the MMP12 gene for Tatars and the genotype rs9619311*T/T of the TIMP3 gene for Russians. The association of the rs494379*G allele of the MMP1 gene and increased risk of developing malignant tumors of the stomach were reported in men. Using the APSampler algorithm, we identified combinations of alleles/genotypes associated with an increased and a reduced risk of developing gastric oncopathologies. The data obtained confirm the influence of the studied polymorphic variants of the genes of matrix metalloproteinases and their tissue inhibitors on the risk of developing gastric cancer and are important for understanding the genetic structure of the studied pathology.

Pro- and anti-inflammatory cytokines modulate the inflammatory response in the gastric mucosa. The analysis of associations of allelic variants of cytokine genes in the process of tumorous...