The role of molecular genetic changes in the structure of the CDH1 gene in the development of gastric cancer in patients from the Republic of Bashkortostan

Abstract

Gastric cancer (GC) is one of the most serious diseases, occupying a leading position among the causes of death from malignant neoplasms in the world. The Republic of Bashkortostan (RB) also has high rates of morbidity and mortality due to malignant neoplasms of the stomach. One of the main genes that determine a high risk of predisposition to this pathology is the CDH1 gene. The aim of the study: Search for changes in the nucleotide sequence in the CDH1 gene in patients with gastric cancer from the Republic of Bashkortostan. Materials and methods: The material for the study was DNA samples of gastric cancer patients and healthy donors living in the RB. Genomic DNA was isolated from peripheral blood lymphocytes by phenol-chloroform extraction. Amplifica-tion was performed using specific primers flanking the studied exon. The study of exons for the presence of changes in the nucleotide sequence was carried out using the SSCP and HRM methods. To verify molecular genetic changes, the Sanger sequencing method was used. Results: The genetic variant rs35741240 (c.1680G>C, p.Thr560=) was found in the 11th exon of the CDH1 gene. Four patients (1.33%) were found to be heterozygous C allele carriers among patients; the incidence of GC genotype among healthy individuals was 0.67% (2 patients). A rare polymorphic locus rs33969373 (c.1896C>T, p.His571=) was also found in the 12th exon of the CDH1 gene. The vari-ant was also detected in the heterozygous state, the frequency of the CT genotype in the group of patients was 1.00% (3 patients), among the control – 0.33% (1 patients). In exon 14 of the CDH1 gene, a synonymous polymorphic locus rs33964119 (c.2253C>T, p.Asn751=) was found. It was shown that this variant in the heterozygous state occurs in 24 patients (8.00%), and among healthy individuals the frequency of the CT genotype was 5.33% (16 patients). Pairwise comparison of the frequencies of alleles and genotypes of the identified loci between the groups of patients and con-trols revealed no statistically significant differences (p>0.05). Conclusion: As a result of the study, we found previously known changes in the nucleotide sequence in exons 11, 12 and 14 of the CDH1 gene (rs35741240, rs33969373 and rs33964119). None of the identified changes is patho-genic.