Poster (Painel)
| 380-2 | Ancestral origin and virulence markers of Helicobacter pylori strains and host genetic structure as predictors of gastric cancer | | Autores: | Batista, S.A. (UFMG - Universidade Federal de Minas Gerais/Faculdade de MedicinaICB/UFMG - Instituto de Ciências Biológicas/Dpto de Microbio) ; Rocha, G.A. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Rocha, A.M.C. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Anacleto, C. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Melo, F.F. (CPQRR/FIOCRUZ - Centro de Pesquisa René Rachou) ; Cunha, R.P.A. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Teixeira, K.N. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Trant, C.G.M.C (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Calixto, R.S. (UFMG - Universidade Federal de Minas Gerais/Faculdade de MedicinaICB/UFMG - Instituto de Ciências Biológicas/Dpto de Microbio) ; Gomes, A.D. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) ; Santos, E.M.T. (ICB/UFMG - Instituto de Ciências Biológicas/Dpto de Biologia Geral) ; Coimbra, R.S. (CPQRR/FIOCRUZ - Centro de Pesquisa René Rachou) ; Lima, A.A.M. (UFC - Universidade Federal do Ceará/Faculdade de Medicina) ; Queiroz, D.M.M. (UFMG - Universidade Federal de Minas Gerais/Faculdade de Medicina) |
Resumo We aimed to investigate the phylogeographic origin of H. pylori strains from gastric cancer patients as well as the genetic structure of the patients to determine whether they are predictors of gastric cancer in an admixed population from South-East Brazil. Phylogeographic origin was evaluated in 103 H. pylori strains from patients with gastric cancer (n=27), duodenal ulcer (n=28) and gastritis, control group (n=48), by sequencing of both strands of 397 to 690 bp per gene of the atpA, efp, mutY, trpC, ureI, and yph house-keeping genes. The sequences were aligned (MUSCLE program) and deposited in the multi-locus sequence typing-MLST database. Neighbor joining tree of H. pylori strains (1,201 classified in ancestral haplogroups and our 103 strains) was created by software MEGA 5.1 using the Kimura model with 10,000 bootstraps. To determine the ethnicity of each patient, 106 validated SNPs were evaluated by Sequenon iPLEX Plataform. We estimated individuals’ ancestry using parental groups: African, European and Brazilian Amerindians employing the software Structure 2.3.3. Data were analyzed by Fisher, χ2, Student and correlation tests. H. pylori strains were classified as hpAfrica1 (73-70.9%) and hpEurope (30-29.1%). hpAfrica1 strains were observed in 88.9% (gastric cancer), 85.7% (duodenal ulcer) and 47.9% (gastritis) patients (p<0.001). However, when the patients were stratified by bacterium virulence markers, the association disappeared (p>0.25). s1i1m1 vacA associated with gastric cancer and s1m1/m2 with duodenal ulcer (p<0.001). The percentage of each ancestry was similar in patients with gastritis and gastric cancer (p>0.46). European ancestry correlated with corpus gastritis (r=0.2, p=0.05) and intestinal metaplasia (r=0.2, p=0.04) in the s1 vacA gastritis group. European ancestry also correlated with European origin of H. pylori strains (r=0.5, p=0.01). H. pylori virulence markers, more than H. pylori ancestry “per se” and genetic structure of the population, are the most important predictors of gastric cancer in the studied admixed population. |