Association of LEC and tnpA Helicobacter pylori genes with gastric cancer in a Brazilian population

Abstract

<p>Abstract</p> <p>Background</p> <p><it>H. pylori </it>seroprevalence in Brazilians varies and is dependent on socioeconomic status, sanitation conditions and ethnicity; furthermore, <it>H. pylori </it>is not always associated with the incidence of gastric cancer, suggesting the role of more virulent strains. The purpose of this study was to analyze the association of more virulent <it>H. pylori </it>strains with gastric cancer.</p> <p>Methods</p> <p>DNA was extracted from gastric biopsies of thirty-four cases of gastric cancer (11 intestinal-type, 23 diffuse-type), and thirty-four of patients with endoscopic gastritis. The presence of <it>cag</it>PAI genes (<it>cagA</it>, <it>cagA </it>promoter, <it>cagE</it>, <it>cagM</it>, <it>tnpB</it>, <it>tnpA</it>, <it>cagT </it>and the left end of the <it>cag</it>II (LEC)) and <it>babA </it>were analyzed by PCR.</p> <p>Results</p> <p>Comparison of <it>H. pylori </it>isolates from gastric cancer and gastritis patients showed significant associations of <it>tnpA </it>and LEC with gastric cancer (73.5% [OR, 6.66; 95% CI, 2.30-19.25] and 58.8% [OR, 10.71; 95% CI, 3.07-37.28] of cases, respectively). Other <it>cag</it>PAI genes were detected in both groups at similar frequencies.</p> <p>Conclusions</p> <p><it>tnpA </it>and LEC of <it>H. pylori cag</it>PAI were associated with gastric cancer; nonetheless, these results were restricted within this group of patients and further studies are needed to confirm these results in a larger sample and determine their role in gastric carcinogenesis.</p