Sirt1 Gene Expression and Gastric Epithelial Cells Tumor Stage in Patients with Helicobacter pylori Infection

Abstract

Introduction: The World Health Organization has categorized Helicobacter pylori as a carcinogen for gastric<br />cancer, which causes human mortality worldwide. A number of studies have shown that H. pylori affects cell signaling<br />in gastric epithelial cells and changes the expression of some proteins such as proinflammatory cytokines. Bacterial<br />infections may alter sirt1 and sirt2 genes expression in inflammatory tissues and cancer cells. In this study, sirt1 and<br />sirt2 genes expression in gastric cancers was surveyed with reference to H. pylori status. Methods: Stomach biopsies<br />were collected from 50 gastric cancer patients, 25 H. pylori-positive and 25 H. pylori-negative as determined by the<br />urea rapid test. Tumor grade was determined by a pathologist. After total RNA extraction from gastric cancer biopsy<br />samples and cDNA synthesis, sirt1 and sirt2 genes expression levels were determined by Real Time PCR and ΔΔCT<br />methods. Results: There was no statistically significant link between H. pylori infection and sirt1 (P<0.899) and sirt2<br />(P<0.169) genes expression in gastric epithelial cells. However, pathologic findings showed that there is a statistically<br />significant relationship between sirt1 gene expression and the tumor grade (P<0.024). Discussion: A statistically<br />significant association was found between sirt1 gene expression and tumor grade of gastric cancers that could be due<br />to effects on progression of cancer cells infected with H. pylori.