Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 18 5 2026 10 05 Analysis of gene expression patterns in various topographic sites of gastritis patients infected with Helicobacter pylori 773 786 Sahar Sarrafzadeh Zargar Department of Biology, Ra.C., Islamic Azad University, Rasht, Iran Masoumeh Anvari Department of Biology, Ra.C., Islamic Azad University, Rasht, Iran Amir Sadeghi Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Abbas Yadegar Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2025 06 29 2026 07 28 Background and Objectives: Helicobacter pylori infection primarily contributes to gastric carcinogenesis. This study examined the expression of cyclin E1, β-catenin, PPAR-δ, and miR-9 in different gastric regions of gastritis patients with and without H. pylori infection. Materials and Methods: Gastric biopsies were obtained from 108 participants divided into three groups, including healthy (n = 15), gastritis (n = 53), and H. pylori-positive gastritis (n = 40). Bacterial culture and molecular characterization were performed to confirm H. pylori presence. Gene expression was assessed using SYBR Green-based RT-qPCR. Statistical analyses revealed correlations between the expression of cyclin E1, β-catenin, PPAR-δ, miR-9, and the presence of H. pylori in patients with gastritis compared to healthy controls. Results: The cagA-positive strains were significantly associated with the expression of cyclin E1, β-catenin, PPAR-δ (P < 0.001), and miR-9 (P < 0.01). Cyclin E1 and β-catenin expression were upregulated in gastritis and H. pylori-positive gastritis patients. The PPAR-δ expression was highest in H. pylori-positive gastritis patients, specifically in the antrum tissues. miR-9 showed significant downregulation in H. pylori-positive gastritis samples. Conclusion: cagA-positive H. pylori infection was linked to distinct gene expression changes that varied by gastric region. Further studies are needed to explore the mechanisms involved. https://ijm.tums.ac.ir/index.php/ijm/article/view/5590 https://ijm.tums.ac.ir/index.php/ijm/article/download/5590/1938