Association between peroxisome proliferator-activated receptor-γ gene polymorphism (Pro12Ala) and Helicobacter pylori infection in gastric carcinogenesis

Abstract

Objective. Helicobacter pylori infection is accompanied by inflammatory processes leading to peptic ulcer and gastric cancer in the minority of infected individuals. The interaction between H. pylori virulence factors, host defense mechanisms and environmental factors determine the outcome of clinical manifestations. One of the host factors involved in the processes of inflammation and carcinogenesis is the peroxisome proliferator-activated receptor-γ (PPAR-γ) molecule. The present case–control study aimed to determine polymorphism of PPAR-γ gene and its association with H. pylori infection and gastrointestinal diseases (peptic ulcer and non-cardia gastric cancer) in Iranian patients. Materials and methods. One hundred and fifty-five patients with upper gastrointestinal diseases (76 peptic ulcer and 79 non-cardia gastric cancer) and 152 matched controls were genotyped for PPAR-γ gene polymorphism (Pro12Ala) by the PCR–RFLP method. Infection with H. pylori was confirmed by histology, the rapid urease test (RUT) and ELISA assay (IgG anti-H. pylori). Results. The frequency of PPAR-γ G (Ala 12) allele was significantly higher in H. pylori positive patients with non-cardia gastric cancer than in controls (22.8% vs. 3.9%, p = 0.027; OR = 3.28; 95% CI = 1.21–8.89), But there was no significant difference without infection (p = 0.7). Moreover, the PPAR-γ polymorphism was not associated with peptic ulcer in the presence or absence of H. pylori infection. Conclusion. Our results indicated PPAR-γ G allele may be an important contributor to non-cardia gastric cancer in Iranian H. pylori infected patients.

Key Words::

• Gastric cancer
• Helicobacter pylori
• inflammation
• peptic ulcer
• PPAR-γ gene polymorphism

Acknowledgements

The authors thank Shiraz Institute for Cancer Research, Shiraz Blood Transfusion Center for their cooperation and Mohsen Hoseini-Farzad for his technical assistance. This study was supported by a grant from Shiraz University of Medical Sciences, Research Deputy (No. 85-2804).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.