Overview of Gene Expression Analysis in Gastric Disease Infected with Helicobacter pylori: CLDN1 and MMP9 Could Be Biomarkers for Early Diagnosis of Gastric Cancer

Chronic Helicobacter pylori infection produces several lesions in the human stomach, which can progress to chronic atrophic gastritis and gastric cancer. To date, there is very little information on gene expression in chronic atrophic gastritis and its relationship with progression to gastric cancer. In this study, we performed a gene expression analysis during chronic atrophic gastritis in order to identify possible biomarkers that allow an early diagnosis of gastric cancer. We studied biopsies from patients with chronic atrophic gastritis and gastric cancer. The biopsies were analyzed by a gene expression microarray and corroborated by qPCR and validated through immunohistochemistry. Our results revealed that gene expression profiles in patients with chronic atrophic gastritis showed molecular changes of the gastric mucosa, leading to gastric cancer. The gene expression profiles of CLDN1, CLDN7, OLFM4, C-MYC and MMP9 were more notable from the chronic atrophic gastritis. The gene expression patterns observed in this study allowed the identification of CLDN1 and MMP9 proteins as promising biomarkers of early stages of gastric cancer development.