Galectin-۹ Expression Profile in Patients with Gastric Cancer and Peptic Ulcer Disease

Background: Chronic inflammation and dys-regulation of the immune system mechanisms are now well established as primary triggers of gastric cancer and peptic ulcer disease. Galectin-۹ (Gal-۹) is a member of the galectin family and known as an inducer of cell aggregation, adhesion and apoptosis. Gal-۹ interaction with its main ligand T-cell immunoglobulin and mucin domain protein-۳ (Tim-۳) leads to the apoptosis of T cells and dys-regulation of the immune responses in different tumors. In the current study, the mRNA expression pattern of Gal-۹ was evaluated in gastric biopsies of patients with gastric cancer and peptic ulcer disease. Methods: In this case control study, gastric biopsies were obtained from ۴۶ patients with gastric cancer, ۴۴ patients with peptic ulcer disease and ۴۱ cases with non-ulcer dyspepsia served as controls who underwent endoscopy for evaluation of their gastric problems. Infection with Helicobacter pylori was determined by rapid urease test for all participants and H&E staining for GC patients. Total RNA was extracted from all gastric tissues and used for cDNA synthesis. Relative expression of Gal-۹ mRNA was determined by Real-Time PCR using β-actin as a housekeeping gene. Results: Gal-۹ was similarly expressed in all three studied groups. No statistical difference was found for Gal-۹ expression between gastric cancer patients and control group (۲-ΔCt =۰.۰۲۲ vs ۰.۰۱۴۴, p=۰.۳۰) and also between peptic ulcer and control groups (۲-ΔCt =۰.۰۸۸ vs ۰.۱۴۴, p=۰.۱۶). No correlation was found for Gal-۹ expression and infection with Helicobacter pylori (۲-ΔCt = ۰.۱ vs ۰.۱۲۹, p=۰.۵۱). Conclusion: Similar expression of Gal-۹ in gastric tissues from patients with gastric cancer, peptic ulcer and also non-ulcer dyspepsia individuals suggest no possible role of this molecule on tumorigenesis and immunoregulatory mechanisms of these gastric disorders.