A F240S polymorphism of protease-activated receptor 2 (PAR2) is not detected in Japanese population with gastro-esophageal symptoms

Trypsin acting at protease-activated receptor 2 (PAR2) has been reported to contribute to a progression of malignant tumors. In addition, a polymorphic form of PAR2 has been also reported to display reduced sensitivity to trypsin. However, a frequency of PAR2 polymorphism is unknown in Japan. The aim of the present study was to clarify a frequency of PAR2 polymorphism in Japan and to evaluate the relation between this polymorphism and gastric cancer. We estimated PAR2 T719C in 106 patients with gastric cancer (GC cases) and 96 patients without gastric cancer (non-GC cases). We employed a single-strand conformation polymorphism analysis after polymerase chain reaction (PCR-SSCP) for detecting of this polymorphism. There was no significant difference between GC and non-GC cases in the distribution of gender (M:F = 2.66 and 2.00, respectively) and age (mean age = 66.12 and 63.50, respectively). Helicobacter pylori (H. pylori) positive ratio was 81.7% (GC cases: 92.0%, non-GC cases: 72.5%, p<.01). Single strand bands of 719C were not detected in all 202 patients by PCR-SSCP. In conclusion, a polymorphism F240S of PAR2 is very rare and does not contribute to the genesis and progression of gastric cancer in Japanese population.