The Role of VASP in Gastric Carcinoma

Vasodilator stimulated phosphoprotein (VASP) is associated with focal adhesions and is thought to be crucial regulators of actin dynamics and associated processes such as cell adhesion and motility. A study was undertaken to analyse VASP expression in normal gastric tissue and gastric carcinomas. Human gastric tissues with adenocarcinomas (n=42) were used. Normal gastric tissue specimens (n=6) were taken from areas a standard distance (5 cm) from resected carcinomas of patients who underwent surgical resection. Carcinomas were classified according to pathological staging and histopathological grades. Tissues were stained for VASP using immunohistochemistry. To further explore VASP expression level in human gastric carcinomas, western blot analysis was performed to analyze VASP protein expression in pairs of gastric tissues and cancers. Normal gastric tissues showed no VASP expression while macrophages and lymphocytes of connective tissue had the strongest immunoreactivity for VASP. Carcinomas (epithelium mucosae, glandular epithelium, vascular endothelial cell, vascular smooth muscle cell) had significantly greater VASP expression than normal epithelium (P<0.01). Moreover, VASP expression in adenocarcinomas increased significantly with more advanced tumor stage (P<0.01). Western blot showed that VASP was expressed at higher levels in cancer tissues compared to adjacent tissues. The spatial and differential expression of VASP in normal gastric tissue and gastric carcinomas suggests that it is likely to be involved in the differentiation of normal gastric cells to carcinomas. The significant increase in the expression of VASP in carcinomas in parallel to pathological staging suggests that it may regulate the invasive behavior of gastric carcinomas as carcinoma invasion is increased in more advanced tumors.