EXPRESSION OF CD44-CONTAINING-VARIANT-EXON-9 (CD44V9) IN GASTRIC ADENOMAS AND ADENOCARCINOMAS - RELATION TO THE PROLIFERATION AND PROGRESSION

The expression of CD44 splice variant containing exon 14 (variant exon 9: CD44v9) was examined immunohistochemically in non-neoplastic mucos a, adenoma and adenocarcinoma of the stomach and analyzed the relation with the expression of Ki-67 antigen and p53 protein. In nonneoplasti c gastric mucosa, basolateral membrane of the epithelial cells in the pyloric glands showed the expression of CD44v9. The epithelial cells i n the intestinal metaplastic mucosa of the stomach sometimes expressed CD44v9. In the neoplastic lesions, the expression of CD44v9 was detec ted in 20% (34/170) of the adenomas and 28% (132/478) of the adenocarc inomas, respectively. The incidence of CD44v9 expression did not diffe r among histological type of gastric carcinoma. Twelve per cent of the adenocarcinomas showed strong expression of CD44v9, whereas non of th e adenomas did. The incidence of CD44v9 expression was significantly h igher in carcinomas invading into muscularis propria or the cases of s tages 3 and 4 in comparison with that in carcinomas limited to submuco sa or the stages 1 and 2 cases (p<0.05). The incidence of positive cas es was higher in carcinomas with lymph node metastasis than those with out metastasis (p<0.05). The expression of CD44v9 was significantly co rrelated with the expression of Ki-67 (p<0.05). It was also correlated with the expression of p53 protein in the tumor cells (p<0.01). These findings overall suggest that the expression of CD44v9 may be associa ted with the development as well as progression of the gastric carcino mas.