EXPRESSION OF GROUP-II PHOSPHOLIPASE-A2 IN MALIGNANT AND NONMALIGNANTHUMAN GASTRIC-MUCOSA

The expression of Group-II phospholipase A2 (M-PLA2) was analysed immu nohistochemically in malignant, non-malignant (including atrophic, hyp erplastic, pseudopyloric metaplastic and intestinal metaplastic) and n ormal human gastric mucosae. M-PLA2 Was consistently detected in the s tem cell lineage, pseudopyloric metaplasia and the generative cells of hyperplastic foveolar epithelium and intestinal metaplasia (IM). In I M, the appearance of M-PLA2 was found to be closely related to the deg ree of development of the brush borders on columnar cells and was espe cially prominent at dense brush borders. Paneth cells of IM, particula rly their secretory products, were strongly immunoreactive for M-PLA2. In gastric cancer, the expression of M-PLA2 was detected exclusively in cancer cells with a low grade of differentiation, and seemed to be intensified in the invading zone of the tumour. These observations sug gest that the expression of M-PLA2 is associated with the proliferativ e kinetics and regeneration of human gastric mucosa, and may indicate a physiological relationship between its expression and metaplasia of small intestinal type. Moreover, the appearance of M-PLA2 may be relat ed to the invasive ability of gastric cancer.