MARKERS OF SURFACE MUCOUS CELL-TYPE HUMAN GASTRIC-CANCER CELLS - GALACTOSE OXIDASE-SCHIFF REACTIVE MUCINS, MONOCLONAL-ANTIBODY SH-9 REACTIVE MUCINS AND CATHEPSIN-E

Cellular differentiation of gastric cancer cells allows the classifica tion of cell type into surface mucous cell, pyloric gland cell, intest inal absorptive cell and goblet cell types by mucin histochemistry and pepsinogen (Pg) immunohistochemistry. Surface mucous cell differentia tion of gastric cancers of each histologic type has previously been de tected by the galactose oxidase-Schiff (GOS) reaction although this is not always positive in all cases. Mucus granules of surface mucous ce lls of normal gastric mucosa show an intense reactivity for SH-9 (mono clonal antibody against CA125-bearing antigenic molecule fragments). C athepsin E is also expressed in the cytoplasm of surface mucous cells, weakly in absorptive cells of duodenal villi and occasionally in pylo ric gland cells. Expression of SH-9 reactive mucin and of cathepsin E were therefore investigated as possible additional markers to distingu ish between the gastric cancer cell type in 203 primary stomach cancer s. SH-9 reactive mucin was found selectively in GOS positive cancer ce lls of surface mucous cell type and/or cancer cells unclassified by mu cin histochemistry. These latter cells were therefore classified into the surface mucous cell category. Cathepsin E was found mainly in canc er cells of the GOS positive surface mucous cell type and occasionally , in intestinal absorptive and pyloric gland cell types. Galactose oxi dase-Schiff, SH-9 and cathepsin E reactive or positive cancer cells we re found in 145 (71.4%),151 (74.4%) and 144 (70.9%), respectively, of the 203 primary stomach cancers investigated.