EXPRESSION OF CATHEPSIN-E IN PANCREAS - A POSSIBLE TUMOR-MARKER FOR PANCREAS, A PRELIMINARY-REPORT

Ductal cancers of the pancreas frequently express markers of gastroint estinal epithelial cells. Cathepsin E (CTSE) is a nonsecretory, intrac ellular, but non-lysosomal proteinase found in the highest concentrati on in the superficial epithelial cells of the stomach. The aims of our study were to examine the expression of CTSE in the pancreas, to esta blish an assay system of CTSE and to evaluate the diagnostic usefulnes s of CTSE in the pancreatic juice. Eleven patients with pancreatic duc tal adenocarcinoma, 10 with mucin-producing adenoma, 3 with intraducta l papillary hyperplasia and 43 with chronic pancreatitis were examined . Surgically resected pancreatic tissues were subjected to immunohisto chemistry for CTSE. Pancreatic juice was collected from the patients a nd subjected to sandwich ELISA and Western analysis for detecting CTSE . Positive staining for CTSE was observed in pancreatic ductal adenoca rcinoma by immunohistochemistry. CTSE was also expressed in mucin-prod ucing adenoma, intraductal papillary hyperplasia and mucinous hyperpla sia. CTSE in the pancreatic juice was present in 8 of 11 patients with pancreatic ductal adenocarcinoma, 5 of 10 patients with mucin-produci ng tumor, 1 of 3 patients with intraductal papillary hyperplasia and 4 of 43 patients with chronic pancreatitis. The detection frequency of CTSE in the pancreatic juice was significantly higher in the patients with pancreatic ductal adenocarcinoma than in the patients with chroni c pancreatitis. Our findings suggest that the expression of CTSE is as sociated with the pathogenesis of pancreatic ductal adenocarcinoma, th at CTSE in the pancreatic juice seems to be a useful marker for a defi nitive diagnosis and that CTSE may be expressed at a relatively early stage of multistep carcinogenesis in pancreatic lesions. (C) 1996 Wile y-Liss, Inc.