Immunohistochemical expression of pancreatic digestive enzymes (trypsin, chymotrypsin, and lipase) was examined in human hepatocellular carcinomas, cholangiocarcinomas and metastatic liver carcinomas. As the results, expression of the enzymes was frequently found in cholangiocarcinoma and metastatic liver carcinomas but not in hepatocellular carcinomas, suggesting that the expression of these enzymes is useful in the differential diagnosis between hepatocellular carcinomas and cholangiocarcinomas and matastatic liver carcinomas.
Expression of proteins and mRNA of pancreatic digestive enzymes (amylase, trypsin, chymotrypsin, and lipase) was investigated in normal and neoplastic epithelia of the human gastrointestinal tract, using immunohistochemistry, Western blot, in situ hybridization, reverse transcriptase-polymerase chain reaction (RT-PCR), and biochemistry. Surgically resected specimens of normal and neoplastic gastrointestinal epithelia were used as materials. Immunohistochemically
, expression of pancreatic digestive enzymes was noted in normal salivary galnds, stomach, duodenum, pancreatic ducts, extrahepatic bile ducts and gall bladder, but not in normal esophagus, small intestine and colon. In neoplasms, immunoreactivities of these enzymes were present in salivary glands tumors, esophageal carcinoma, gastric adenoma and adenocarcinoma, pancreatic carcinoma, extrahepatic bile duct carcinoma, gall bladder carcinoma, and colonic adenoma and adenocarcinoma. The specificity of the immunoreactivities was confirmed by Western blot analysis. In situ hybridization technique showed that mRNA was present in epithelia of normal stomach, duodenum and gall bladder, but not in normal esophagus, small intestine or colon. RT-PCR technique revealed specific signals of mRNA of pancreatic enzymes in normal stomach and duodenum. Biochemical analysis for the enzymes' activity showed that normal stomach and gall bladder had the enzymes' activity but normal colon did not. These data suggest that proteins and mRNA of pancreatic digestive enzymes are present in the normal salivary glands, stomach, duodenum, pancreatic ducts, extrahepatic bile ducts and gall bladder but not in the normal esophagus, small intestine or colon. The data also suggest that epithelial neoplasms of the gastrointestinal tract frequently express the proteins and mRNA of the pancreatic digestive enzymes. Less