AIM:To identify the expression of Caspase-1(interleukin-1β converting enzyme)and its role in adenoma of thepancreas and chronic pancreatitis.METHODS:The expression of Caspase-1 was assessed in42 pancreatic cancer tissue samples,38 chronic pancreatitisspecimens,and 9 normal pancreatic tissues byimmunohistochemistry and Western blot analysis.RESULTS:Overexpression of Caspase-1 was observed inboth disorders,but there were differences in the expressionpatterns in distinct morphologic compartments.Pancreaticcancer tissues showed a clear cytoplasmatic overexpressionof Caspase-1 in tumor cells of 71% of the tumors,whereasnormal pancreatic tissues showed only occasionalimmunoreactivity.In chronic pancreatitis,overexpression ofCaspase-1 was found in atrophic acinar cells(89 %),hyperplastic ducts(87 %),and dedifferentiating acinar cells(84 %).Although in atrophic cells a clear nuclear expressionwas found,hyperplastic ducts and dedifferentiating acinarcells showed clear cytoplasmic expression.Westem blot analysisrevealed a marked expression of the 45 kDa precursor ofCaspase-1 in pancreatic cancer and chronic pancreatitis(80 %and 86 %,respectively).Clear bands at 30 kDa,whichsuggested the p10-p20 heterodimer of active Caspase-1,werefound in 60 % of the cancer tissue and 14 % of the pancreatitistissue specimens,but not in normal pancreatic tissues.CONCLUSION: Overexpression of Caspase-1 is a frequent event in pancreatic disorders and its differential expression patterns may reflect two functions of the protease. One is its participation in the apoptotic pathway in atrophic acinar cells and tumor-surrounding pancreatitis tissue, the other is its possible role in proliferative processes in pancreatic cancer cells and hyperplastic duct cells and dedifferentiating acinar cells in chronic pancreatitis. AIM: To identify the expression of Caspase-1 (interleukin-1β converting enzyme) and its role in adenoma of the pancreas and chronic pancreatitis. METHODS: The expression of Caspase-1 was assessed in 42 pancreatic cancer tissue samples, 38 Chronic pancreatitis tissue, and 9 normal pancreatic tissues by immunohistochemistry and Western blot analysis .RESULTS: Overexpression of Caspase-1 was observed inboth disorders, but there were differences in the expression patterns in distinct morphologic compartments. Pancreatic cancer tissues showed a clear cytoplasmatic overexpression of Caspase-1 in tumor cells of 71% of the tumors, annormal pancreatic cells showed only occasional immunogenic activity. In chronic pancreatitis, overexpression of Caspase-1 was found in atrophic acinar cells (89%), hyperplastic ducts (87%), and dedifferentiating acinar cells clear nuclear expression was found, hyperplastic ducts and dedifferentiating acinar cells showed clear cytoplasmic expression. We stem blot analysisrevealed a marked expression of the 45 kDa precursor of Caspase-1 in pancreatic cancer and chronic pancreatitis (80% and 86%, respectively) .Clear bands at 30 kDa, which identified the p10-p20 heterodimer of active Caspase-1, were found in 60% of the cancer tissue and 14% of the pancreatitississue specimens, but not in normal pancreatic tissues. CONCLUSION: Overexpression of Caspase-1 is a frequent event in pancreatic disorders and its differential expression patterns may reflect two functions of the protease. One is its participation in the apoptotic pathway in atrophic acinar cells and tumor-surrounding pancreatitis tissue, the other is its possible role in proliferative processes in pancreatic cancer cells and hyperplastic duct cells and dedifferentiating acinar cells in chronic pancreatitis.