Reduced expression of caspase-8 and cleaved caspase-3 in pancreatic ductal adenocarcinoma cells.

Pancreatic ductal adenocarcinoma (PDAC) is a rare neoplasm that affects the gastrointestinal system, and is characterized by a high mortality rate. It has been demonstrated that apoptosis has a significant role in the regulation of cancer cells. Therefore, the aim of the present study was to immunohistochemically assess the expression of proteins belonging to the caspase family, namely caspase-8, pro-caspase-3 and cleaved (active) caspase-3 in pancreatic cancer. The study group consisted of 29 patients exhibiting PDAC. Protein expression was evaluated by immunohistochemical methods. The expression of caspase-8 in normal cells was negative in 17.2% of cases and positive in 82.8% of cases. All cases demonstrated pro-caspase-3 expression in normal pancreatic cells, compared with 93.1% of cancer cells. Staining for activated caspase-3 was positive in 27 normal tissue cases, compared with positivity in only 10 cancer cases. Caspase-8 expression positively correlated with cleaved caspase-3 expression in the cytoplasm of cancer cells (P<0.002). Caspase-3 expression was identified to correlate with inflammatory peritumoral infiltration (P<0.015). No correlation was observed between caspase expression and any other clinicopathological parameters. The results of the present study demonstrated aberrant initiation of cancer cell apoptosis in PDAC via a decrease in caspase-8 expression, which may lead to disorders in the activation of effector caspase-3.