- 【Updated on May 12, 2025】 Integration of CiNii Dissertations and CiNii Books into CiNii Research
- Trial version of CiNii Research Knowledge Graph Search feature is available on CiNii Labs
- 【Updated on June 30, 2025】Suspension and deletion of data provided by Nikkei BP
- Regarding the recording of “Research Data” and “Evidence Data”
Description
The aspartic proteinase family, each member of which has two essential aspartyl residues at the active site, includes pepsins, renin, cathepsin D, and cathepsin E (CTSE). Unlike pepsins, CTSE is a non-secretory, intracellular, but non-lysosomal proteinase found in the highest concentration in the superficial epithelial cells of the stomach (1,2). CTSE has been also localized to several lymphoid associated tissues (3,4). Although CTSE is thought to play an important role in the cell, the function of this proteinase is still unclear. Since it is not secreted into the stomach, it does not appear to have a role in digestion of dietary protein. Due to its intracellular location and distribution in lymphoid associated tissue, it has been suggested that the enzyme may have a role in immune function. It would be of great help in facilitating studies on the function of CTSE to determine the biological behavior of the enzyme in pathophysiological conditions. In the present study, we demonstrated the expression of CTSE in pancreatic ductal adenocarcinomas.