New insights into hereditary pancreatitis

Hereditary pancreatic cancer: a clinical perspective

Pancreatic cancer is an extraordinarily deadly disease and is responsible for over 220,000 deaths worldwide each year. One of the greatest risk factors for developing pancreatic cancer is a positive family history. Hereditary pancreatitis patients have a greatly elevated pancreatic cancer risk and individuals with cystic fibrosis may rarely develop this cancer, but often at very young ages. Various genetically linked cancer syndromes have been associated with pancreatic cancer in mutation-positive family members. Finally, familial pancreatic cancer-defined as families with two or more first-degree relatives who have pancreatic cancer but do not have a known cancer syndrome-is a known entity whose disease-causing mutation remains unidentified. This article describes research to date on hereditary pancreatic cancer, addresses how best clinicians should recognise hereditary forms of pancreatic cancer and explains the emotional burden of discovering a potentially lethal mutation. Many controversies and unanswered questions in hereditary pancreatic cancer remain.

Trypsin activity is not involved in premature, intrapancreatic trypsinogen activation

A premature and intracellular activation of digestive zymogens is thought to be responsible for the onset of pancreatitis. Because trypsin has a critical role in initiating the activation cascade of digestive enzymes in the gut, it has been assumed that trypsin also initiates intracellular zymogen activation in the pancreas. We have tested this hypothesis in isolated acini and lobules from rat pancreas. Intracellular trypsinogen activation was induced by supramaximal secretagogue stimulation and measured using either specific trypsin substrates or immunoreactivity of the trypsinogen activation peptide (TAP). To prevent a trypsin-induced trypsinogen activation, we used the cell-permeant, highly specific, and reversible inhibitor Nalpha-(2-naphthylsulfonyl)-3-amidinophenylalanine-carboxymethylpiperazide (S124), and to prevent cathepsin-induced trypsinogen activation, we used the cysteine protease inhibitor E-64d. Incubation of acini or lobules in the presence of S124 completely prevented the generation of trypsin activity in response to supramaximal caerulein but had no effect whatsoever on the generation of TAP. Conversely, when trypsin activity was recovered at the end of the experiment by either washout of S124 from acini or extensive dilution of lobule homogenates, it was up to 400% higher than after caerulein alone and corresponded, in molar terms, to the generation of TAP. Both trypsin activity and TAP release were inhibited in parallel by E-64d. We conclude that caerulein-induced trypsinogen activation in the pancreas is caused by an E-64d-inhibitable mechanism such as cathepsin-induced trypsinogen activation, and neither involves nor requires intracellular trypsin activity. Specific trypsin inhibition, on the other hand, prevents 80% of trypsin inactivation or autodegradation in the pancreas.