What are the pancreatic target cells for gastrin and its CCKB receptor? Is this a couple for cancerous cells?
Jean Morisset, Jean Lainé, Marzena Biernat, Sophie Julien
Med Sci Monit 2004; 10(10): RA242-246
The objectives of this review are to summarize, analyse and discuss the roles played by the CCK receptor subtypes and their agonists on pancreatic enzyme secretion, pancreas growth and regeneration, define the receptors specific target cells and evaluate the role of gastrin in pancreatic pathologies including cancer. In rodents, it is clear that the CCKARs present on pancreatic acinar cells play a major role in enzyme secretion. In large mammals, CCK does not seem to be the final mediator of enzyme release. In rat, gastrin and its CCKBR seem responsible for foetal pancreas growth while after birth, CCK was shown to be the most potent trophic factor via occupation of its CCKAR. In pig and human, no one has yet established a direct link between CCK, gastrin and pancreas growth. In rodent's pancreas, the CCKAR were observed on acinar cells as well as on islet's alpha and beta cells; in six other species, the CCKAR were present only on alpha and beta cells with the CCKBR always present on delta cells. The CCKBRs were overexpressed in acute pancreatitis and in metaplastic pancreas following duct ligation. In pancreatic cancer cells, a gastrin autocrine loop involving the CCKBR was suggested. The presence of both CCKR-subtypes and gastrin was observed in many pancreatic tumors; however, their role in cancer growth remains controversial.
Keywords: Gastrins - metabolism, Animals, Gastrins - metabolism, Humans, Pancreas - secretion, Pancreatic Neoplasms - secretion, Receptor, Cholecystokinin A - metabolism, Receptor, Cholecystokinin B - metabolism, Regeneration