G protein-coupled receptor signaling in human ductal pancreatic cancer cells: neurotensin responsiveness and mitogenic stimulation.
Neuropeptides and their corresponding G protein-coupled receptors (GPCRs) are increasingly implicated in the autocrine/paracrine stimulation of growth of human cancers. We report that neurotensin induced rapid Ca2+ mobilization from intracellular stores followed by Ca2+ influx in five human ductal pancreatic cancer cell lines: HPAF-II, Capan-1, Capan-2, PANC-1, and MIA PaCa-2. In addition, most cell lines exhibited Ca2+ responses to multiple neuropeptides including bombesin, bradykinin, cholecystokinin, and vasopressin and to bioactive lipids, including lysophosphatidic acid (LPA), that also act via GPCRs. The well-differentiated line HPAF-II responded to at least seven independent GPCR agonists. The concentrations of neurotensin required to induce half-maximal effects (EC50) in HPAF-II and PANC-1 cells were 5 and 8nM, respectively. Digital fluorescence image analysis to measure Ca2+ responses in single cells revealed that 90% or more of HPAF-II and PANC-1 cells responded to 10nM neurotensin. Addition of neurotensin to PANC-1 cells also induced rapid and dose-dependent extracellular-regulated protein kinase (ERK-1 and ERK-2) activation and subsequently, stimulated DNA synthesis. The signaling complexity of GPCRs uncovered by these studies reveals a new aspect in the biology of human pancreatic cancer and could offer the basis for new approaches to the treatment of this disease.
Ryder
N M
NM
Department of Surgery School of Medicine, University of California, Los Angeles 90095-1786, USA.
Guha
S
S
Hines
O J
OJ
Reber
H A
HA
Rozengurt
E
E
D001839:Bombesin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007425:Intracellular Membranes / Q000378:metabolism; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology; D009496:Neurotensin / Q000494:pharmacology; D009994:Osmolar Concentration; D010183:Pancreatic Ducts; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000503:physiopathology*; D011956:Receptors, Cell Surface / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014407:Tumor Cells, Cultured
D008934:Mitogens; D011956:Receptors, Cell Surface; D009496:Neurotensin; D020928:Mitogen-Activated Protein Kinases; D019204:GTP-Binding Proteins; D001839:Bombesin; D002118:Calcium