Characterization of functional thrombin receptors in human pancreatic tumor cells (MIA PACA-2).
In this article, the "tethered ligand" thrombin receptor was identified on human pancreatic tumor cells, MIA PaCa-2, using immunofluorescence studies with a monoclonal anti-thrombin receptor antibody. Pharmacological characterization, using 3H-labeled thrombin receptor activating peptide-6 (TRAP-6) as radioligand, demonstrated a single class of high-affinity binding sites (KD = 9.1+/-1.8 x 10(-7) M) and a binding capacity of 13.9+/-0.7 fmol/mg protein. These binding sites represent functional thrombin receptors, as shown by alpha-thrombin- and TRAP-6-induced mobilization of free intracellular calcium, protein kinase C translocation from cytosol to the cell membrane, and stimulation of DNA synthesis in MIA PaCa-2 cells. These results provide the first identification of tethered ligand thrombin receptor in human pancreatic cancer cells and suggest thrombin receptor involvement in mechanisms of human pancreatic tumor progression.
Rudroff
C
C
Department of Surgery, Friedrich Schiller University Jena, Germany.
Schafberg
H
H
Nowak
G
G
Weinel
R
R
Scheele
J
J
Kaufmann
R
R
D002118:Calcium / Q000378:metabolism; D004273:DNA, Neoplasm / Q000096:biosynthesis; D005455:Fluorescent Antibody Technique; D006801:Humans; D010190:Pancreatic Neoplasms / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D018179:Receptors, Thrombin / Q000032:analysis* / Q000378:metabolism; D014316:Tritium; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D010446:Peptide Fragments; D018179:Receptors, Thrombin; C082835:thrombin receptor peptide (42-47); D014316:Tritium; D011493:Protein Kinase C; D002118:Calcium