Gastrin secretion by gastrinoma cells in long-term culture

Gastrinoma cells from surgical specimens of a primary pancreatic tumor and an hepatic metastasis in two patients with a Zollinger-Ellison syndrome were grown and subcultured for 7 mo. Cultured cells displayed a strong reactivity to heptadecapeptide gastrin antibody and maintained an ultrastructural appearance resembling that of the original tumor cells with the presence of secretory granules of variable size and electron density. Cultured cells also showed the ability to secrete immunoreactive gastrin, and this secretion was further concentration-dependently stimulated by secretin (10(-10)-10(-6) M), carbachol (10(-6) M), and bombesin (10(-10)-10(-6) M). The latter peptide was the more potent stimulant with a maximal effect at 10(-9) M (460 +/- 20% of basal release; P less than 0.05). This stimulation occurred in the absence of extracellular Ca2+ and was potentiated by the addition of dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP; 10(-3) M) into the culture medium. The somatostatin analogue, somatostatin-(201-995), did not alter basal gastrin release but inhibited secretin, carbachol, and bombesin stimulation. Moreover, DBcAMP (10(-3) M) and Ca2+ (1-3 mM) stimulated gastrin release; Ca2+ ionophore A23187 (6 micrograms/ml) enhanced gastrin response to Ca2+ in the early time intervals of incubation. Furthermore the phorbol ester derivative, 12-O-tetradecanoyl phorbol-13-acetate, dramatically stimulated gastrin release (10 times the basal value). We conclude that gastrinoma cells can be cultured over an extended period with maintenance of their capacity to secrete gastrin in response to various hormones and mediators.(ABSTRACT TRUNCATED AT 250 WORDS)