Zitzmann, Kathrin; Andersen, Sandra; Vlotides, George; Spoettl, Gerald; Zhang, Shengwen; Datta, Rakesh; Culler, Michael; Göke, Burkhard; Auernhammer, Christoph J. (2013): The Novel Somatostatin Receptor 2/Dopamine Type 2 Receptor Chimeric Compound BIM-23A758 Decreases the Viability of Human GOT1 Midgut Carcinoid Cells. In: Neuroendocrinology, Nr. 2: S. 128-136




The majority of neuroendocrine tumors (NETs) of thegastro-enteropancreatic system coexpress sornatostatin receptors (SSTRs)and dopamine type 2 receptors (D2R), thus providing a rationale for theuse of novel SSTR2/D2R chimeric compounds in NET disease. Here weinvestigate the antitumor potential of the SSTR2/D2R chimeric compoundsBIM-23A760 and BIM-23A758 in comparison to the selective SSTR2 agonistBIM-23023 and the selective D2R agonist BIM-53097 on human NET celllines of heterogeneous origin. While having only minor effects on humanpancreatic and bronchus carcinoid cells (BONI and NCI-H727), BIM-23A758induced significant antitumor effects in human midgut carcinoid cells(GOT1). These effects involved apoptosis induction as well as inhibitionof mitogen-activated protein kinase and Akt signaling. Consistent withtheir antitumor response to BIM-23A758, GOT1 cells showed relativelyhigh expression levels of SSTR2 and D2R mRNA. In particular, GOT1 cellshighly express the short transcript variant of D2R. In contrast toBIM-23A758, the SSTR2/D2R chimeric compound BIM-23A760 as well as theindividual SSTR2 and D2R agonistic compounds BIM-23023 and BIM-53097induced no or only minor antitumor responses in the examined NET celllines. Taken together, our findings suggest that the novel SSTR2/D2Rchimeric compound BIM-23A758 might be a promising substance for thetreatment of NETs highly expressing SSTR2 and D2R. In particular, asufficient expression of the short transcript variant of DR2 might playa pivotal role for effective treatment.