The novel somatostatin receptor 2/dopamine type 2 receptor chimeric compound BIM-23A758 decreases the viability of human GOT1 midgut carcinoid cells

Neuroendocrinology. 2013;98(2):128-36. doi: 10.1159/000353784. Epub 2013 Jul 31.

Abstract

The majority of neuroendocrine tumors (NETs) of the gastroenteropancreatic system coexpress somatostatin receptors (SSTRs) and dopamine type 2 receptors (D2R), thus providing a rationale for the use of novel SSTR2/D2R chimeric compounds in NET disease. Here we investigate the antitumor potential of the SSTR2/D2R chimeric compounds BIM-23A760 and BIM-23A758 in comparison to the selective SSTR2 agonist BIM-23023 and the selective D2R agonist BIM-53097 on human NET cell lines of heterogeneous origin. While having only minor effects on human pancreatic and bronchus carcinoid cells (BON1 and NCI-H727), BIM-23A758 induced significant antitumor effects in human midgut carcinoid cells (GOT1). These effects involved apoptosis induction as well as inhibition of mitogen-activated protein kinase and Akt signaling. Consistent with their antitumor response to BIM-23A758, GOT1 cells showed relatively high expression levels of SSTR2 and D2R mRNA. In particular, GOT1 cells highly express the short transcript variant of D2R. In contrast to BIM-23A758, the SSTR2/D2R chimeric compound BIM-23A760 as well as the individual SSTR2 and D2R agonistic compounds BIM-23023 and BIM-53097 induced no or only minor antitumor responses in the examined NET cell lines. Taken together, our findings suggest that the novel SSTR2/D2R chimeric compound BIM-23A758 might be a promising substance for the treatment of NETs highly expressing SSTR2 and D2R. In particular, a sufficient expression of the short transcript variant of DR2 might play a pivotal role for effective treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Carcinoid Tumor / genetics
  • Carcinoid Tumor / pathology*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Dopamine / analogs & derivatives*
  • Dopamine / pharmacology
  • Humans
  • Intestinal Neoplasms / genetics
  • Intestinal Neoplasms / pathology*
  • Receptors, Dopamine D2 / agonists
  • Receptors, Dopamine D2 / genetics
  • Receptors, Somatostatin / agonists
  • Receptors, Somatostatin / genetics
  • Recombinant Fusion Proteins / pharmacology*
  • Somatostatin / analogs & derivatives*
  • Somatostatin / pharmacology
  • Transcriptome

Substances

  • Antineoplastic Agents
  • DRD2 protein, human
  • Receptors, Dopamine D2
  • Receptors, Somatostatin
  • Recombinant Fusion Proteins
  • somatostatin receptor 3
  • somatostatin receptor type 1
  • Somatostatin
  • somatostatin receptor 2
  • TBR-760
  • Dopamine

Supplementary concepts

  • Carcinoid Tumors, Intestinal