title: SOM230, a new somatostatin analogue, is highly effective in the therapy of growth hormone/prolactin-secreting pituitary adenomas.
abstract: OBJECTIVE
  We have previously shown that transgenic mice ubiquitously overexpressing the HMGA2 gene develop growth hormone/prolactin-secreting pituitary adenomas. This animal model has been used to evaluate the therapeutic efficacy of SOM230, a somatostatin analogue with high affinity for the somatostatin receptor subtypes 1, 2, 3, and 5, on the growth of the pituitary adenomas.
  
  
  METHODS
  Four groups of 3- and 9-month-old HMGA2 transgenic mice were treated for 3 months with a continuous s.c. injection of two different dosages of SOM230 (5 or 50 microg/kg/h), one dose of octreotide, corresponding to that used in human therapy, and a placebo, respectively. The development of the tumor before and after therapy was monitored by magnetic resonance imaging of the pituitary region and evaluation of the serum prolactin levels.
  
  
  RESULTS
  The highest dose of SOM230 induced a drastic regression of the tumor, whereas octreotide was not able to induce any significant tumor regression, although tumor progression was significantly slowed down. No significant differences were observed between the animals treated with the lowest dose of SOM230 and those receiving placebo.
  
  
  CONCLUSIONS
  These results clearly support the efficacy of the SOM230 treatment in human pituitary adenomas secreting prolactin based on the dramatic tumor shrinkage and fall in prolactin levels. This beneficial effect could be of crucial clinical usefulness in patients bearing tumors resistant to dopaminergic drugs.
authors.affiliation: Istituto di Endocrinologia ed Oncologia Sperimentale del CNR e/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II, Naples, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Fedele
authors.forename: Ivana
authors.initials: I
authors.lastname: De Martino
authors.forename: Rosario
authors.initials: R
authors.lastname: Pivonello
authors.forename: Andrea
authors.initials: A
authors.lastname: Ciarmiello
authors.forename: M Laura
authors.initials: ML
authors.lastname: Del Basso De Caro
authors.forename: Rosa
authors.initials: R
authors.lastname: Visone
authors.forename: Dario
authors.initials: D
authors.lastname: Palmieri
authors.forename: Giovanna M
authors.initials: GM
authors.lastname: Pierantoni
authors.forename: Claudio
authors.initials: C
authors.lastname: Arra
authors.forename: Herbert A
authors.initials: HA
authors.lastname: Schmid
authors.forename: Leo
authors.initials: L
authors.lastname: Hofland
authors.forename: Gaetano
authors.initials: G
authors.lastname: Lombardi
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.forename: Alfredo
authors.initials: A
authors.lastname: Fusco
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000188:drug therapy* / Q000473:pathology; D025743:HMGA2 Protein / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D010911:Pituitary Neoplasms / Q000188:drug therapy* / Q000473:pathology; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D025743:HMGA2 Protein; D013004:Somatostatin; C517782:pasireotide