scholarly journals Somatostatin Receptor Subtypes mRNA in TSH-Secreting Pituitary Adenomas: A Case Showing a Dramatic Reduction in Tumor Size During Short Octreotide Treatment

2007 ◽  
Vol 54 (3) ◽  
pp. 371-378 ◽  
Author(s):  
Kazuhiko HORIGUCHI ◽  
Masanobu YAMADA ◽  
Ryohei UMEZAWA ◽  
Teturo SATOH ◽  
Koshi HASHIMOTO ◽  
...  
Keyword(s):  
Tumor Size ◽  
Pituitary Adenomas ◽  
Somatostatin Receptor ◽  
Receptor Subtypes ◽  
Dramatic Reduction ◽  
Somatostatin Receptor Subtypes ◽  
Octreotide Treatment

scholarly journals Expression of Somatostatin Receptor 2 in Somatotropinoma Correlated with the Short-Term Efficacy of Somatostatin Analogues

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Wenjuan Liu ◽  
Lina Xie ◽  
Min He ◽  
Ming Shen ◽  
Jingjing Zhu ◽  
...  
Keyword(s):  
Tumor Size ◽  
Tumor Volume ◽  
Somatostatin Receptor ◽  
Somatostatin Analogues ◽  
Receptor Subtypes ◽  
Short Term ◽  
Pituitary Growth Hormone ◽  
Term Efficacy ◽  
Somatostatin Receptor Subtypes ◽  
Pretreated Group

The expression of somatostatin receptor subtypes (SSTRs) in pituitary growth hormone- (GH-) secreting adenomas may predict the response to somatostatin analogues (SSA). Our aim was to evaluate the value of the immunohistochemical (IHC) scores of 2 subtypes, SSTR2 and SSTR5, in predicting the short-term efficacy of SSA therapy in patients with active acromegaly. Ninety-three newly diagnosed acromegalic patients were included in our study. These patients were categorized into either a SSA-pretreated group (SA, n=63) or a direct-surgery group (DS, n=30), depending on whether or not presurgical SSA treatment was received. IHC analysis, using a 12-grade scoring system, with rabbit monoclonal antibodies against SSTR2 and SSTR5, was performed on all adenoma tissues. The reduction of GH, IGF-1, and tumor size after treatment with SSA for 3 months was measured. Compared with that in the DS group, SSTR2 expression was lower in the SA group. Additionally, in the SA group, SSTR2 expression was positively correlated with the reduction of IGF-1 and tumor volume. However, there was no correlation between the SSTR5 score and the efficacy of SSA. In conclusion, the protein expression of SSTR2, but not of SSTR5, is a valuable indicator in predicting biochemical and tumor size response to short-term SSA treatment in acromegalic patients.

scholarly journals Molecular and functional properties of densely and sparsely granulated GH-producing pituitary adenomas

2013 ◽  
Vol 169 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Bernhard Mayr ◽  
Rolf Buslei ◽  
Marily Theodoropoulou ◽  
Günter K Stalla ◽  
Michael Buchfelder ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Molecular Level ◽  
Secretory Granules ◽  
Somatostatin Receptor ◽  
Receptor Subtypes ◽  
Membrane Expression ◽  
Cytoplasmic Expression ◽  
Somatotroph Adenoma ◽  
Somatostatin Receptor Subtypes

ObjectiveGH-producing pituitary adenomas display two distinct morphological patterns of cytoplasmic GH-containing secretory granules, namely the densely and sparsely granulated somatotroph adenoma subtype. It is unknown whether these morphological variants reflect distinct pathophysiological entities at the molecular level.MethodsIn 28 GH-producing adenoma tissues from a consecutive set of patients undergoing pituitary surgery for acromegaly, we studied the GH granulation pattern, the expression of somatostatin receptor subtypes (SSTR) as well as the calcium, cAMP and ZAC1 pathways in primary adenoma cell cultures.ResultsThe expression ofGSPoncogene was similar between densely and sparsely granulated somatotroph adenoma cells. There were no differences in the calcium, cAMP and ZAC1 pathways as well as in their regulation by SSTR agonists. SSTR2 was exclusively expressed in densely but not in sparsely granulated tumours (membrane expression 86 vs 0%; cytoplasmic expression 67 vs 0%). By contrast, expression of SSTR5 was only found in sparsely but not in densely granulated somatotroph adenomas (membrane expression 29 vs 0%; cytoplasmic expression 57 vs 0%).ConclusionsOur results indicate that different granulation patterns in GH-producing adenomas do not reflect differences in pathways and factors pivotal for somatotroph differentiation and function.In vitro, the vast majority of both densely and sparsely granulated tumour cells were responsive to SSTR activation at the molecular level. Sparsely granulated adenomas lacking SSTR2, but expressing SSTR5, might be responsive to novel SSTR agonists with increased affinity to SSTR5.

scholarly journals Preclinical and clinical experiences with the role of somatostatin receptors in the treatment of pituitary adenomas

2007 ◽  
Vol 156 (suppl_1) ◽  
pp. S45-S51 ◽  
Author(s):  
Joost van der Hoek ◽  
Steven W J Lamberts ◽  
Leo J Hofland
Keyword(s):  
Pituitary Adenomas ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Physiological Role ◽  
Receptor Subtypes ◽  
Clinical Experiences ◽  
Endocrine Diseases ◽  
Somatostatin Receptor Subtypes ◽  
Preclinical And Clinical Studies

The patho-physiological role of somatostatin receptor subtypes (sst) in neuro endocrine diseases has gained enhanced scientific interest in the past few years. The development of novel somatotropin-release inhibiting factor analogs, both sst-specific and universal ligands, seem promising as a tool to further increase fundamental insights in sst function. Eventually, this research should result in novel medical therapeutic opportunities in patients suffering from neuro-endocrine diseases. In the present review, the functional role of sst in all types of pituitary adenomas, based on recent preclinical and clinical studies, is being discussed.

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