%0 Journal Article
%A Ibanez-Costa, Alejandro
%A Rivero-Cortes, Esther
%A Vazquez-Borrego, Mari C.
%A Gahete, Manuel D.
%A Jimenez-Reina, Luis
%A Venegas-Moreno, Eva
%A de la Riva, Andres
%A Angel Arraez, Miguel
%A Gonzalez-Molero, Inmaculada
%A Schmid, Herbert A.
%A Maraver-Selfa, Silvia
%A Gavilan-Villarejo, Inmaculada
%A Antonio Garcia-Arnes, Juan
%A Japon, Miguel A.
%A Soto-Moreno, Alfonso
%A Galvez, Maria A.
%A Luque, Raul M.
%A Castano, Justo P.
%T Octreotide and pasireotide (dis)similarly inhibit pituitary tumor cells in vitro
%D 2016
%@ 0022-0795
%U http://hdl.handle.net/10668/19187
%X Somatostatin analogs (SSA) are the mainstay of pharmacological treatment for pituitary adenomas. However, some patients escape from therapy with octreotide, a somatostatin receptor 2 (sst2)-preferring SSA, and pasireotide, a novel multi-sst-preferring SSA, may help to overcome this problem. It has been proposed that correspondence between sst1-sst5 expression pattern and SSA-binding profile could predict patient's response. To explore the cellular/molecular features associated with octreotide/pasireotide response, we performed a parallel comparison of their in vitro effects, evaluating sst1-sst5 expression, intracellular Ca2+ signaling ([Ca2+](i)), hormone secretion and cell viability, in a series of 85 pituitary samples. Somatotropinomas expressed sst5>sst2, yet octreotide reduced [Ca2+](i) more efficiently than pasireotide, while both SSA similarly decreased growth hormone release/expression and viability. Corticotropinomas predominantly expressed sst5, but displayed limited response to pasireotide, while octreotide reduced functional endpoints. Non-functioning adenomas preferentially expressed sst3 but, surprisingly, both SSA increased cell viability. Prolactinomas mainly expressed sst1 but were virtually unresponsive to SSA. Finally, both SSA decreased [Ca2+](i) in normal pituitaries. In conclusion, both SSA act in vitro on pituitary adenomas exerting both similar and distinct effects; however, no evident correspondence was found with the sst1-sst5 profile. Thus, it seems plausible that additional factors, besides the simple abundance of a given sst, critically influence the SSA response.
%K Growth-hormone
%K Receptor subtypes
%K Quantitative-analysis
%K Aggressive features
%K Medical-treatment
%K Cushings-disease
%K Acth release
%K Adenomas
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