Evolutionary history of the somatostatin and somatostatin receptors.

Somatostatin and its receptors have a critical role in mammalian growth through their control pattern of secretion of growth hormone, but the evolutionary history of somatostatin and somatostatin receptors are ill defined. We used comparative whole genome analysis of Danio rerio, Carassius auratus, Xenopus tropicalis, Gallus gallus, Monodelphis domestica, Homo sapiens, Sus scrofa, Bos taurus, Mus musculus, Rattus norvegicus, Canis lupus familiaris, Ovis aries, Equus caballus, Pan troglodytes and Macaca mulatto to identify somatostatin and somatostatin receptors in each species. To date, we have identified a minimum of two genes of somatostatin and five somatostatin receptor genes in mammalian species with variable forms. We established a clear evolutionary history of the somatostatin system and traced the origin of the somatostatin system to 395 million years ago (MYA), identifying critical steps in their evolution.

Somatostatin receptors subtypes 2 and 5, dopamine receptor type 2 expression and gsp status as predictors of octreotide LAR® responsiveness in acromegaly / Expressão dos receptores da somatostatina subtipos 2 e 5 e do receptor da dopamina tipo 2 e gsp status como preditores de resposta ao octreotide LAR® na acromegalia

We present two acromegalic patients in which clinical and molecular data are discussed in regard to their ability to predict long term octreotide LAR® therapy response. Case reports: Patient 1: female, 36 years old at diagnosis. Basal GH and IGF-I at diagnosis were 133 ng/mL and 181 percent above the upper limit of reference values (ULRV), respectively. Growth hormone during acute test with subcutaneous octreotide decreased from 133 to 13 ng/mL. Patient started on primary octreotide LAR® therapy (20mg q28 days) and achieved biochemical parameters of disease control after 6 months. Molecular analysis of tumor fragments: gsp +; quantitative analysis of SSTR (somatostatin receptor) and DR (dopamine receptor) mRNA - SSTR2 23954; SSTR5 2407; DR2 total 17016 copies. Patient 2: male, 38 years old at diagnosis. Basal GH and IGF-I at diagnosis were 120 ng/mL and 114 percent ULRV, respectively. Patient underwent non-curative trans-sphenoidal surgery. Post-operative GH and IGF-I were 112 ng/mL and 137 percent ULRV, respectively. Growth hormone during acute test with subcutaneous octreotide decreased from 112 to 7 ng/mL. Octreotide LAR® therapy (20 mg q28 days) was then initiated. After 6 months of treatment, patient did not attain biochemical control of disease and displayed increased tumor volume. Molecular analysis of tumor fragments: gsp not done; quantitative analysis of SSTR and DR mRNA - SSTR2 416; SSTR5 3767; DR2 total 3439 copies. In conclusion, these two cases illustrate how laboratory data can be conflicting as predictors of octreotide LAR® responsiveness and how molecular analysis of tumor fragments can help explain different behaviors in clinically similar patients.

Apresentamos dois pacientes acromegálicos nos quais dados clínicos e moleculares são discutidos quanto à sua capacidade de predizer a resposta a longo prazo ao tratamento com octreotide LAR®. Relato dos casos: Paciente 1: Feminina, 36 anos de idade ao diagnóstico. GH e IGF-I ao diagnóstico 133 ng/mL e 181 por cento acima do limite superior do valor de referência (LSVR), respectivamente. GH durante o teste agudo com octreotide subcutâneo diminuiu de 133 para 13 ng/mL. Foi iniciado tratamento primário com octreotide LAR® (20 mg q28 dias) e a paciente alcançou os parâmetros bioquímicos de controle de doença depois de seis meses. Análise molecular do tumor: gsp +; análise quantitativa do mRNA de SSTR (receptores de somatostatina) e DR (receptor de dopamina) - SSTR2 23.954; SSTR5 2.407; DR2 total 17.016 cópias. Paciente 2: Masculino, 38 anos de idade ao diagnóstico. GH e IGF-I ao diagnóstico 120 ng/mL e 114 por cento LSVR, respectivamente. Paciente foi submetido à cirurgia trans-esfenoidal não-curativa. GH e IGF-I pós-operatórios 112 ng/mL e 137 por cento LSVR, respectivamente. GH durante o teste agudo diminuiu de 112 para 7 ng/mL. Foi iniciado tratamento com octreotide LAR® (20 mg q28 dias). Após seis meses o paciente não alcançou controle bioquímico e apresentou aumento do volume tumoral. Análise molecular do tumor: gsp não estudado; análise quantitativa do mRNA de SSTR e DR - SSTR2 416; SSTR5 3.767; DR2 total 3.439 cópias. Em conclusão, estes dois casos ilustram como dados laboratoriais podem ser conflitantes enquanto preditores de resposta ao tratamento com octreotide LAR® e como a análise molecular de fragmentos do tumor pode ajudar a explicar comportamentos diferentes em pacientes clinicamente semelhantes.