RESUMO
CONTEXT: Hypersecretion of PTHrP is a relatively common cause of malignancy-related hypercalcemia but has only been described in a few cases of neuroendocrine tumors (NET). OBJECTIVE: The aim of this case report is to describe the clinical syndrome, complex therapeutic interventions, and unusual complications caused by persistent PTHrP hypersecretion in a patient with a pancreatic NET. CASE ILLUSTRATION: A 58-yr-old male patient presented with nonspecific abdominal pain and was found to have severe hypercalcemia secondary to a well-differentiated NET of the pancreas associated with extensive liver metastases. Elevated ionized calcium levels accompanied by low serum PTH and remarkably elevated PTHrP concentrations were consistent with PTHrP-related hypercalcemia that proved to be resistant to various chemotherapeutic regimens and supportive therapy. Partial control of the humoral syndrome was obtained only after the application of cytoreductive interventions and the introduction of various molecular targeted therapies. Due to persistent PTHrP action, bone disease emerged in the form of brown tumors. DISCUSSION: The manifestation of paraneoplastic syndrome due to PTHrP hypersecretion, despite its rareness in NET, should be considered in the differential diagnosis of hypercalcemia in such tumors. Moreover, the appearance of bone lesions in this setting may be in the context of metabolic bone disease and could be misdiagnosed as bone metastases.
Assuntos
Hipercalcemia/etiologia , Tumores Neuroendócrinos/fisiopatologia , Neoplasias Pancreáticas/fisiopatologia , Dor Abdominal/etiologia , Humanos , Hipercalcemia/fisiopatologia , Hipercalcemia/terapia , Hiperparatireoidismo/etiologia , Hiperparatireoidismo/fisiopatologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Tumores Neuroendócrinos/secundário , Tumores Neuroendócrinos/terapia , Osteíte Fibrosa Cística/etiologia , Osteíte Fibrosa Cística/patologia , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/terapia , Proteína Relacionada ao Hormônio Paratireóideo/sangue , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
BACKGROUND: A significant number of patients with chronic obstructive pulmonary disease (COPD) exhibit skeletal muscle wasting and decreased capillary area formation, which correlate with increased mortality. AIM: To determine the molecular mechanisms mediating decreased capillary formation in COPD. METHODS: 24 patients with COPD and 12 matching controls were recruited. Patients with COPD were classified into mild, moderate and severe groups according to GOLD (global initiative for chronic obstructive lung disease) criteria. Biopsy specimens were obtained from the tibialis anterior muscle. Fibre typing and capillary formation, together with messenger RNA (mRNA) expression of hypoxia-inducible factors (HIF1alpha and HIF3alpha), vascular endothelial growth factors (VEGF-A, VEGF-B and VEGF-C isoforms) and von Hippel-Lindau (VHL) protein, were determined. VHL expression and localisation were further studied by immunohistochemistry. RESULTS: Skeletal muscle capillary formation decreased significantly with increasing disease severity. Compared with controls, a tendency to mRNA overexpression of HIF1alpha, HIF3alpha and VEGF isoforms was observed in mild and moderate COPD, which decreased at the severe stage. In contrast, skeletal muscle biopsy samples from patients with COPD exhibited significant overexpression of VHL at both the mRNA and protein level by immunohistochemistry. VHL protein was further determined to be localised to satellite cells. CONCLUSIONS: Overexpression of VHL was identified in the skeletal muscle of patients with COPD. Increased VHL activity may have a negative effect on transduction of the hypoxic signal and may contribute to decreased capillarisation in skeletal muscles of patients with COPD.
Assuntos
Músculo Esquelético/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Idoso , Antropometria , Proteínas Reguladoras de Apoptose , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Biópsia , Capilares/patologia , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/patologia , Reação em Cadeia da Polimerase/métodos , Doença Pulmonar Obstrutiva Crônica/patologia , RNA Mensageiro/genética , Proteínas Repressoras , Índice de Gravidade de Doença , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Regulação para Cima , Fatores de Crescimento do Endotélio Vascular/biossíntese , Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
BACKGROUND: Chromogranin (Cg) A is expressed in neuroendocrine and neuronal tissues. It is involved in the generation of secretory granules and is cleaved to form biologically active peptides. Targeted ablation of the Chga gene resulted in increased plasma catecholamines, high blood pressure, and decreased size and number of adrenal medullary chromaffin granules. The aim of this study was to determine whether Chga null mice display changes in the morphology and function of the endocrine pancreas. MATERIALS AND METHODS: Sections of pancreata from Chga-/-, Chga+/- and Chga+/+ mice, were immunostained with antibodies against synaptophysin, CgA, CgB, secretogranin II and the four major pancreatic islet hormones. Plasma was analysed for glucose, insulin, glucagon, somatostatin and pancreatic polypeptide (PP). RESULTS: CgA epitopes were undetectable in the islets of Chga-/- animals. CgB and secretogranin II epitopes were expressed in the islets of all animal groups albeit with decreased expression in Chga-/- islets. The islet number and size were decreased in the Chga-/- animals compared with Chga+/+. The proportion of insulin cells was decreased but somatostatin and PP cells were increased in Chga-/- mice compared to Chga+/+ mice. The nuclear size was decreased in insulin cells and increased in somatostatin cells in Chga-/- mice. Plasma insulin level was markedly decreased in the Chga-/- mice although fasting plasma glucose and glucagon were normal. CONCLUSION: Ablation of the Chga gene affected the islet volume, the composition, distribution and nuclear size of islet cell types and plasma insulin concentration. Our data indicate decreased insulin cell function and increased glucagon cell function. Our study shows that CgA exerts a significant influence on the endocrine pancreas with importance in maintaining islet volume, cellular composition and function.
Assuntos
Cromogranina A/fisiologia , Ilhotas Pancreáticas/crescimento & desenvolvimento , Ilhotas Pancreáticas/fisiologia , Animais , Contagem de Células , Tamanho Celular , Cromogranina A/deficiência , Cromogranina A/genética , Cromogranina B/metabolismo , Imuno-Histoquímica , Insulina/sangue , Ilhotas Pancreáticas/anatomia & histologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hormônios Pancreáticos/metabolismo , Secretogranina II/metabolismoRESUMO
Chromogranins and secretogranins belong to the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In earlier publications we have described the development of region-specific antibodies against CgA and CgB. In this study we describe antibodies to SgII and SgIII and their usefulness for immunohistochemical staining. Peptides homologous to defined parts of secretogranins II and III were selected and synthesized. Antibodies were raised and immunostainings were performed on normal human pancreas. The SgII 154-165 (N-terminal secretoneurin), SgII 172-186 (C-terminal secretoneurin) and SgIII antibodies immunostained all insulin-immunoreactive cells, most of the glucagon cells and some of the pancreatic polypeptide cells. The SgII 225-242 antibody immunostained only the insulin-containing cells. None of the antibodies immunostained the somatostatin cells. This study is the first observation of the expression of SgIII in human tissues, where we show expression of SgIII in three of the four major islet cell types in human pancreas.
Assuntos
Cromograninas/análise , Ilhotas Pancreáticas/química , Secretogranina II/análise , Adulto , Animais , Anticorpos/isolamento & purificação , Anticorpos/farmacologia , Cromograninas/imunologia , Glucagon/análise , Humanos , Imuno-Histoquímica , Insulina/análise , Polipeptídeo Pancreático/análise , Fragmentos de Peptídeos/análise , Ratos , Secretogranina II/imunologiaRESUMO
CASE REPORT: A 48-year-old male with known hypothyreosis consulted his physician for symptoms compatible with TIA (transient ischemic attacks). Computer tomography (CT) in December 2001 revealed an irregular, lobulated mass in the processus uncinatus of the pancreas head. A CT examination 14 months later revealed status quo. In July 2004, a new CT showed an increase in size of the expansive pancreatic mass. The patient was operated on in August 2004 with a preliminary diagnosis of incidentaloma of the pancreas. The pathological examination showed a 4 x 3.5 x 2.5 cm large tumour. Histology revealed an intraductal serrated adenoma. The epithelial fronds had sawtooth-like configurations. An area with early invasive carcinoma was found. The tumour had progressed slowly during the 2.7 years of surveillance. Serrated neoplasia in the duodenum may result in similar cases in the future.
Assuntos
Adenoma/patologia , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
During the preimmunohistochemical era, silver stains were an important part of the staining arsenal for identifying certain tissue structures and cell types in tissue sections. Some of them were useful for demonstrating endocrine cells, especially in the gastrointestinal tract. Until the late 1950s, silver stains, particularly those identifying endocrine cells, were accompanied by a number of technical difficulties resulting from uncontrolled staining factors. In the 1960s, new silver stains were developed for endocrine cell types and these stains gave reproducible results. One of the "older" silver stains and two of the "newer" ones are emphasized in this presentation, namely the Masson, the Grimelius and the Sevier-Munger techniques. The Masson stain demonstrates the enterochromaffin (EC, serotonin) cells, the Grimelius stain is a broad endocrine cell marker, and the Sevier-Munger technique demonstrates EC and EC-like cells and the C-cells of the thyroid. Especially in the preimmunohistochemical era, these staining methods often were used for histopathological diagnosis, particularly the Grimelius technique. The silver stains were developed empirically, and with few exceptions the chemical background is not known. Staining protocols are included.
Assuntos
Neuroendocrinologia/métodos , Neurônios/citologia , Coloração pela Prata/métodos , Colo/citologia , Ilhotas Pancreáticas/citologia , Microscopia Eletrônica , Coloração pela Prata/instrumentaçãoRESUMO
During the last 10 years many attempts have been made to estimate the number of enterochromaffin-like (ECL) cells in various animal studies. This is the first presentation of an unbiased stereological estimator of the total number of histamine-positive ECL cells per rat and linked to estimators of related parameters: total volume of the oxyntic mucosa, total oxyntic mucosal surface area, total oxyntic serosal surface area, surface amplification factor, average thickness of the oxyntic mucosa, total and mean volume of the ECL cells, total number of oxyntic glands and pits, mean number of ECL cells per gland, and mean number of ECL cells and glands per oxyntic serosal surface area. This study is the first application of the smooth fractionator and includes a description of all sources of sampling variance in the smooth fractionator design with newly developed predictors.
Assuntos
Separação Celular/métodos , Fracionamento Químico/métodos , Células Enterocromafins/fisiologia , Mucosa/fisiologia , Animais , Contagem de Células , Feminino , Técnicas In Vitro , Modelos Biológicos , Controle de Qualidade , Ratos , Ratos Wistar , Coloração e RotulagemRESUMO
Patients with anaplastic thyroid carcinoma can rarely be cured, but every effort should be made to prevent death due to suffocation. Between 1984 and 1999, 55 consecutive patients with anaplastic thyroid carcinoma were prospectively treated according to a combined regimen consisting of hyperfractionated radiotherapy, doxorubicin, and when feasible surgery. Radiotherapy was carried out for 5 days a week. The daily fraction until 1988 was 1.0 Gyx2 (A) and 1989-92 1.3 Gyx2 (B). Thereafter 1.6 Gyx2 (C) was administered. Radiotherapy was administered to a total target dose of 46 Gy; of which 30 Gy was administered preoperatively in the first two protocols (A and B), while the whole dose was given preoperatively in the third protocol (C). The therapy was otherwise identical. Twenty mg doxorubicin was administered intravenously weekly. Surgery was possible in 40 patients. No patient failed to complete the protocol due to toxicity. In only 13 cases (24%) was death attributed to local failure. Five patients (9%) 'had a survival' exceeding 2 years. No signs of local recurrence were seen in 33 patients (60%); 5 out of 16 patients in Protocol A, 11 out of 17 patients in Protocol B, 17 out of 22 patients in Protocol C (P=0.017). In the 40 patients undergoing additional surgery, no signs of local recurrence were seen in 5 out of 9 patients, 11 out of 14 patients and 17 out of 17 patients, respectively (P=0.005).
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Carcinoma/terapia , Fracionamento da Dose de Radiação , Doxorrubicina/uso terapêutico , Neoplasias da Glândula Tireoide/terapia , Tireoidectomia , Idoso , Idoso de 80 Anos ou mais , Carcinoma/mortalidade , Carcinoma/patologia , Protocolos Clínicos , Terapia Combinada , Estudos de Viabilidade , Feminino , Humanos , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Cuidados Pós-Operatórios , Estudos Prospectivos , Qualidade de Vida , Taxa de Sobrevida , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/patologiaRESUMO
Antibodies to six specific regions of the chromogranin A (CgA) molecule were used to study their immunoreactivity in human neuroendocrine (NE) tumors. Tissue specimens from endocrine pancreatic tumors (n = 14), duodenal carcinoids (n = 2), bronchial carcinoids (n = 5), ileal carcinoids (n = 5) appendix carcinoids (n = 2), medullary thyroid carcinomas (n = 6), parathyroid adenomas (n = 2), and pheochromocytomas (n = 8) were analyzed. The results showed that the NE tumor types expressed varying numbers of CgA fragments. A variation in frequency of the expression of immunoreactive cells was sometimes seen also within the same tumor type. The midportion fragment CgA 176-195 (chromacin) was the only fragment expressed in all tumors. Benign and malignant tumors expressed different patterns, being especially true of insulinomas and pheochromocytomas. These findings suggest that region-specific antibodies to CgA fragments can be used as a diagnostic tool for the characterization of NE tumors.
Assuntos
Neoplasias Brônquicas/metabolismo , Tumor Carcinoide/metabolismo , Cromograninas/metabolismo , Neoplasias do Sistema Digestório/metabolismo , Neoplasias das Glândulas Endócrinas/metabolismo , Adenoma/metabolismo , Adenoma/patologia , Neoplasias Brônquicas/patologia , Tumor Carcinoide/patologia , Carcinoma Medular/metabolismo , Carcinoma Medular/patologia , Cromogranina A , Cromograninas/classificação , Cromograninas/imunologia , Neoplasias do Sistema Digestório/patologia , Neoplasias das Glândulas Endócrinas/patologia , Humanos , Imuno-Histoquímica , Insulinoma/metabolismo , Insulinoma/patologia , Feocromocitoma/metabolismo , Feocromocitoma/patologiaRESUMO
Adenomas of the adrenal cortex cause different disorders depending on the main steroid synthesized and released. The aim of this research is to increase our understanding of the pathophysiology of steroidogenesis in adrenocortical disorders by comparing the release of steroids from adrenocortical adenomas in vitro with the messenger RNA (mRNA) expression of steroid synthesizing enzymes. Fourteen patients with adrenal tumors were included in the present study; nine were diagnosed with primary aldosteronism and three with Cushing's syndrome. Two patients had an adrenal tumor discovered on computed tomography (CT) during workup for an unrelated disease. Serum cortisol, plasma aldosterone, and urinary catecholamines were normal. Tissue was taken for in vitro steroid release, and aldosterone and cortisol in the medium after a 1-hour incubation were determined. Oligonucleotide probes with sequences complementary to mRNAs encoding for the steroid synthesizing enzymes 11 beta-hydroxylase (CYP11B1), 18-hydroxylase (CYP11B2), 17 alpha-hydroxylase (CYP17), and 21-hydroxylase (CYP21) were synthesized (Genset, Paris, France) and in situ hybridization was performed. Moderate expression of CYP11B2 and low expression of CYP11B1 were seen in the zona glomerulosa. The zona fasciculata of the control adrenals expressed a high signal of CYP11B1, whereas the expression of CYP11B2 was very low. There was considerable variation in aldosterone release from the aldosteronomas, whereas the tumors from the Cushing patients showed no detectable release of aldosterone. In contrast, tumors from patients with primary aldosteronism, Cushing's syndrome, and no hyperfunction all had the ability to synthesize and release cortisol in vitro. The highest cortisol release was found in tumors from patients with Cushing's syndrome, but also the nonhyperfunctioning tumors and some of the aldosteronomas released significant amounts of cortisol. The two patients with highest release of aldosterone in vitro showed the highest expression of CYP11B2 and the lowest expression of CYP11B1 and CYP17. The remaining aldosteronomas had low expression of CYP11B2, similar to the two other groups. Expression of CYP11B1 was high as expected in the Cushing adenomas, but also the two nonhyperfunctioning tumors and some of the aldosteronomas showed a moderate expression. Adenomas from Cushing's syndrome, nonhyperfunctioning adenomas, and some of the aldosterone-producing adenomas had moderate to high expression of CYP17. This paper presents new means for functional characterization of adrenocortical tumors. Diagnosis of an aldosteronoma is often difficult, and with the advent of these methods it is possible to determine the functional capacity of a tumor, once it is removed. This is of special interest if the patient remains hypertensive postoperatively, and it is not clear whether the patient indeed had a functioning tumor.
Assuntos
Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/metabolismo , Adenoma Adrenocortical/genética , Adenoma Adrenocortical/metabolismo , Aldosterona/análise , Citocromo P-450 CYP11B2/genética , Hidrocortisona/análise , RNA Mensageiro/genética , Esteroide 17-alfa-Hidroxilase/genética , Neoplasias do Córtex Suprarrenal/enzimologia , Adenoma Adrenocortical/enzimologia , Adulto , Idoso , Síndrome de Cushing/enzimologia , Síndrome de Cushing/genética , Feminino , Humanos , Hiperaldosteronismo/enzimologia , Hiperaldosteronismo/genética , Hibridização In Situ , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Técnicas de Sonda Molecular , Esteroide 11-beta-Hidroxilase/genéticaRESUMO
With the aid of IGF2 and VEGF in situ hybridization; tyrosine hydroxylase, chromogranin A, and Ki67 immunohistochemistry; and TUNEL staining applied to a large series of clinical neuroblastomas and to an animal model, we show here that stroma-poor neuroblastomas show evidence of chromaffin differentiation similar to that of type 1 small intensely fluorescent (SIF) cells and that this occurs in a vascular-dependent fashion, indicating a role for local tumor hypoxia in the differentiation process.
Assuntos
Células Cromafins/química , Ganglioneuroblastoma/patologia , Ganglioneuroma/patologia , Neuroblastoma/patologia , Oxigênio/metabolismo , Animais , Apoptose , Biomarcadores , Diferenciação Celular , Hipóxia Celular , Cromogranina A , Cromograninas/análise , Fatores de Crescimento Endotelial/análise , Ganglioneuroblastoma/química , Ganglioneuroblastoma/metabolismo , Ganglioneuroma/química , Ganglioneuroma/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Fator de Crescimento Insulin-Like II/análise , Antígeno Ki-67/análise , Linfocinas/análise , Proteínas de Neoplasias/análise , Transplante de Neoplasias , Neuroblastoma/irrigação sanguínea , Neuroblastoma/química , Neuroblastoma/metabolismo , Ratos , Ratos Nus , Sistema Nervoso Simpático/química , Sistema Nervoso Simpático/citologia , Sistema Nervoso Simpático/embriologia , Transplante Heterólogo , Tirosina 3-Mono-Oxigenase/análise , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
In earlier studies a high-molecular-weight (HMW) insulin-like growth factor-II (IGF-II) peptide was identified in adult human pancreas and localized to the insulin-producing B-cells. This peptide has now been investigated in neoplastic insulin cells. Forty endocrine pancreatic tumours and 17 pancreatic adenocarcinomas of ductal type were included in the study. All cases were investigated with immunohistochemical techniques using antibodies to IGF-II, insulin, pro-insulin, glucagon, somatostatin, pancreatic polypeptide, gastrin and vasoactive intestinal peptide (VIP). Frozen tissue from nine tumours and two normal pancreatic glands was extracted, gel separated, and quantified using radioimmunoassay. The tumours were also investigated by in situ hybridization. IGF-II-immunoreactive cells were found in nearly all the 18 insulin-producing tumours (16/18), in a minority of the other endocrine tumours, but not in pancreatic adenocarcinomas. All extracts from the endocrine tumours showed varying amounts of IGF-II and had different molecular-weight forms. The immunohistochemical and radioimmunoassay findings are both based on immunological binding and were further confirmed by Northern blot and in situ hybridization. These results show that IGF-II is expressed in insulin-producing tumours as well as in pancreatic tumours producing other peptides, in contrast to normal pancreatic islets where IGF-II is found exclusively in insulin-producing cells.
Assuntos
Carcinoma Ductal Pancreático/química , Fator de Crescimento Insulin-Like II/análise , Neoplasias Pancreáticas/química , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Northern Blotting/métodos , Carcinoma Ductal Pancreático/patologia , Feminino , Humanos , Técnicas Imunoenzimáticas , Hibridização In Situ/métodos , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/análise , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/análise , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Ilhotas Pancreáticas/química , Ilhotas Pancreáticas/patologia , Ligantes , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , RadioimunoensaioRESUMO
We have previously reported data establishing the human parathyroid gland as a target organ for vitamin A. In the present study, we identified Ito-like cells in parathyroid glands, suggesting local stores of vitamin A. Furthermore, we used immunohistochemistry to investigate the expression of the cellular retinol-binding protein type 1 and the cellular retinoic acid-binding protein type 1 (CRABP I) in histologically normal glands, in remnants of "normal" glandular tissue adjacent to adenoma, in adenomas, and in hyperplastic glands of chief cell type. All normal and abnormal glands displayed immunoreactivity to the two antibodies. CRABP I appeared in the cytoplasm, cell membranes, and nuclear membranes in normal glands, but only exceptionally in the nuclear membranes in abnormal glands. Since retinoic acid inhibits the secretion of parathyroid hormone and CRABP I is thought to play a key role in regulating the amount of retinoic acid available to interact with specific nuclear receptors, these data may suggest impaired transport of retinoic acid to cell nuclei, thus contributing to the development of hyperparathyroidism.
Assuntos
Adenoma/metabolismo , Glândulas Paratireoides/metabolismo , Neoplasias das Paratireoides/metabolismo , Receptores do Ácido Retinoico/metabolismo , Proteínas de Ligação ao Retinol/metabolismo , Adenoma/patologia , Adulto , Idoso , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Feminino , Humanos , Hiperplasia/metabolismo , Hiperplasia/patologia , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/patologia , Neoplasias das Paratireoides/patologia , Proteínas Celulares de Ligação ao RetinolRESUMO
Synaptic vesicle protein 2 (SV2) is a glycoprotein identified in the nervous system of several species, including man, but its occurrence in the human neuroendocrine (NE) cell system has not been investigated. By using a monoclonal antibody to SV2, immunoreactivities were demonstrated in NE cell types in human gastrointestinal tract, pancreas, anterior pituitary gland, thyroid, parathyroid, and adrenal medulla, and also in chief cells of gastric oxyntic mucosa. Immunoelectron microscopy of pancreatic islets revealed SV2 immunoreactivity in secretory granules. Comparison of SV2, synaptophysin, and chromogranin A immunoreactivity showed more SV2- and synaptophysin- than chromogranin A-immunoreactive cells in the antrum and pancreas. In the other gastrointestinal regions and in the other endocrine organs more SV2- than synaptophysin-immunoreactive cells were seen. More chromogranin A- than SV2-immunoreactive cells were observed in duodenum, colon, and parathyroid. Various NE tumors were examined and all contained SV2-immunoreactive cells. The staining patterns with the three markers agreed well, except in hindgut carcinoids, which showed strong SV2 immunoreactivity, weak synaptophysin but no chromogranin A immunostaining. In pituitary adenomas more cells were immunoreactive to SV2 than to the other two antibodies. In conclusion, SV2 is recognized as a further broad marker for NE cells and widens the arsenal of diagnostic tools for NE tumors. It is of special importance for identifying hindgut carcinoids.
Assuntos
Glicoproteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Sistemas Neurossecretores/metabolismo , Biomarcadores , Cromogranina A , Cromograninas/metabolismo , Neoplasias das Glândulas Endócrinas/metabolismo , Neoplasias das Glândulas Endócrinas/patologia , Humanos , Microscopia Eletrônica , Microscopia Imunoeletrônica , Neoplasias do Sistema Nervoso/metabolismo , Neoplasias do Sistema Nervoso/patologia , Sistemas Neurossecretores/patologia , Sistemas Neurossecretores/ultraestrutura , Valores de Referência , Sinaptofisina/metabolismoRESUMO
Knowledge concerning tissue-specific expression of the five somatostatin receptor subtypes is of great importance in understanding their physiological function. We developed rabbit polyclonal antibodies specific for each human somatostatin receptor subtype and report our results concerning the expression in normal endocrine pancreatic cells. The antibodies were produced by immunizing rabbits with fragments specific for the five cloned somatostatin receptor subtypes. Colocalization of these somatostatin receptors with the four major islet hormones--insulin, glucagon, somatostatin, and pancreatic polypeptide--was studied in normal human endocrine pancreatic cells, using double-immunofluorescence staining. High expression of somatostatin receptor subtypes 1, 3, and 4 was found in all endocrine pancreatic cells. Somatostatin receptor subtype 2 was frequently expressed in alpha and beta cells, whereas expression was low in pancreatic polypeptide cells and intermediate in delta cells. Somatostatin receptor subtype 5 was expressed in most beta and delta cells but almost absent in alpha and pancreatic polypeptide cells. There is a variability in the normal expression of somatostatin receptor subtypes among the different human endocrine pancreatic cells. Knowledge of this expression and the physiological function mediated by these receptors will be valuable in the future when considering treatment of endocrine disorders.
Assuntos
Ilhotas Pancreáticas/metabolismo , Receptores de Somatostatina/classificação , Receptores de Somatostatina/metabolismo , Animais , Especificidade de Anticorpos , Glucagon/metabolismo , Humanos , Imuno-Histoquímica , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Polipeptídeo Pancreático/metabolismo , Coelhos , Receptores de Somatostatina/imunologia , Somatostatina/metabolismo , Células Secretoras de Somatostatina/metabolismoRESUMO
The mechanisms involved in stromal reactions and fibrosis in solid malignant tumours are incompletely understood. In the present study, collagen type I production was investigated in tissues and cell lines derived from human undifferentiated (anaplastic) thyroid carcinomas, a highly aggressive, often fibrotic malignancy with mesenchymal phenotype. In situ hybridization showed the expression of pro-alpha1(I) collagen mRNA throughout the stromal part of the tumours. However, immunofluorescence staining using an anti-pro-collagen type I antibody revealed the synthesis of pro-collagen type I protein mainly in stromal cells juxtaposed to nests of tumour cells. In one out of five tissue samples from human undifferentiated thyroid carcinomas, pro-alpha1(I) collagen mRNA expression was also found in a small number of tumour cells. Several well-characterized cell lines established from undifferentiated thyroid carcinomas, two from tumours included in the present study, expressed both pro-alpha1(I) collagen and prolyl 4-hydroxylase mRNA, and three of these cell lines also synthesized native triple-helical collagen type I. Taken together, these data suggest that stromal fibroblasts are the main producers of collagen type I in anaplastic thyroid tumours. The carcinoma cells seem to play a regulatory role, stimulating the synthesis of collagen type I protein in the surrounding stroma by increasing pro-alpha1(I) collagen mRNA translation. However, collagen type I production by the carcinoma cells might also contribute to the marked desmoplasia commonly seen in these tumours.
Assuntos
Carcinoma/metabolismo , Colágeno/biossíntese , Neoplasias da Glândula Tireoide/metabolismo , Northern Blotting , Carcinoma/patologia , Colagenases/metabolismo , Fibrose , Imunofluorescência , Humanos , Hibridização In Situ , RNA Mensageiro , Neoplasias da Glândula Tireoide/patologia , Células Tumorais CultivadasRESUMO
In this study we have characterized chromosomal imbalances in a panel of 29 parathyroid carcinomas using comparative genomic hybridization (CGH). The most frequently detected imbalances were losses of 1p and 13q that were seen in >40% of the cases. The commonly occurring regions of loss were assigned to 1p21-p22 (41%), 13q14-q31 (41%), 9p21-pter (28%), 6q22-q24 (24%), and 4q24 (21%), whereas gains preferentially involved 19p (45%), Xc-q13 (28%), 9q33-qter (24%), 1q31-q32 (21%) and 16p (21%). The distribution of CGH alterations supports the idea of a progression of genetic events in the development of parathyroid carcinoma, where gains of Xq and 1q would represent relatively early events that are followed by loss of 13q, 9p, and 1p, and by gain of 19p. A sex-dependent distribution was also evident for two of the common alterations with preferential gain of 1q in female cases and of Xq in male cases. When the CGH profiles for the 29 carcinomas were compared with our previously published results for sporadic parathyroid adenomas, highly significant differences were revealed. Loss of 1p, 4q, and 13q as well as gains of 1q, 9q, 16p, 19p and Xq were significantly more common in the carcinomas than in the adenomas. In contrast, loss of the 11q13 region, which is the most common CGH abnormality in sporadic adenomas, was not detected in any of the carcinomas. Taken together, the findings identify several candidate locations for tumor suppressor genes and oncogenes that are potentially involved in parathyroid carcinogenesis.
Assuntos
Aberrações Cromossômicas , Neoplasias das Paratireoides/genética , Adenoma/genética , Adenoma/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hibridização de Ácido Nucleico/métodos , Glândulas Paratireoides/metabolismo , Glândulas Paratireoides/patologia , Neoplasias das Paratireoides/patologiaRESUMO
OBJECTIVE: Mutations in the RET proto-oncogene are found in about one third of sporadic medullary thyroid carcinomas (MTCs), mostly affecting codon 918. Glial cell line derived neurotropic factor (GDNF) and its membrane-bound GDNF family receptor alpha (GFRalpha-1), as well as neurturin (NTN) and its membrane-bound receptor GFRalpha-2 form a complex with the RET product, a receptor tyrosine kinase, resulting in downstream signaling to the nucleus. DESIGN: To elucidate the role of these RET ligands in MTC tumorigenesis, their expression was determined in 15 MTC samples, one papillary thyroid carcinoma (PTC) and three normal thyroid tissue specimens. METHODS: The mRNA expression of RET, GDNF, GFRalpha-1, NTN and GFRalpha-2 was investigated by mRNA in situ hybridization, and confirmed by reverse transcription-PCR analysis. RESULTS: None of the five genes was expressed in the normal thyroids or in the PTC. All MTCs showed expression of RET, 13 expressed GDNF, 12 expressed GFRalpha-1 and 9 expressed NTN and GFRalpha-2. In 7 of the tumors RET, GDNF and GFRalpha-1 were expressed at high levels, and in five of these seven tumors NTN and GFRalpha-2 genes were also expressed at high levels. The high level of expression was preferentially seen in tumor cells adjacent to stroma and connective tissue. All MTCs without expression of the RET ligands harbored the RET codon 918 mutation. CONCLUSIONS: The results suggest that this signaling pathway is important for MTC development, and that it may be activated by expression of the RET ligand complexes by the tumor cells themselves.
Assuntos
Carcinoma Medular/metabolismo , Proteínas de Drosophila , Fatores de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Adulto , Idoso , Códon/genética , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial , Humanos , Hibridização In Situ , Ligantes , Masculino , Pessoa de Meia-Idade , Mutação , Fatores de Crescimento Neural/genética , Proteínas do Tecido Nervoso/genética , Neurturina , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-ret , RNA Mensageiro/metabolismo , Receptores Proteína Tirosina Quinases/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Glucose-induced insulin release is markedly decreased in the spontaneously diabetic Goto-Kakizaki (GK) rat pancreas. This defect was recently shown to be reversed by forskolin which markedly enhances cAMP generation in GK islets. These effects of forskolin were associated with overexpression of type-3 adenylyl cyclase (AC) mRNA due to the presence of two functional point mutations in the promoter region of AC3 gene in GK rat. Nine AC isoforms have been described, but their expression pattern in relation to the main pancreatic islet cell types, as well as their involvement in the diabetic state, is still unknown. Using antibodies raised against AC1-8, we have studied by double immunofluorescence the localisation of these AC isoforms in different endocrine cell types in both normal and diabetic GK rat pancreas. Our results demonstrated a clear immunoreaction (IR) to AC1-4 and 6 in normal and GK islet beta-cells, while a smaller number of ACs were expressed in alpha- and delta-cells. No AC-IR was observed in pancreatic polypeptide cells. Moreover, we have found an increased IR of the Ca2+-stimulated ACl, AC3 and AC8 in diabetic beta- and alpha-cells, compared with the corresponding IR in control pancreas. Most noticeable was the eliciting of a markedly enhanced AC8-IR in GK rat beta- and alpha-cells, in contrast to a barely discernible AC8-IR in corresponding normal cells. In conclusion, AC expression exhibits a complex pattern in the endocrine pancreas, with specific differences between the normal and diabetic state.
Assuntos
Adenilil Ciclases/química , Diabetes Mellitus Tipo 2/enzimologia , Pâncreas/enzimologia , Animais , Anticorpos , Especificidade de Anticorpos , Modelos Animais de Doenças , Glândulas Endócrinas/enzimologia , Glândulas Endócrinas/imunologia , Glândulas Endócrinas/patologia , Regulação da Expressão Gênica , Glucagon/metabolismo , Imuno-Histoquímica , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/enzimologia , Ilhotas Pancreáticas/imunologia , Masculino , Camundongos , Pâncreas/patologia , Isoformas de Proteínas/imunologia , Ratos , Ratos Endogâmicos , Ratos Wistar , Somatostatina/metabolismoRESUMO
BACKGROUND: The incidence of parathyroid cancer in patients with hyperparathyroidism is less than 1%. However, these few cases cause diagnostic problems in the absence of clear-cut invasion of adjacent organs or metastasis. New markers are needed to increase diagnostic accuracy. METHODS: Thirty-one parathyroid tumors from patients with primary hyperparathyroidism were collected worldwide. Eighteen tumors were classified as unequivocal cancers, whereas 13 tumors were considered equivocal because of a lack of infiltrative growth or evidence of recurrence. Paraffin sections were hybridized with a 35S-labeled riboprobe complementary to gelatinase A mRNA, dipped in photographic emulsion, developed, counterstained, and then evaluated by light- and dark-field microscopy. RESULTS: Fourteen of the 18 unequivocal parathyroid cancers expressed gelatinase A, as compared with the equivocal tumors, of which only 4 of 13 showed expression. The strongest hybridization signal was seen in stromal cells at the tumor border, most likely fibroblasts and macrophages. No expression was detected in tumor cells. CONCLUSIONS: Invasive growth of many tumors is facilitated by proteolytic enzymes, such as gelatinase A. The presence of gelatinase A mRNA in parathyroid tumors strengthens the suspicion of malignancy but cannot be used as a definitive marker of malignancy.