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1.
Eur J Haematol ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38780264

RESUMO

BACKGROUND: This study aimed to determine whether implementing a rapid response system (RRS) is associated with improved short-term outcomes in critically ill patients with haematological malignancies. METHODS: Our monocentric pre- versus post-intervention study was conducted between January 2012 and April 2020. RRS was activated at early signs of haemodynamic or respiratory failure. The primary outcome was the reduction in Sequential Organ Failure Assessment (SOFA) score on Day 3 after intensive care unit (ICU) admission. Secondary outcomes included time to ICU admission and mortality. RESULTS: A total of 209 patients with a median age of 59 years were enrolled (108 in the pre-intervention period and 101 in the post-intervention period). 22% of them had received an allogeneic transplant. The post-intervention period was associated with a shorter time to ICU admission (195 vs. 390 min, p < .001), a more frequent favourable trend in SOFA score (57% vs. 42%, adjusted odds ratio, 2.02, 95% confidence interval, 1.09 to 3.76), no significant changes in ICU (22% vs. 26%, p = .48) and 1-year (62% vs. 58%, p = .62) mortality rates. CONCLUSION: Detection of early organ failure and activation of an RRS was associated with faster ICU admission and lower SOFA scores on Day 3 of admission in critically ill patients with haematological malignancies.

2.
NPJ Precis Oncol ; 7(1): 44, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37202469

RESUMO

Zebrafish xenotransplantation models are increasingly applied for phenotypic drug screening to identify small compounds for precision oncology. Larval zebrafish xenografts offer the opportunity to perform drug screens at high-throughput in a complex in vivo environment. However, the full potential of the larval zebrafish xenograft model has not yet been realized and several steps of the drug screening workflow still await automation to increase throughput. Here, we present a robust workflow for drug screening in zebrafish xenografts using high-content imaging. We established embedding methods for high-content imaging of xenografts in 96-well format over consecutive days. In addition, we provide strategies for automated imaging and analysis of zebrafish xenografts including automated tumor cell detection and tumor size analysis over time. We also compared commonly used injection sites and cell labeling dyes and show specific site requirements for tumor cells from different entities. We demonstrate that our setup allows us to investigate proliferation and response to small compounds in several zebrafish xenografts ranging from pediatric sarcomas and neuroblastoma to glioblastoma and leukemia. This fast and cost-efficient assay enables the quantification of anti-tumor efficacy of small compounds in large cohorts of a vertebrate model system in vivo. Our assay may aid in prioritizing compounds or compound combinations for further preclinical and clinical investigations.

4.
Cancer Radiother ; 25(3): 213-221, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33402290

RESUMO

PURPOSE: Helical Tomotherapy (HT) appears as a valuable technique for total body irradiation (TBI) to create highly homogeneous and conformal dose distributions with more precise repositioning than conventional TBI techniques. The aim of this work is to describe the technique implementation, including treatment preparation, planning and dosimetric monitoring of TBI delivered in our institution from October 2016 to March 2019. MATERIAL AND METHOD: Prior to patient care, irradiation protocol was set up using physical phantoms. Gafchromic films were used to assess dose distribution homogeneity and evaluate imprecise patient positioning impact. Sixteen patients' irradiations with a prescribed dose of 12Gy were delivered in 6 fractions of 2Gy over 3 days. Pre-treatment quality assurance (QA) was performed for the verification of dose distributions at selected positions. In addition, in-vivo dosimetry was carried out using optically stimulated luminescence dosimeters (OSLD). RESULTS: Planning evaluation, as well as results of pre-treatment verifications, are presented. In-vivo dosimetry showed the strong consistency of OSLD measured doses. OSLD mean relative dose differences between measurement and calculation were respectively +0,96% and -2% for armpit and hands locations, suggesting better reliability for armpit OSLD positioning. Repercussion of both longitudinal and transversal positioning inaccuracies on phantoms is depicted up to 2cm shifts. CONCLUSION: The full methodology to set up TBI protocol, as well as dosimetric evaluation and pre-treatment QA, were presented. Our investigations reveal strong correspondence between planned and delivered doses shedding light on the dose reliability of OSLD for HT based TBI in-vivo dosimetry.


Assuntos
Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Irradiação Corporal Total/métodos , Fracionamento da Dose de Radiação , Transplante de Células-Tronco Hematopoéticas , Humanos , Linfoma Anaplásico de Células Grandes/terapia , Linfoma de Células T/terapia , Posicionamento do Paciente/métodos , Imagens de Fantasmas , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Radiometria/métodos , Reprodutibilidade dos Testes , Condicionamento Pré-Transplante/métodos
5.
Cell Death Discov ; 6: 64, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32728477

RESUMO

Rhabdomyosarcoma (RMS) is the most frequent form of pediatric soft-tissue sarcoma. It is divided into two main subtypes: ERMS (embryonal) and ARMS (alveolar). Current treatments are based on chemotherapy, surgery, and radiotherapy. The 5-year survival rate has plateaued at 70% since 2000, despite several clinical trials. RMS cells are thought to derive from the muscle lineage. During development, myogenesis includes the expansion of muscle precursors, the elimination of those in excess by cell death and the differentiation of the remaining ones into myofibers. The notion that these processes may be hijacked by tumor cells to sustain their oncogenic transformation has emerged, with RMS being considered as the dark side of myogenesis. Thus, dissecting myogenic developmental programs could improve our understanding of RMS molecular etiology. We focused herein on ANT1, which is involved in myogenesis and is responsible for genetic disorders associated with muscle degeneration. ANT1 is a mitochondrial protein, which has a dual functionality, as it is involved both in metabolism via the regulation of ATP/ADP release from mitochondria and in regulated cell death as part of the mitochondrial permeability transition pore. Bioinformatics analyses of transcriptomic datasets revealed that ANT1 is expressed at low levels in RMS. Using the CRISPR-Cas9 technology, we showed that reduced ANT1 expression confers selective advantages to RMS cells in terms of proliferation and resistance to stress-induced death. These effects arise notably from an abnormal metabolic switch induced by ANT1 downregulation. Restoration of ANT1 expression using a Tet-On system is sufficient to prime tumor cells to death and to increase their sensitivity to chemotherapy. Based on our results, modulation of ANT1 expression and/or activity appears as an appealing therapeutic approach in RMS management.

6.
Ann Pharm Fr ; 78(3): 230-241, 2020 May.
Artigo em Francês | MEDLINE | ID: mdl-32248952

RESUMO

INTRODUCTION: Idiosyncratic drug-induced agranulocytosis is a rare but potentially serious haematological disorder. The pathophysiological mechanisms are complex and poorly understood. We aimed at investigating agranulocytosis drug related causes from the myelograms with "myeloid maturation arrest" performed in our university hospital over the last seven years. METHODS: A retrospective analysis of myelograms collected for agranulocytosis was performed from 1st January 2010 to 31th December 2016. We used the method of Bégaud et al. for drug causality assessment. RESULTS: Among the 104 myelograms analysed, 41 agranulocytosis were drug-induced, whose 28 were idiosyncratic. Among these 28 cases, 26 different drugs were involved. Agranulocytosis was a known adverse reaction in the summary of the product characteristics for 24 drugs, mainly associated with undetermined frequency (n=7). Mean onset latency was 38.1 days after starting the drug (calculated for n=23 cases) and granulocyte growth factors were used in 50% of cases without shortening the mean delay of blood count recovery. Bone marrow presented hypereosinophilia in 29% of cases. Pharmacovigilance reporting rate was 48%. CONCLUSION: A "maturation arrest" in the myelogram is not pathognomonic for idiosyncratic drug-induced agranulocytosis. This rare event require multidisciplinary care involving haematologists, biologists and pharmacovigilance experts. Agranulocytosis reporting rate was high compared with usual adverse drug reaction reporting rate (5 to 10%), probably related to the potential severity of this event.


Assuntos
Agranulocitose/induzido quimicamente , Hospitais Universitários , Adulto , Idoso , Idoso de 80 Anos ou mais , Agranulocitose/epidemiologia , Contagem de Células Sanguíneas , Medula Óssea/patologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mielografia , Farmacovigilância , Estudos Retrospectivos , Adulto Jovem
9.
Br J Cancer ; 108(12): 2485-94, 2013 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-23695022

RESUMO

BACKGROUND: The use of ß-blockers for the management of hypertension has been recently associated with significant clinical benefits in cancer patients. Herein, we investigated whether ß-blockers could be used in combination with chemotherapy for the treatment of neuroblastoma. METHODS: Seven ß-blockers were tested for their antiproliferative and anti-angiogenic properties alone, and in combination with chemotherapy in vitro; the most potent drug combinations were evaluated in vivo in the TH-MYCN mouse model of neuroblastoma. RESULTS: Three ß-blockers (i.e., carvedilol, nebivolol and propranolol) exhibited potent anticancer properties in vitro and interacted synergistically with vincristine, independently of P-glycoprotein expression. ß-blockers potentiated the anti-angiogenic, antimitochondrial, antimitotic and ultimately pro-apoptotic effects of vincristine. In vivo, ß-blockers alone transiently slowed tumour growth as compared with vehicle only (P<0.01). More importantly, when used in combination, ß-blockers significantly increased the tumour regression induced by vincristine (P<0.05). This effect was associated with an increase in tumour angiogenesis inhibition (P<0.001) and ultimately resulted in a four-fold increase in median survival, as compared with vincristine alone (P<0.01). CONCLUSION: ß-blockers can increase treatment efficacy against neuroblastoma, and their combination with chemotherapy may prove beneficial for the treatment of this disease and other drug-refractory cancers.


Assuntos
Neoplasias Abdominais/tratamento farmacológico , Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Angiogênese/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neuroblastoma/tratamento farmacológico , Neoplasias Abdominais/irrigação sanguínea , Neoplasias Abdominais/patologia , Inibidores da Angiogênese/administração & dosagem , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Camundongos , Camundongos Transgênicos , Neovascularização Patológica/tratamento farmacológico , Neuroblastoma/irrigação sanguínea , Neuroblastoma/patologia
10.
Biochim Biophys Acta ; 1807(6): 679-88, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21216222

RESUMO

Microtubule-Targeting Agents (MTAs) constitute a class of drugs largely used for cancer treatment in adults and children. In cancer cells, they suppress microtubule dynamics, and induce cell death via the mitochondrial intrinsic pathway. To date, links between mitochondria and microtubule network disturbance in MTAs mechanism of action are not obvious. The aim of the present contribution is to provide elements that could answer to the question: how far are mitochondria essential to anticancer chemotherapy that targets the microtubule cytoskeleton? We review the main molecular candidates to link microtubule alteration with the apoptotic mitochondrial pathway control. Involvement of direct targeting of mitochondria in MTA efficacy is also discussed. Furthermore, we line up current evidence and emerging concepts on the participation of both mitochondria and microtubule in MTA neurotoxic side effects. To decipher the interconnections between the mitochondrial and the microtubule networks may help to improve cancer cell response to chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mitocôndrias/fisiologia , Neoplasias/tratamento farmacológico , Moduladores de Tubulina/uso terapêutico , Animais , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Resultado do Tratamento , Moduladores de Tubulina/administração & dosagem , Moduladores de Tubulina/farmacologia
11.
Mol Pharmacol ; 74(4): 1072-83, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18593821

RESUMO

Among the new microtubule-targeted agents, the epothilone family of molecules has shown promising anticancer potential, and clinical trials are currently underway for patupilone (epothilone B) in various cancer indications. In this study, we characterized novel aspects of patupilone's cellular action that may underlie its potent cytotoxicity in human neuroblastoma cells. Patupilone induced mitochondrial membrane potential collapse, mitochondrial morphological changes, and cytochrome c release, leading to apoptosis. Within the first 2 h, patupilone increased the generation of reactive oxygen species (ROS; i.e., superoxides and hydrogen peroxide, 33+/-6 and 51+/-3% increase, respectively), specifically from mitochondria. ROS scavengers and mitochondrial DNA depletion [rho(-) cells] significantly protected cells against patupilone cytotoxicity, indicating that ROS generation is a key event in the initial phase of apoptosis. Although the Bim expression level was not modified by patupilone, this proapoptotic protein accumulated in the mitochondrial compartment (2.4-fold increase at IC70) after only a 6-h treatment. In contrast, Bax and Bcl-2 mitochondrial levels were not changed during treatment. It is noteworthy that ROS inhibition prevented Bim relocalization to mitochondria and mitochondrial membrane changes induced by patupilone. Altogether, our data reveal that patupilone-mediated ROS production by mitochondria initiates the intrinsic signaling cascade by inducing Bim accumulation in mitochondria. These results might explain the superior activity of patupilone in tumor cells compared with paclitaxel that is, until now, the clinical reference among microtubule-stabilizing agents. Furthermore, our data highlight the importance of mitochondria that simultaneously assume the role of activator and integrator of apoptotic signals triggered by patupilone.


Assuntos
Apoptose/efeitos dos fármacos , Epotilonas/farmacologia , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Moduladores de Tubulina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Humanos , Indicadores e Reagentes/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/fisiologia , Neuroblastoma/tratamento farmacológico , Transdução de Sinais/fisiologia , Sais de Tetrazólio/metabolismo , Fatores de Tempo , Proteína X Associada a bcl-2/metabolismo
12.
Curr Cancer Drug Targets ; 7(8): 713-29, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18220532

RESUMO

Microtubule-Targeting Agents (MTAs) constitute a class of drugs largely used in cancer treatment. Among them, both taxanes and Vinca-alkaloids are known to inhibit cancer cell proliferation by inducing cell cycle arrest and subsequent apoptosis. These agents modify the cytoskeleton by affecting the tubulin/microtubule system. In cancer cells, both classes suppress microtubule dynamics through inhibition of microtubule dynamic instability and treadmilling, and commonly induce diverse signals responsible for cell death initiation and execution via the mitochondrial intrinsic pathway. However, links between microtubule network disturbance and the involvement of mitochondria in apoptosis are not obvious, and one may think that they could be independent. Nevertheless, several intracellular proteins could connect microtubules and the apoptotic machinery. The aim of the present review is to provide elements that could answer to the question: is microtubule disruption dispensable for MTA-induced apoptosis? The first section is focused on the mechanisms responsible for the MTA-mediated apoptosis. Then, links between cell cycle regulators and apoptosis are underlined since MTA induce cell cycle arrest by inhibiting microtubules. In the third part, the potential involvement of microtubule-sequestered and/or -transported proteins in apoptotic signalisation is discussed. Lastly, the possible role of the tubulin/microtubule system in direct effects of MTAs on mitochondria is summarized. Thus, it becomes clear that microtubule network and apoptosis are deeply linked in MTA effectiveness, through a cascade of cellular events. It could lead to identification of new biomarkers of MTA effectiveness, that could improve combinatorial therapy with MTAs and provide crucial arms to circumvent resistance of cancer cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Tubulina (Proteína)/efeitos dos fármacos , Apoptose/fisiologia , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Tubulina (Proteína)/metabolismo
13.
Dermatology ; 212(3): 221-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16549917

RESUMO

BACKGROUND: Microcystic adnexal carcinoma (MAC) is a rare cutaneous neoplasm, with a high rate of local recurrences. OBJECTIVE: A series of MAC was analyzed and compared to previously published cases. METHODS: Seven cases of MAC were identified in the register of the institution. Medical and pathological records were reviewed. RESULTS: The primary MAC were located on the face in all patients, and 85% were initially misdiagnosed. The mean follow-up duration was 108 months. The recurrence rate was high: 4 patients developed recurrences. In 3 patients, the course of the disease was severe: one of them developed pathologically proven lung metastasis. CONCLUSION: The present study and review of the literature confirm the clinically aggressive evolution of MAC and its rare ability to give rise to metastasis. Long-term clinical follow-ups with imaging investigations are mandatory.


Assuntos
Carcinoma de Apêndice Cutâneo/patologia , Neoplasias Faciais/patologia , Neoplasias Pulmonares/secundário , Neoplasias Cutâneas/patologia , Adulto , Carcinoma Basocelular/diagnóstico , Carcinoma de Apêndice Cutâneo/diagnóstico , Carcinoma de Apêndice Cutâneo/cirurgia , Diagnóstico Diferencial , Neoplasias Faciais/diagnóstico , Neoplasias Faciais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/cirurgia
14.
Arch Pediatr ; 13(1): 69-75, 2006 Jan.
Artigo em Francês | MEDLINE | ID: mdl-16298120

RESUMO

Over the last 2 decades, the role of apoptosis in anticancer agent cytotoxicity has become clear. Defects in the regulation of apoptosis (programmed cell death) make important contributions to the pathogenesis and progression of most cancers and leukemias. Apoptosis defects also have a key role in cell resistance to chemotherapy. Mitochondria play a central part in cell death in response to anticancer agents. Most of these agents target mitochondria via caspases or other regulator elements of the apoptotic machinery. Nevertheless, some anticancer agents, already in clinical use (paclitaxel, vinblastine, lonidamine, etoposide, arsenic trioxide) or in pre-clinical development (betulinic acid, MT21), directly target and permeabilize mitochondria. The acknowledgement of mitochondria as a new target for anticancer agents provides a new way to bypass cancer cell chemoresistance.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Ensaios Clínicos como Assunto , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/fisiopatologia
15.
Am J Clin Oncol ; 27(5): 472-6, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15596913

RESUMO

This phase II study evaluated docetaxel-5-fluorouracil (5-FU) in locally recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN). Patients were divided into 2 cohorts--those previously treated with chemotherapy and those nonpretreated--that received docetaxel 75 mg/m2 (day 1) plus 5-FU 1,000 mg/m2/day (days 1-5 every 3 weeks). Of 63 patients entered, 20 (31.7%) were pretreated and 43 (68.3%) were nonpretreated. Fifty-nine patients (93.7%) had received prior radiotherapy. After inclusion of 20 patients, the 5-FU dose was reduced to 750 mg/m2/day due to unacceptable toxicity. The overall response rate (ORR) was 20.6% on radiologic review (22.2%, investigator assessment). Pretreated patients achieved an ORR of 25.0% versus 18.6% for nonpretreated patients. This unexpected finding was partly attributed to differences in patient characteristics between the groups. Overall major grade 3 to 4 toxicities comprised neutropenia (66.6%), febrile neutropenia (31.7%), and mucositis (31.7%). Grade 3 to 4 toxicities were lower at the reduced 5-FU dose (750 mg/m2/day): Febrile neutropenia declined from 40.0% to 27.9%; mucositis declined from 55.0% to 20.9%. Three treatment-related deaths occurred (2 with 5-FU 750 mg/m2/day, 1 with 5-FU 1,000 mg/m2/day). Docetaxel-5-FU appears active in locally recurrent and/or metastatic SCCHN with acceptable toxicity at the dose of 5-FU 750 mg/m2.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adulto , Idoso , Carcinoma de Células Escamosas/secundário , Docetaxel , Feminino , Fluoruracila/administração & dosagem , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Taxoides/administração & dosagem
16.
Oftalmologia ; 56(1): 62-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12886686

RESUMO

A good sensitizer for photodynamic therapy (PDT) should be a very selective reagent, which should fastly eliminate from healthy tissues. Furthermore it should have a strong absorption in the red light and good energy transfer properties to molecular oxygen to produce singlet oxygen. All these specifications imply that many second generation photosensitizers (porphyrins, chlorins, bacteriochlorins...) have been modified in order to improve their properties, but however, few have received the approval by regulatory authorities. One way to increase the selectivity of a photosensitizer is coupling it to a vector. Carbohydrate-bound porphyrins were found to be of great interest because of the specific affinity of particular carbohydrates for some tumour cells, the increasing of plasmatic life time and solubility. In this study, we report the synthesis and the photophysical properties (absorption, fluorescence, singlet oxygen formation) of new glycosylated porphyrins. Then, in vitro photocytotoxic properties were evaluated on the human colon adenocarcinoma cell line HT29.


Assuntos
Fotoquimioterapia , Porfirinas/uso terapêutico , Gráficos por Computador , Ensaios de Seleção de Medicamentos Antitumorais , Glicosilação , Células HT29 , Humanos , Porfirinas/síntese química , Porfirinas/farmacocinética , Espectrometria de Fluorescência
17.
Phys Rev Lett ; 89(18): 183403, 2002 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-12398599

RESUMO

By selecting specific decay reactions in high-energy collisions (60 keV/amu) of hydrogen cluster ions with a helium target (utilizing event-by-event data of a recently developed multicoincidence experiment) and by deriving corresponding temperatures for these microcanonical cluster ensembles (analyzing respective fragment distributions), we are able to construct caloric curves for H+3(H2)(m) cluster ions (6

18.
Phys Rev Lett ; 87(20): 203401, 2001 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-11690473

RESUMO

High-energy collisions ( 60 keV/amu) of hydrogen cluster ions with a helium target have been completely analyzed on an event-by-event basis. By selecting specific decay reactions we can start after the energizing collision with a microcanonical cluster ion ensemble of fixed excitation energy and we derive corresponding temperatures of the decaying cluster ions. The relation between the temperature and the excitation energy (caloric curve) exhibits the typical prerequisites of a first-order phase transition in a finite system, in the present case signaling the transition from a bound cluster to the gas phase.

19.
Eur J Endocrinol ; 140(6): 561-9, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10366411

RESUMO

The expression pattern of the GnRH receptor was investigated in a variety of normal and neoplastic human tissues by RT-PCR-Southern blotting. In addition to the full-length cDNA (sb1), we identified two other transcripts: the first (sb2) was characterized by a 128 bp deletion as previously described; the second was an unexpected finding composed of a shorter cDNA (sb3), the sequence of which revealed a 220 bp deletion corresponding in size to exon 2. These three transcripts were found in normal pituitary and pituitary adenomas, and in granulosa tumors, but not in testis, where sb2 was lacking. Only sb1 was expressed in normal, fibrocystic and malignant breast tissue. No transcript with a full-length region was found in endometrium, intestine or lymphocytes. This is the first report that shows that splicing of the gonadotropin-releasing hormone receptor gene is tissue dependent. We also determined the intron-exon nucleotide sequence of the gene and identified an MaeIII polymorphic site in exon 1 created by a silent C453T transition found in 10% of unrelated French whites.


Assuntos
Receptores LHRH/genética , Adenoma/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Complementar/análise , Regulação da Expressão Gênica , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Hipófise/metabolismo , Neoplasias Hipofisárias/metabolismo , Splicing de RNA , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testículo/metabolismo
20.
Clin Endocrinol (Oxf) ; 49(1): 115-23, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9797855

RESUMO

OBJECTIVE: Given the central role of the GnRH receptor (GnRHR) in the regulation of the gonadotrophin secretion, it might be implicated directly or indirectly in the pathogenesis of gonadotroph tumours. DESIGN: We determined if GnRHR mRNA was expressed in gonadotroph tumours using RT-PCR and analysed the GnRHR gene for the presence of mutations in its coding region, using direct sequencing of PCR products. Results were analysed according to the pattern of expression of alpha, beta-FSH and beta-LH subunit (SU) genes. SUBJECTS: RNA was extracted from 20 gonadotroph tumours identified by immunohistochemistry (> 10% of stained cells): 9 adenomas were functioning (high serum gonadotrophin levels), 3 were associated with high alpha-SU levels and 8 were nonfunctioning. Genomic DNA was extracted from 64 normal subjects. RESULTS: We found GnRHR mRNA in 12 tumours (60%): 8/9 functioning (88%), 1/3 alpha-secreting (33%) and 3/8 nonfunctioning (37.5%) gonadotroph adenomas. There was a significant association between GnRHR expression and immunostaining for beta-FSH (P = 0.014). The nucleotide sequence of the amplified products was identical to that of human pituitary except for the presence, in 3 functioning adenomas, of a silent C to T transition at nucleotide 453 encoding for the serine residue situated in the second intracellular loop at position 151. Heterozygosity provided evidence that both alleles were transcribed in these tumours. This substitution creates a Mae III restriction site. Genomic DNA from normal subjects were then tested for the presence of this new polymorphism. The frequency of the heterozygosity (18.7%) was not significantly different from that found in gonadotroph tumours (25%) and this new Mae III polymorphism site cannot be used as a tumoural marker. CONCLUSION: The GnRHR gene is preferentially expressed in functioning rather than in nonfunctioning gonadotroph adenomas, but no mutations altering the coding region of the gene were found to further substantiate its role in the pathogenesis of gonadotroph tumours.


Assuntos
Adenoma/genética , Adenoma/metabolismo , Gonadotropinas Hipofisárias/metabolismo , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Receptores LHRH/genética , Adolescente , Adulto , Idoso , Sequência de Bases , Feminino , Expressão Gênica , Heterozigoto , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo Genético
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