RESUMO
Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.
Assuntos
Cordoma/terapia , Guias de Prática Clínica como Assunto , Humanos , Recidiva Local de NeoplasiaRESUMO
BACKGROUND: Four international study groups undertook a large study in resectable osteosarcoma, which included two randomised controlled trials, to determine the effect on survival of changing post-operative chemotherapy based on histological response. PATIENTS AND METHODS: Patients with resectable osteosarcoma aged ≤40 years were treated with the MAP regimen, comprising pre-operatively of two 5-week cycles of cisplatin 120 mg/m(2), doxorubicin 75 mg/m(2), methotrexate 12 g/m(2) × 2 (MAP) and post-operatively two further cycles of MAP and two cycles of just MA. Patients were randomised after surgery. Those with ≥10% viable tumour in the resected specimen received MAP or MAP with ifosfamide and etoposide. Those with <10% viable tumour were allocated to MAP or MAP followed by pegylated interferon. Longitudinal evaluation of quality of life was undertaken. RESULTS: Recruitment was completed to the largest osteosarcoma study to date in 75 months. Commencing March 2005, 2260 patients were registered from 326 centres across 17 countries. About 1334 of 2260 registered patients (59%) were randomised. Pre-operative chemotherapy was completed according to protocol in 94%. Grade 3-4 neutropenia affected 83% of cycles and 59% were complicated by infection. There were three (0.13%) deaths related to pre-operative chemotherapy. At definitive surgery, 50% of patients had at least 90% necrosis in the resected specimen. CONCLUSIONS: New models of collaboration are required to successfully conduct trials to improve outcomes of patients with rare cancers; EURAMOS-1 demonstrates achievability. Considerable regulatory, financial and operational challenges must be overcome to develop similar studies in the future. The trial is registered as NCT00134030 and ISRCTN 67613327.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Adolescente , Neoplasias Ósseas/cirurgia , Criança , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Terapia Combinada , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Etoposídeo/administração & dosagem , Etoposídeo/efeitos adversos , Feminino , Humanos , Ifosfamida/administração & dosagem , Ifosfamida/efeitos adversos , Interferon-alfa/administração & dosagem , Interferon-alfa/efeitos adversos , Masculino , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Terapia Neoadjuvante , Osteossarcoma/cirurgia , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/efeitos adversos , Qualidade de Vida , Projetos de Pesquisa , Adulto JovemRESUMO
Although fibrous dysplasia (FD) is a benign fibro-osseous lesion, locally aggressive behaviour has rarely been described but is poorly characterised. In this study, we document clinical, radiological and pathological (including molecular genetics) findings in three cases of locally aggressive FD, two of which involved the ribs. Lesions in these cases, one of which was a recurrent lesion, were followed up for 2-7 years. All of the lesions showed typical histological features of FD but were characterised by extension through the bone cortex into the extra-osseous soft tissue. The lesions did not exhibit overexpression/amplification of CDK4 and MDM2; in two of the cases, a GNAS mutation was identified. Our findings confirm that FD can rarely exhibit locally aggressive behaviour with extension beyond the bone compartment into the surrounding soft tissue; these lesions can be distinguished from low-grade intramedullary osteosarcoma by lack of amplification/overexpression of CDK4 and MDM2 and the presence of a GNAS mutation.
Assuntos
Displasia Fibrosa Óssea/patologia , Adulto , Idoso , Proteínas de Ciclo Celular , Quinase 4 Dependente de Ciclina/análise , Feminino , Displasia Fibrosa Óssea/diagnóstico por imagem , Displasia Fibrosa Óssea/genética , Displasia Fibrosa Óssea/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/análise , Proteínas Proto-Oncogênicas/análise , Tomografia Computadorizada por Raios XRESUMO
Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed 'Up & Go' testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%. There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions. Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group.
Assuntos
Ectromelia/cirurgia , Fêmur/anormalidades , Desigualdade de Membros Inferiores/cirurgia , Procedimentos Ortopédicos/métodos , Adolescente , Adulto , Criança , Feminino , Fêmur/cirurgia , Seguimentos , Humanos , Desigualdade de Membros Inferiores/congênito , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Qualidade de Vida , Amplitude de Movimento Articular , Inquéritos e Questionários , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Neurofibromatosis type 1 is one of the most common familial diseases, the hallmark of which is the development of multiple neurofibromas. These are benign nerve sheath tumours, which can transform into malignant peripheral nerve sheath tumours (MPNST). METHODS: The aim of this study was to identify differentially expressed microRNA (miRNA) in neurofibromas and MPNST obtained from patients with neurofibromatosis type 1 using microarray analysis. Differential expression was validated by reverse transcription quantitative-PCR, and functional studies were performed after transfection of miRNA oligonucleotide mimics into MPNST cells. RESULTS: Sixteen miRNA were significantly differentially expressed in MPNST compared with NF, and of these fourteen were downregulated in MPNST: these included miR-30e*, miR-29c*, miR-29c, miR-340*, miR-30c, miR-139-5p, miR-195, miR-151-5p, miR-342-5p, miR-146a, miR-150, miR-223, let-7 a and let-7 g with a false discovery rate of q=8.48E-03 for the least significant miRNA. In contrast, miR-210 and miR-339-5p were upregulated in MPNST compared with neurofibromas. Prediction softwares/algorithms identified a list of genes targeted by miR-29c including extracellular matrix genes and matrix metalloproteinase (MMP)-2, all of which are reported to be involved in cell migration and invasion. Functional studies in a MPNST cell line, sNF96.2, using a mimic of the mature miR-29c showed reduced invasion, whereas there was no change in proliferation. Zymography of the manipulated cells showed that MMP2 activity was also reduced when miR-29c expression was forced in sNF96.2. CONCLUSION: We provide evidence that reduction of miR-29c has a pivotal role in the progression of nerve sheath tumours and results by increasing the invasive/migratory properties of nerve sheath tumours.
Assuntos
Genes Supressores , MicroRNAs , Neoplasias de Bainha Neural/genética , Linhagem Celular Tumoral , Progressão da Doença , Regulação para Baixo , Matriz Extracelular/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Neurofibromatose 1/genéticaRESUMO
A case of multiple-site osteosarcomas in the jaw of a 56-year-old patient is reported. The disease occurred consecutively at three different sites (left maxilla, left mandible, right mandible) separated by time intervals of 12 and 18 months, respectively. Metachronous osteosarcomas of the long bones is a rare form of osteosarcoma and implies multiple lesions appearing at different times, each one behaving clinically as a primary lesion. The pathogenesis of this disease is unknown as it is unclear whether the lesions represent independent primary tumours or metastatic disease.
Assuntos
Neoplasias Mandibulares/patologia , Neoplasias Maxilares/patologia , Segunda Neoplasia Primária/patologia , Osteossarcoma/patologia , Condrossarcoma Mesenquimal/patologia , Diagnóstico Diferencial , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Pessoa de Meia-Idade , Esvaziamento Cervical , Invasividade Neoplásica , Estadiamento de Neoplasias , Procedimentos de Cirurgia Plástica , Retalhos CirúrgicosRESUMO
Elastofibroma dorsi is an uncommon, benign, slow-growing soft-tissue tumour of uncertain aetiology. It classically presents as an ill-defined mass at the inferior pole of the scapula with symptoms which include swelling, discomfort, snapping, stiffness and occasionally pain. We report the symptoms, function and outcome after treatment of 21 elastofibromas in 15 patients. All were diagnosed by MRI and early in the series four also underwent CT-guided biopsy to confirm the diagnosis. In all, 18 tumours were excised and three were observed. After excision, the mean visual analogue score for pain decreased from 4.6 (0 to 10) pre-operatively to 2.4 (0 to 8) post-operatively (p = 0.04). The mean shoulder function, at a mean follow-up of 4.2 years (3 months to 16 years), was 78.1% (30 to 100) using the Stanmore percentage of normal shoulder assessment scoring system. The mean range of forward flexion improved from 135 degrees (70 degrees to 180 degrees ) to 166 degrees (100 degrees to 180 degrees ) after excision (p = 0.005). In four patients a post-operative haematoma formed; one required evacuation. Three patients developed a post-operative seroma requiring needle aspiration and one developed a superficial infection which was treated with antibiotics. Our findings support previous reports suggesting that a pre-operative tissue diagnosis is not necessary in most cases since the lesion can be confidently diagnosed by MRI, when interpreted in the light of appropriate clinical findings. Surgical excision in symptomatic patients, is helpful. It has been suggested that elastofibroma is caused by a local tissue reaction and is not a true neoplastic process. A strong association has been noted between elastofibroma and repetitive use of the shoulder, which is supported by our findings.
Assuntos
Fibroma/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico , Adulto , Idoso , Feminino , Fibroma/cirurgia , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Amplitude de Movimento Articular , Escápula , Articulação do Ombro/fisiopatologia , Neoplasias de Tecidos Moles/cirurgia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
BACKGROUND: Different treatment strategies for low-grade chondrosarcomas are reported in the literature with variable outcomes. The aim of this study was to assess the oncological and functional outcomes associated with intralesional curettage and cementation of the lesion as a treatment strategy. PATIENTS AND METHODS: We performed a retrospective review of 39 consecutive patients with intramedullary low-grade chondrosarcoma of long bones treated by intralesional curettage and cementation at our institution between 1999 and 2005. RESULTS: There were 10 males and 29 females with a mean age of 55.5 years (32-82), and a mean follow-up of 5.1 years (3-8.7). Local recurrence occurred in two patients (5%) within the first two years following index surgery. Both were treated by re-curettage and cementation of the resultant defects. A second local recurrence developed a year later in one of these two patients, for which a further curettage followed by local liquid nitrogen treatment was performed. Overall, there were no cases of post-operative complications or metastases. The patients were assessed using the Musculoskeletal Tumour Society scoring system (MSTS) to determine limb function. The average score achieved was 94% (79-100%). CONCLUSION: Intralesional curettage is an effective treatment strategy for low-grade intramedullary chondrosarcoma of long bones, with excellent oncological and functional results. Careful case selection with stringent clinical and radiographic follow-up is recommended.
Assuntos
Neoplasias Ósseas/cirurgia , Condrossarcoma/cirurgia , Curetagem/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasia Residual , Estudos RetrospectivosRESUMO
We report a case which highlights the progression of osteofibrous dysplasia to adamantinoma and questions whether intralesional curettage is the appropriate treatment. The role of a joint-sparing massive endoprosthesis using cortical fixation is demonstrated and we describe a unique biomedical design which resulted in the manufacture of an end cap to allow amputation through a custom-made proximal tibial replacement, rather than an above-knee amputation following recurrence.
Assuntos
Adamantinoma/cirurgia , Amputação Cirúrgica/métodos , Doenças do Desenvolvimento Ósseo/cirurgia , Neoplasias Ósseas/cirurgia , Recidiva Local de Neoplasia/cirurgia , Adamantinoma/patologia , Adulto , Doenças do Desenvolvimento Ósseo/patologia , Neoplasias Ósseas/patologia , Diagnóstico Diferencial , Progressão da Doença , Feminino , Humanos , Recidiva Local de Neoplasia/patologia , Dor/cirurgia , Esqui/lesões , Fraturas da Tíbia/complicaçõesRESUMO
Chordomas are radio- and chemo-resistant tumours and metastasise in as many as 40% of patients. The aim of this study was to identify potential molecular targets for the treatment of chordoma. In view of the reported association of chordoma and tuberous sclerosis complex syndrome, and the available therapeutic agents against molecules in the PI3K/AKT/TSC1/TSC2/mTOR pathway, a tissue microarray of 50 chordoma cases was analysed for expression of active molecules involved in this signalling pathway by immunohistochemistry and a selected number by western blot analysis. Chordomas were positive for p-AKT (92%), p-TSC2 (96%), p-mTOR (27%), total mTOR (75%), p-p70S6K (62%), p-RPS6 (22%), p-4E-BP1 (96%) and eIF-4E (98%). Phosphatase and tensin homologue deleted on chromosome 10 expression was lost in 16% of cases. Mutations failed to be identified in PI3KCA and RHEB1 in the 23 cases for which genomic DNA was available. Fluorescence in situ hybridisation analysis for mTOR and RPS6 loci showed that 11 of 33 and 21 of 44 tumours had loss of one copy of the respective genes, results which correlated with the loss of the relevant total proteins. Fluorescence in situ hybridisation analysis for loci containing TSC1 and TSC2 revealed that all cases analysed harboured two copies of the respective genes. On the basis of p-mTOR and or p-p70S6K expression there is evidence indicating that 65% of the chordomas studied may be responsive to mTOR inhibitors, rapamycin or its analogues, and that patients may benefit from combined therapy including drugs that inhibit AKT.
Assuntos
Cordoma/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Cordoma/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Pessoa de Meia-Idade , Complexos Multiproteicos , Análise de Sequência com Séries de Oligonucleotídeos , Fosfatidilinositol 3-Quinases/metabolismo , Análise Serial de Proteínas , Proteínas , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR , Fatores de Transcrição/metabolismo , Esclerose Tuberosa/tratamento farmacológico , Esclerose Tuberosa/genética , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa , Proteína 2 do Complexo Esclerose Tuberosa , Proteínas Supressoras de Tumor/metabolismo , Adulto JovemRESUMO
Seventy indoor-reared sheep were divided into 10 groups to test the efficacy of the experimental fasciolicide, compound alpha (15mg/kg) against triclabendazole (TCBZ)-resistant and TCBZ-susceptible F. hepatica infections. Activity against the Sligo TCBZ-resistant isolate was tested at three time points post-infection (p.i.): 3 days, 4 weeks and 12 weeks (Groups 1-3, respectively). A parallel trial was carried out using TCBZ (10mg/kg) (Groups 5-7): this provided a direct comparison between the efficacies of the two drugs. Group 4 served as an untreated Sligo control. Groups 8 and 9 were setup to test the efficacy of TCBZ and compound alpha against 12-week-old and 4-week-old TCBZ-susceptible, Cullompton infections, respectively. Group 10 served as an untreated Cullompton control. Sheep were sacrificed at 16 weeks p.i. and efficacies were determined. All remaining flukes were collected and measured, before being processed for whole-mount staining to assess the condition of their reproductive structures (testis, vitellaria, ovary and uterus). A second study was carried out to test the activity of compound alpha (15mg/kg) against mature 12-week-old TCBZ-susceptible F. hepatica infections in sheep. Eighteen sheep were divided into two groups, A and B. Group A was treated and Group B served as an untreated control group. Efficacy was determined by reduction in faecal egg counts. The results showed that, whilst compound alpha was very active against adult TCBZ-susceptible flukes, producing a 100% reduction in faecal egg counts, it only caused a 62.5% reduction in fluke burden against juvenile flukes. Moreover, compound alpha was not effective against any stage of infection with TCBZ-resistant F. hepatica in sheep. Data from the trial also revealed biological differences between the two isolates. Thus, Sligo flukes were smaller in size and produced fewer eggs than the Cullompton flukes and their cysts were less infective to sheep. However, they reached the bile ducts more quickly and their eggs appeared in the faeces >2 weeks earlier.
Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Imidazóis/farmacologia , Naftalenos/farmacologia , Doenças dos Ovinos/tratamento farmacológico , Animais , Fasciolíase/tratamento farmacológico , Fasciolíase/parasitologia , Feminino , Masculino , Ovinos , Doenças dos Ovinos/parasitologia , TriclabendazolRESUMO
Here we investigate the function of zebrafish Bcl-2 family proteins and demonstrate important conservation of function across zebrafish and mammalian systems. We have isolated a zebrafish ortholog of mammalian BIM and show that it is the most toxic of the zebrafish BH3-only genes examined, sharing this characteristic with the mammalian BIM gene. The zebrafish bad gene shows a complete lack of embryonic lethality, but like mammalian BAD, its pro-apoptotic activity is regulated through phosphorylation of critical serines. We also found that the pattern of mitochondrial dysfunction observed by zebrafish BH3 domain peptides in a mammalian cytochrome c release assay recapitulates the pattern of embryonic lethality induced by the respective mRNA injections in vivo. In contrast to zebrafish Bim, Bid exhibited only weak binding to zebrafish Bcl-2 and moderate-to-weak overall lethality in zebrafish embryos and isolated mitochondria. Given that zebrafish Bcl-2 binds strongly to mammalian BID and BIM peptides and proteins, the protein identified as the zebrafish Bid ortholog has different properties than mammalian BID. Overall, our results demonstrate the high degree of functional conservation between zebrafish and mammalian Bcl-2 family proteins, thus validating the zebrafish as a model system to further dissect the molecular mechanisms that regulate apoptosis in future forward genetic and chemical modifier screens.
Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Proteínas de Membrana/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Sequência de Aminoácidos , Animais , Apoptose , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular , Sistema Nervoso Central/efeitos da radiação , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Mutação , Domínios e Motivos de Interação entre Proteínas , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/química , Tolerância a Radiação , Homologia de Sequência de Aminoácidos , Serina/genética , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Proteína de Morte Celular Associada a bcl/química , Proteína de Morte Celular Associada a bcl/metabolismoRESUMO
Eight indoor-reared, crossbred sheep with no pre-exposure to Fasciola hepatica were infected, by oral gavage, with 200 metacercarial cysts of the triclabendazole-susceptible, Cullompton isolate of F. hepatica. Anthelmintic dosing occurred at 4 weeks post-infection using 15mg/kg compound alpha. Two treated sheep per time period were euthanized at 24h, 48h and 72h post-treatment with compound alpha. The two sheep from the control group were euthanized alongside the 24h alpha-treated sheep. Juvenile flukes were recovered from each of the sheeps' liver and processed for examination by electron microscopy. The surface morphology of the flukes' tegument was assessed using scanning electron microscopy (SEM). The ultrastructure of the tegumental syncytium and underlying tegumental cells and connections and somatic musculature were investigated using transmission electron microscopy (TEM). Both the SEM and TEM results revealed a level of disruption that increased with time, culminating at 72h with extensive tegumental loss and substantial degeneration of the cell bodies. The effects of compound alpha on the surface morphology were not particularly apparent until 48h post-treatment, when disruption included swelling and blebbing of the tegument. At 72h post-treatment, SEM revealed loss of the entire syncytial layer over large areas of the flukes. In the areas where the syncytium was lost and the basal lamina exposed, lesions of varying sizes had developed, revealing underlying tissues. Though minor forms of disruption to the ultrastructure of the syncytium were observed using TEM 24h post-treatment, it was at 48h post-treatment that substantial stress responses occurred. They included the presence of autophagic vacuoles and 'open' bodies at the apex of the syncytium and swelling of the basal infolds. The mitochondria within the syncytium and tegumental cells became progressively more disrupted over the three time periods and, by 72h post-treatment, they were frequently distorted and swollen in appearance, and contained severely swollen cristae. By 72h, the number of secretory bodies, particularly T1 bodies, had become significantly depleted in their respective cell bodies, cytoplasmic processes and in the tegumental syncytium. Both the circular and longitudinal muscle bundles were severely disrupted 72h post-treatment. They frequently contained a reduced number of muscle fibres and, in more severe instances, there was an absence of fibres altogether.
Assuntos
Anti-Helmínticos/farmacologia , Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Imidazóis/uso terapêutico , Naftalenos/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Animais , Fasciola hepatica/ultraestrutura , Fasciolíase/tratamento farmacológico , Fasciolíase/parasitologia , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/parasitologia , Gastroenteropatias/veterinária , Tegumento Comum , Ovinos , Doenças dos Ovinos/parasitologiaRESUMO
The Epstein-Barr and Kaposi's sarcoma gamma-herpesviruses (KSHVs) are associated with certain cancers, and encode B-cell leukemia/lymphoma 2 (BCL-2) homologs, BHRF-1 and KSHV BCL-2, respectively. Little is known, however, about the molecular interactions allowing viral BCL-2 homologs to mediate their anti-apoptotic function. Cellular anti-apoptotic proteins, such as BCL-2 and MCL-1, prevent death via selective interactions with pro-death BH3-only proteins. To investigate whether BHRF-1 and KSHV BCL-2 function similarly, we made recombinant BHRF-1 and KSHV BCL-2 proteins. We identified the individual binding patterns for BHRF-1 and KSHV BCL-2 to BH3 domains. These studies surprisingly showed that KSHV BCL-2 is more closely related to MCL-1 than to BCL-2, a result confirmed by sequence analysis. GST-BHRF-1 and GST-KSHV BCL-2 bound BH3-only family proteins from human cells. BHRF-1 protected mammalian cells from growth factor withdrawal, etoposide and adriamycin. We found that both BCL-2 and BHRF-1 sequestered pro-death BH3-only proteins under growth factor-deficient conditions. Finally, we tested the ability of a panel of BH3 peptides to inhibit BHRF-1 and KSHV BCL-2 function in a mitochondrial model of apoptosis. We found that each could be inhibited by the select group of BH3 peptides identified in our binding assay. Our studies define the biochemical interactions underlying BHRF-1 and KSHV BCL-2 anti-apoptotic function, and identify peptides that are prototypic inhibitors of this function.
Assuntos
Proteínas Oncogênicas/antagonistas & inibidores , Proteínas Oncogênicas/química , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/química , Sequência de Aminoácidos , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular , Dano ao DNA , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Proteínas Oncogênicas/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Virais/metabolismoRESUMO
Four patients who developed malignant synovial tumours are described; one with chondromatosis developed a synovial chondrosarcoma and three with pigmented villonodular synovitis developed malignant change. The relevant literature is discussed.
Assuntos
Condromatose Sinovial/etiologia , Membrana Sinovial/metabolismo , Sinovite Pigmentada Vilonodular/etiologia , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/patologia , Transformação Celular Neoplásica/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Membrana Sinovial/patologia , Resultado do TratamentoAssuntos
Biomarcadores Tumorais/genética , Neoplasias Musculares/genética , Proteínas de Fusão Oncogênica/genética , Sarcoma Sinovial/genética , Adulto , Sequência de Bases , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Dados de Sequência Molecular , Transcrição Gênica/genéticaRESUMO
Oncogenic osteomalacia (OO) is an acquired form of hypophosphataemic osteomalacia, which is associated most commonly with the development of a benign phosphaturic mesenchymal tumour mixed connective tissue type (PMTMCT). PMTMCTs are generally well vascularised tumours, and many have in the past been classified as haemangiomas and haemangiopericytomas. Although these tumours show some morphological variation, it has been proposed that they represent a distinct histopathological entity. Our aim in this study was to determine by immunohistochemistry the vascular profile of PMTMCT. Using monoclonal antibodies directed against several vascular markers, including the lymphatic endothelial cell antigens LYVE 1 and podoplanin, we found that PMTMCTs, in contrast to haemangiomas and haemangiopericytomas, contain lymphatic vessels. Taken with previous observations that PMTMCTs overexpress FGF23 and other gene products, this finding provides further evidence that most osteomalacia associated mesenchymal tumours represent a discrete pathological entity.
Assuntos
Neoplasias Ósseas/patologia , Vasos Linfáticos/patologia , Mesenquimoma/patologia , Osteomalacia/patologia , Feminino , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/análise , Humanos , Masculino , Glicoproteínas de Membrana/análise , Pessoa de Meia-Idade , Fosfatos/urinaRESUMO
AIMS: To report on the mutation-specific restriction enzyme digest (MSRED) method using paraffin-embedded tissue as a means of detecting GNAS1 mutations in fibrous dysplasia (FD), and to determine if any of the reported GNAS1 mutations in endocrine neoplasms, not previously documented in FD, can be found in FD. METHODS AND RESULTS: Sixty-seven cases of extragnathic FD were analysed as two groups, 1997-2002 and 2003-06, chosen because tissue fixation and decalcification methods were more accurately recorded in the latter. MSRED revealed that between 2003 and 2006, 93% of 28 'in house' extragnathic cases harboured a GNAS1 mutation, compared with 75% of 32 cases before 2003. Fixation times of no more than 48 h and decalcification in ethylenediamine tetraacetic acid gave the best results. Of the 56 mutations detected (five gnathic, 51 extragnathic), 32 (57%) were R201H, 21 (38%) were R201C and three (5%) were Q227L. Two Q227L extragnathic cases had unusual clinical/radiological findings. No mutations were detected in osteofibrous dysplasia. CONCLUSION: Detection of GNAS1 mutations by MSRED is a valuable adjunct to the histopathological diagnosis of FD. This is the first report of a Q227L mutation in FD, although it has been previously documented in pituitary adenoma.
Assuntos
Códon/genética , Displasia Fibrosa Óssea/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Testes Genéticos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Criança , Pré-Escolar , Cromograninas , Análise Custo-Benefício , Análise Mutacional de DNA , Feminino , Displasia Fibrosa Óssea/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica , Testes Genéticos/economia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Radiografia , Mapeamento por Restrição/métodos , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Human mesenchymal stem cell (hMSC) proliferation and development is regulated by many signalling pathways. gamma-Secretases play an important role in Notch signalling as well as other processes that are involved in developmental decisions, but their role in hMSC proliferation and cell fate decisions has not been explored. OBJECTIVE: To investigate the role of gamma-secretases in hMSC proliferation and differentiation. MATERIALS AND METHODS: Using the gamma-secretase inhibitor N-[N-(3,5-Difluorophenacetyl-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), we investigated their role in hMSC growth and differentiation to chondrogenic, osteogenic and adipogenic fates. RESULTS: We found that inhibiting gamma-secretases reduced the rate of hMSC proliferation, and altered hMSC differentiation in vitro. Addition of DAPT had an inhibitory effect on chondrogenesis resulting in impaired cartilage matrix production and altered chondrocyte morphology. DAPT treated chrodrocytic pellets had reduced levels of Hes1 and Hey1 suggesting that these effects are mediated via Notch signalling. Addition of the DAPT inhibitor to osteogenic cultures did not alter the appearance of bone markers, however, adipogenesis occurred in these cultures in a DAPT concentration-dependent manner. DAPT did not enhance adipogenesis in the presence of a potent adipogenic cocktail, but had an adipogenic effect when combined with dexamethasone only. CONCLUSION: We conclude that gamma-secretases play an important role in both hMSC proliferation and differentiation.