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INTRODUCTION: Fibromyalgia causes long-term pain. It affects at least 2% of the population, the majority being women. In addition, extended symptoms corresponding to vitamin B12 deficiency occur. Findings from several studies have indicated that vitamin B12 may be a possible treatment for pain in fibromyalgia. The aim of the proposed study is to evaluate whether vitamin B12 decreases pain sensitivity and the experience of pain (ie, hyperalgesia and allodynia) in women with fibromyalgia. METHODS AND ANALYSIS: The study is a randomised, placebo-controlled, single-blind, clinical trial with two parallel groups which are administered mecobalamin (vitamin B12) or placebo over 12 weeks. 40 Swedish women aged 20-70 years with an earlier recorded diagnosis of fibromyalgia are randomised into the placebo group or the treatment group, each consisting of 20 participants. Outcomes consist of questionnaires measured at baseline and after 12 weeks of treatment. A final re-evaluation will then follow 12 weeks after treatment ends. The primary outcome is tolerance time, maximised to 3 min, which is assessed using the cold pressor test. In order to broaden the understanding of the lived experience of participants, qualitative interviews will be conducted using a phenomenological approach on a lifeworld theoretical basis (reflective lifeworld research approach). ETHICS AND DISSEMINATION: The protocol for the study is approved by the local ethical committee at Linkoping (EPM; 2018/294-31, appendices 2019-00347 and 2020-04482). The principles of the Helsinki Declaration are followed regarding oral and written consent to participate, confidentiality and the possibility to withdraw participation from the study at any time. The results will primarily be communicated through peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: NCT05008042.
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Fibromialgia , Humanos , Feminino , Masculino , Fibromialgia/complicações , Fibromialgia/tratamento farmacológico , Método Simples-Cego , Dor , Vitaminas , Resultado do Tratamento , Método Duplo-Cego , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Chemotherapy resistance and relapses are common in high-risk neuroblastoma (NB). Here, we developed a clinically relevant in vivo treatment protocol mimicking the first-line five-chemotherapy treatment regimen of high-risk NB and applied this protocol to mice with MYCN-amplified NB patient-derived xenografts (PDXs). Genomic and transcriptomic analyses were used to reveal NB chemoresistance mechanisms. Intrinsic resistance was associated with high genetic diversity and an embryonic phenotype. Relapsed NB with acquired resistance showed a decreased adrenergic phenotype and an enhanced immature mesenchymal-like phenotype, resembling multipotent Schwann cell precursors. NBs with a favorable treatment response presented a lineage-committed adrenergic phenotype similar to normal neuroblasts. Novel integrated phenotypic gene signatures reflected treatment response and patient prognosis. NB organoids established from relapsed PDX tumors retained drug resistance, tumorigenicity, and transcriptional cell states. This work sheds light on the mechanisms of NB chemotherapy response and emphasizes the importance of transcriptional cell states in chemoresistance.
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High-dose methotrexate (HDMTX) is a central component in the treatment of acute lymphoblastic leukemia, osteosarcoma, and some lymphomas and brain tumors. MTX is given at lethal doses and then is followed by rescue treatment with folinic acid (FA). Despite FA rescue, many patients suffer severe toxicity. The pharmacokinetics of FA rescue have not been sufficiently studied. However, optimization of FA rescue could potentially increase anti-tumor effects, whilst decreasing organ toxicity. Here, we describe our efforts to establish and optimize a liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the simultaneous determination of five essential components of the folate cycle, as well as MTX and its two metabolites. The method was applied to 6 individual patients receiving HDMTX, with 3 or 4 measurements for each patient. The method allows analysis of samples that were initially frozen. This notion, together with the test results in the 6 pilot patients, shows the feasibility of this method to study MTX and FA pharmacokinetics during HDMTX treatment. The method has the potential to optimize HDMTX and FA rescue treatment in individual patients.
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Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Cromatografia Líquida/métodos , Ácido Fólico/sangue , Metotrexato/administração & dosagem , Metotrexato/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Espectrometria de Massas em Tandem/métodos , Relação Dose-Resposta a Droga , Ácido Fólico/administração & dosagem , Humanos , Projetos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangueRESUMO
High-risk neuroblastoma has a poor prognosis despite intense treatment, demonstrating the need for new therapeutic strategies. Here we evaluated the effects of rigosertib (ON-01910.Na) in preclinical models of high-risk neuroblastoma. Among several hundred cancer cell lines representing 24 tumor types, neuroblastoma was the most sensitive to rigosertib. Treatment of MYCN-amplified neuroblastoma organoids resulted in organoid disintegration, decreased cell viability, and increased apoptotic cell death. Neuroblastoma response to rigosertib involved G2M cell cycle arrest and decreased phosphorylation of AKT (Ser473) and ERK1/2 (Thr202/Tyr204). Rigosertib delayed tumor growth and prolonged survival of mice carrying neuroblastoma MYCN-amplified PDX tumors (median survival: 31 days, treated; 22 days, vehicle) accompanied with increased apoptosis in treated tumors. We further identified vincristine and rigosertib as a potential promising drug combination treatment. Our results show that rigosertib might be a useful therapeutic agent for MYCN-amplified neuroblastomas, especially in combination with existing agents.
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Neuroblastoma is a childhood malignancy with often dismal prognosis; relapse is common despite intense treatment. Here, we used human tumor organoids representing multiple MYCN-amplified high-risk neuroblastomas to perform a high-throughput drug screen with approved or emerging oncology drugs. Tumor-selective effects were calculated using drug sensitivity scores. Several drugs with previously unreported anti-neuroblastoma effects were identified by stringent selection criteria. ARRY-520, an inhibitor of kinesin spindle protein (KSP), was among those causing reduced viability. High expression of the KSP-encoding gene KIF11 was associated with poor outcome in neuroblastoma. Genome-scale loss-of-function screens in hundreds of human cancer cell lines across 22 tumor types revealed that KIF11 is particularly important for neuroblastoma cell viability. KSP inhibition in neuroblastoma patient-derived xenograft (PDX) cells resulted in the formation of abnormal monoastral spindles, mitotic arrest, up-regulation of mitosis-associated genes, and apoptosis. In vivo, KSP inhibition caused regression of MYCN-amplified neuroblastoma PDX tumors. Furthermore, treatment of mice harboring orthotopic neuroblastoma PDX tumors resulted in increased survival. Our results suggested that KSP inhibition could be a promising treatment strategy in children with high-risk neuroblastoma.
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Cinesinas , Neuroblastoma , Animais , Apoptose , Linhagem Celular Tumoral , Cinesinas/genética , Camundongos , Recidiva Local de Neoplasia , Neuroblastoma/tratamento farmacológicoRESUMO
Neuroblastoma is a childhood solid tumour originating from undifferentiated neural progenitor cells of the sympathetic nervous system. Drug resistance of childhood cancer neuroblastoma is a serious clinical problem. In the present study, we aimed to identify novel drugs that can inhibit the growth and survival of chemoresistant neuroblastoma. High-throughput screening identified a small molecule, epi-enprioline that was able to induce apoptosis of vincristine-resistant neuroblastoma cells via the mitochondrial apoptotic pathway. Epi-enprioline reduced tumour growth in multiple preclinical models, including an orthotopic neuroblastoma patient-derived xenograft model in vivo. In summary, our data suggest that epi-enprioline can be considered as a lead compound for the treatment of vincristine-resistant neuroblastoma uncovering a novel strategy, which can be further explored as a treatment for drug-resistant neuroblastoma.
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Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neuroblastoma/tratamento farmacológico , Piridinas/farmacologia , Animais , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Feminino , Ensaios de Triagem em Larga Escala/métodos , Humanos , Camundongos , Camundongos Nus , Bibliotecas de Moléculas Pequenas/farmacologia , Vincristina/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The PI3K pathway is a major driver of cancer progression. However, clinical resistance to PI3K inhibition is common. IBL-302 is a novel highly specific triple PIM, PI3K, and mTOR inhibitor. Screening IBL-302 in over 700 cell lines representing 47 tumor types identified neuroblastoma as a strong candidate for PIM/PI3K/mTOR inhibition. IBL-302 was more effective than single PI3K inhibition in vitro, and IBL-302 treatment of neuroblastoma patient-derived xenograft (PDX) cells induced apoptosis, differentiated tumor cells, and decreased N-Myc protein levels. IBL-302 further enhanced the effect of the common cytotoxic chemotherapies cisplatin, doxorubicin, and etoposide. Global genome, proteome, and phospho-proteome analyses identified crucial biological processes, including cell motility and apoptosis, targeted by IBL-302 treatment. While IBL-302 treatment alone reduced tumor growth in vivo, combination therapy with low-dose cisplatin inhibited neuroblastoma PDX growth. Complementing conventional chemotherapy treatment with PIM/PI3K/mTOR inhibition has the potential to improve clinical outcomes and reduce severe late effects in children with high-risk neuroblastoma.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neuroblastoma/tratamento farmacológico , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Piridinas/farmacologia , Pirimidinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Tiofenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Feminino , Humanos , Camundongos Nus , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/enzimologia , Neuroblastoma/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Piridinas/uso terapêutico , Pirimidinas/uso terapêutico , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Tiofenos/uso terapêutico , Carga Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Patient-derived xenografts (PDX) and the Avatar, a single PDX mirroring an individual patient, are emerging tools in preclinical cancer research. However, the consequences of intratumor heterogeneity for PDX modeling of biomarkers, target identification, and treatment decisions remain underexplored. In this study, we undertook serial passaging and comprehensive molecular analysis of neuroblastoma orthotopic PDXs, which revealed strong intrinsic genetic, transcriptional, and phenotypic stability for more than 2 years. The PDXs showed preserved neuroblastoma-associated gene signatures that correlated with poor clinical outcome in a large cohort of patients with neuroblastoma. Furthermore, we captured spatial intratumor heterogeneity using ten PDXs from a single high-risk patient tumor. We observed diverse growth rates, transcriptional, proteomic, and phosphoproteomic profiles. PDX-derived transcriptional profiles were associated with diverse clinical characteristics in patients with high-risk neuroblastoma. These data suggest that high-risk neuroblastoma contains elements of both temporal stability and spatial intratumor heterogeneity, the latter of which complicates clinical translation of personalized PDX-Avatar studies into preclinical cancer research.Significance: These findings underpin the complexity of PDX modeling as a means to advance translational applications against neuroblastoma. Cancer Res; 78(20); 5958-69. ©2018 AACR.
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Estadiamento de Neoplasias , Transplante de Neoplasias , Neuroblastoma/terapia , Animais , Biomarcadores Tumorais/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Genótipo , Humanos , Lactente , Masculino , Camundongos , Neuroblastoma/genética , Neuroblastoma/patologia , Polimorfismo de Nucleotídeo Único , Proteômica , Transcriptoma , Pesquisa Translacional BiomédicaRESUMO
We report an enterovirus D68 (EV-D68) outbreak in Stockholm Sweden in 2016. Between 22 August and 25 September EV-D68 was detected in 74/495 respiratory samples analysed at the Karolinska University Hospital. During the peak week, 30/91 (33%) samples were EV-D68 positive. Viral protein (VP)P4/VP2 sequencing revealed that cases were caused by B3 lineage strains. Forty-four (59%) EV-D68-positive patients were children aged ≤ 5 years. Ten patients had severe respiratory or neurological symptoms and one died.
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Surtos de Doenças , Enterovirus Humano D/genética , Enterovirus Humano D/isolamento & purificação , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Enterovirus/isolamento & purificação , Variação Genética , Criança , Pré-Escolar , Enterovirus/classificação , Enterovirus Humano D/classificação , Feminino , Humanos , Lactente , Masculino , Filogenia , Infecções Respiratórias/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Suécia/epidemiologia , Proteínas Estruturais Virais/genéticaRESUMO
BACKGROUND: Breast cancer is a very heterogeneous disease and some patients are cured by the surgical removal of the primary tumour whilst other patients suffer from metastasis and spreading of the disease, despite adjuvant therapy. A number of prognostic and treatment predictive factors have been identified such as tumour size, oestrogen (ER) and progesterone (PgR) receptor status, human epidermal growth factor receptor type 2 (HER2) status, histological grade, Ki67 and age. Lymph node involvement is also assessed during surgery to determine if the tumour has spread which requires dissection of the axilla and adjuvant treatment. The prognostic and treatment predictive factors assessing the nature of the tumour are all routinely based on the status of the primary tumour. RESULTS: We have analysed a unique tumour set of fourteen primary breast cancer tumours with matched synchronous axillary lymph node metastases and a set of nine primary tumours with, later developed, matched distant metastases from different sites in the body. We used a pairwise tumour analysis (from the same individual) since the difference between the same tumour-type in different patients was greater. Glycopeptide capture was used in this study to selectively isolate and quantify N-linked glycopeptides from tumours mixtures and the captured glycopeptides were subjected to label-free quantitative tandem mass spectrometry analysis. Differentially expressed proteins between primary tumours and matched lymph node metastasis and distant metastasis were identified. Two of the top hits, ATPIF1 and tubulin ß-chain were validated by immunohistochemistry to be differentially regulated. CONCLUSIONS: We show that the expression of a large number of glycosylated proteins change between primary tumours and matched lymph node metastases and distant metastases, confirming that cancer cells undergo a molecular transformation during the spread to a secondary site. The proteins are part of important pathways such as cell adhesion, migration pathways and immune response giving insight into molecular changes needed for the tumour to spread. The large difference between primary tumours and lymph node and distant metastases also suggest that treatment should be based on the phenotype of the lymph node and distant metastases.
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UNLABELLED: Soft tissue sarcomas (STS) are malignant tumors of mesenchymal origin. A substantial portion of these tumors exhibits complex karyotypes and lack characterized chromosomal aberrations. Owing to such properties, both histopathologic and molecular classification of these tumors has been a significant challenge. This study examines the protein expression of a large number of human STS, including subtype heterogeneity, using two-dimensional gel proteomics. In addition, detailed proteome profiles of a subset of pleomorphic STS specimens using an in-depth mass-spectrometry approach identified subgroups within the leiomyosarcomas with distinct protein expression patterns. Pathways analysis indicates that key biologic nodes like apoptosis, cytoskeleton remodeling, and telomere regulation are differentially regulated among these subgroups. Finally, investigating the similarities between protein expression of leiomyosarcomas and undifferentiated pleomorphic sarcomas (UPS) revealed similar protein expression profiles for these tumors, in comparison with pleomorphic leiomyosarcomas. IMPLICATIONS: These results suggest that UPS tumors share a similar lineage as leiomyosarcomas and are likely to originate from different stages of differentiation from mesenchymal stem cells to smooth muscle cells.
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Extremidades/patologia , Perfilação da Expressão Gênica/métodos , Leiomiossarcoma/metabolismo , Leiomiossarcoma/patologia , Proteômica/métodos , Transdução de Sinais , Parede Torácica/patologia , Idoso , Idoso de 80 Anos ou mais , Apoptose , Citoesqueleto/metabolismo , Redes Reguladoras de Genes , Humanos , Espectrometria de Massas , Pessoa de Meia-Idade , Homeostase do TelômeroRESUMO
WNT5A has been identified as an important ligand in the malignant progression of a number of tumours. Although WNT5A signalling is often altered in cancer, the ligand's role as either a tumour suppressor or oncogene varies between tumour types and is a contemporary issue for investigators of ß-catenin-independent WNT signalling in oncology. Here, we report that one of the initial effects of active WNT5A signalling in malignant melanoma cells is an alteration in cellular energy metabolism and specifically an increase in aerobic glycolysis. This was found to be at least in part due to an increase in active Akt signalling and lactate dehydrogenase (LDH) activity. The clinical relevance of these findings was strengthened by a strong correlation (P < 0.001) between the expression of WNT5A and LDH isoform V in a cohort of melanocytic neoplasms. We also found effects of WNT5A on energy metabolism in breast cancer cells, but rather than promoting aerobic glycolysis as it does in melanoma, WNT5A signalling increased oxidative phosphorylation rates in breast cancer cells. These findings support a new role for WNT5A in the metabolic reprogramming of cancer cells that is a context- dependent event.
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Melanoma/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Linhagem Celular Tumoral , Glicólise , Humanos , L-Lactato Desidrogenase/metabolismo , Espectrometria de Massas , Proteína Wnt-5aRESUMO
Tumor progression and prognosis in breast cancer patients are difficult to assess using current clinical and laboratory parameters, where a pathological grading is indicative of tumor aggressiveness. This grading is based on assessments of nuclear grade, tubule formation, and mitotic rate. We report here the first protein signatures associated with histological grades of breast cancer, determined using a novel affinity proteomics approach. We profiled 52 breast cancer tissue samples by combining nine antibodies and label-free LC-MS/MS, which generated detailed quantified proteomic maps representing 1,388 proteins. The results showed that we could define in-depth molecular portraits of histologically graded breast cancer tumors. Consequently, a 49-plex candidate tissue protein signature was defined that discriminated between histological grades 1, 2, and 3 of breast cancer tumors with high accuracy. Highly biologically relevant proteins were identified, and the differentially expressed proteins indicated further support for the current hypothesis regarding remodeling of the tumor microenvironment during tumor progression. The protein signature was corroborated using meta-analysis of transcriptional profiling data from an independent patient cohort. In addition, the potential for using the markers to estimate the likelihood of long-term metastasis-free survival was also indicated. Taken together, these molecular portraits could pave the way for improved classification and prognostication of breast cancer.
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Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma/genética , Carcinoma/patologia , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/mortalidade , Carcinoma/diagnóstico , Carcinoma/mortalidade , Progressão da Doença , Intervalo Livre de Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Prognóstico , Proteômica/métodos , Proteômica/estatística & dados numéricos , Transcriptoma , Microambiente Tumoral/genéticaRESUMO
Metastases to the spinal cord from glioblastoma multiforme (GBM) are uncommon, but important to have in mind when patients with a history of GBM present with symptoms that do not correlate with the primary disease pattern. We report a rare case, where a male with GBM, six months after tumour excision followed by concomitant radio- and chemotherapy, presented with gait disturbance and unspecific neurological symptoms of the lower right limb. Magnetic resonance imaging of columna totalis revealed both intra- and extramedullary metastases in the spinal cord. The patient died one month later.
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Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Neoplasias da Medula Espinal/secundário , Adulto , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Evolução Fatal , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Glioblastoma/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias da Medula Espinal/complicações , Neoplasias da Medula Espinal/radioterapiaRESUMO
Epithelial ovarian carcinoma has in general a poor prognosis since the vast majority of tumors are genomically unstable and clinically highly aggressive. This results in rapid progression of malignancy potential while still asymptomatic and thus in late diagnosis. It is therefore of critical importance to develop methods to diagnose epithelial ovarian carcinoma at its earliest developmental stage, that is, to differentiate between benign tissue and its early malignant transformed counterparts. Here we present a shotgun quantitative proteomic screen of benign and malignant epithelial ovarian tumors using iTRAQ technology with LC-MALDI-TOF/TOF and LC-ESI-QTOF MS/MS. Pathway analysis of the shotgun data pointed to the PI3K/Akt signaling pathway as a significant discriminatory pathway. Selected candidate proteins from the shotgun screen were further confirmed in 51 individual tissue samples of normal, benign, borderline or malignant origin using LC-MRM analysis. The MRM profile demonstrated significant differences between the four groups separating the normal tissue samples from all tumor groups as well as perfectly separating the benign and malignant tumors with a ROC-area of 1. This work demonstrates the utility of using a shotgun approach to filter out a signature of a few proteins only that discriminates between the different sample groups.
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Proteínas de Neoplasias/metabolismo , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Proteínas 14-3-3/metabolismo , Sequência de Aminoácidos , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Carcinoma Epitelial do Ovário , Feminino , Humanos , Dados de Sequência Molecular , Proteínas de Neoplasias/análise , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Ovário/metabolismo , Ovário/patologia , Proteoma/análise , Curva ROC , Análise de Sequência de Proteína , Transdução de Sinais , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Células Tumorais CultivadasRESUMO
Nontransient hypoxia is strongly associated with malignant lesions, resulting in aggressive behavior and resistance to treatment. We present an analysis of mRNA and protein expression changes in neuroblastoma cell lines occurring upon the transition from normoxia to hypoxia. The correlation between mRNA and protein level changes was poor, although some known hypoxia-driven genes and proteins correlated well. We present previously undescribed membrane proteins expressed under hypoxic conditions that are candidates for evaluation as biomarkers.
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Biomarcadores/química , Membrana Celular/química , Hipóxia/metabolismo , Proteínas de Membrana/química , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Humanos , Espectrometria de Massas/métodos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Análise em Microsséries , Neoplasias/química , Neoplasias/metabolismo , Neoplasias/patologia , RNA Mensageiro/metabolismo , Eletroforese em Gel Diferencial Bidimensional/métodosRESUMO
BETA-microseminoprotein (MSP), a 10 kDa protein in human seminal plasma, binds human cysteine-rich secretory protein-3 (CRISP-3) with high affinity. CRISP-3 is a member of the family of CRISPs, which are widespread among animals. In this work we show that human as well as porcine MSP binds catrin, latisemin, pseudecin, and triflin, which are CRISPs present in the venoms of the snakes Crotalus atrox, Laticauda semifasciata, Pseudechis porphyriacus, and Trimeresurus flavoviridis, respectively. The CRISPs were purified from the venoms by affinity chromatography on a human MSP column and their identities were settled by gel electrophoresis and mass spectrometry. Their interactions with human and porcine MSPs were studied with size exclusion chromatography and surface plasmon resonance measurements. The binding affinities at 25 degrees C were between 10(-10)M and 10(-7)M for most of the interactions, with higher affinities for the interactions with porcine MSP compared to human MSP and with Elapidae CRISPs compared to Viperidae CRISPs. The high affinities of the bindings in spite of the differences in amino acid sequence between the MSPs as well as between the CRISPs indicate that the binding is tolerant to amino acid sequence variation and raise the question how universal this cross-species reaction between MSPs and CRISPs is.
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Cisteína/química , Sêmen/química , Venenos de Serpentes/química , Sequência de Aminoácidos , Animais , Cromatografia em Gel , Venenos Elapídicos/química , Eletroforese em Gel de Poliacrilamida , Humanos , Cinética , Espectrometria de Massas , Dados de Sequência Molecular , Ressonância de Plasmônio de Superfície , Suínos , Venenos de Víboras/químicaRESUMO
Gamma-glutamyl carboxylase catalyzes the modification of specific glutamyl residues to gamma-carboxyglutamyl (Gla) residues in precursor proteins that possess the appropriate gamma-carboxylation recognition signal within the propeptide region. We describe the immunopurification and first biochemical characterization of an invertebrate high molecular weight Gla-containing protein with homologues in mammals. The protein, named GlaCrisp, was isolated from the venom of the marine cone snail Conus marmoreus. GlaCrisp gave intense signals in Western blot experiments employing the Gla-specific antibody M3B, and the presence of Gla was chemically confirmed by amino acid analysis after alkaline hydrolysis. Characterization of a full-length cDNA clone encoding GlaCrisp deduced a precursor containing an N-terminal signal peptide but, unlike other Gla-containing proteins, no apparent propeptide. The predicted mature protein of 265 amino acid residues showed considerable sequence similarity to the widely distributed cysteine-rich secretory protein family and closest similarity (65% identity) to the recently described substrate-specific protease Tex31. In addition, two cDNA clones encoding the precursors of two isoforms of GlaCrisp were identified. The predicted precursor isoforms differed at three amino acid positions (-6, 9, and 25). Analysis by Edman degradation and nanoelectrospray ionization mass spectrometry, before and after methyl esterfication, identified a Gla residue at amino acid position 9 in GlaCrisp. This is the first example of a Gla-containing protein without an obvious gamma-carboxylation recognition site. The results define a new class of Gla proteins and support the notion that gamma-carboxylation of glutamyl residues is phylogenetically older than blood coagulation and the vertebrate lineage.
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Ácido 1-Carboxiglutâmico/metabolismo , Carbono-Carbono Ligases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Carbono-Carbono Ligases/química , Carbono-Carbono Ligases/genética , Clonagem Molecular , Conotoxinas/metabolismo , Primers do DNA , Isoenzimas/química , Isoenzimas/metabolismo , Espectrometria de Massas , Dados de Sequência Molecular , Peso Molecular , Fragmentos de Peptídeos/química , Reação em Cadeia da Polimerase , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , CaramujosRESUMO
OBJECTIVE: Gas6 is a member of the vitamin K-dependent protein family. Gas6-deficient mice were found to be resistant to thrombosis because of defective platelet function. Mouse Gas6 was demonstrated to be present in platelets and found to be involved in platelet aggregation. The aim of this study was to investigate the presence of Gas6 in human platelets and plasma and determine its role in platelet function. METHODS AND RESULTS: The presence of Gas6 in human platelets and plasma was analyzed using sensitive immunologic methods. Mass spectrometry and ELISA were used to identify and quantify Gas6 in plasma. Gas6 was demonstrated to be present in human plasma, at a concentration determined to be 13 to 23 ng/mL (0.16 to 0.28 nM). Furthermore, plasma Gas6 levels were found to be lower in patients administered with warfarin. However, Gas6 was undetectable in human platelets. CONCLUSIONS: This is the first report to identify and quantify Gas6 in human plasma. However, Gas6 protein was not detected in human platelets, suggesting that any potential platelet-specific function could be because of Gas6 from the circulation. These findings open up new directions regarding the role of Gas6 in normal and pathophysiological situations such as inflammation, autoimmune disease, thrombosis and arteriosclerosis.