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1.
Cancer Cell ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39232581

RESUMO

Diffuse hemispheric gliomas, H3G34R/V-mutant (DHG-H3G34), are lethal brain tumors lacking targeted therapies. They originate from interneuronal precursors; however, leveraging this origin for therapeutic insights remains unexplored. Here, we delineate a cellular hierarchy along the interneuron lineage development continuum, revealing that DHG-H3G34 mirror spatial patterns of progenitor streams surrounding interneuron nests, as seen during human brain development. Integrating these findings with genome-wide CRISPR-Cas9 screens identifies genes upregulated in interneuron lineage progenitors as major dependencies. Among these, CDK6 emerges as a targetable vulnerability: DHG-H3G34 tumor cells show enhanced sensitivity to CDK4/6 inhibitors and a CDK6-specific degrader, promoting a shift toward more mature interneuron-like states, reducing tumor growth, and prolonging xenograft survival. Notably, a patient with progressive DHG-H3G34 treated with a CDK4/6 inhibitor achieved 17 months of stable disease. This study underscores interneuronal progenitor-like states, organized in characteristic niches, as a distinct vulnerability in DHG-H3G34, highlighting CDK6 as a promising clinically actionable target.

2.
Sci Adv ; 9(43): eadi8986, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889970

RESUMO

Various cellular sources hamper interpretation of positron emission tomography (PET) biomarkers in the tumor microenvironment (TME). We developed an approach of immunomagnetic cell sorting after in vivo radiotracer injection (scRadiotracing) with three-dimensional (3D) histology to dissect the cellular allocation of PET signals in the TME. In mice with implanted glioblastoma, translocator protein (TSPO) radiotracer uptake per tumor cell was higher compared to tumor-associated microglia/macrophages (TAMs), validated by protein levels. Translation of in vitro scRadiotracing to patients with glioma immediately after tumor resection confirmed higher single-cell TSPO tracer uptake of tumor cells compared to immune cells. Across species, cellular radiotracer uptake explained the heterogeneity of individual TSPO-PET signals. In consideration of cellular tracer uptake and cell type abundance, tumor cells were the main contributor to TSPO enrichment in glioblastoma; however, proteomics identified potential PET targets highly specific for TAMs. Combining cellular tracer uptake measures with 3D histology facilitates precise allocation of PET signals and serves to validate emerging novel TAM-specific radioligands.


Assuntos
Glioblastoma , Glioma , Humanos , Camundongos , Animais , Glioblastoma/diagnóstico por imagem , Glioblastoma/metabolismo , Microambiente Tumoral , Glioma/patologia , Tomografia por Emissão de Pósitrons/métodos , Microglia/metabolismo , Proteínas de Transporte/metabolismo , Receptores de GABA/metabolismo
3.
J Neurol Surg A Cent Eur Neurosurg ; 84(1): 91-94, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35668672

RESUMO

BACKGROUND: Spinal tuberculosis is a manifestation of extrapulmonary tuberculosis. The incidence of tuberculosis is low in high-income countries; however, globally, it still remains one of the most frequent fatal infectious diseases. Because of its rarity in developed countries, spinal tuberculosis can be mistaken for malignant tumors of the spine, especially in case of an atypical radiologic manifestation and without pulmonary affection. METHODS: We present the case of a 39-year-old man from South India with quickly progressing gait disturbance and hypesthesia below the Th10 level. Magnetic resonance imaging revealed an osteolytic lesion of the vertebral arch Th2 with central necrosis and compression of the spinal cord altogether highly suspicious for spinal metastasis. RESULTS: After surgical removal of the mass by laminectomy, the patient regained normal neurologic function. Histology revealed a severe granulomatous inflammation and DNAhybridization of polymerase chain reaction (PCR) products detected Mycobacterium tuberculosis-specific DNA in the sample. Biopsy of an enlarged hilar lymphnode allowed us to obtain material to successfully perform a drug resistance test to start specific antimicrobial therapy. CONCLUSION: Spinal tuberculosis, even with atypical radiologic appearance, has to be considered a differential diagnosis in patients with provenance from endemic countries. A multidisciplinary diagnostic approach helps perform antimicrobial susceptibility testing to avoid delaying the start of antibiotic therapy.


Assuntos
Neoplasias da Coluna Vertebral , Tuberculose da Coluna Vertebral , Masculino , Humanos , Adulto , Tuberculose da Coluna Vertebral/diagnóstico por imagem , Tuberculose da Coluna Vertebral/tratamento farmacológico , Tuberculose da Coluna Vertebral/cirurgia , Corpo Vertebral/patologia , Corpo Vertebral/cirurgia , Coluna Vertebral/cirurgia , Laminectomia/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia
4.
Eur J Cancer ; 178: 37-48, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399909

RESUMO

BACKGROUND: In patients with RAS wild-type metastatic colorectal cancer, depth of response (DpR) has gained importance as a novel end-point in clinical trials. We investigated the overall DpR, as well as the prognostic and predictive impact of DpR to induction therapy (six cycles of 5-fluorouracil, leucovorin [FU/FA], oxaliplatin [FOLFOX] and panitumumab [Pmab]) on consecutive maintenance therapy (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial. METHODS: Central radiological assessment was performed according to RECIST 1.1. DpR was defined as percentage change in tumour diameter within defined time intervals (induction therapy, maintenance therapy, total course of therapy). For prognostic and predictive analyses, median DpR (

Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Neoplasias Retais , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Fluoruracila/uso terapêutico , Quimioterapia de Indução , Leucovorina/uso terapêutico , Panitumumabe , Neoplasias Retais/tratamento farmacológico
5.
Nat Genet ; 54(12): 1881-1894, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36471067

RESUMO

Histone 3 lysine27-to-methionine (H3-K27M) mutations most frequently occur in diffuse midline gliomas (DMGs) of the childhood pons but are also increasingly recognized in adults. Their potential heterogeneity at different ages and midline locations is vastly understudied. Here, through dissecting the single-cell transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs, we delineate how age and anatomical location shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation. We show that stem-like oligodendroglial precursor-like cells, present across all clinico-anatomical groups, display varying levels of maturation dependent on location. We reveal a previously underappreciated relationship between mesenchymal cancer cell states and age, linked to age-dependent differences in the immune microenvironment. Further, we resolve the spatial organization of H3-K27M DMG cell populations and identify a mitotic oligodendroglial-lineage niche. Collectively, our study provides a powerful framework for rational modeling and therapeutic interventions.


Assuntos
Glioma , Humanos , Criança , Glioma/genética , Histonas/genética , Metionina , Mutação , Racemetionina , Microambiente Tumoral/genética
6.
Cancer Discov ; 12(12): 2880-2905, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36305736

RESUMO

Diffuse midline gliomas are uniformly fatal pediatric central nervous system cancers that are refractory to standard-of-care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape. To interrogate for epigenetic dependencies, we performed a CRISPR screen and show that patient-derived H3K27M-glioma neurospheres are dependent on core components of the mammalian BAF (SWI/SNF) chromatin remodeling complex. The BAF complex maintains glioma stem cells in a cycling, oligodendrocyte precursor cell-like state, in which genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacologic suppression, opposes proliferation, promotes progression of differentiation along the astrocytic lineage, and improves overall survival of patient-derived xenograft models. In summary, we demonstrate that therapeutic inhibition of the BAF complex has translational potential for children with H3K27M gliomas. SIGNIFICANCE: Epigenetic dysregulation is at the core of H3K27M-glioma tumorigenesis. Here, we identify the BRG1-BAF complex as a critical regulator of enhancer and transcription factor landscapes, which maintain H3K27M glioma in their progenitor state, precluding glial differentiation, and establish pharmacologic targeting of the BAF complex as a novel treatment strategy for pediatric H3K27M glioma. See related commentary by Beytagh and Weiss, p. 2730. See related article by Mo et al., p. 2906.


Assuntos
Epigenoma , Glioma , Animais , Humanos , Mutação , Glioma/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Células-Tronco Neoplásicas/metabolismo , Mamíferos/genética , Mamíferos/metabolismo , DNA Helicases/genética , Proteínas Nucleares/genética
7.
Br J Radiol ; 95(1130): 20210881, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34919419

RESUMO

OBJECTIVES: Radiography remains the mainstay of diagnostic and follow-up imaging. In view of the risks and the increasing use of ionizing radiation, dose reduction is a key issue for research and development. The introduction of digital radiography and the associated access to image postprocessing have opened up new opportunities to minimize the radiation dosage. These advances are contingent upon quality controls to ensure adequate image detail and maintenance of diagnostic confidence. The purpose of this study was to investigate the clinical applicability of postprocessed low-dose images in skeletal radiography. METHODS: In our study setting, the median radiation dose for full dose X-rays was 9.61 dGy*cm2 for pelvis, 1.20 dGy*cm2 for shoulder and 18.64 dGy*cm2 for lumbar spine exams. Based on these values, we obtained 200 radiographs for each anatomic region in four consecutive steps, gradually reducing the dose to 84%, 71%, 60% and 50% of the baseline using an automatic exposure control (AEC). 549 patients were enrolled for a total of 600 images. All X-rays were postprocessed with a spatial noise reduction algorithm. Two radiologists assessed the diagnostic value of the radiographs by rating the visualization of anatomical landmarks and image elements on a five-point Likert scale. A mean-sum score was calculated by averaging the two reader's total scores. Given the non-parametric distribution, we used the Mann-Whitney U test to evaluate the scores. RESULTS: Median dosage at full dose accounted for 38.4%, 48 and 53.2% of the German reference dose area product for shoulder, pelvis and lumbar spine, respectively. The applied radiation was incrementally reduced to 21.5%, 18.4% and 18.7% of the respective reference value for shoulder, pelvis and lumbar spine. Throughout the study, we observed an estimable tendency of superior quality at higher dosage in overall image quality. Statistically significant differences in image quality were restricted to the 50% dose groups in shoulder and lumbar spine images. Regardless of the applied dosage, 598 out of 600 images were of sufficient diagnostic value. CONCLUSION: In digital radiography image postprocessing allows for extensive reduction of radiation dosage. Despite a trend of superior image detail at higher dose levels, overall quality and, more importantly, diagnostic utility of low-dose images was not significantly affected. Therefore, our results not only confirm the clinical utility of postprocessed low-dose radiographs, but also suggest a widespread deployment of this advanced technology to ensure further dose limitations in clinical practice. ADVANCES IN KNOWLEDGE: The diagnostic image quality of postprocessed skeletal radiographs is not significantly impaired even after extensive dose reduction by up to 20% of the reference value.


Assuntos
Vértebras Lombares/diagnóstico por imagem , Ossos Pélvicos/diagnóstico por imagem , Doses de Radiação , Intensificação de Imagem Radiográfica , Ombro/diagnóstico por imagem , Algoritmos , Osso e Ossos/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição à Radiação/prevenção & controle , Intensificação de Imagem Radiográfica/normas , Radiografia/estatística & dados numéricos , Valores de Referência , Estatísticas não Paramétricas
8.
J Ind Microbiol Biotechnol ; 48(7-8)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34323925

RESUMO

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by fungi of the Ustilaginaceae family in the presence of hydrophobic carbon sources like plant oils. In the present study, we investigated the structural composition of MELs produced from castor oil using seven different microorganisms and compared them to MEL structures resulting from other plant oils. Castor oil is an industrially relevant plant oil that presents as an alternative to currently employed edible plant oils like rapeseed or soybean oil. The main fatty acid in castor oil is the mono-hydroxylated ricinoleic acid, providing the possibility to produce novel MEL structures with interesting features. Analysis of the produced MELs from castor oil by different chromatographic and mass spectrometry techniques revealed that all seven microorganisms were generally able to integrate hydroxylated fatty acids into the MEL molecule, although at varying degrees. These novel MELs containing a hydroxy fatty acid (4-O-[2'-O-alka(e)noyl-3'-O-hydroxyalka(e)noyl-4'/6'-O-acetyl-ß-D-mannopyranosyl]-erythritol) were more hydrophilic than conventional MEL and therefore showed a different elution behavior in chromatography. Large shares of novel hydroxy MELs (around 50% of total MELs) were found for the two MEL-B/C producing species Ustilago siamensis and Ustilago shanxiensis, but also for the MEL-A/B/C producer Moesziomyces aphidis (around 25%). In addition, tri-acylated hydroxylated MELs with a third long-chain fatty acid esterified to the free hydroxyl group of the hydroxy fatty acid were identified for some species. Overall, production of MEL from castor oil with the investigated organisms provided a complex mixture of various novel MEL structures that can be exploited for further research.


Assuntos
Óleo de Rícino , Tensoativos , Basidiomycota , Glicolipídeos
9.
Neurooncol Adv ; 3(1): vdab169, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34988452

RESUMO

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood brainstem tumor for which radiation is the only treatment. Case studies report a clinical response to ONC201 for patients with H3K27M-mutant gliomas. Oncoceutics (ONC201) is only available in the United States and Japan; however, in Germany, DIPG patients can be prescribed and dispensed a locally produced compound-ONC201 German-sourced ONC201 (GsONC201). Pediatric oncologists face the dilemma of supporting the administration of GsONC201 as conjecture surrounds its authenticity. Therefore, we compared GsONC201 to original ONC201 manufactured by Oncoceutics Inc. METHODS: Authenticity of GsONC201 was determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Biological activity was shown via assessment of on-target effects, in vitro growth, proliferation, and apoptosis analysis. Patient-derived xenograft mouse models were used to assess plasma and brain tissue pharmacokinetics, pharmacodynamics, and overall survival (OS). The clinical experience of 28 H3K27M+ mutant DIPG patients who received GsONC201 (2017-2020) was analyzed. RESULTS: GsONC201 harbored the authentic structure, however, was formulated as a free base rather than the dihydrochloride salt used in clinical trials. GsONC201 in vitro and in vivo efficacy and drug bioavailability studies showed no difference compared to Oncoceutics ONC201. Patients treated with GsONC201 (n = 28) showed a median OS of 18 months (P = .0007). GsONC201 patients who underwent reirradiation showed a median OS of 22 months compared to 12 months for GsONC201 patients who did not (P = .012). CONCLUSIONS: This study confirms the biological activity of GsONC201 and documents the OS of patients who received the drug; however, GsONC201 was never used as a monotherapy.

10.
BMC Musculoskelet Disord ; 21(1): 20, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31926549

RESUMO

BACKGROUND: Lateral tibial split fractures (LTSF) usually require surgical therapy with screw or plate osteosynthesis. Excellent anatomical reduction of the fracture is thereby essential to avoid post-traumatic osteoarthritis. In clinical practice, a gap and step of 2 mm have been propagated as maximum tolerable limit. To date, biomechanical studies regarding tibial fractures have been limited to pressure measurement, but the relationship between dissipated energy (DE) as a friction parameter and reduction accuracy in LTSF has not been investigated. In past experiments, we developed a new method to measure DE in ovine knee joints. To determine weather non-anatomical fracture reduction with lateral gap or vertical step condition leads to relevant changes in DE in the human knee joint, we tested the applicability of the new method on human LTSFs and investigated whether the current limit of 2 mm gap and step is durable from a biomechanical point of view. METHODS: Seven right human, native knee joint specimens were cyclically moved under 400 N axial load using a robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. First, DE was measured after an anterolateral approach had been performed (condition "native"). Then a LTSF was set with a chisel, reduced anatomically, fixed with two set screws and DE was measured ("even"). DE of further reductions was then measured with gaps of 1 mm and 2 mm, and a 2 mm step down or a 2 mm step up was measured. RESULTS: We successfully established a measurement protocol for DE in human knee joints with LTSF. While gaps led to small though statistically significant increase (1 mm gap:ΔDE compared with native = 0.030 J/cycle, (+ 21%), p = 0.02; 2 mm gap:ΔDE = 0.032 J/cycle, (+ 22%), p = 0.009), this increase almost doubled when reducing in a step-down condition (ΔDE = 0.058 J/cycle, (+ 56%), p = 0.042) and even tripled in the step-up condition (ΔDE = 0.097 J/cycle, (+ 94%), p = 0.004). CONCLUSIONS: Based on our biomechanical findings, we suggest avoiding step conditions in the daily work in the operating theatre. Gap conditions can be handled a bit more generously.


Assuntos
Fixação Interna de Fraturas/métodos , Articulação do Joelho/fisiopatologia , Fraturas da Tíbia/cirurgia , Humanos , Fraturas da Tíbia/fisiopatologia
11.
Int J Oncol ; 54(5): 1853-1863, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30864675

RESUMO

Hepatoblastoma (HB) is the most common liver tumor in children under the age of 3 years worldwide. While many patients achieve good outcomes with surgical resection and conventional chemotherapy, there is still a high­risk population that exhibits a poor treatment response and unfavorable prognosis, which warrants the search for novel treatment options. In recent years, it has become clear that genetic events alone are not sufficient to explain the aggressive phenotype of this embryonal malignancy. Instead, epigenetic modifications and aberrant gene expression seem to be key drivers of HB. In the present study, expression analyses such as reverse transcription­quantitative polymerase chain reaction revealed that the oncogene, MYCN proto­oncogene basic­helix­loop­helix transcription factor (MYCN) was upregulated in HB and other pediatric liver tumors, due to the transcriptional activity of its antisense transcript MYCN opposite strand (MYCNOS). Pyrosequencing demonstrated the hypomethylated regions in the promoter of MYCN and MYCNOS, suggesting that an epigenetic mechanism may underlie the induction of aberrant expression. Transient MYCN knockdown in HB cells resulted in growth inhibition over time. In addition, treating HB cells with the MYCN inhibitors JQ1 and MLN8237 led to the significant downregulation of MYCN either at the mRNA or protein levels, respectively. The underlying mechanism of action of the two inhibitors was revealed to be associated with the induction of dose­dependent growth arrest, by arresting cells at either the G1/G0 or G2 phase. Furthermore, MLN8237 and JQ1 were able to cause spindle disturbances and/or apoptosis in HB cells. The present results suggest that MYCN may be a promising biomarker for HB and a potential therapeutic target in patients with tumors overexpressing MYCN.


Assuntos
Azepinas/farmacologia , Metilação de DNA , Hepatoblastoma/genética , Neoplasias Hepáticas/genética , Proteína Proto-Oncogênica N-Myc/genética , Proteínas de Neoplasias/genética , Pirimidinas/farmacologia , RNA Antissenso/genética , Triazóis/farmacologia , Adolescente , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Criança , Pré-Escolar , Metilação de DNA/efeitos dos fármacos , Detecção Precoce de Câncer , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lactente , Recém-Nascido , Masculino , Proteína Proto-Oncogênica N-Myc/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
12.
Science ; 360(6386): 331-335, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29674595

RESUMO

Gliomas with histone H3 lysine27-to-methionine mutations (H3K27M-glioma) arise primarily in the midline of the central nervous system of young children, suggesting a cooperation between genetics and cellular context in tumorigenesis. Although the genetics of H3K27M-glioma are well characterized, their cellular architecture remains uncharted. We performed single-cell RNA sequencing in 3321 cells from six primary H3K27M-glioma and matched models. We found that H3K27M-glioma primarily contain cells that resemble oligodendrocyte precursor cells (OPC-like), whereas more differentiated malignant cells are a minority. OPC-like cells exhibit greater proliferation and tumor-propagating potential than their more differentiated counterparts and are at least in part sustained by PDGFRA signaling. Our study characterizes oncogenic and developmental programs in H3K27M-glioma at single-cell resolution and across genetic subclones, suggesting potential therapeutic targets in this disease.


Assuntos
Neoplasias Encefálicas/patologia , Carcinogênese/genética , Glioma/patologia , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Oncogenes , Neoplasias Encefálicas/genética , Proliferação de Células , Glioma/genética , Histonas/metabolismo , Humanos , Proteína Quinase 7 Ativada por Mitógeno/genética , Mutação , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos
13.
Clin Epigenetics ; 10: 27, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29507645

RESUMO

Background: Hepatoblastoma (HB) is the most common liver tumor of childhood and occurs predominantly within the first 3 years of life. In accordance to its early manifestation, HB has been described to display an extremely low mutation rate. As substitute, epigenetic modifiers seem to play an exceptional role in its tumorigenesis, which holds promise to develop targeted therapies and establish biomarkers for patient risk stratification. Results: We examined the role of a newly described protein complex consisting of three epigenetic regulators, namely E3 ubiquitin-like containing PHD and RING finger domain 1 (UHRF1), ubiquitin-specific-processing protease 7 (USP7), and DNA methyltransferase 1 (DNMT1), in HB. We found the complex to be located on the promoter regions of the pivotal HB-associated tumor suppressor genes (TSGs) HHIP, IGFBP3, and SFRP1 in HB cells, thereby leading to strong repression through DNA methylation and histone modifications. Consequently, knockdown of UHRF1 led to DNA demethylation and loss of the repressive H3K9me2 histone mark at the TSG loci with their subsequent transcriptional reactivation. The observed growth impairment of HB cells upon UHRF1 knockdown could be attributed to reduced expression of genes involved in cell cycle progression, negative regulation of cell death, LIN28B signaling, and the adverse 16-gene signature, as revealed by global RNA sequencing. Clinically, overexpression of UHRF1 in primary tumor tissues was significantly associated with poor survival and the prognostic high-risk 16-gene signature. Conclusion: These findings suggest that UHRF1 is critical for aberrant TSG silencing and sustained growth signaling in HB and that UHRF1 overexpression levels might serve as a prognostic biomarker and potential molecular target for HB patients.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Hepatoblastoma/genética , Neoplasias Hepáticas/genética , Regiões Promotoras Genéticas , Proteínas Supressoras de Tumor/genética , Regulação para Cima , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferase 1/genética , Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Hepatoblastoma/mortalidade , Humanos , Neoplasias Hepáticas/mortalidade , Prognóstico , Análise de Sobrevida , Ubiquitina-Proteína Ligases , Peptidase 7 Específica de Ubiquitina/genética
14.
Cancer Biol Ther ; 17(11): 1168-1176, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27635950

RESUMO

Hepatoblastoma (HB) is the most common liver tumor of childhood, usually occurring in children under the age of 3 y. The prognosis of patients presenting with distant metastasis, vascular invasion and advanced tumor stages remains poor and children that do survive often face severe late effects from the aggressive chemotherapy regimen. To identify potential new therapeutics for high risk HB we used a 1,000-gene expression signature as input for a Connectivity Map (CMap) analysis, which predicted histone deacetylase (HDAC) inhibitors as a promising therapy option. Subsequent expression analysis of primary HB and HB cell lines revealed a general overexpression of HDAC1 and HDAC2, which has been suggested to be predictive for the efficacy of HDAC inhibition. Accordingly, treatment of HB cells with the HDAC inhibitors SAHA and MC1568 resulted in a potent reduction of cell viability, induction of apoptosis, reactivation of epigenetically suppressed tumor suppressor genes, and the reversion of the 16-gene HB classifier toward the more favorable expression signature. Most importantly, the combination of HDAC inhibitors and cisplatin - a major chemotherapeutic agent of HB treatment - revealed a strong synergistic effect, even at significantly reduced doses of cisplatin. Our findings suggest that HDAC inhibitors skew HB cells toward a more favorable prognostic phenotype through changes in gene expression, thus indicating a targeted molecular mechanism that seems to enhance the anti-proliferative effects of conventional chemotherapy. Thus, adding HDAC inhibitors to the treatment regimen of high risk HB could potentially improve outcomes and reduce severe late effects.


Assuntos
Hepatoblastoma/tratamento farmacológico , Inibidores de Histona Desacetilases/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Pré-Escolar , Cisplatino/administração & dosagem , Cisplatino/farmacologia , Sinergismo Farmacológico , Feminino , Células Hep G2 , Hepatoblastoma/enzimologia , Hepatoblastoma/genética , Hepatoblastoma/patologia , Inibidores de Histona Desacetilases/administração & dosagem , Histona Desacetilases/biossíntese , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Fatores de Risco , Transcriptoma
15.
Radiol Oncol ; 48(4): 339-47, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25435846

RESUMO

BACKGROUND: To evaluate the clinical efficacy of In-111 DTPA octreotide SPECT/CT and Ga-68 DOTATOC PET/CT for detection of primary tumors in patients with either neuroendocrine tumor of unknown primary (NETUP) or clinically suspected primary NET (SNET). PATIENTS AND METHODS: A total of 123 patients were included from 2006 to 2009, 52 received Ga-68 DOTATOC PET/CT (NETUP, 33; SNET, 19) and 71 underwent In-111 DTPA octreotide SPECT/CT (50; 21). The standard of reference included histopathology or clinical verification based on follow-up examinations. RESULTS: In the NETUP group Ga-68 DOTATOC detected primaries in 15 patients (45.5%) and In-111 DTPA octreotide in 4 patients (8%) (p < 0.001); in the SNET group, only 2 primaries could be detected, all by Ga-68 DOTATOC. In patients with NETUP, primary tumors could be found significantly more often than in patients with SNET (p = 0.01). Out of these 21 patients 14 patients were operated. CONCLUSION: Ga-68 DOTATOC PET/CT is preferable to In-111 DTPA octreotide SPECT/CT when searching for primary NETs in patients with NETUP but should be used with caution in patients with SNET.

16.
J Hepatol ; 61(6): 1312-20, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25135868

RESUMO

BACKGROUND & AIMS: Hepatoblastoma (HB) is the most common childhood liver cancer and occasionally presents with histological and clinical features reminiscent of hepatocellular carcinoma (HCC). Identification of molecular mechanisms that drive the neoplastic continuation towards more aggressive HCC phenotypes may help to guide the new stage of targeted therapies. METHODS: We performed comprehensive studies on genetic and chromosomal alterations as well as candidate gene function and their clinical relevance. RESULTS: Whole-exome sequencing identified HB as a genetically very simple tumour (2.9 mutations per tumour) with recurrent mutations in ß-catenin (CTNNB1) (12/15 cases) and the transcription factor NFE2L2 (2/15 cases). Their HCC-like progenies share the common CTNNB1 mutation, but additionally exhibit a significantly increased mutation number and chromosomal instability due to deletions of the genome guardians RAD17 and TP53, accompanied by telomerase reverse-transcriptase (TERT) promoter mutations. Targeted genotyping of 33 primary tumours and cell lines revealed CTNNB1, NFE2L2, and TERT mutations in 72.5%, 9.8%, and 5.9% of cases, respectively. All NFE2L2 mutations affected residues of the NFE2L2 protein that are recognized by the KEAP1/CUL3 complex for proteasomal degradation. Consequently, cells transfected with mutant NFE2L2 were insensitive to KEAP1-mediated downregulation of NFE2L2 signalling. Clinically, overexpression of the NFE2L2 target gene NQO1 in tumours was significantly associated with metastasis, vascular invasion, the adverse prognostic C2 gene signature, as well as poor outcome. CONCLUSIONS: Our study demonstrates the importance of CTNNB1 mutations and NFE2L2-KEAP1 pathway activation in HB development and defines loss of genomic stability and TERT promoter mutations as prominent characteristics of aggressive HB with HCC features.


Assuntos
Carcinoma Hepatocelular/genética , Genômica , Hepatoblastoma/genética , Neoplasias Hepáticas/genética , Análise de Sequência de DNA , Adulto , Biópsia , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Criança , DNA de Neoplasias/genética , Hepatoblastoma/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína 1 Associada a ECH Semelhante a Kelch , Neoplasias Hepáticas/patologia , Mutação/genética , Fator 2 Relacionado a NF-E2/genética , Estudos Retrospectivos , Telomerase/genética , beta Catenina/genética
17.
Ann Nucl Med ; 26(9): 738-43, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22865406

RESUMO

PURPOSE: To evaluate the impact of Ga-68 DOTATOC PET/CT on diagnosis and therapeutic management of patients with multiple endocrine neoplasia (MEN). MATERIALS AND METHODS: We did 28 Ga-68 DOTATOC PET/CT in 21 MEN patients (10 female, 11 men; mean age 41.3 years). 109 lesions detected were classified into MEN-associated lesions [i.e., neuroendocrine tumors (NET)] and non-MEN-associated lesions for PET, CT, and PET/CT. The impact of Ga-68 DOTATOC PET/CT on diagnosis and therapeutic management of patients with MEN were assessed by the records of the interdisciplinary NET tumor board including histopathological findings, clinical and radiological follow-up. RESULTS: Ga-68 DOTATOC PET/CT had an impact on diagnosis and therapeutic management in 10/21 (47.6%) MEN patients. For detecting NET lesions in MEN patients Ga-68 DOTATOC PET/CT reached a sensitivity/specificity of 91.7%/93.5%. There was a significant difference for the detection rate between Ga-68 DOTATOC PET/CT and CT alone (p < 0.001) both using contrast-agent (p = 0.002) or not (p < 0.001) and also a significant difference between contrast-enhanced (CE-) CT and non-CE-CT alone (p = 0.006). CONCLUSIONS: GA-68 DOTATOC PET/CT allows a high detection rate of NET lesions in the context of MEN-1 syndrome as well as influence therapeutic management in nearly up to half of the patients. GA-68 DOTATOC PET/CT should include a CE-CT to improve MEN-associated NET lesion detection.


Assuntos
Imagem Multimodal , Neoplasia Endócrina Múltipla/diagnóstico por imagem , Neoplasia Endócrina Múltipla/terapia , Octreotida/análogos & derivados , Compostos Organometálicos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
18.
PLoS One ; 6(5): e19983, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21611146

RESUMO

BACKGROUND: After ischemia of the CNS, extracellular adenosine 5'-triphosphate (ATP) can reach high concentrations due to cell damage and subsequent increase of membrane permeability. ATP may cause cellular degeneration and death, mediated by P2X and P2Y receptors. METHODOLOGY/PRINCIPAL FINDINGS: The effects of inhibition of P2 receptors by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on electrophysiological, functional and morphological alterations in an ischemia model with permanent middle cerebral artery occlusion (MCAO) were investigated up to day 28. Spontaneously hypertensive rats received PPADS or vehicle intracerebroventricularly 15 minutes prior MCAO for up to 7 days. The functional recovery monitored by qEEG was improved by PPADS indicated by an accelerated recovery of ischemia-induced qEEG changes in the delta and alpha frequency bands along with a faster and sustained recovery of motor impairments. Whereas the functional improvements by PPADS were persistent at day 28, the infarct volume measured by magnetic resonance imaging and the amount of TUNEL-positive cells were significantly reduced by PPADS only until day 7. Further, by immunohistochemistry and confocal laser scanning microscopy, we identified both neurons and astrocytes as TUNEL-positive after MCAO. CONCLUSION: The persistent beneficial effect of PPADS on the functional parameters without differences in the late (day 28) infarct size and apoptosis suggests that the early inhibition of P2 receptors might be favourable for the maintenance or early reconstruction of neuronal connectivity in the periinfarct area after ischemic incidents.


Assuntos
Antagonistas do Receptor Purinérgico P2/farmacologia , Antagonistas do Receptor Purinérgico P2/uso terapêutico , Fosfato de Piridoxal/análogos & derivados , Recuperação de Função Fisiológica/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/fisiopatologia , Animais , Morte Celular/efeitos dos fármacos , Eletroencefalografia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Atividade Motora/efeitos dos fármacos , Fosfato de Piridoxal/farmacologia , Fosfato de Piridoxal/uso terapêutico , Ratos , Ratos Endogâmicos SHR , Teste de Desempenho do Rota-Rod , Acidente Vascular Cerebral/complicações , Fatores de Tempo
19.
Mol Biol Cell ; 22(5): 570-80, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21209314

RESUMO

The multifunctional signal adapter protein Ras and Rab interactor 1 (RIN1) is a Ras effector protein involved in the regulation of epithelial cell processes such as cell migration and endocytosis. RIN1 signals via two downstream pathways, namely the activation of Rab5 and Abl family kinases. Protein kinase D (PKD) phosphorylates RIN1 at serine 351 in vitro, thereby regulating interaction with 14-3-3 proteins. Here, we report the identification of serine 292 in RIN1 as an in vivo PKD phosphorylation site. PKD-mediated phosphorylation at this site was confirmed with a phospho-specific antibody and by mass spectrometry. We demonstrate that phosphorylation at serine 292 controls RIN1-mediated inhibition of cell migration by modulating the activation of Abl kinases. We further provide evidence that RIN1 in vivo phosphorylation at serine 351 occurs independently of PKD. Collectively, our data identify a novel PKD signaling pathway through RIN1 and Abl kinases that is involved in the regulation of actin remodeling and cell migration.


Assuntos
Movimento Celular , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína Quinase C/metabolismo , Actinas/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Anticorpos/imunologia , Células HEK293 , Humanos , Dados de Sequência Molecular , Fosforilação , Fosfosserina/metabolismo , Transporte Proteico , Proteínas Tirosina Quinases/metabolismo , Frações Subcelulares/metabolismo , Proteínas Supressoras de Tumor/metabolismo
20.
Immunol Invest ; 40(2): 130-49, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20923331

RESUMO

As observed in most molluscan hemocyanins, high-mannose type glycans were identified in hemocyanins from Rapana venosa (RvH), Helix lucorum (HlH) and keyhole limpet (Megatura crenulata). In addition, a glycan with a branching structure containing xylose, fucose and terminal methyl hexose was identified in ß-HlH. We have examined the immuno-adjuvant properties of hemocyanins, their derivatives and conjugates associated with the cell mediated immunity in experimental tumor-bearing animals with ascites tumor of Guerin. After immunization of the animals with the experimental vaccine preparations, the highest values of splenic lymphocytes were observed in groups immunized with the conjugates RvH-TAg, ß-HlH-TAg and KLH-TAg (42.3%; 40.8% and 40.58%, respectively) than with the native hemocyanins (36.5%; 35.1% and 32.4%, respectively). The immunization of rats with the hemocyanins ß-HlH, RvH and KLH and their conjugates, prolonged the median survival time of tumor-bearing animals compared with non-immunized animals (39, 33, 31 and 7 days, respectively). Both hemocyanins ß-HlH and RvH activate the immune system of the experimental animals and therefore could be a good alternative for KLH. For this reason they could be included into the composition of non-specific anti-tumor vaccines to enhance their effectiveness.


Assuntos
Antineoplásicos/farmacologia , Hemocianinas/farmacologia , Moluscos/química , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/metabolismo , Animais , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Vacinas Anticâncer/imunologia , Glicopeptídeos/análise , Glicopeptídeos/química , Glicopeptídeos/isolamento & purificação , Glicosilação , Imunização , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Mitógenos/farmacologia , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/mortalidade , Neoplasias Experimentais/patologia , Ratos , Baço/citologia , Baço/efeitos dos fármacos , Análise de Sobrevida , Espectrometria de Massas em Tandem
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