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2.
J Am Soc Mass Spectrom ; 31(3): 742-751, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-31971791

RESUMO

Ion mobility spectrometry (IMS) represents a considerable asset for analytics of complex samples as it allows for rapid mass spectrometric separation of compounds. IMS is even more useful for the separation of isobaric compounds when classical separation methods such as liquid chromatography or electrophoresis cannot be used, e.g., during matrix-assisted laser desorption/ionization (MALDI) analyses of biological surfaces. In the present study, we proved the usefulness of IMS for pharmacological applications of MALDI analyses on tissue sections. To illustrate our proof-of-concept, we used the anthelmintic drug mebendazole (MBZ) as a model. Using this exemplary drug, we demonstrated the possibility of using ion mobility to discriminate a drug in tissues from the biological background that masked its signal at low concentrations. In this proof-of-concept, the IMS mode together with the use of a profiling approach for sample preparation enabled quantification of the model drug MBZ from tissue sections in the concentration range 5 to 5,000 ng/g and with a limit of detection of 1 ng/g of tissue, within 2 h. This study highlights the importance of IMS as a separation method for on-surface quantification of drugs in tissue sections.

3.
Acta Neuropathol ; 139(2): 287-303, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31677015

RESUMO

Pilocytic astrocytoma (PA) is the most common pediatric glioma, arising from a single driver MAPK pathway alteration. Classified as a grade I tumor according to the 2016 WHO classification, prognosis is excellent with a 10-year survival rate > 95% after surgery. However, rare cases present with anaplastic features, including an unexpected high mitotic/proliferative index, thus posing a diagnostic and therapeutic challenge. Based on small histomolecular series and case reports, such tumors arising at the time of diagnosis or recurrence have been designated by many names including pilocytic astrocytoma with anaplastic features (PAAF). Recent DNA methylation-profiling studies performed mainly on adult cases have revealed that PAAF exhibit a specific methylation signature, thus constituting a distinct methylation class from typical PA [methylation class anaplastic astrocytoma with piloid features-(MC-AAP)]. However, the diagnostic and prognostic significance of MC-AAP remains to be determined in children. We performed an integrative work on the largest pediatric cohort of PAAF, defined according to strict criteria: morphology compatible with the diagnosis of PA, with or without necrosis, ≥ 4 mitoses for 2.3 mm2, and MAPK pathway alteration. We subjected 31 tumors to clinical, imaging, morphological and molecular analyses, including DNA methylation profiling. We identified only one tumor belonging to the MC-AAP (3%), the others exhibiting a methylation profile typical for PA (77%), IDH-wild-type glioblastoma (7%), and diffuse leptomeningeal glioneuronal tumor (3%), while three cases (10%) did not match to a known DNA methylation class. No significant outcome differences were observed between PAAF with necrosis versus no necrosis (p = 0.07), or with 4-6 mitoses versus 7 or more mitoses (p = 0.857). Our findings argue that the diagnostic histomolecular criteria established for anaplasia in adult PA are not of diagnostic or prognostic value in a pediatric setting. Further extensive and comprehensive integrative studies are necessary to accurately define this exceptional entity in children.

4.
Clin Cancer Res ; 25(22): 6788-6800, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31481512

RESUMO

PURPOSE: Diffuse intrinsic pontine gliomas (DIPG) are the most severe pediatric brain tumors. Although accepted as the standard therapeutic, radiotherapy is only efficient transiently and not even in every patient. The goal of the study was to identify the underlying molecular determinants of response to radiotherapy in DIPG. EXPERIMENTAL DESIGN: We assessed in vitro response to ionizing radiations in 13 different DIPG cellular models derived from treatment-naïve stereotactic biopsies reflecting the genotype variability encountered in patients at diagnosis and correlated it to their principal molecular alterations. Clinical and radiologic response to radiotherapy of a large cohort of 73 DIPG was analyzed according to their genotype. Using a kinome-wide synthetic lethality RNAi screen, we further identified target genes that can sensitize DIPG cells to ionizing radiations. RESULTS: We uncover TP53 mutation as the main driver of increased radioresistance and validated this finding in four isogenic pairs of TP53WT DIPG cells with or without TP53 knockdown. In an integrated clinical, radiological, and molecular study, we show that TP53MUT DIPG patients respond less to irradiation, relapse earlier after radiotherapy, and have a worse prognosis than their TP53WT counterparts. Finally, a kinome-wide synthetic lethality RNAi screen identifies CHK1 as a potential target, whose inhibition increases response to radiation specifically in TP53MUT cells. CONCLUSIONS: Here, we demonstrate that TP53 mutations are driving DIPG radioresistance both in patients and corresponding cellular models. We suggest alternative treatment strategies to mitigate radioresistance with CHK1 inhibitors. These findings will allow to consequently refine radiotherapy schedules in DIPG.

5.
Oncogene ; 38(38): 6479-6490, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31324890

RESUMO

Diffuse intrinsic pontine glioma (or DIPG) are pediatric high-grade gliomas associated with a dismal prognosis. They harbor specific substitution in histone H3 at position K27 that induces major epigenetic dysregulations. Most clinical trials failed so far to increase survival, and radiotherapy remains the most efficient treatment, despite only transient tumor control. We conducted the first lentiviral shRNA dropout screen in newly diagnosed DIPG to generate a cancer-lethal signature as a basis for the development of specific treatments with increased efficacy and reduced side effects compared to existing anticancer therapies. The analysis uncovered 41 DIPG essential genes among the 672 genes of human kinases tested, for which several distinct interfering RNAs impaired cell expansion of three different DIPG stem-cell cultures without deleterious effect on two control neural stem cells. Among them, PLK1, AURKB, CHEK1, EGFR, and GSK3A were previously identified by similar approach in adult GBM indicating common dependencies of these cancer cells and pediatric gliomas. As expected, we observed an enrichment of genes involved in proliferation and cell death processes with a significant number of candidates belonging to PTEN/PI3K/AKT and EGFR pathways already under scrutiny in clinical trials in this disease. We highlighted VRK3, a gene involved especially in cell cycle regulation, DNA repair, and neuronal differentiation, as a non-oncogenic addiction in DIPG. Its repression totally blocked DIPG cell growth in the four cellular models evaluated, and induced cell death in H3.3-K27M cells specifically but not in H3.1-K27M cells, supporting VRK3 as an interesting and promising target in DIPG.


Assuntos
Neoplasias do Tronco Encefálico/genética , Fosfotransferases/genética , Proteínas Serina-Treonina Quinases/fisiologia , RNA Interferente Pequeno/fisiologia , Análise de Sequência de RNA/métodos , Neoplasias do Tronco Encefálico/diagnóstico , Neoplasias do Tronco Encefálico/patologia , Sobrevivência Celular/genética , Células Cultivadas , /patologia , Genes Essenciais , Células HEK293 , Humanos , Fosfatidilinositol 3-Quinases/análise , Fosfatidilinositol 3-Quinases/genética , Fosfotransferases/análise , Prognóstico , Proteínas Serina-Treonina Quinases/análise , Proteínas Serina-Treonina Quinases/genética , RNA Interferente Pequeno/análise
6.
Neurosurgery ; 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31342064

RESUMO

BACKGROUND: No link has been demonstrated between diffuse intrinsic pontine glioma and developmental venous anomaly in pediatric patients. OBJECTIVE: To determine the prevalence of developmental venous anomaly in a pediatric cohort of diffuse intrinsic pontine glioma. METHODS: We performed a retrospective cohort study (1998-2017) of consecutive pediatric patients harboring a diffuse intrinsic pontine glioma (experimental set, n = 162) or a craniopharyngioma (control set, n = 142) in a tertiary pediatric neurosurgical center. The inclusion criteria were the following: age <18 yr at diagnosis; histopathological diagnosis of diffuse intrinsic pontine glioma or craniopharyngioma according to the 2016 World Health Organization classification of tumors of the central nervous system; no previous oncological treatment; and available preoperative magnetic resonance imaging performed with similar acquisition protocol. RESULTS: We found a significantly higher prevalence of developmental venous anomaly in the experimental set of 162 diffuse intrinsic pontine gliomas (24.1%) than in the control set of 142 craniopharyngiomas (10.6%; P = .001). The prevalence of developmental venous anomalies was not significantly impacted by demographic data (sex, age at diagnosis, and underlying pathological condition), biomolecular analysis (H3-K27M-mutant subgroup, H3.1-K27M-mutant subgroup, and H3.3-K27M-mutant subgroup), or imaging findings (anatomic location, anatomic extension, side, and obstructive hydrocephalus) of the studied diffuse intrinsic pontine gliomas. CONCLUSION: We report a higher prevalence of developmental venous anomaly in pediatric diffuse intrinsic pontine glioma patients than in control patients, which suggests a potential underlying common predisposition or a causal relationship that will require deeper investigations.

7.
Neurobiol Pain ; 5: 100021, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31194066

RESUMO

Despite enormous investment in research and development of novel treatments, there remains a lack of predictable, effective, and safe therapeutics for human chronic neuropathic pain (NP) afflictions. NP continues to increase among the population and treatments remain a major unmet public health care need. In recent years, numerous costly (time and money) failures have occurred attempting to translate successful animal pain model results, typically using rodents, to human clinical trials. These continued failures point to the essential need for better animal models of human pain conditions. To address this challenge, we have previously developed a peripheral neuritis trauma (PNT) model of chronic pain induced by a proximal sciatic nerve irritation in pigs, which have a body size, metabolism, skin structure, and cutaneous innervation more similar to humans. Here, we set out to determine the extent that the PNT model presents with cutaneous neuropathologies consistent with those associated with human chronic NP afflictions. Exactly as is performed in human skin biopsies, extensive quantitative multi-molecular immunofluorescence analyses of porcine skin biopsies were performed to assess cutaneous innervation and skin structure. ChemoMorphometric Analysis (CMA) results demonstrated a significant reduction in small caliber intraepidermal nerve fiber (IENF) innervation, altered dermal vascular innervation, and aberrant analgesic/algesic neurochemical properties among epidermal keratinocytes, which are implicated in modulating sensory innervation. These comprehensive pathologic changes very closely resemble those observed from CMA of human skin biopsies collected from NP afflictions. The results indicate that the porcine PNT model is more appropriate for translational NP research compared with commonly utilized rodent models. Because the PNT model creates cutaneous innervation and keratinocyte immunolabeling alterations consistent with human NP conditions, use of this animal model for NP testing and treatment response characteristics will likely provide more realistic results to direct successful translation to humans.

8.
EuroIntervention ; 15(8): 722-730, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31062694

RESUMO

AIMS: Pulmonary arterial hypertension is a devastating disease characterised by pulmonary vascular remodelling and right heart failure. Radio-frequency pulmonary artery denervation (PDN) has improved pulmonary haemodynamics in preclinical and early clinical studies; however, denervation depth is limited. High-frequency non-focused ultrasound can deliver energy to the vessel adventitia, sparing the intima and media. We therefore aimed to investigate the feasibility, safety and efficacy of ultrasound PDN. METHODS AND RESULTS: Histological examination demonstrated that innervation of human pulmonary arteries is predominantly sympathetic (71%), with >40% of nerves at a depth of >4 mm. Finite element analysis of ultrasound energy distribution and ex vivo studies demonstrated generation of temperatures >47ºC to a depth of 10 mm. In domestic swine, PDN reduced mean pulmonary artery pressure induced by thromboxane A2 in comparison to sham. No adverse events were observed up to 95 days. Histological examination identified structural and immunohistological changes of nerves in PDN-treated animals, with sparing of the intima and media and reduced tyrosine hydroxylase staining 95 days post procedure, indicating persistent alteration of the structure of sympathetic nerves. CONCLUSIONS: Ultrasound PDN is safe and effective in the preclinical setting, with energy delivery to a depth that would permit targeting sympathetic nerves in humans.


Assuntos
Denervação , Hipertensão Pulmonar/terapia , Artéria Pulmonar/inervação , Simpatectomia , Animais , Débito Cardíaco , Ablação por Cateter , Insuficiência Cardíaca , Humanos , Artéria Pulmonar/patologia , Artéria Pulmonar/cirurgia , Suínos , Simpatectomia/instrumentação , Simpatectomia/métodos , Sistema Nervoso Simpático
9.
Brain Stimul ; 12(1): 1-8, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30181107

RESUMO

BACKGROUND: Essential tremor (ET) is one of the most common movement disorders of adults, characterized by postural and kinetic tremor. With drug treatment only partially efficient, new treatments are being developed. OBJECTIVES: The goal of this study was to demonstrate the feasibility of non-thermal focused-ultrasound (FUS) to induce tremor-suppression in an ET rat model. METHODS: Harmaline-induced tremor rats were treated with FUS along the inferior olivary (IO) system. EMG was recorded continuously during treatment in order to quantify FUS-induced tremor suppression. T2-weighted MRI was performed immediately following treatment and periodically thereafter. RESULTS: FUS treatment at an intensity of 27.2 W/cm2 (Isppa) induced significant reduction of tremor in 12 out of 13 ET rats. Tremor frequency was reduced from 6.2 ±â€¯2.8 to 2 ±â€¯1 Hz, p < 0.0003. In 6 of the 12 responding rats, tremor was completely suppressed. Response duration was 70 ±â€¯61s, on average. FUS induced motor response, depicted as movement of the tail and/or the limbs synchronized with the FUS sonication, was also demonstrated both in ET rats and in naïve rats when treated in the medulla oblongata region. CONCLUSIONS: These results demonstrate the feasibly for obtaining significant tremor reduction or tremor suppression induced by non-thermal, non-invasive, reversible focused-ultrasound.


Assuntos
Tremor Essencial/terapia , Terapia por Ultrassom/métodos , Animais , Tremor Essencial/etiologia , Harmalina/toxicidade , Masculino , Ratos
10.
Brain Pathol ; 29(3): 325-335, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30325077

RESUMO

Ependymoma with RELA fusion has been defined as a novel entity of the revised World Health Organization 2016 classification of tumors of the central nervous system (CNS), characterized by fusion transcripts of the RELA gene and consequent pathological activation of the NFkB pathway. These tumors represent the majority of supratentorial ependymomas in children. The validation of diagnostic tools to identify this clinically relevant ependymoma entity is essential. Here, we have used interphase fluorescent in situ hybridization (FISH) for C11orf95 and RELA, immunohistochemistry (IHC) for p65-RelA and the recently developed DNA methylation-based classification besides conventional histopathology, and compared the precision of the methods in 40 supratentorial pediatric brain tumors diagnosed as ependymomas in the past years. Reverse transcription PCR (RT-PCR) and RNA sequencing were performed to explore discordant cases. Furthermore, we integrated imaging and clinical features as additional layers of information. The concordance between nuclear RelA expression by IHC and RELA FISH was 100%. Concordance between IHC and DNA methylation profiling, and between FISH and DNA methylation profiling was also high (96.4% and 95.2%, respectively). Thirty-four out of 40 (85%) cases were confirmed by integrated diagnoses as ependymal tumors, including 22 RELA-fused ependymomas (71% of ependymal tumors), two YAP1-fused ependymomas (6%), six non-RELA/non-YAP1 ependymomas (18%) and four ependymal/subependymal mixed tumors (12%). Ependymal/subependymal mixed tumors had an excellent clinical outcome despite the presence of histopathological signs of malignancy, suggesting that these tumors should not be diagnosed as classic ependymomas. DNA methylation profiling helped in the differential diagnosis of RELA-fused ependymomas. IHC and FISH, which are available in the majority of pathology laboratories, are valuable tools to identify RELA-fused ependymomas.


Assuntos
Metilação de DNA , Ependimoma/diagnóstico , Ependimoma/genética , Neoplasias Supratentoriais/diagnóstico , Neoplasias Supratentoriais/genética , Fator de Transcrição RelA/genética , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Ependimoma/metabolismo , Ependimoma/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente/métodos , Lactente , Masculino , NF-kappa B/metabolismo , Proteínas/genética , Proteínas/metabolismo , Neoplasias Supratentoriais/metabolismo , Neoplasias Supratentoriais/patologia , Fator de Transcrição RelA/metabolismo
11.
J Neurooncol ; 141(2): 253-263, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30446898

RESUMO

PURPOSE: Diffuse intrinsic pontine glioma is the most aggressive form of high grade glioma in children with no effective therapies. There have been no improvements in survival in part due poor understanding of underlying biology, and lack of representative in vitro and in vivo models. Recently, it has been found feasible to use both biopsy and autopsy tumors to generate cultures and xenograft models. METHODS: To further model development, we evaluated the collective international experience from 8 collaborating centers to develop DIPG pre-clinical models from patient-derived autopsies and biopsies. Univariate and multivariate analysis was performed to determine key factors associated with the success of in vitro and in vivo PDX development. RESULTS: In vitro cultures were successfully established from 57% of samples (84.2% of biopsies and 38.2% of autopsies). Samples transferred in DMEM media were more likely to establish successful culture than those transported in Hibernate A. In vitro cultures were more successful from biopsies (84.2%) compared with autopsies (38.2%) and as monolayer on laminin-coated plates than as neurospheres. Primary cultures successfully established from autopsy samples were more likely to engraft in animal models than cultures established from biopsies (86.7% vs. 47.4%). Collectively, tumor engraftment was more successful when DIPG samples were directly implanted in mice (68%), rather than after culturing (40.7%). CONCLUSION: This multi-center study provides valuable information on the success rate of establishing patient-derived pre-clinical models of DIPG. The results can lead to further optimization of DIPG model development and ultimately assist in the investigation of new therapies for this aggressive pediatric brain tumor.


Assuntos
Neoplasias do Tronco Encefálico/fisiopatologia , Neoplasias do Tronco Encefálico/terapia , Glioma/fisiopatologia , Glioma/terapia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Neoplasias do Tronco Encefálico/genética , Sobrevivência Celular , Células Cultivadas , Modelos Animais de Doenças , Glioma/genética , Histonas/genética , Humanos , Camundongos , Mutação , Estudos Retrospectivos
12.
J Neurooncol ; 141(2): 265, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30484110

RESUMO

There are two errors and one omission in the original article. Author Gottardo's correct name is Nicholas G. Gottardo, author Hulleman's correct affiliation is no. 3 (VUMC, Amsterdam), and the Acknowledgements should include the following sentence: "We would like to thank Dr Angel Montero Carcaboso (Hospital Sant Joan de Deu, Barcelona, Spain) for generously supplying the HSJD-DIPG007 cells."

13.
Cell Stem Cell ; 23(6): 859-868.e5, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30416072

RESUMO

Critical features of stem cells include anchoring within a niche and activation upon injury. Notch signaling maintains skeletal muscle satellite (stem) cell quiescence by inhibiting differentiation and inducing expression of extracellular components of the niche. However, the complete spectrum of how Notch safeguards quiescence is not well understood. Here, we perform Notch ChIP-sequencing and small RNA sequencing in satellite cells and identify the Notch-induced microRNA-708, which is a mirtron that is highly expressed in quiescent cells and sharply downregulated in activated cells. We employ in vivo and ex vivo functional studies, in addition to live imaging, to show that miR-708 regulates quiescence and self-renewal by antagonizing cell migration through targeting the transcripts of the focal-adhesion-associated protein Tensin3. Therefore, this study identifies a Notch-miR708-Tensin3 axis and suggests that Notch signaling can regulate satellite cell quiescence and transition to the activation state through dynamic regulation of the migratory machinery.


Assuntos
Movimento Celular/genética , MicroRNAs/genética , Receptores Notch/metabolismo , Células Satélites de Músculo Esquelético/citologia , Transdução de Sinais , Nicho de Células-Tronco , Animais , Feminino , Masculino , Camundongos , Camundongos Transgênicos
14.
Acta Neuropathol Commun ; 6(1): 117, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30396367

RESUMO

Diffuse midline glioma (DMG), H3 K27M-mutant, is a new entity in the updated WHO classification grouping together diffuse intrinsic pontine gliomas and infiltrating glial neoplasms of the midline harboring the same canonical mutation at the Lysine 27 of the histones H3 tail.Two hundred and fifteen patients younger than 18 years old with centrally-reviewed pediatric high-grade gliomas (pHGG) were included in this study. Comprehensive transcriptomic (n = 140) and methylation (n = 80) profiling was performed depending on the material available, in order to assess the biological uniqueness of this new entity compared to other midline and hemispheric pHGG.Tumor classification based on gene expression (GE) data highlighted the similarity of K27M DMG independently of their location along the midline. T-distributed Stochastic Neighbor Embedding (tSNE) analysis of methylation profiling confirms the discrimination of DMG from other well defined supratentorial tumor subgroups. Patients with diffuse intrinsic pontine gliomas (DIPG) and thalamic DMG exhibited a similarly poor prognosis (11.1 and 10.8 months median overall survival, respectively). Interestingly, H3.1-K27M and H3.3-K27M primary tumor samples could be distinguished based both on their GE and DNA methylation profiles, suggesting that they might arise from a different precursor or from a different epigenetic reorganization.These differences in DNA methylation profiles were conserved in glioma stem-like cell culture models of DIPG which mimicked their corresponding primary tumor. ChIP-seq profiling of H3K27me3 in these models indicate that H3.3-K27M mutated DIPG stem cells exhibit higher levels of H3K27 trimethylation which are correlated with fewer genes expressed by RNAseq. When considering the global distribution of the H3K27me3 mark, we observed that intergenic regions were more trimethylated in the H3.3-K27M mutated cells compared to the H3.1-K27M mutated ones.H3 K27M-mutant DMG represent a homogenous group of neoplasms compared to other pediatric gliomas that could be further separated based on the type of histone H3 variant mutated and their respective epigenetic landscapes. As these characteristics drive different phenotypes, these findings may have important implication for the design of future trials in these specific types of neoplasms.


Assuntos
Neoplasias Encefálicas/genética , Epigenômica , Glioma/genética , Histonas/genética , Mutação/genética , Transcriptoma/fisiologia , Adolescente , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Metilação de DNA/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Glioma/patologia , Humanos , Lisina/genética , Masculino , Metionina/genética , Análise de Componente Principal , Células Tumorais Cultivadas
15.
J Pain Res ; 11: 2279-2293, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30349354

RESUMO

Background: Rodent models are frequently used in the research of pain and continue to provide valuable data on the mechanisms driving pain, although they are criticized due to limited translational ability to human conditions. Previously we have suggested pigs as a model for development of drugs for neuropathic pain. In this study, we investigate the spontaneous behavior of pigs following peripheral neuritis trauma (PNT)-induced neuropathic pain. Methods: A computerized monitoring system was used to evaluate the changes in open field test in addition to applying a composite behavior scoring system. The data suggest that the PNT operation did not affect the animal's ability to walk as the total distance walked by PNT animals was not significantly different from the total distance walked by sham-operated animals. However, PNT animals expressed a significant change in the pattern of walking. This effect was unrelated to the time that the animals spent in the open field. Following treatment with different drugs (morphine, buprenorphine, or gabapentin), the walking pattern of the animals in the open field changed in a drug-specific manner. In addition, the detailed behavior score revealed drug-specific changes following treatment. Results: Pharmacokinetic analysis of the drug concentration in blood and cerebrospinal fluid correlated with the behavioral analysis. Conclusion: The data of this study suggest that the open field test together with the detailed behavior score applied in this model are a powerful tool to assess the spontaneous behavior of pigs following PNT-induced neuropathic pain.

16.
J Clin Oncol ; 36(19): 1963-1972, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29746225

RESUMO

Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of < 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age < 3 or > 10 years (11% v 3% and 33% v 23%, respectively; P < .001) and with longer symptom duration ( P < .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials.


Assuntos
Neoplasias do Tronco Encefálico/diagnóstico , Sobreviventes de Câncer/estatística & dados numéricos , Glioma/diagnóstico , Adolescente , Adulto , Neoplasias do Tronco Encefálico/diagnóstico por imagem , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/terapia , Criança , Pré-Escolar , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/terapia , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Sistema de Registros , Adulto Jovem
17.
Nature ; 557(7707): 714-718, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29795344

RESUMO

The cell microenvironment, which is critical for stem cell maintenance, contains both cellular and non-cellular components, including secreted growth factors and the extracellular matrix1-3. Although Notch and other signalling pathways have previously been reported to regulate quiescence of stem cells4-9, the composition and source of molecules that maintain the stem cell niche remain largely unknown. Here we show that adult muscle satellite (stem) cells in mice produce extracellular matrix collagens to maintain quiescence in a cell-autonomous manner. Using chromatin immunoprecipitation followed by sequencing, we identified NOTCH1/RBPJ-bound regulatory elements adjacent to specific collagen genes, the expression of which is deregulated in Notch-mutant mice. Moreover, we show that Collagen V (COLV) produced by satellite cells is a critical component of the quiescent niche, as depletion of COLV by conditional deletion of the Col5a1 gene leads to anomalous cell cycle entry and gradual diminution of the stem cell pool. Notably, the interaction of COLV with satellite cells is mediated by the Calcitonin receptor, for which COLV acts as a surrogate local ligand. Systemic administration of a calcitonin derivative is sufficient to rescue the quiescence and self-renewal defects found in COLV-null satellite cells. This study reveals a Notch-COLV-Calcitonin receptor signalling cascade that maintains satellite cells in a quiescent state in a cell-autonomous fashion, and raises the possibility that similar reciprocal mechanisms act in diverse stem cell populations.


Assuntos
Proteína Semelhante a Receptor de Calcitonina/metabolismo , Colágeno/metabolismo , Músculo Esquelético/citologia , Receptores Notch/metabolismo , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Transdução de Sinais , Nicho de Células-Tronco , Animais , Diferenciação Celular , Proliferação de Células , Autorrenovação Celular , Colágeno/genética , Regulação da Expressão Gênica , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/metabolismo , Camundongos , Transcrição Genética
18.
Sci Rep ; 8(1): 4208, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523801

RESUMO

Skeletal muscle satellite cells are quiescent adult resident stem cells that activate, proliferate and differentiate to generate myofibres following injury. They harbour a robust proliferation potential and self-renewing capacity enabling lifelong muscle regeneration. Although several classes of microRNAs were shown to regulate adult myogenesis, systematic examination of stage-specific microRNAs during lineage progression from the quiescent state is lacking. Here we provide a genome-wide assessment of the expression of small RNAs during the quiescence/activation transition and differentiation by RNA-sequencing. We show that the majority of small RNAs present in quiescent, activated and differentiated muscle cells belong to the microRNA class. Furthermore, by comparing expression in distinct cell states, we report a massive and dynamic regulation of microRNAs, both in numbers and amplitude, highlighting their pivotal role in regulation of quiescence, activation and differentiation. We also identify a number of microRNAs with reliable and specific expression in quiescence including several maternally-expressed miRNAs generated at the imprinted Dlk1-Dio3 locus. Unexpectedly, the majority of class-switching miRNAs are associated with the quiescence/activation transition suggesting a poised program that is actively repressed. These data constitute a key resource for functional analyses of miRNAs in skeletal myogenesis, and more broadly, in the regulation of stem cell self-renewal and tissue homeostasis.


Assuntos
Linhagem da Célula/genética , MicroRNAs/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Análise de Sequência de RNA , Animais , Autorrenovação Celular/genética , Cromossomos de Mamíferos/genética , Perfilação da Expressão Gênica , Homeostase/genética , Camundongos , Desenvolvimento Muscular , Regeneração
19.
Ultrasound Med Biol ; 44(5): 1022-1030, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29501283

RESUMO

The goal of this study was to determine the feasibility of focused ultrasound-based neuromodulation affecting auditory evoked potentials (AEPs) in animals. Focused ultrasound-induced suppression of AEPs was performed in 22 rats and 5 pigs: Repetitive sounds were produced, and the induced AEPs were recorded before and repeatedly after FUS treatment of the auditory pathway. All treated animals exhibited a decrease in AEP amplitude post-treatment in contrast to animals undergoing the sham treatment. Suppression was weaker for rats treated at 2.3 W/cm2 (amplitudes decreased to 59.8 ± 3.3% of baseline) than rats treated at 4.6 W/cm2 (36.9 ± 7.5%, p <0.001). Amplitudes of the treated pigs decreased to 27.7 ± 5.9% of baseline. This effect lasted between 30 min and 1 mo in most treated animals. No evidence of heating during treatment or later brain damage/edema was observed. These results demonstrate the feasibility of inducing significant neuromodulation with non-thermal, non-invasive, reversible focused ultrasound. The long recovery times may have clinical implications.


Assuntos
Vias Auditivas/fisiopatologia , Potenciais Evocados Auditivos , Ondas Ultrassônicas , Estimulação Acústica , Animais , Estudos de Viabilidade , Feminino , Masculino , Modelos Animais , Ratos , Ratos Sprague-Dawley , Suínos
20.
J Pharm Biomed Anal ; 151: 151-158, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29328982

RESUMO

Metabolite reference standards are often not available, which results in a lack of MS/MS spectra for library matching. Consequently, the identification of suspected metabolites proves to be challenging. The present study aims at structurally elucidating the MS/MS fragmentation behavior of selected benzimidazole anthelmintics to theoretically predict characteristic product ions for rapid and systematic tentative metabolite identification. A set of common characteristic product ions was identified from accurate mass MS/MS experiments for five parent compounds. It was hypothesized that the mass shift of any metabolic transformation at the parent molecule also is observable in the mass spectrum of the corresponding metabolite. This was tested and verified with six metabolite reference standards and subsequently, formulated as a general prediction scheme. The approach was integrated into a rapid MSe QTOF workflow and tested in mouse plasma for mebendazole and its metabolites. The presented scheme allows the prediction of characteristic product ions for suspected unknown metabolites. These can be matched with measured product ions of suspected metabolites for tentative identification. The theoretically predicted spectra can contribute to the tentative identification of unknown compounds in non-target and suspect screening approaches.


Assuntos
Anti-Helmínticos/metabolismo , Benzimidazóis/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Anti-Helmínticos/análise , Benzimidazóis/análise , Cromatografia Líquida/métodos , Camundongos , Camundongos Nus
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