Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 183
Filtrar
2.
Neuro Oncol ; 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33130881

RESUMO

BACKGROUND: Malignant astrocytic gliomas in children show a remarkable biological and clinical diversity. Small in-frame insertions or missense mutations in the EGFR gene have recently been identified in a distinct subset of pediatric-type bithalamic gliomas with a unique DNA methylation pattern. METHODS: Here, we investigated an epigenetically homogeneous cohort of malignant gliomas (n=58) distinct from other subtypes and enriched for pediatric cases and thalamic location, in comparison with this recently identified subtype of pediatric bithalamic gliomas. RESULTS: EGFR gene amplification was detected in 16/58 (27%) tumors, and missense mutations or small in-frame insertions in EGFR were found in 20/30 tumors with available sequencing data (67%; five of them co-occurring with EGFR amplification). Additionally, eight of the 30 tumors (27%) harbored an H3.1 or H3.3 K27M mutation (six of them with a concomitant EGFR alteration). All tumors tested showed loss of H3K27me3 staining, with evidence of EZHIP overexpression in the H3 wildtype cases. Although some tumors indeed showed a bithalamic growth pattern, a significant proportion of tumors occurred in the unilateral thalamus or in other (predominantly midline) locations. CONCLUSIONS: Our findings present a distinct molecular class of pediatric-type malignant gliomas largely overlapping with the recently reported bithalamic gliomas characterized by EGFR alteration, but additionally showing a broader spectrum of EGFR alterations and tumor localization. Global H3K27me3 loss in this group appears to be mediated by either H3 K27 mutation or EZHIP overexpression. EGFR inhibition may represent a potential therapeutic strategy in these highly aggressive gliomas.

3.
Neuron ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33065047

RESUMO

Despite considerable recent advances in understanding and treating many other cancers, malignant brain tumors remain associated with low survival or severe long-term sequelae. Limited progress, including development of immunotherapies, relates in part to difficulties in accurately reproducing brain microenvironment with current preclinical models. The cellular interactions among resident microglia, recruited tumor-associated macrophages, stromal cells, glial cells, neurons, and cancer cells and how they affect tumor growth or behavior are emerging, yet many questions remain. The role of the blood-brain barrier, extracellular matrix components, and heterogeneity among tumor types and within different regions of a single tumor further complicate the matter. Here, we focus on brain microenvironment features impacted by tumor biology. We also discuss limits of current preclinical models and how complementary models, such as humanized animals and organoids, will allow deeper mechanistic insights on cancer biology, allowing for more efficient testing of therapeutic strategies, including immunotherapy, for brain cancers.

5.
Neurooncol Adv ; 2(Suppl 1): i98-i106, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32642735

RESUMO

Background: Pediatric neurofibromatosis type 1 (NF1)-associated optic pathway gliomas (OPGs) exhibit different clinico-radiological features, treatment, and outcome compared with sporadic OPGs. While NF1-associated OPGs are caused by complete loss-of-function of the NF1 gene, other genetic alterations of the RAS-MAPK pathway are frequently described in the sporadic cases. We identified a group of patients who presented OPGs with typical radiological features of NF1-associated OPGs but without the NF1 diagnostic criteria. We aim to investigate into the possible molecular mechanisms underlying this "NF1-like" pediatric OPGs presentation. Methods: We analyzed clinico-radiological features of 16 children with NF1-like OPGs and without NF1 diagnostic criteria. We performed targeted sequencing of the NF1 gene in constitutional samples (n = 16). The RAS-MAPK pathway major genes were sequenced in OPG tumor samples (n = 11); BRAF FISH and IHC analyses were also performed. Results: In one patient's blood and tumor samples, we identified a NF1 nonsense mutation (exon 50: c.7285C>T, p.Arg2429*) with ~8% and ~70% VAFs, respectively, suggesting a mosaic NF1 mutation limited to the brain (segmental NF1). This patient presented signs of neurodevelopmental disorder. We identified a somatic alteration of the RAS-MAPK pathway in eight tumors: four BRAF activating p.Val600Glu mutations, three BRAF:KIAA oncogenic fusions, and one putative gain-of-function complex KRAS indel inframe mutation. Conclusions: NF1-like OPGs can rarely be associated with mosaic NF1 that needs specific constitutional DNA analyses for diagnosis. Further studies are warranted to explore unknown predisposition condition leading to the NF1-like OPG presentation, particularly in patients with the association of a neurodevelopmental disorder.

6.
Neuro Oncol ; 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32628746

RESUMO

BACKGROUND: The aim of the project was to identify risk factors associated with visual progression and treatment indications in pediatric patients with Neurofibromatosis type 1 associated optic pathway gliomas (NF1-OPG). METHODS: A multi-disciplinary expert group consisting of ophthalmologists, pediatric neuro-oncologists, neurofibromatosis specialists and neuro-radiologists involved in therapy trials assembled a cohort of children with NF1-OPG from six European countries with complete clinical, imaging and visual outcome datasets. Using methods developed during a consensus workshop, visual and imaging data were reviewed by the expert team and analyzed to identify associations between factors at diagnosis with visual and imaging outcomes. RESULTS: 83 patients (37 males, 46 females, mean age 5.1±2.6 years; 1-13.1 years) registered in the European treatment-trial SIOP LGG-2004 (recruited 2004-2012) were included. They were either observed or treated (at diagnosis/ after follow-up).In multivariable analysis, factors present at diagnosis associated with adverse visual outcomes included: multiple visual signs and symptoms (adjOR 8.33, 95%CI 1.9-36.45); abnormal visual behavior (adjOR 4.15, 95%CI 1.20-14.34); new onset of visual symptoms (adjOR 4.04, 95%CI 1.26-12.95) and optic atrophy (adjOR 3.73, 95%CI 1.13-12.53). Squint, posterior visual pathway tumor involvement, and bilateral pathway tumor involvement, showed borderline significance. Treatment appeared to reduce tumor size but improved vision in only 10/45 treated patients. Children with visual deterioration after primary observation are more likely to improve with treatment than children treated at diagnosis. CONCLUSIONS: The analysis identified the importance of symptomatology, optic atrophy and history of vision loss as predictive factors for poor visual outcomes in children with NF1-OPG.

7.
Neurooncol Adv ; 2(1): vdaa075, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666050

RESUMO

Background: New rescue regimens are needed for pediatric refractory/recurrent low-grade glioma. Nilotinib is a tyrosine kinase inhibitor that has potential synergistic effects with vinblastine on angiogenesis, tumor cell growth, and immunomodulation. Methods: This phase I trial aimed to determine the recommended doses of this combination for phase II trials (RP2D) using the dual-agent Bayesian continual reassessment method. Nilotinib was given orally twice daily (BID) in combination with once-weekly vinblastine injections for a maximum of 12 cycles of 28 days (clinicaltrials.gov, NCT01884922). Results: Thirty-five pediatric patients were enrolled across 4 dose levels. The median age was 7 years and 10 had neurofibromatosis type 1. Patients had received a median of 3 prior treatment lines and 25% had received more than 4 previous treatment lines. Dose-limiting toxicity (DLT) during cycle 1 was hematologic, dermatologic, and cardiovascular. The RP2D was identified at 3 mg/m2 weekly for vinblastine with 230 mg/m2 BID for nilotinib (estimated probability of DLT = 18%; 95% credibility interval, 7-29%). Fifteen patients completed the 12 cycles; 2 stopped therapy prematurely due to toxicity and 18 due to disease progression. Three patients achieved a partial response leading to an objective response rate of 8.8% (95% confidence interval [CI], 1.9-23.7), and the disease control rate was 85.3% (95% CI, 68.9-95.1). The 12-month progression-free survival was 37.1% (95% CI, 23.2-53.67). Conclusions: Vinblastine and nilotinib combination was mostly limited by myelosuppression and dermatologic toxicity. The efficacy of the combination at the RP2D is currently evaluated in a randomized phase II trial comparing this regimen to vinblastine alone.

8.
Neuro Oncol ; 22(11): 1686-1695, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-32267940

RESUMO

BACKGROUND: Previous pilot studies have shown the feasibility of preoperative chemotherapy in patients with medulloblastoma, but benefits and risks compared with initial surgery have not been assessed. METHODS: Two therapeutic strategies were retrospectively compared in 92 patients with metastatic medulloblastoma treated at Gustave Roussy between 2002 and 2015: surgery at diagnosis (n = 54, group A) and surgery delayed after carboplatin and etoposide-based neoadjuvant therapy (n = 38, group B). Treatment strategies were similar in both groups. RESULTS: The rate of complete tumor excision was significantly higher in group B than in group A (93.3% vs 57.4%, P = 0.0013). Postoperative complications, chemotherapy-associated side effects, and local progressions were not increased in group B. Neoadjuvant chemotherapy led to a decrease in the primary tumor size in all patients; meanwhile 4/38 patients experienced a distant progression. The histological review of 19 matched tumor pairs (before and after chemotherapy) showed that proliferation was reduced and histological diagnosis feasible and accurate even after neoadjuvant chemotherapy. The 5-year progression-free and overall survival rates were comparable between groups. Comparison of the longitudinal neuropsychological data showed that intellectual outcome tended to be better in group B (the mean predicted intellectual quotient value was 6 points higher throughout the follow-up). CONCLUSION: Preoperative chemotherapy is a safe and efficient strategy for metastatic medulloblastoma. It increases the rate of complete tumor excision and may improve the neuropsychological outcome without jeopardizing survival. KEY POINTS: 1. Preoperative chemotherapy increases the rate of complete tumor removal.2. No additional risk (toxic or disease progression) is linked to the delayed surgery.3. Preoperative chemotherapy could have a positive impact on the neuropsychological outcome of patients.

9.
Cancer Lett ; 479: 13-22, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32112904

RESUMO

The treatment of primary brain tumors, especially malignant gliomas, remains challenging. The failure of most treatments for this disease is partially explained by the blood-brain barrier (BBB), which prevents circulating molecules from entering the brain parenchyma. Ultrasound-induced BBB disruption (US-BBBD) has recently emerged as a promising strategy to improve the delivery of therapeutic agents to brain tumors. A large body of preclinical studies has demonstrated that the association of low-intensity pulsed ultrasound with intravenous microbubbles can transiently open the BBB in a localized manner. The safety of this technique has been assessed in numerous preclinical studies in both small and large animal models. A large panel of therapeutic agents have been delivered to the brain in preclinical models, demonstrating both tumor control and increased survival. This technique has recently entered clinical trials with encouraging preliminary data. In this review, we describe the mechanisms and histological effects of US-BBBD and summarize the preclinical studies published to date. We furthermore provide an overview of the current clinical development and future potential of this promising technology.

11.
Neuro Oncol ; 22(8): 1190-1202, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32025728

RESUMO

BACKGROUND: Considering that pediatric high-grade gliomas (HGGs) are biologically distinct from their adult counterparts, the objective of this study was to define the landscape of HGGs in adolescents and young adults (AYAs). METHODS: We performed a multicentric retrospective study of 112 AYAs from adult and pediatric Ile-de-France neurosurgical units, treated between 1998 and 2013 to analyze their clinicoradiological and histomolecular profiles. The inclusion criteria were age between 15 and 25 years, histopathological HGG diagnosis, available clinical data, and preoperative and follow-up MRI. MRI and tumoral samples were centrally reviewed. Immunohistochemistry and complementary molecular techniques such as targeted/next-generation sequencing, whole exome sequencing, and DNA-methylation analyses were performed to achieve an integrated diagnosis according to the 2016 World Health Organization (WHO) classification. RESULTS: Based on 80 documented AYA patients, HGGs constitute heterogeneous clinicopathological and molecular groups, with a predominant representation of pediatric subtypes (histone H3-mutants, 40%) but also adult subtypes (isocitrate dehydrogenase [IDH] mutants, 28%) characterized by the rarity of oligodendrogliomas, IDH mutants, and 1p/19q codeletion and the relative high frequency of "rare adult IDH mutations" (20%). H3G34-mutants (14%) represent the most specific subgroup in AYAs. In the H3K27-mutant subgroup, non-brainstem diffuse midline gliomas are more frequent (66.7%) than diffuse intrinsic pontine gliomas (23.8%), contrary to what is observed in children. We found that WHO grade has no prognostic value, but molecular subgrouping has major prognostic importance. CONCLUSIONS: HGGs in AYAs could benefit from a specific classification, driven by molecular subtyping rather than age group. Collaborative efforts are needed from pediatric and adult neuro-oncology teams to improve the management of HGGs in AYAs.

12.
Clin Cancer Res ; 26(8): 1856-1865, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-31924736

RESUMO

PURPOSE: The HERBY trial evaluated the benefit of the addition of the antiangiogenic agent Bevacizumab (BEV) to radiotherapy/temozolomide (RT/TMZ) in pediatric patients with newly diagnosed non-brainstem high-grade glioma (HGG). The work presented here aims to correlate imaging characteristics and outcome measures with pathologic and molecular data. EXPERIMENTAL DESIGN: Radiological, pathologic, and molecular data were correlated with trial clinical information to retrospectively re-evaluate event-free survival (EFS) and overall survival (OS). RESULTS: One-hundred thirteen patients were randomized to the RT/TMZ arm (n = 54) or the RT/TMZ+BEV (BEV arm; n = 59). The tumor arose in the cerebral hemispheres in 68 patients (Cerebral group) and a midline location in 45 cases (Midline group). Pathologic diagnosis was available in all cases and molecular data in 86 of 113. H3 K27M histone mutations were present in 23 of 32 Midline cases and H3 G34R/V mutations in 7 of 54 Cerebral cases. Total/near-total resection occurred in 44 of 68 (65%) Cerebral cases but in only 5 of 45 (11%) Midline cases (P < 0.05). Leptomeningeal metastases (27 cases, 13 with subependymal spread) at relapse were more frequent in Midline (17/45) than in Cerebral tumors (10/68, P < 0.05). Mean OS (14.1 months) and EFS (9.0 months) in Midline tumors were significantly lower than mean OS (20.7 months) and EFS (14.9 months) in Cerebral tumors (P < 0.05). Pseudoprogression occurred in 8 of 111 (6.2%) cases. CONCLUSIONS: This study has shown that the poor outcome of midline tumors (compared with cerebral) may be related to (1) lesser surgical resection, (2) H3 K27M histone mutations, and (3) higher leptomeningeal dissemination.

13.
Neurosurg Focus ; 48(1): E10, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31896084

RESUMO

Pediatric brain tumors are the most common solid tumor and the first cause of cancer death in childhood, adolescence, and young adulthood. Current treatments are far from optimal in most of these tumors and the prognosis remains dismal for many of them. One of the main causes of the failure of current medical treatments is in part due to the existence of the blood-brain barrier (BBB), which limits drug delivery to tumors. Opening of the BBB with low-intensity pulsed ultrasound (LIPU) has emerged during the last 2 decades as a promising technique for enhancing drug delivery to the brain. In preclinical models, enhanced delivery of a wide range of therapeutic agents, from low-molecular-weight drugs, to antibodies and immune cells, has been observed as well as tumor control and increased survival. This technique has recently entered clinical trials with extracranial and intracranial devices. The safety and feasibility of this technique has furthermore been shown in patients treated monthly for recurrent glioblastoma receiving carboplatin chemotherapy. In this review, the characteristics of the BBB in the most common pediatric brain tumors are reviewed. Then, principles and mechanisms of BBB disruption with ultrasound (US) are summarized and described at the histological and biological levels. Lastly, preclinical studies that have used US-induced BBB opening in tumor models, recent clinical trials, and the potential use of this technology in pediatrics are provided.

14.
Neuro Oncol ; 22(1): 116-127, 2020 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-31419298

RESUMO

BACKGROUND: The World Health Organization (WHO) adult glioma grading system is questionable in pediatric high-grade gliomas (pHGGs), which are biologically distinct from adult HGGs. We took advantage of the neuropathological review data obtained during one of the largest prospective randomized pHGG trials, namely HERBY (NCT01390948), to address this issue in children with newly diagnosed non-brainstem HGG. METHODS: HGG diagnosis was confirmed by pre-randomization, real-time central pathology review using WHO 2007 criteria, followed by a consensus review blinded to clinical factors and outcomes. We evaluated association between WHO 2007 grade and other clinical/radiological/biological characteristics and the prognostic value of WHO 2007 grade, midline location, and selected biomarkers (Ki-67 index/Olig2/CD34/EGFR/p53/H3F3A K27M mutation) on overall survival. RESULTS: Real-time central neuropathological review was feasible in a multicenter study, with a mean time of 2.4 days, and led to the rejection of HGG diagnosis in 20 of 163 cases (12.3%). The different grading criteria and resulting WHO grade were not significantly associated with overall survival in the entire population (n = 118) or in midline and non-midline subgroups. H3F3A K27M mutation was significantly associated with poor outcome. No significant prognostic value was observed for grade, even after regrading H3F3A K27M-mutated midline glioma as grade IV (WHO 2016). Midline location and a high Ki-67 index (≥20%) were associated with poor outcome (P = 0.004 and P = 0.04, respectively). A 10% increase in Ki-67 index was associated with a hazard ratio of 1.53 (95% CI: 1.27-1.83; P < 0.0001). CONCLUSION: Our findings suggest that WHO grade III versus IV has no prognostic value in pediatric HGG.

15.
Neurosurgery ; 86(4): 517-523, 2020 04 01.
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.


Assuntos
Neoplasias do Tronco Encefálico/complicações , Malformações Vasculares do Sistema Nervoso Central/complicações , Malformações Vasculares do Sistema Nervoso Central/epidemiologia , Glioma Pontino Intrínseco Difuso/complicações , Criança , Estudos de Coortes , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Prevalência , Estudos Retrospectivos
16.
Acta Neuropathol ; 139(2): 287-303, 2020 02.
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.

18.
Clin Cancer Res ; 25(22): 6788-6800, 2019 11 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.


Assuntos
Neoplasias do Tronco Encefálico/metabolismo , Glioma Pontino Intrínseco Difuso/metabolismo , Tolerância a Radiação , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/mortalidade , Neoplasias do Tronco Encefálico/radioterapia , Ciclo Celular/genética , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos da radiação , Glioma Pontino Intrínseco Difuso/genética , Glioma Pontino Intrínseco Difuso/mortalidade , Glioma Pontino Intrínseco Difuso/radioterapia , Relação Dose-Resposta à Radiação , Técnicas de Silenciamento de Genes , Histonas/genética , Histonas/metabolismo , Humanos , Mutação , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/efeitos da radiação , Prognóstico , Interferência de RNA , RNA Interferente Pequeno/genética , Tolerância a Radiação/genética , Proteína Supressora de Tumor p53/genética
19.
J Neurooncol ; 145(1): 177-184, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31522324

RESUMO

INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) is a rare clinically, neuro-radiologically, and molecularly defined malignancy of the brainstem with a median overall survival of approximately 11 months. Our aim is to evaluate the current tendency for its treatment in Europe in order to develop (inter)national consensus guidelines. METHODS: Healthcare professionals specialized in DIPG were asked to fill in an online survey with questions regarding usual treatment strategies at diagnosis and at disease progression in their countries and/or their centers, respectively. RESULTS: Seventy-four healthcare professionals responded to the survey, of which 87.8% were pediatric oncologists. Only 13.5% of the respondents biopsy all of their patients, 41.9% biopsy their patients infrequently. More than half of the respondents (54.1%) treated their patients with radiotherapy only at diagnosis, whereas 44.6% preferred radiotherapy combined with chemotherapy. When the disease progresses, treatment strategies became even more diverse, and the tendency for no treatment increased from 1.4% at diagnosis to 77.0% after second progression. 36.5% of the healthcare professionals treat children younger than 3 years differently than older children at diagnosis. This percentage decreased, when the disease progresses. Most of the participants (51.4%) included less than 25% of their patients in clinical trials. CONCLUSION: This survey demonstrates a large heterogeneity of treatment regimens, especially at disease progression. We emphasize the need for international consensus guidelines for the treatment of DIPG, possible by more collaborative clinical trials.


Assuntos
Neoplasias do Tronco Encefálico/diagnóstico , Neoplasias do Tronco Encefálico/terapia , Glioma Pontino Intrínseco Difuso/diagnóstico , Glioma Pontino Intrínseco Difuso/terapia , Biópsia , Terapia Combinada , Progressão da Doença , Humanos , Prognóstico
20.
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 , Glioma Pontino Intrínseco Difuso/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 , Glioma Pontino Intrínseco Difuso/diagnóstico , Glioma Pontino Intrínseco Difuso/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
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...