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1.
Neuro Oncol ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32166329

RESUMO

BACKGROUND: Diffuse midline gliomas (DMG), including brainstem DIPG, are incurable pediatric high grade gliomas (pHGG). Mutations in the H3 histone tail (H3.1/3.3-K27M) are a feature of DIPG, rendering them therapeutically sensitive to small-molecule inhibition of chromatin modifiers. Pharmacological inhibition of lysine specific demethylase-1 (LSD1) is clinically relevant but has not been carefully investigated in pHGG or DIPG. METHODS: Patient-derived DIPG cell lines, orthotopic mouse models, and pHGG datasets were used to evaluate effects of LSD1 inhibitors on cytotoxicity and immune gene expression. Immune cell cytotoxicity was assessed in DIPG cells pre-treated with LSD1 inhibitors and informatics platforms were used to determine immune infiltration of pHGG. RESULTS: Selective cytotoxicity and an immunogenic gene signature was established in DIPG cell lines using clinically-relevant LSD1 inhibitors. Pediatric HGG patient sequencing data demonstrated survival benefit of this LSD1-dependent gene signature. Pre-treatment of DIPG with these inhibitors increased lysis by natural killer (NK) cells. Catalytic LSD1 inhibitors induced tumor regression and augmented NK cell infusion in vivo to reduce tumor burden. CIBERSORT analysis of patient data confirmed NK infiltration is beneficial to patient survival while CD8 T-cells are negatively prognostic. Catalytic LSD1 inhibitors are non-perturbing to NK cells while scaffolding LSD1 inhibitors are toxic to NK cells and do not induce the gene signature in DIPG cells. CONCLUSIONS: LSD1 inhibition using catalytic inhibitors is both selectively cytotoxic and promotes an immune gene signature that increases NK cell killing in vitro and in vivo, representing a therapeutic opportunity for pHGG.

2.
Neuro Oncol ; 22(2): 195-206, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32078691

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is a rare but deadly pediatric brainstem tumor. To date, there is no effective therapy for DIPG. Transcriptomic analyses have revealed DIPGs have a distinct profile from other pediatric high-grade gliomas occurring in the cerebral hemispheres. These unique genomic characteristics coupled with the younger median age group suggest that DIPG has a developmental origin. The most frequent mutation in DIPG is a lysine to methionine (K27M) mutation that occurs on H3F3A and HIST1H3B/C, genes encoding histone variants. The K27M mutation disrupts methylation by polycomb repressive complex 2 on histone H3 at lysine 27, leading to global hypomethylation. Histone 3 lysine 27 trimethylation is an important developmental regulator controlling gene expression. This review discusses the developmental and epigenetic mechanisms driving disease progression in DIPG, as well as the profound therapeutic implications of epigenetic programming.

3.
Clin Cancer Res ; 25(18): 5572-5583, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31227500

RESUMO

PURPOSE: Radiotherapy (RT) has long been and remains the only treatment option for diffuse intrinsic pontine glioma (DIPG). However, all patients show evidence of disease progression within months of completing RT. No further clinical benefit has been achieved using alternative radiation strategies. Here, we tested the hypothesis that histone demethylase inhibition by GSK-J4 enhances radiation-induced DNA damage, making it a potential radiosensitizer in the treatment of DIPG.Experimental Design: We evaluated the effects of GSK-J4 on genes associated with DNA double-strand break (DSB) repair in DIPG cells by RNA sequence, ATAC sequence, and quantitative real-time PCR. Radiation-induced DNA DSB repair was analyzed by immunocytochemistry of DSB markers γH2AX and 53BP1, DNA-repair assay, and cell-cycle distribution. Clonogenic survival assay was used to determine the effect of GSK-J4 on radiation response of DIPG cells. In vivo response to radiation monotherapy and combination therapy of RT and GSK-J4 was evaluated in patient-derived DIPG xenografts. RESULTS: GSK-J4 significantly reduced the expression of DNA DSB repair genes and DNA accessibility in DIPG cells. GSK-J4 sustained high levels of γH2AX and 53BP1 in irradiated DIPG cells, thereby inhibiting DNA DSB repair through homologous recombination pathway. GSK-J4 reduced clonogenic survival and enhanced radiation effect in DIPG cells. In vivo studies revealed increased survival of animals treated with combination therapy of RT and GSK-J4 compared with either monotherapy. CONCLUSIONS: Together, these results highlight GSK-J4 as a potential radiosensitizer and provide a rationale for developing combination therapy with radiation in the treatment of DIPG.

4.
Neuro Oncol ; 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31242287
5.
Neurosurgery ; 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31225627

RESUMO

BACKGROUND: An impermeable blood-brain barrier and drug efflux via ATP-binding cassette (ABC) transporters such as p-glycoprotein may contribute to underwhelming efficacy of peripherally delivered agents to treat diffuse intrinsic pontine glioma (DIPG). OBJECTIVE: To explore the pharmacological augmentation of convection-enhanced delivery (CED) infusate for DIPG. METHODS: The efficacy of CED dasatinib, a tyrosine kinase inhibitor, in a transgenic H3.3K27M mutant murine model was assessed. mRNA expression of ABCB1 (p-glycoprotein) was analyzed in 14 tumor types in 274 children. In Vitro viability studies of dasatinib, the p-glycoprotein inhibitor, tariquidar, and dexamethasone were performed in 2 H3.3K27M mutant cell lines. Magnetic resonance imaging (MRI) was used to evaluate CED infusate (gadolinium/dasatinib) distribution in animals pretreated with tariquidar and dexamethasone. Histological assessment of apoptosis was performed. RESULTS: Continuous delivery CED dasatinib improved median overall survival (OS) of animals harboring DIPG in comparison to vehicle (39.5 and 28.5 d, respectively; P = .0139). Mean ABCB1 expression was highest in K27M gliomas. In Vitro, the addition of tariquidar and dexamethasone further enhanced the efficacy of dasatinib (P < .001). In Vivo, MRI demonstrated no difference in infusion dispersion between animals pretreated with dexamethasone plus tariquidar prior to CED dasatinib compared to the CED dasatinib. However, tumor apoptosis was the highest in the pretreatment group (P < .001). Correspondingly, median OS was longer in the pretreatment group (49 d) than the dasatinib alone group (39 d) and no treatment controls (31.5 d, P = .0305). CONCLUSION: ABC transporter inhibition plus dexamethasone enhances the efficacy of CED dasatinib, resulting in enhanced tumor cellular apoptosis and improved survival in H3.3K27M mutant DIPG.

6.
Cancer Res ; 79(16): 4026-4041, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31201162

RESUMO

Diffuse intrinsic pontine gliomas (DIPG) are incurable brain tumors with an aggressive onset. Apart from irradiation, there are currently no effective therapies available for patients with DIPG, who have a median survival time of less than one year. Most DIPG cells harbor mutations in genes encoding histone H3 (H3K27M) proteins, resulting in a global reduction of H3K27 trimethylation and activation of oncogenic signaling pathways. Here we show that the H3K27M mutations contribute to RAS pathway signaling, which is augmented by additional RAS activators including PDGFRA. H3K27M mutation led to increased expression of receptor tyrosine kinases (RTK). A RAS pathway functional screen identified ERK5, but not ERK1/2, as a RAS pathway effector important for DIPG growth. Suppression of ERK5 decreased DIPG cell proliferation and induced apoptosis in vitro and in vivo. In addition, depletion or inhibition of ERK5 significantly increased survival of mice intracranially engrafted with DIPG cells. Mechanistically, ERK5 directly stabilized the proto-oncogene MYC at the protein level. Collectively, our data demonstrate an underappreciated role of H3K27M in RAS activation and reveal novel therapeutic targets for treating DIPG tumors. SIGNIFICANCE: These findings identify the H3K27M mutation as an enhancer of RAS activation in DIPG and ERK5 as a novel, immediately actionable molecular target. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/16/4026/F1.large.jpg.

7.
Acta Neuropathol Commun ; 7(1): 64, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036068

RESUMO

Pediatric high grade gliomas (pHGG), including diffuse intrinsic pontine gliomas (DIPGs), are aggressive tumors with a dismal outcome. Radiotherapy (RT) is part of the standard of care of these tumors; however, radiotherapy only leads to a transient clinical improvement. Delta-24-RGD is a genetically engineered tumor-selective adenovirus that has shown safety and clinical efficacy in adults with recurrent gliomas. In this work, we evaluated the feasibility, safety and therapeutic efficacy of Delta-24-RGD in combination with radiotherapy in pHGGs and DIPGs models. Our results showed that the combination of Delta-24-RGD with radiotherapy was feasible and resulted in a synergistic anti-glioma effect in vitro and in vivo in pHGG and DIPG models. Interestingly, Delta-24-RGD treatment led to the downregulation of relevant DNA damage repair proteins, further sensitizing tumors cells to the effect of radiotherapy. Additionally, Delta-24-RGD/radiotherapy treatment significantly increased the trafficking of immune cells (CD3, CD4+ and CD8+) to the tumor niche compared with single treatments. In summary, administration of the Delta-24-RGD/radiotherapy combination to pHGG and DIPG models is safe and significantly increases the overall survival of mice bearing these tumors. Our data offer a rationale for the combination Delta-24-RGD/radiotherapy as a therapeutic option for children with these tumors. SIGNIFICANCE: Delta-24-RGD/radiotherapy administration is safe and significantly increases the survival of treated mice. These positive data underscore the urge to translate this approach to the clinical treatment of children with pHGG and DIPGs.

8.
Nat Commun ; 10(1): 2235, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138805

RESUMO

Pediatric high-grade glioma (pHGG) and diffuse intrinsic pontine gliomas (DIPGs) are aggressive pediatric brain tumors in desperate need of a curative treatment. Oncolytic virotherapy is emerging as a solid therapeutic approach. Delta-24-RGD is a replication competent adenovirus engineered to replicate in tumor cells with an aberrant RB pathway. This virus has proven to be safe and effective in adult gliomas. Here we report that the administration of Delta-24-RGD is safe in mice and results in a significant increase in survival in immunodeficient and immunocompetent models of pHGG and DIPGs. Our results show that the Delta-24-RGD antiglioma effect is mediated by the oncolytic effect and the immune response elicited against the tumor. Altogether, our data highlight the potential of this virus as treatment for patients with these tumors. Of clinical significance, these data have led to the start of a phase I/II clinical trial at our institution for newly diagnosed DIPG (NCT03178032).


Assuntos
Adenoviridae , Neoplasias do Tronco Encefálico/terapia , Glioma/terapia , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Neoplasias do Tronco Encefálico/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Simulação por Computador , Modelos Animais de Doenças , Glioma/patologia , Humanos , Técnicas In Vitro , Camundongos , Gradação de Tumores , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Nat Commun ; 10(1): 1023, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833574

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is an incurable pediatric brain tumor, with approximately 25% of DIPGs harboring activating ACVR1 mutations that commonly co-associate with H3.1K27M mutations. Here we show that in vitro expression of ACVR1 R206H with and without H3.1K27M upregulates mesenchymal markers and activates Stat3 signaling. In vivo expression of ACVR1 R206H or G328V with H3.1K27M and p53 deletion induces glioma-like lesions but is not sufficient for full gliomagenesis. However, in combination with PDGFA signaling, ACVR1 R206H and H3.1K27M significantly decrease survival and increase tumor incidence. Treatment of ACVR1 R206H mutant DIPGs with exogenous Noggin or the ACVR1 inhibitor LDN212854 significantly prolongs survival, with human ACVR1 mutant DIPG cell lines also being sensitive to LDN212854 treatment. Together, our results demonstrate that ACVR1 R206H and H3.1K27M promote tumor initiation, accelerate gliomagenesis, promote a mesenchymal profile partly due to Stat3 activation, and identify LDN212854 as a promising compound to treat DIPG.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Astrocitoma/metabolismo , Neoplasias do Tronco Encefálico/metabolismo , Genoma Humano/genética , Glioma/metabolismo , Histonas/metabolismo , Receptores de Ativinas Tipo I/genética , Animais , Astrocitoma/tratamento farmacológico , Astrocitoma/genética , Astrocitoma/patologia , Neoplasias do Tronco Encefálico/tratamento farmacológico , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/patologia , Proteínas de Transporte/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Glioma/tratamento farmacológico , Glioma/genética , Glioma/patologia , Histonas/genética , Humanos , Camundongos , Mutação , Fator de Crescimento Derivado de Plaquetas/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Quinolinas/farmacologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
11.
Front Oncol ; 8: 191, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29904623

RESUMO

Diffuse intrinsic pontine gliomas (DIPGs) are incurable childhood brain tumors, whereby the standard of care is focal radiation, a treatment that provides temporary relief for most patients. Surprisingly, decades of clinical trials have failed to identify additional therapies that can prolong survival in this disease. In this conference manuscript, we discuss how genetic engineered mouse modeling techniques with the use of a retroviral gene delivery system can help dissect the complex pathophysiology of this disease. With this approach, autochthonous murine DIPG models can be readily induced to (1) help interrogate the function of novel genetic alterations in tumorigenesis, (2) identify candidate cells of origin for this disease, (3) address how region-specific differences in the central nervous system influence the process of gliomagenesis, and (4) evaluate novel therapeutics in an immunocompetent model.

12.
PLoS One ; 12(6): e0178593, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28582410

RESUMO

The PI3K/Akt/mTOR signaling pathway is aberrantly activated in various pediatric tumors. We conducted a phase I study of the Akt inhibitor perifosine in patients with recurrent/refractory pediatric CNS and solid tumors. This was a standard 3+3 open-label dose-escalation study to assess pharmacokinetics, describe toxicities, and identify the MTD for single-agent perifosine. Five dose levels were investigated, ranging from 25 to 125 mg/m2/day for 28 days per cycle. Twenty-three patients (median age 10 years, range 4-18 years) with CNS tumors (DIPG [n = 3], high-grade glioma [n = 5], medulloblastoma [n = 2], ependymoma [n = 3]), neuroblastoma (n = 8), Wilms tumor (n = 1), and Ewing sarcoma (n = 1) were treated. Only one DLT occurred (grade 4 hyperuricemia at dose level 4). The most common grade 3 or 4 toxicity at least possibly related to perifosine was neutropenia (8.7%), with the remaining grade 3 or 4 toxicities (fatigue, hyperglycemia, fever, hyperuricemia, and catheter-related infection) occurring in one patient each. Pharmacokinetics was dose-saturable at doses above 50 mg/m2/day with significant inter-patient variability, consistent with findings reported in adult studies. One patient with DIPG (dose level 5) and 4 of 5 patients with high-grade glioma (dose levels 2 and 3) experienced stable disease for two months. Five subjects with neuroblastoma (dose levels 1 through 4) achieved stable disease which was prolonged (≥11 months) in three. No objective responses were noted. In conclusion, the use of perifosine was safe and feasible in patients with recurrent/refractory pediatric CNS and solid tumors. An MTD was not defined by the 5 dose levels investigated. Our RP2D is 50 mg/m2/day.


Assuntos
Antineoplásicos/farmacocinética , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Fosforilcolina/análogos & derivados , Adolescente , Antineoplásicos/efeitos adversos , Neoplasias do Sistema Nervoso Central/patologia , Criança , Pré-Escolar , Esquema de Medicação , Ependimoma/tratamento farmacológico , Ependimoma/patologia , Feminino , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Hiperuricemia/induzido quimicamente , Hiperuricemia/diagnóstico , Masculino , Meduloblastoma/tratamento farmacológico , Meduloblastoma/patologia , Neuroblastoma/patologia , Neutropenia/induzido quimicamente , Neutropenia/diagnóstico , Fosforilcolina/efeitos adversos , Fosforilcolina/farmacocinética , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/patologia , Resultado do Tratamento , Tumor de Wilms/tratamento farmacológico , Tumor de Wilms/patologia
13.
Mol Cancer Res ; 15(9): 1243-1254, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28522693

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive pediatric brainstem tumor genetically distinguished from adult GBM by the high prevalence of the K27M mutation in the histone H3 variant H3.3 (H3F3A). This mutation reprograms the H3K27me3 epigenetic landscape of DIPG by inhibiting the H3K27-specific histone methyltransferase EZH2. This globally reduces H3K27me2/3, critical repressive marks responsible for cell fate decisions, and also causes focal gain of H3K27me3 throughout the epigenome. To date, the tumor-driving effects of H3.3K27M remain largely unknown. Here, it is demonstrated that H3.3K27M cooperates with PDGF-B in vivo, enhancing gliomagenesis and reducing survival of p53 wild-type (WT) and knockout murine models of DIPG. H3.3K27M expression drives increased proliferation of tumor-derived murine neurospheres, suggesting that cell-cycle deregulation contributes to increased malignancy in mutant tumors. RNA sequencing on tumor tissue from H3.3K27M-expressing mice indicated global upregulation of PRC2 target genes, and a subset of newly repressed genes enriched in regulators of development and cell proliferation. Strikingly, H3.3K27M induced targeted repression of the p16/ink4a (CDKN2A) locus, a critical regulator of the G0-G1 to S-phase transition. Increased levels of H3K27me3 were observed at the p16 promoter; however, pharmacologic reduction of methylation at this promoter did not rescue p16 expression. Although DNA methylation is also present at this promoter, it is not K27M dependent. Intriguingly, inhibition of DNA methylation restores p16 levels and is cytotoxic against murine tumor cells. Importantly, these data reveal that H3.3K27M-mediated p16 repression is an important mechanism underlying the proliferation of H3.3K27M tumor cells, as in vivo cdkn2a knockout eliminates the survival difference between H3.3K27M and H3.3WT tumor-bearing mice.Implications: This study shows that H3.3K27M mutation and PDGF signaling act in concert to accelerate gliomagenesis in a genetic mouse model and identifies repression of p16 tumor suppressor as a target of H3.3K27M, highlighting the G1-S cell-cycle transition as a promising therapeutic avenue. Mol Cancer Res; 15(9); 1243-54. ©2017 AACR.


Assuntos
Neoplasias do Tronco Encefálico/metabolismo , Neoplasias do Tronco Encefálico/patologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Glioma/metabolismo , Glioma/patologia , Histonas/metabolismo , Animais , Neoplasias do Tronco Encefálico/genética , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina/genética , Modelos Animais de Doenças , Glioma/genética , Histonas/genética , Camundongos , Camundongos Endogâmicos C57BL
14.
PLoS One ; 12(1): e0169485, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28052119

RESUMO

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG), or high-grade brainstem glioma (BSG), is one of the major causes of brain tumor-related deaths in children. Its prognosis has remained poor despite numerous efforts to improve survival. Panobinostat, a histone deacetylase inhibitor, is a targeted agent that has recently shown pre-clinical efficacy and entered a phase I clinical trial for the treatment of children with recurrent or progressive DIPG. METHODS: A collaborative pre-clinical study was conducted using both a genetic BSG mouse model driven by PDGF-B signaling, p53 loss, and ectopic H3.3-K27M or H3.3-WT expression and an H3.3-K27M orthotopic DIPG xenograft model to confirm and extend previously published findings regarding the efficacy of panobinostat in vitro and in vivo. RESULTS: In vitro, panobinostat potently inhibited cell proliferation, viability, and clonogenicity and induced apoptosis of human and murine DIPG cells. In vivo analyses of tissue after short-term systemic administration of panobinostat to genetically engineered tumor-bearing mice indicated that the drug reached brainstem tumor tissue to a greater extent than normal brain tissue, reduced proliferation of tumor cells and increased levels of H3 acetylation, demonstrating target inhibition. Extended consecutive daily treatment of both genetic and orthotopic xenograft models with 10 or 20 mg/kg panobinostat consistently led to significant toxicity. Reduced, well-tolerated doses of panobinostat, however, did not prolong overall survival compared to vehicle-treated mice. CONCLUSION: Our collaborative pre-clinical study confirms that panobinostat is an effective targeted agent against DIPG human and murine tumor cells in vitro and in short-term in vivo efficacy studies in mice but does not significantly impact survival of mice bearing H3.3-K27M-mutant tumors. We suggest this may be due to toxicity associated with systemic administration of panobinostat that necessitated dose de-escalation.


Assuntos
Neoplasias do Tronco Encefálico/tratamento farmacológico , Engenharia Genética , Glioma/tratamento farmacológico , Ácidos Hidroxâmicos/uso terapêutico , Indóis/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Acetilação/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Neoplasias do Tronco Encefálico/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Células Clonais , Glioma/patologia , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacocinética , Ácidos Hidroxâmicos/farmacologia , Indóis/farmacocinética , Indóis/farmacologia , Concentração Inibidora 50 , Camundongos Endogâmicos C57BL , Panobinostat , Resultado do Tratamento
15.
Neuro Oncol ; 19(2): 153-161, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27282398

RESUMO

High-grade gliomas in children are different from those that arise in adults. Recent collaborative molecular analyses of these rare cancers have revealed previously unappreciated connections among chromatin regulation, developmental signaling, and tumorigenesis. As we begin to unravel the unique developmental origins and distinct biological drivers of this heterogeneous group of tumors, clinical trials need to keep pace. It is important to avoid therapeutic strategies developed purely using data obtained from studies on adult glioblastoma. This approach has resulted in repetitive trials and ineffective treatments being applied to these children, with limited improvement in clinical outcome. The authors of this perspective, comprising biology and clinical expertise in the disease, recently convened to discuss the most effective ways to translate the emerging molecular insights into patient benefit. This article reviews our current understanding of pediatric high-grade glioma and suggests approaches for innovative clinical management.


Assuntos
Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica/patologia , Glioma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Criança , Glioma/genética , Glioma/metabolismo , Humanos , Gradação de Tumores , Prognóstico
16.
Int J Cancer ; 140(2): 480-484, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27649927

RESUMO

AKT plays a pivotal role in driving the malignant phenotype of many cancers, including high-risk neuroblastoma (HR-NB). AKT signaling, however, is active in normal tissues, raising concern about excessive toxicity from its suppression. The oral AKT inhibitor perifosine showed tolerable toxicity in adults and in our phase I trial in children with solid tumors (clinicaltrials.gov NCT00776867). We now report on the HR-NB experience. HR-NB patients received perifosine 50-75 mg m-2  day-1 after a loading dose of 100-200 mg m-2 on day 1, and continued on study until progressive disease. The 27 HR-NB patients included three treated for primary refractory disease and 24 with disease resistant to salvage therapy after 1-5 (median 2) relapses; only one had MYCN-amplified HR-NB. Pharmacokinetic studies showed µM concentrations consistent with cytotoxic levels in preclinical models. Nine patients (all MYCN-non-amplified) remained progression-free through 43+ to 74+ (median 54+) months from study entry, including the sole patient to show a complete response and eight patients who had persistence of abnormal 123 I-metaiodobenzylguanidine skeletal uptake but never developed progressive disease. Toxicity was negligible in all 27 patients, even with the prolonged treatment (11-62 months, median 38) in the nine long-term progression-free survivors. The clinical findings (i) confirm the safety of therapeutic serum levels of an AKT inhibitor in children; (ii) support perifosine for MYCN-non-amplified HR-NB as monotherapy after completion of standard treatment or combined with other agents (based on preclinical studies) to maximize antitumor effects; and (iii) highlight the welcome possibility that refractory or relapsed MYCN-non-amplified HR-NB is potentially curable.


Assuntos
Antineoplásicos/uso terapêutico , Neuroblastoma/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilcolina/análogos & derivados , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adolescente , Adulto , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/metabolismo , Neuroblastoma/metabolismo , Fosforilcolina/uso terapêutico , Adulto Jovem
17.
Pediatr Blood Cancer ; 64(7)2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28035748

RESUMO

BACKGROUND: The PI3K/AKT/mTOR pathway is aberrantly activated in many pediatric solid tumors including gliomas and medulloblastomas. Preclinical data in a pediatric glioma model demonstrated that the combination of perifosine (AKT inhibitor) and temsirolimus (mTOR inhibitor) is more potent at inhibiting the axis than either agent alone. We conducted this study to assess pharmacokinetics and identify the maximum tolerated dose for the combination. PROCEDURE: We performed a standard 3+3 phase I, open-label, dose-escalation study in patients with recurrent/refractory pediatric solid tumors. Four dose levels of perifosine (25-75 mg/m2 /day) and temsirolimus (25-75 mg/m2 IV weekly) were investigated. RESULTS: Twenty-three patients (median age 8.5 years) with brain tumors (diffuse intrinsic pontine glioma [DIPG] n = 8, high-grade glioma n = 6, medulloblastoma n = 2, ependymoma n = 1), neuroblastoma (n = 4), or rhabdomyosarcoma (n = 2) were treated. The combination was generally well tolerated and no dose-limiting toxicity was encountered. The most common grade 3 or 4 toxicities (at least possibly related) were thrombocytopenia (38.1%), neutropenia (23.8%), lymphopenia (23.8%), and hypercholesterolemia (19.0%). Pharmacokinetic findings for temsirolimus were similar to those observed in the temsirolimus single-agent phase II pediatric study and pharmacokinetic findings for perifosine were similar to those in adults. Stable disease was seen in 9 of 11 subjects with DIPG or high-grade glioma; no partial or complete responses were achieved. CONCLUSIONS: The combination of these AKT and mTOR inhibitors was safe and feasible in patients with recurrent/refractory pediatric solid tumors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias/tratamento farmacológico , Fosforilcolina/análogos & derivados , Sirolimo/análogos & derivados , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Fosforilcolina/administração & dosagem , Fosforilcolina/efeitos adversos , Fosforilcolina/farmacocinética , Sirolimo/administração & dosagem , Sirolimo/efeitos adversos , Sirolimo/farmacocinética , Adulto Jovem
18.
Oncotarget ; 8(6): 9366-9374, 2017 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-28030841

RESUMO

Corticosteroids, such as dexamethasone, are routinely used as palliative care in neuro-oncology for their anti-inflammatory benefits, however many patients experience dose limiting side effects caused by glucocorticoid response element (GRE)-mediated transcription. The purpose of this study was to use a murine model to investigate a new steroid alternative, vamorolone, which promises to reduce side effects through dissociating GRE-mediated transcription and NF-κB -mediated anti-inflammatory actions. To compare vamorolone to dexamethasone in reducing pro-inflammatory signals in vitro, murine glioma cells were treated with dexamethasone, vamorolone or vehicle control. Changes in mRNA expression were assessed using the nanostring inflammatory platform. Furthermore, drug efficacy, post-treatment behavioral activity and side effects were assessed by treating two cohorts of brain tumor bearing mice with dexamethasone, vamorolone, or vehicle control. Our investigation showed that treatment with vamorolone resulted in a reduction of pro-inflammatory signals in tumor cells in vitro similar to treatment with dexamethasone. Treatment with vamorolone resulted in a better safety profile in comparison to dexamethasone treatment. Vamorolone- treated mice showed similar or better activity and survival when compared to dexamethasone-treated mice. Our data indicate vamorolone is a potential steroid-sparing alternative for treating patients with brain tumors.


Assuntos
Anti-Inflamatórios/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Citocinas/metabolismo , Dexametasona/farmacologia , Glioma/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Esteroides/farmacologia , Animais , Anti-Inflamatórios/toxicidade , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Citocinas/genética , Dexametasona/toxicidade , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Camundongos Endogâmicos NOD , Camundongos SCID , Atividade Motora/efeitos dos fármacos , NF-kappa B/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos
20.
Mol Cancer Ther ; 15(5): 819-29, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26883271

RESUMO

Dasatinib is a multikinase inhibitor in clinical trials for glioma, and thus far has failed to demonstrate significant efficacy. We investigated whether the ABC efflux transporters ABCG2 and ABCB1 expressed in the blood-brain barrier (BBB), are limiting the efficacy of dasatinib in the treatment of glioma using genetic and pharmacologic approaches. We utilized a genetic brainstem glioma mouse model driven by platelet-derived growth factor-B and p53 loss using abcg2/abcb1 wild-type (ABC WT) or abcg2/abcb1 knockout mice (ABC KO). First, we observed that brainstem glioma tumor latency is significantly prolonged in ABC KO versus ABC WT mice (median survival of 47 vs. 34 days). Dasatinib treatment nearly doubles the survival of brainstem glioma-bearing ABC KO mice (44 vs. 80 days). Elacridar, an ABCG2 and ABCB1 inhibitor, significantly increases the efficacy of dasatinib in brainstem glioma-bearing ABC WT mice (42 vs. 59 days). Pharmacokinetic analysis demonstrates that dasatinib delivery into the normal brain, but not into the tumor core, is significantly increased in ABC KO mice compared with ABC WT mice. Surprisingly, elacridar did not significantly increase dasatinib delivery into the normal brain or the tumor core of ABC WT mice. Next, we demonstrate that the tight junctions of the BBB of this model are compromised as assessed by tissue permeability to Texas Red dextran. Finally, elacridar increases the cytotoxicity of dasatinib independent of ABCG2 and ABCB1 expression in vitro In conclusion, elacridar improves the efficacy of dasatinib in a brainstem glioma model without significantly increasing its delivery to the tumor core. Mol Cancer Ther; 15(5); 819-29. ©2016 AACR.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Neoplasias do Tronco Encefálico/metabolismo , Dasatinibe/farmacologia , Glioma/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Acridinas/farmacologia , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Barreira Hematoencefálica/metabolismo , Neoplasias do Tronco Encefálico/tratamento farmacológico , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/patologia , Linhagem Celular Tumoral , Dasatinibe/administração & dosagem , Dasatinibe/farmacocinética , Modelos Animais de Doenças , Sinergismo Farmacológico , Expressão Gênica , Glioma/tratamento farmacológico , Glioma/genética , Glioma/patologia , Humanos , Camundongos , Camundongos Knockout , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-sis , Tetra-Hidroisoquinolinas/farmacologia , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
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