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BACKGROUND: Certain paediatric nervous system malignancies have dismal prognoses. Retinoic acid (RA) is used in neuroblastoma treatment, and preclinical data indicate potential benefit in selected paediatric brain tumour entities. However, limited single-agent efficacy necessitates combination treatment approaches. METHODS: We performed drug sensitivity profiling of 76 clinically relevant drugs in combination with RA in 16 models (including patient-derived tumouroids) of the most common paediatric nervous system tumours. Drug responses were assessed by viability assays, high-content imaging, and apoptosis assays and RA relevant pathways by RNAseq from treated models and patient samples obtained through the precision oncology programme INFORM (n = 2288). Immunoprecipitation detected BCL-2 family interactions, and zebrafish embryo xenografts were used for in vivo efficacy testing. RESULTS: Group 3 medulloblastoma (MBG3) and neuroblastoma models were highly sensitive to RA treatment. RA induced differentiation and regulated apoptotic genes. RNAseq analysis revealed high expression of BCL2L1 in MBG3 and BCL2 in neuroblastomas. Co-treatments with RA and BCL-2/XL inhibitor navitoclax synergistically decreased viability at clinically achievable concentrations. The combination of RA with navitoclax disrupted the binding of BIM to BCL-XL in MBG3 and to BCL-2 in neuroblastoma, inducing apoptosis in vitro and in vivo. CONCLUSIONS: RA treatment primes MBG3 and NB cells for apoptosis, triggered by navitoclax cotreatment.
Assuntos
Apoptose , Sinergismo Farmacológico , Meduloblastoma , Neuroblastoma , Tretinoína , Peixe-Zebra , Humanos , Animais , Tretinoína/farmacologia , Meduloblastoma/tratamento farmacológico , Meduloblastoma/patologia , Meduloblastoma/metabolismo , Meduloblastoma/genética , Apoptose/efeitos dos fármacos , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , Neuroblastoma/metabolismo , Neuroblastoma/genética , Linhagem Celular Tumoral , Compostos de Anilina/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Sulfonamidas/farmacologia , Proteína bcl-X/genética , Proteína bcl-X/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Camundongos , Neoplasias Cerebelares/tratamento farmacológico , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/metabolismo , Neoplasias Cerebelares/genética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteína Proto-Oncogênica N-MycRESUMO
ABSTRACT: Relapse after anti-CD19 chimeric antigen receptor (CD19-CAR) occurs in a substantial proportion of patients with lymphoid malignancies. We assessed the potential benefits of co-administering CD20-targeting bispecific antibodies (CD20-BsAbs) with CD19-CAR T cells with the aim of enhancing immunotherapeutic efficacy. Addition of CD20-BsAbs to cocultures of CD19-CARs and primary samples of B-cell malignancies, comprising malignant B cells and endogenous T cells, significantly improved killing of malignant cells and enhanced the expansion of both endogenous T cells and CD19-CAR T cells. In an immunocompetent mouse model of chronic lymphocytic leukemia, relapse after initial treatment response frequently occurred after CD19-CAR T-cell monotherapy. Additional treatment with CD20-BsAbs significantly enhanced the treatment response and led to improved eradication of malignant cells. Higher efficacy was accompanied by improved T-cell expansion with CD20-BsAb administration and led to longer survival with 80% of the mice being cured with no detectable malignant cell population within 8 weeks of therapy initiation. Collectively, our in vitro and in vivo data demonstrate enhanced therapeutic efficacy of CD19-CAR T cells when combined with CD20-BsAbs in B-cell malignancies. Activation and proliferation of both infused CAR T cells and endogenous T cells may contribute to improved disease control.
Assuntos
Anticorpos Biespecíficos , Antígenos CD19 , Antígenos CD20 , Imunoterapia Adotiva , Leucemia Linfocítica Crônica de Células B , Animais , Camundongos , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/terapia , Leucemia Linfocítica Crônica de Células B/patologia , Humanos , Antígenos CD19/imunologia , Antígenos CD20/imunologia , Anticorpos Biespecíficos/uso terapêutico , Imunoterapia Adotiva/métodos , Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Brain tumors are the leading cause of cancer-related death in children. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of pediatric brain cancers are limited and hard to establish. We present a protocol that enables efficient generation, expansion, and biobanking of pediatric brain cancer organoids. Utilizing our protocol, we have established patient-derived organoids (PDOs) from ependymomas, medulloblastomas, low-grade glial tumors, and patient-derived xenograft organoids (PDXOs) from medulloblastoma xenografts. PDOs and PDXOs recapitulate histological features, DNA methylation profiles, and intratumor heterogeneity of the tumors from which they were derived. We also showed that PDOs can be xenografted. Most interestingly, when subjected to the same routinely applied therapeutic regimens, PDOs respond similarly to the patients. Taken together, our study highlights the potential of PDOs and PDXOs for research and translational applications for personalized medicine.
Assuntos
Bancos de Espécimes Biológicos , Neoplasias Encefálicas , Humanos , Criança , Xenoenxertos , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/patologia , Organoides/patologiaRESUMO
Glioblastoma is the most aggressive brain tumor in adults. Treatment failure is predominantly caused by its high invasiveness and its ability to induce a supportive microenvironment. As part of this, a major role for tumor-associated macrophages/microglia (TAMs) in glioblastoma development was recognized. Phospholipids are important players in various fundamental biological processes, including tumor-stroma crosstalk, and the bioactive lipid sphingosine-1-phosphate (S1P) has been linked to glioblastoma cell proliferation, invasion, and survival. Despite the urgent need for better therapeutic approaches, novel strategies targeting sphingolipids in glioblastoma are still poorly explored. Here, we showed that higher amounts of S1P secreted by glioma cells are responsible for an active recruitment of TAMs, mediated by S1P receptor (S1PR) signaling through the modulation of Rac1/RhoA. This resulted in increased infiltration of TAMs in the tumor, which, in turn, triggered their pro-tumorigenic phenotype through the inhibition of NFkB-mediated inflammation. Gene set enrichment analyses showed that such an anti-inflammatory microenvironment correlated with shorter survival of glioblastoma patients. Inhibition of S1P restored a pro-inflammatory phenotype in TAMs and resulted in increased survival of tumor-bearing mice. Taken together, our results establish a crucial role for S1P in fine-tuning the crosstalk between glioma and infiltrating TAMs, thus pointing to the S1P-S1PR axis as an attractive target for glioma treatment.
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Background: Inhibition of the sonic hedgehog (SHH) pathway with Smoothened (SMO) inhibitors is a promising treatment strategy in SHH-activated medulloblastoma, especially in adult patients. However, the problem is that tumors frequently acquire resistance to the treatment. To understand the underlying resistance mechanisms and to find ways to overcome the resistance, preclinical models that became resistant to SMO inhibition are needed. Methods: To induce SMO inhibitor resistant tumors, we have treated a patient-derived xenograft (PDX) model of SHH medulloblastoma, sensitive to SMO inhibition, with 20 mg/kg Sonidegib using an intermitted treatment schedule. Vehicle-treated and resistant models were subjected to whole-genome and RNA sequencing for molecular characterization and target engagement. In vitro drug screens (76 drugs) were performed using Sonidegib-sensitive and -resistant lines to find other drugs to target the resistant lines. One of the top hits was then validated in vivo. Results: Nine independent Sonidegib-resistant PDX lines were generated. Molecular characterization of the resistant models showed that eight models developed missense mutations in SMO and one gained an inactivating point mutation in MEGF8, which acts downstream of SMO as a repressor in the SHH pathway. The in vitro drug screen with Sonidegib-sensitive and -resistant lines identified good efficacy for Selinexor in the resistant line. Indeed, in vivo treatment with Selinexor revealed that it is more effective in resistant than in sensitive models. Conclusions: We report the first human SMO inhibitor resistant medulloblastoma PDX models, which can be used for further preclinical experiments to develop the best strategies to overcome the resistance to SMO inhibitors in patients.
RESUMO
T cell exhaustion limits anti-tumor immunity and responses to immunotherapy. Here, we explored the microenvironmental signals regulating T cell exhaustion using a model of chronic lymphocytic leukemia (CLL). Single-cell analyses identified a subset of PD-1hi, functionally impaired CD8+ T cells that accumulated in secondary lymphoid organs during disease progression and a functionally competent PD-1int subset. Frequencies of PD-1int TCF-1+ CD8+ T cells decreased upon Il10rb or Stat3 deletion, leading to accumulation of PD-1hi cells and accelerated tumor progression. Mechanistically, inhibition of IL-10R signaling altered chromatin accessibility and disrupted cooperativity between the transcription factors NFAT and AP-1, promoting a distinct NFAT-associated program. Low IL10 expression or loss of IL-10R-STAT3 signaling correlated with increased frequencies of exhausted CD8+ T cells and poor survival in CLL and in breast cancer patients. Thus, balance between PD-1hi, exhausted CD8+ T cells and functional PD-1int TCF-1+ CD8+ T cells is regulated by cell-intrinsic IL-10R signaling, with implications for immunotherapy.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Imunoterapia/métodos , Leucemia Linfocítica Crônica de Células B/imunologia , Receptores de Interleucina-10/metabolismo , Subpopulações de Linfócitos T/imunologia , Animais , Linhagem Celular Tumoral , Células Cultivadas , Microambiente Celular , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Humanos , Imunidade , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição NFATC/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Interleucina-10/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Fator de Transcrição AP-1/metabolismoRESUMO
BACKGROUND: Medulloblastomas with chromothripsis developing in children with Li-Fraumeni Syndrome (germline TP53 mutations) are highly aggressive brain tumors with dismal prognosis. Conventional photon radiotherapy and DNA-damaging chemotherapy are not successful for these patients and raise the risk of secondary malignancies. We hypothesized that the pronounced homologous recombination deficiency in these tumors might offer vulnerabilities that can be therapeutically utilized in combination with high linear energy transfer carbon ion radiotherapy. METHODS: We tested high-precision particle therapy with carbon ions and protons as well as topotecan with or without PARP inhibitor in orthotopic primary and matched relapsed patient-derived xenograft models. Tumor and normal tissue underwent longitudinal morphological MRI, cellular (markers of neurogenesis and DNA damage-repair), and molecular characterization (whole-genome sequencing). RESULTS: In the primary medulloblastoma model, carbon ions led to complete response in 79% of animals irrespective of PARP inhibitor within a follow-up period of 300 days postirradiation, as detected by MRI and histology. No sign of neurologic symptoms, impairment of neurogenesis or in-field carcinogenesis was detected in repair-deficient host mice. PARP inhibitors further enhanced the effect of proton irradiation. In the postradiotherapy relapsed tumor model, median survival was significantly increased after carbon ions (96 days) versus control (43 days, P < .0001). No major change in the clonal composition was detected in the relapsed model. CONCLUSION: The high efficacy and favorable toxicity profile of carbon ions warrants further investigation in primary medulloblastomas with chromothripsis. Postradiotherapy relapsed medulloblastomas exhibit relative resistance compared to treatment-naïve tumors, calling for exploration of multimodal strategies.
Assuntos
Neoplasias Cerebelares , Cromotripsia , Radioterapia com Íons Pesados , Síndrome de Li-Fraumeni , Meduloblastoma , Animais , Carbono , Neoplasias Cerebelares/tratamento farmacológico , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/radioterapia , Humanos , Meduloblastoma/tratamento farmacológico , Meduloblastoma/radioterapia , CamundongosRESUMO
Diffuse intrinsic pontine glioma (DIPG) is an aggressive childhood tumor of the brainstem with currently no curative treatment available. The vast majority of DIPGs carry a histone H3 mutation leading to a lysine 27-to-methionine exchange (H3K27M). We engineered human induced pluripotent stem cells (iPSCs) to carry an inducible H3.3-K27M allele in the endogenous locus and studied the effects of the mutation in different disease-relevant neural cell types. H3.3-K27M upregulated bivalent promoter-associated developmental genes, producing diverse outcomes in different cell types. While being fatal for iPSCs, H3.3-K27M increased proliferation in neural stem cells (NSCs) and to a lesser extent in oligodendrocyte progenitor cells (OPCs). Only NSCs gave rise to tumors upon induction of H3.3-K27M and TP53 inactivation in an orthotopic xenograft model recapitulating human DIPGs. In NSCs, H3.3-K27M leads to maintained expression of stemness and proliferative genes and a premature activation of OPC programs that together may cause tumor initiation.
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Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/parasitologia , Glioma/genética , Glioma/patologia , Histonas/genética , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Neurais/patologia , Animais , Linhagem Celular , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCIDRESUMO
Medulloblastoma is a malignant childhood brain tumor arising from the developing cerebellum. In Sonic Hedgehog (SHH) subgroup medulloblastoma, aberrant activation of SHH signaling causes increased proliferation of granule neuron progenitors (GNPs), and predisposes these cells to tumorigenesis. A second, cooperating genetic hit is often required to push these hyperplastic cells to malignancy and confer mutation-specific characteristics associated with oncogenic signaling. Somatic loss-of-function mutations of the transcriptional corepressor BCOR are recurrent and enriched in SHH medulloblastoma. To investigate BCOR as a putative tumor suppressor, we used a genetically engineered mouse model to delete exons 9/10 of Bcor (BcorΔE9-10 ) in GNPs during development. This mutation leads to reduced expression of C-terminally truncated BCOR (BCORΔE9-10). While BcorΔE9-10 alone did not promote tumorigenesis or affect GNP differentiation, BcorΔE9-10 combined with loss of the SHH receptor gene Ptch1 resulted in fully penetrant medulloblastomas. In Ptch1+/- ;BcorΔE9-10 tumors, the growth factor gene Igf2 was aberrantly up-regulated, and ectopic Igf2 overexpression was sufficient to drive tumorigenesis in Ptch1+/- GNPs. BCOR directly regulates Igf2, likely through the PRC1.1 complex; the repressive histone mark H2AK119Ub is decreased at the Igf2 promoter in Ptch1+/- ;BcorΔE9-10 tumors. Overall, our data suggests that BCOR-PRC1.1 disruption leads to Igf2 overexpression, which transforms preneoplastic cells to malignant tumors.
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Neoplasias Cerebelares/genética , Regulação Neoplásica da Expressão Gênica/genética , Proteínas Hedgehog/metabolismo , Meduloblastoma/genética , Proteínas do Grupo Polycomb/metabolismo , Proteínas Repressoras/genética , Animais , Carcinogênese/genética , Modelos Animais de Doenças , Proteínas Hedgehog/genética , Humanos , Camundongos , Mutação , Receptor Patched-1/genética , Proteínas do Grupo Polycomb/genética , Proteínas Repressoras/metabolismo , Deleção de SequênciaRESUMO
Embryonal tumours with multilayered rosettes (ETMRs) are aggressive paediatric embryonal brain tumours with a universally poor prognosis1. Here we collected 193 primary ETMRs and 23 matched relapse samples to investigate the genomic landscape of this distinct tumour type. We found that patients with tumours in which the proposed driver C19MC2-4 was not amplified frequently had germline mutations in DICER1 or other microRNA-related aberrations such as somatic amplification of miR-17-92 (also known as MIR17HG). Whole-genome sequencing revealed that tumours had an overall low recurrence of single-nucleotide variants (SNVs), but showed prevalent genomic instability caused by widespread occurrence of R-loop structures. We show that R-loop-associated chromosomal instability can be induced by the loss of DICER1 function. Comparison of primary tumours and matched relapse samples showed a strong conservation of structural variants, but low conservation of SNVs. Moreover, many newly acquired SNVs are associated with a mutational signature related to cisplatin treatment. Finally, we show that targeting R-loops with topoisomerase and PARP inhibitors might be an effective treatment strategy for this deadly disease.
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MicroRNAs/genética , Neoplasias Embrionárias de Células Germinativas/genética , RNA Helicases DEAD-box/genética , DNA Topoisomerases Tipo I/genética , Humanos , Mutação , Neoplasias Embrionárias de Células Germinativas/diagnóstico , Inibidores de Poli(ADP-Ribose) Polimerases , Poli(ADP-Ribose) Polimerases/genética , Polimorfismo de Nucleotídeo Único , RNA Longo não Codificante , Recidiva , Ribonuclease III/genéticaRESUMO
YAP1 fusion-positive supratentorial ependymomas predominantly occur in infants, but the molecular mechanisms of oncogenesis are unknown. Here we show YAP1-MAMLD1 fusions are sufficient to drive malignant transformation in mice, and the resulting tumors share histo-molecular characteristics of human ependymomas. Nuclear localization of YAP1-MAMLD1 protein is mediated by MAMLD1 and independent of YAP1-Ser127 phosphorylation. Chromatin immunoprecipitation-sequencing analyses of human YAP1-MAMLD1-positive ependymoma reveal enrichment of NFI and TEAD transcription factor binding site motifs in YAP1-bound regulatory elements, suggesting a role for these transcription factors in YAP1-MAMLD1-driven tumorigenesis. Mutation of the TEAD binding site in the YAP1 fusion or repression of NFI targets prevents tumor induction in mice. Together, these results demonstrate that the YAP1-MAMLD1 fusion functions as an oncogenic driver of ependymoma through recruitment of TEADs and NFIs, indicating a rationale for preclinical studies to block the interaction between YAP1 fusions and NFI and TEAD transcription factors.
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Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias Encefálicas/metabolismo , Carcinogênese/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ependimoma/metabolismo , Fatores de Transcrição NFI/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Carcinogênese/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Proteínas de Ligação a DNA/genética , Ependimoma/genética , Ependimoma/patologia , Células HEK293 , Humanos , Camundongos , Fatores de Transcrição NFI/genética , Células NIH 3T3 , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Proteínas Nucleares/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAPRESUMO
Glioblastomas strongly invade the brain by infiltrating into the white matter along myelinated nerve fiber tracts even though the myelin protein Nogo-A prevents cell migration by activating inhibitory RhoA signaling. The mechanisms behind this long-known phenomenon remained elusive so far, precluding a targeted therapeutic intervention. This study demonstrates that the prevalent activation of AKT in gliomas increases the ER protein-folding capacity and enables tumor cells to utilize a side effect of RhoA activation: the perturbation of the IRE1α-mediated decay of SPARC mRNA. Once translation is initiated, glioblastoma cells rapidly secrete SPARC to block Nogo-A from inhibiting migration via RhoA. By advanced ultramicroscopy for studying single-cell invasion in whole, undissected mouse brains, we show that gliomas require SPARC for invading into white matter structures. SPARC depletion reduces tumor dissemination that significantly prolongs survival and improves response to cytostatic therapy. Our finding of a novel RhoA-IRE1 axis provides a druggable target for interfering with SPARC production and underscores its therapeutic value.
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Neoplasias Encefálicas/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Proteínas de Neoplasias/fisiologia , Proteínas Nogo/biossíntese , Osteonectina/biossíntese , Biossíntese de Proteínas , Substância Branca/patologia , Proteína rhoA de Ligação ao GTP/fisiologia , Animais , Ligação Competitiva , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Invasividade Neoplásica , Proteínas Nogo/genética , Osteonectina/genética , Domínios Proteicos , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Receptores de Esfingosina-1-Fosfato/fisiologia , Células Tumorais Cultivadas , Substância Branca/metabolismoRESUMO
Brain tumors are the leading cause of cancer-related death in children. Genomic studies have provided insights into molecular subgroups and oncogenic drivers of pediatric brain tumors that may lead to novel therapeutic strategies. To evaluate new treatments, better preclinical models adequately reflecting the biological heterogeneity are needed. Through the Children's Oncology Group ACNS02B3 study, we have generated and comprehensively characterized 30 patient-derived orthotopic xenograft models and seven cell lines representing 14 molecular subgroups of pediatric brain tumors. Patient-derived orthotopic xenograft models were found to be representative of the human tumors they were derived from in terms of histology, immunohistochemistry, gene expression, DNA methylation, copy number, and mutational profiles. In vivo drug sensitivity of targeted therapeutics was associated with distinct molecular tumor subgroups and specific genetic alterations. These models and their molecular characterization provide an unprecedented resource for the cancer community to study key oncogenic drivers and to evaluate novel treatment strategies.
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Bancos de Espécimes Biológicos , Neoplasias Encefálicas/patologia , Imuno-Histoquímica , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Linhagem Celular Tumoral , Criança , Pré-Escolar , Metilação de DNA/genética , Feminino , Genômica , Humanos , Masculino , Camundongos , Mutação , PediatriaRESUMO
BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR) is a rare and aggressive embryonal brain tumor that solely occurs in infants and young children and has only recently been recognized as a separate brain tumor entity in the World Health Organization classification for CNS tumors. Patients have a very dismal prognosis with a median survival of 12 months upon diagnosis despite aggressive treatment. The aim of this study was to develop novel treatment regimens in a preclinical drug screen in order to inform potentially more active clinical trial protocols. METHODS: We have carried out an in vitro and in vivo drug screen using the ETMR cell line BT183 and its xenograft model. Furthermore, we have generated the first patient-derived xenograft (PDX) model for ETMR and evaluated our top drug candidates in an in vitro drug screen using this model. RESULTS: BT183 cells are very sensitive to the topoisomerase inhibitors topotecan and doxorubicin, to the epigenetic agents decitabine and panobinostat, to actinomycin D, and to targeted drugs such as the polo-like kinase 1 (PLK1) inhibitor volasertib, the aurora kinase A inhibitor alisertib, and the mammalian target of rapamycin (mTOR) inhibitor MLN0128. In xenograft mice, monotherapy with topotecan, volasertib, and actinomycin D led to a temporary response in tumor growth and a significant increase in survival. Finally, using multi-agent treatment regimens of topotecan or doxorubicin combined with methotrexate and vincristine, the response in tumor growth and survival was further increased compared with mice receiving single treatments. CONCLUSIONS: We have identified several promising candidates for combination therapies in future clinical trials for ETMR patients.