Scientific Publications

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  • Results Per Page

14 Results

2022

Current studies and future directions for medulloblastoma: A review from the pacific pediatric neuro-oncology consortium (PNOC) disease working group

Cooney T, Lindsay H, Leary S, Wechsler-Reya R.

Neoplasia. 2022 Dec 11;35:100861. doi: 10.1016/j.neo.2022.100861. Online ahead of print. NO ABSTRACT PMID:36516489 DOI:10.1016/j.neo.2022.100861

December 11, 2022
Neuro-Oncology

Characterization of an RNA binding protein interactome reveals a context-specific post-transcriptional landscape of MYC-amplified medulloblastoma

Kameda-Smith MM, Zhu H, Luo EC, Suk Y, Xella A, Yee B, Chokshi C, Xing S, Tan F, Fox RG, Adile AA, Bakhshinyan D, Brown K, Gwynne WD, Subapanditha M, Miletic P, Picard D, Burns I, Moffat J, Paruch K, Fleming A, Hope K, Provias JP, Remke M, Lu Y, Reya T, Venugopal C, Reimand J, Wechsler-Reya RJ, Yeo GW, Singh SK.

Nat Commun. 2022 Dec 6;13(1):7506. doi: 10.1038/s41467-022-35118-3. NO ABSTRACT PMID:36473869 DOI:10.1038/s41467-022-35118-3

December 6, 2022
Neuro-Oncology

N-myc mediated translation control is a therapeutic vulnerability in medulloblastoma

Kuzuoglu-Ozturk D, Aksoy O, Schmidt C, Lea R, Larson JD, Phelps RRL, Nasholm N, Holt M, Contreras A, Huang M, Wong-Michalak S, Shao H, Wechsler-Reya R, Phillips JJ, Gestwicki JE, Ruggero D, Weiss WA.

Cancer Res. 2022 Oct 20:CAN-22-0945. doi: 10.1158/0008-5472.CAN-22-0945. Online ahead of print. ABSTRACT Deregulation of N-myc is a leading cause of malignant brain tumors in children. To target N-myc-driven medulloblastoma, most research has focused on identifying genomic alterations or on the analysis of the medulloblastoma transcriptome. Here, we have broadly characterized the translatome of medulloblastoma and shown that N-myc unexpectedly drives selective translation of transcripts that promote protein homeostasis. Cancer cells are constantly exposed to proteotoxic stress associated with alterations in protein production or folding. It remains poorly understood how cancers cope with proteotoxic stress to promote their growth. Here, our data unexpectedly revealed that N-myc regulates the expression of specific components (~5%) of the protein folding machinery at the translational level through the major cap binding protein, eukaryotic initiation factor eIF4E. Reducing eIF4E levels in mouse models of medulloblastoma blocked tumorigenesis. Importantly, targeting Hsp70, a protein folding chaperone translationally regulated by N-myc, suppressed tumor growth in mouse and human medulloblastoma xenograft models. These findings reveal a previously hidden molecular program that promotes medulloblastoma formation and identify new therapies that may have impact in the clinic. PMID:36264168 DOI:10.1158/0008-5472.CAN-22-0945

October 20, 2022
Neuro-Oncology

Safety and efficacy of intraventricular immunovirotherapy with oncolytic HSV-1 for CNS cancers

Kang KD, Bernstock JD, Totsch SK, Gary SE, Rocco A, Nan L, Li R, Etminan T, Han X, Beierle EA, Eisemann T, Wechsler-Reya RJ, Bae S, Whitley R, Gillespie GY, Markert JM, Friedman GK.

Clin Cancer Res. 2022 Oct 14:CCR-22-1382. doi: 10.1158/1078-0432.CCR-22-1382. Online ahead of print. ABSTRACT PURPOSE: Oncolytic virotherapy with herpes simplex virus-1 (HSV) has shown promise for treatment of pediatric and adult brain tumors; however, completed and ongoing clinical trials have utilized intratumoral/peritumoral oncolytic HSV (oHSV) inoculation due intraventricular/intrathecal toxicity concerns. Intratumoral delivery requires an invasive neurosurgical procedure, limits repeat injections, and precludes direct targeting of metastatic and leptomeningeal disease. To address these limitations, we determined causes of toxicity from intraventricular oHSV and established methods for mitigating toxicity to treat disseminated brain tumors in mice. EXPERIMENTAL DESIGN: HSV-sensitive CBA/J mice received intraventricular vehicle, inactivated oHSV, or treatment doses (1×107 plaque-forming units) of oHSV, and toxicity was assessed by weight loss and immunohistochemistry. Protective strategies to reduce oHSV toxicity, including intraventricular low-dose oHSV or interferon inducer polyinosinic-polycytidylic acid (poly I:C) prior to oHSV treatment dose, were evaluated and then utilized to assess intraventricular oHSV treatment of multiple models of disseminated CNS disease. RESULTS: A standard treatment dose of intraventricular oHSV damaged ependymal cells via virus replication and induction of CD8+ T cells, whereas vehicle or inactivated virus resulted in no toxicity. Subsequent doses of intraventricular oHSV caused little additional toxicity. Interferon induction with phosphorylation of eukaryotic initiation factor-2α (eIF2α) via intraventricular pretreatment with low-dose oHSV or poly I:C mitigated ependyma toxicity. This approach enabled safe delivery of multiple treatment doses of clinically relevant oHSV G207 and prolonged survival in disseminated brain tumor models. CONCLUSIONS: Toxicity from intraventricular oHSV can be mitigated resulting in therapeutic benefit. These data support clinical translation of intraventricular G207. PMID:36239623 DOI:10.1158/1078-0432.CCR-22-1382

October 14, 2022
Neuro-Oncology

Dormant SOX9-positive cells facilitate MYC-driven recurrence of medulloblastoma

Borgenvik A, Holmberg KO, Bolin S, Zhao M, Savov V, Rosén G, Hutter S, Garancher A, Suryo Rahmanto A, Bergström T, Olsen TK, Mainwaring OJ, Sattanino D, Verbaan AD, Rusert JM, Sundstrom A, Ballester Bravo M, Dang Y, Wenz AS, Richardson S, Fotaki G, Hill RM, Dubuc AM, Kalushkova A, Remke M, Cancer M, Jernberg-Wiklund H, Giraud G, Chen X, Taylor MD, Sangfelt O, Clifford SC, Schuller U, Wechsler-Reya RJ, Weishaupt H, Swartling FJ.

Cancer Res. 2022 Oct 11:CAN-22-2108. doi: 10.1158/0008-5472.CAN-22-2108. Online ahead of print. ABSTRACT Relapse is the leading cause of death in patients with medulloblastoma, the most common malignant pediatric brain tumor. A better understanding of the mechanisms underlying recurrence could lead to more effective therapies for targeting tumor relapses. Here, we observed that SOX9, a transcription factor and stem cell/glial fate marker, is limited to rare, quiescent cells in high-risk medulloblastoma with MYC amplification. In paired primary-recurrent patient samples, SOX9-positive cells accumulated in medulloblastoma relapses. SOX9 expression anti-correlated with MYC expression in murine and human medulloblastoma cells. However, SOX9-positive cells were plastic and could give rise to a MYC high state. To follow relapse at the single-cell level, an inducible dual Tet model of medulloblastoma was developed, in which MYC expression was redirected in vivo from treatment-sensitive bulk cells to dormant SOX9-positive cells using doxycycline treatment. SOX9 was essential for relapse initiation and depended on suppression of MYC activity to promote therapy resistance, epithelial-mesenchymal transition, and immune escape. p53 and DNA repair pathways were downregulated in recurrent tumors, while MGMT was upregulated. Recurrent tumor cells were found to be sensitive to treatment with an MGMT inhibitor and doxorubicin. These findings suggest that recurrence-specific targeting coupled with DNA repair inhibition comprises a potential therapeutic strategy in patients affected by medulloblastoma relapse. PMID:36219398 DOI:10.1158/0008-5472.CAN-22-2108

October 11, 2022
Neuro-Oncology

Development of GPC2-directed chimeric antigen receptors using mRNA for pediatric brain tumors

Foster JB, Griffin C, Rokita JL, Stern A, Brimley C, Rathi K, Lane MV, Buongervino SN, Smith T, Madsen PJ, Martinez D, Delaidelli A, Sorensen PH, Wechsler-Reya RJ, Karikó K, Storm PB, Barrett DM, Resnick AC, Maris JM, Bosse KR.

J Immunother Cancer. 2022 Sep;10(9):e004450. doi: 10.1136/jitc-2021-004450. ABSTRACT BACKGROUND: Pediatric brain tumors are the leading cause of cancer death in children with an urgent need for innovative therapies. Glypican 2 (GPC2) is a cell surface oncoprotein expressed in neuroblastoma for which targeted immunotherapies have been developed. This work aimed to characterize GPC2 expression in pediatric brain tumors and develop an mRNA CAR T cell approach against this target. METHODS: We investigated GPC2 expression across a cohort of primary pediatric brain tumor samples and cell lines using RNA sequencing, immunohistochemistry, and flow cytometry. To target GPC2 in the brain with adoptive cellular therapies and mitigate potential inflammatory neurotoxicity, we used optimized mRNA to create transient chimeric antigen receptor (CAR) T cells. We developed four mRNA CAR T cell constructs using the highly GPC2-specific fully human D3 single chain variable fragment for preclinical testing. RESULTS: We identified high GPC2 expression across multiple pediatric brain tumor types including medulloblastomas, embryonal tumors with multilayered rosettes, other central nervous system embryonal tumors, as well as definable subsets of highly malignant gliomas. We next validated and prioritized CAR configurations using in vitro cytotoxicity assays with GPC2-expressing neuroblastoma cells, where the light-to-heavy single chain variable fragment configurations proved to be superior. We expanded the testing of the two most potent GPC2-directed CAR constructs to GPC2-expressing medulloblastoma and high-grade glioma cell lines, showing significant GPC2-specific cell death in multiple models. Finally, biweekly locoregional delivery of 2-4 million GPC2-directed mRNA CAR T cells induced significant tumor regression in an orthotopic medulloblastoma model and significantly prolonged survival in an aggressive orthotopic thalamic diffuse midline glioma xenograft model. No GPC2-directed CAR T cell related neurologic or systemic toxicity was observed. CONCLUSION: Taken together, these data show that GPC2 is a highly differentially expressed cell surface protein on multiple malignant pediatric brain tumors that can be targeted safely with local delivery of mRNA CAR T cells, laying the framework for the clinical translation of GPC2-directed immunotherapies for pediatric brain tumors. PMID:36167467 | DOI:10.1136/jitc-2021-004450

September 27, 2022
Neuro-Oncology

“A novel serum extracellular vesicle protein signature to monitor glioblastoma tumor progression”

Tzaridis T, Weller J, Bachurski D, Shakeri F, Schaub C, Hau P, Buness A, Schlegel U, Steinbach JP, Seidel C, Goldbrunner R, Schäfer N, Wechsler-Reya RJ, Hallek M, Scheffler B, Glas M, Haeberle L, Herrlinger U, Coch C, Reiners KS, Hartmann G.

Int J Cancer. 2022 Aug 27. doi: 10.1002/ijc.34261. Online ahead of print. ABSTRACT Detection of tumor progression in patients with glioblastoma remains a major challenge. Extracellular vesicles (EVs) are potential biomarkers and can be detected in the blood of patients with glioblastoma. In this study, we evaluated the potential of serum-derived EVs from glioblastoma patients to serve as biomarker for tumor progression. EVs from serum of glioblastoma patients and healthy volunteers were separated by size exclusion chromatography and ultracentrifugation. EV markers were defined by using a proximity-extension assay and bead-based flow cytometry. Tumor progression was defined according to modified RANO criteria. EVs from the serum of glioblastoma patients (n=67) showed an upregulation of CD29, CD44, CD81, CD146, C1QA, and histone H3 as compared to serum EVs from healthy volunteers (p value range: <0.0001 – 0.08). For two independent cohorts of glioblastoma patients, we noted upregulation of C1QA, CD44, and histone H3 upon tumor progression, but not in patients with stable disease. In a multivariable logistic regression analysis, a combination of CD29, CD44, CD81, C1QA, and histone H3 correlated with RANO-defined tumor progression with an AUC of 0.76. Measurement of CD29, CD44, CD81, C1QA, and histone H3 in serum-derived EVs of glioblastoma patients, along with standard MRI assessment, has the potential to improve detection of true tumor progression and thus could be a useful biomarker for clinical decision making. PMID:36054558 | DOI:10.1002/ijc.34261

August 27, 2022
Neuro-Oncology

The long non-coding RNA SPRIGHTLY and its binding partner PTBP1 regulate exon 5 skipping of SMYD3 transcripts in group 4 medulloblastomas

Lee B, Katsushima K, Pokhrel R, Yuan M, Stapleton S, Jallo G, Wechsler-Reya RJ, Eberhart CG, Ray A, Perera RJ.

Neurooncol Adv. 2022 Aug 2;4(1):vdac120. doi: 10.1093/noajnl/vdac120. eCollection 2022 Jan-Dec. ABSTRACT BACKGROUND: Although some of the regulatory genes, signaling pathways, and gene regulatory networks altered in medulloblastomas (MB) are known, the roles of non-coding RNAs, particularly long non-coding RNAs (lncRNAs), are poorly described. Here we report that the lncRNA SPRIGHTLY (SPRY4-IT1) gene is upregulated in group 4 medulloblastoma (G4 MB). METHODS: SPRIGHTLY expression was assessed in MB subgroup patient-derived xenografts, cell lines, and patient samples. The effect of SPRIGHTLY hemizygous deletion on proliferation, invasion, apoptosis, and colony formation were assessed in vitro and on tumor growth in vivo. dChIRP pull-down assays were used to assess SPRIGHTLY-binding partners, confirmed by immunoprecipitation. SMYD3 ΔE5 transcripts were examined in cell lines and publicly available RNA-seq data. Pathway analysis was performed by phospho-kinase profiling and RNA-seq. RESULTS: CRISPR/Cas9 deletion of SPRIGHTLY reduced cell viability and invasion and increased apoptosis in G4 MB cell lines in vitro. SPRIGHTLY hemizygous-deleted G4 MB cells injected into mouse cerebellums produced smaller tumors than those derived from parental cells expressing both copies of SPRIGHTLY. SPRIGHTLY lncRNA bound to the intronic region of the SMYD3 pre-mRNA transcript. SPRIGHTLY also interacted with PTPB1 protein to regulate SMYD3 exon skipping to produce an aberrant protein. SPRIGHTLY-driven SMYD3 regulation enhanced the expression of EGFR pathway genes in G4 MB cell lines and activated cell coagulation/hemostasis-related gene expression, suggesting a novel oncogenic role in G4 MB. CONCLUSIONS: These results demonstrate the importance of SPRIGHTLY lncRNA as a promoter of G4 MB and the role of the SPRIGHTLY-SMYD3-PTPB1 axis as an important oncogenic regulator in MB. PMID:36267874 DOI:10.1093/noajnl/vdac120

August 2, 2022
Neuro-Oncology

Coming in from the cold: overcoming the hostile immune microenvironment of medulloblastoma

Eisemann T, Wechsler-Reya RJ. 

Genes Dev. 2022 May 1;36(9-10):514-532. doi: 10.1101/gad.349538.122. ABSTRACT Medulloblastoma is an aggressive brain tumor that occurs predominantly in children. Despite intensive therapy, many patients die of the disease, and novel therapies are desperately needed. Although immunotherapy has shown promise in many cancers, the low mutational burden, limited infiltration of immune effector cells, and immune-suppressive microenvironment of medulloblastoma have led to the assumption that it is unlikely to respond to immunotherapy. However, emerging evidence is challenging this view. Here we review recent preclinical and clinical studies that have identified mechanisms of immune evasion in medulloblastoma, and highlight possible therapeutic interventions that may give new hope to medulloblastoma patients and their families. PMID:35680424 | DOI:10.1101/gad.349538.122

May 1, 2022
Neuro-Oncology

Conventional Therapies Deplete Brain-Infiltrating Adaptive Immune Cells in a Mouse Model of Group 3 Medulloblastoma Implicating Myeloid Cells as Favorable Immunotherapy Targets

Abbas Z, George C, Ancliffe M, Howlett M, Jones AC, Kuchibhotla M, Wechsler-Reya RJ, Gottardo NG, Endersby R.

Front Immunol. 2022 Mar 3;13:837013. doi: 10.3389/fimmu.2022.837013. eCollection 2022. ABSTRACT Medulloblastoma is the most common childhood brain cancer. Mainstay treatments of radiation and chemotherapy have not changed in decades and new treatment approaches are crucial for the improvement of clinical outcomes. To date, immunotherapies for medulloblastoma have been unsuccessful, and studies investigating the immune microenvironment of the disease and the impact of current therapies are limited. Preclinical models that recapitulate both the disease and immune environment are essential for understanding immune-tumor interactions and to aid the identification of new and effective immunotherapies. Using an immune-competent mouse model of aggressive Myc-driven medulloblastoma, we characterized the brain immune microenvironment and changes induced in response to craniospinal irradiation, or the medulloblastoma chemotherapies cyclophosphamide or gemcitabine. The role of adaptive immunity in disease progression and treatment response was delineated by comparing survival outcomes in wildtype C57Bl/6J and in mice deficient in Rag1 that lack mature T and B cells. We found medulloblastomas in wildtype and Rag1-deficient mice grew equally fast, and that craniospinal irradiation and chemotherapies extended survival equally in wildtype and Rag1-deficient mice, suggesting that tumor growth and treatment response is independent of T and B cells. Medulloblastomas were myeloid dominant, and in wildtype mice, craniospinal irradiation and cyclophosphamide depleted T and B cells in the brain. Gemcitabine treatment was found to minimally alter the immune populations in the brain, resulting only in a depletion of neutrophils. Intratumorally, we observed an abundance of Iba1+ macrophages, and we show that CD45high cells comprise the majority of immune cells within these medulloblastomas but found that existing markers are insufficient to clearly delineate resident microglia from infiltrating macrophages. Ultimately, brain resident and peripheral macrophages dominate the brain and tumor microenvironment and are not depleted by standard-of-care medulloblastoma therapies. These populations therefore present a favorable target for immunotherapy in combination with front-line treatments. PMID:35309309 | PMC:PMC8928748 | DOI:10.3389/fimmu.2022.837013

March 3, 2022
Neuro-Oncology

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