bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2022‒07‒24
fourteen papers selected by
Oltea Sampetrean
Keio University

  1. Nat Commun. 2022 Jul 21. 13(1): 4214
      Glioblastoma multiforme (GBM) is an aggressive brain cancer with a poor prognosis and few treatment options. Here, building on the observation of elevated lactate (LA) in resected GBM, we develop biomimetic therapeutic nanoparticles (NPs) that deliver agents for LA metabolism-based synergistic therapy. Because our self-assembling NPs are encapsulated in membranes derived from glioma cells, they readily penetrate the blood-brain barrier and target GBM through homotypic recognition. After reaching the tumors, lactate oxidase in the NPs converts LA into pyruvic acid (PA) and hydrogen peroxide (H2O2). The PA inhibits cancer cell growth by blocking histones expression and inducing cell-cycle arrest. In parallel, the H2O2 reacts with the delivered bis[2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl] oxalate to release energy, which is used by the co-delivered photosensitizer chlorin e6 for the generation of cytotoxic singlet oxygen to kill glioma cells. Such a synergism ensures strong therapeutic effects against both glioma cell-line derived and patient-derived xenograft models.
  2. Neuro Oncol. 2022 Jul 22. pii: noac177. [Epub ahead of print]
      BACKGROUND: DNA methylation-based tumor classification allows an enhanced distinction into subgroups of glioblastoma. However, the clinical benefit of DNA methylation-based stratification of glioblastomas remains inconclusive.METHODS: Multicentric cohort study including 430 patients with newly diagnosed glioblastoma subjected to global DNA methylation profiling. Outcome measures included overall survival (OS), progression-free survival (PFS), prognostic relevance of EOR and MGMT promoter methylation status as well as surgical benefit for recurrent glioblastoma.
    RESULTS: 345 patients (80.2%) fulfilled the inclusion criteria. DNA methylation subclasses RTK I, RTK II, and mesenchymal (MES) revealed no significant survival differences (p = 0.06). 305 Patients receiving combined adjuvant therapy (RTK I: Ref.; RTK II: HR 0.9 [95% CI, 0.64-1.28]; p = 0.56; MES: 0.69 [0.47-1.02]; p = 0.06). RTK I (GTR/near GTR: Ref.; PR: HR 2.87 [95% CI, 1.36-6.08]; p < 0.01) or RTK II (GTR/near GTR: Ref.; PR: HR 5.09 [95% CI, 2.80-9.26]; p < 0.01) tumors who underwent gross-total resection (GTR) or near GTR had a longer OS and PFS than partially resected patients. The MES subclass showed no survival benefit for a maximized EOR (GTR/near GTR: Ref.; PR: HR 1.45 [95% CI, 0.68-3.09]; p = 0.33). Therapy response-predictive value of MGMT promoter methylation was evident for RTK I (HR 0.37 [95% CI, 0.19-0.71]; p < 0.01) and RTK II (HR 0.56 [95% CI, 0.34-0.91]; p = 0.02) but not the MES subclass (HR 0.52 [95% CI, 0.27-1.02]; p = 0.06). For local recurrence (n=112), re-resection conveyed a progression-to-overall survival (POS) benefit (p < 0.01), which was evident in RTK I (p = 0.03) and RTK II (p < 0.01) tumors, but not in MES tumors (p = 0.33).
    CONCLUSION: We demonstrate a survival benefit from maximized EOR for newly diagnosed and recurrent glioblastomas of the RTK I and RTK II but not the MES subclass. Hence, it needs to be debated whether the MES subclass should be treated with maximal surgical resection, especially when located in eloquent areas and at time of recurrence.
  3. Clin Cancer Res. 2022 Jul 18. pii: CCR-22-0444. [Epub ahead of print]
      PURPOSE: Liquid biopsy offers an attractive platform for non-invasive tumor diagnosis, prognostication and prediction of glioblastoma clinical outcomes. Prior studies report that 30-50% of GBM lesions characterized by EGFR amplification also harbor the EGFRvIII mutation.EXPERIMENTAL DESIGN: A novel digital droplet PCR (ddPCR) assay for high GC content amplicons was developed and optimized for sensitive detection of EGFRvIII in tumor tissue and circulating extracellular vesicle RNA (EV RNA) isolated from the plasma of glioma patients.
    RESULTS: Our optimized qPCR assay detected EGFRvIII mRNA in 81% (95% CI, 68% - 94%) of EGFR amplified glioma tumor tissue, indicating a higher than previously reported prevalence of EGFRvIII in glioma. Using the optimized ddPCR assay in discovery and blinded validation cohorts, we detected EGFRvIII mutation in 73% (95% CI, 64% - 82%) of patients with a specificity of 98% (95% CI, 87% - 100%), compared with qPCR tumor tissue analysis. Additionally, upon longitudinal monitoring in 4 patients, we report detection of EGFRvIII in the plasma of patients with different clinical outcomes, rising with tumor progression, and decreasing in response to treatment.
    CONCLUSION: This study demonstrates the feasibility of detecting EGFRvIII mutation in plasma using a highly sensitive and specific ddPCR assay. We also show a higher than previously reported EGFRvIII prevalence in glioma tumor tissue. Several features of the assay are favorable for clinical implementation for detection and monitoring of EGFRvIII positive tumors.
  4. Neurooncol Pract. 2022 Aug;9(4): 259-270
      Knowledge about inherited and acquired genetics of adult diffuse glioma has expanded significantly over the past decade. Genomewide association studies (GWAS) stratified by histologic subtype identified six germline variants that were associated specifically with glioblastoma (GBM) and 12 that were associated with lower grade glioma. A GWAS performed using the 2016 WHO criteria, stratifying patients by IDH mutation and 1p/19q codeletion (as well as TERT promoter mutation), discovered that many of the known variants are associated with specific WHO glioma subtypes. In addition, the GWAS stratified by molecular group identified two additional novel regions: variants in D2HGDH that were associated with tumors that had an IDH mutation and a variant near FAM20C that was associated with tumors that had both IDH mutation and 1p/19q codeletion. The results of these germline associations have been used to calculate polygenic risk scores, from which to estimate relative and absolute risk of overall glioma and risk of specific glioma subtypes. We will review the concept of polygenic risk models and their potential clinical utility, as well as discuss the published adult diffuse glioma polygenic risk models. To date, these prior genetic studies have been done on European populations. Using the published glioma polygenic risk model, we show that the genetic associations published to date do not generalize across genetic ancestries, demonstrating that genetic studies need to be done on more diverse populations.
    Keywords:  genetics; glioma; polygenic; risk; variants
  5. Neuro Oncol. 2022 Jul 21. pii: noac179. [Epub ahead of print]
      BACKGROUND: The loss of neurogenic tumor suppressor microRNAs miR-124, miR-128, and miR-137 is associated with glioblastoma's undifferentiated state. Most of their impact comes via the repression of a network of oncogenic transcription factors. We conducted a high-throughput functional siRNA screen in glioblastoma cells and identify E74 like ETS transcription factor 4 (ELF4) as the leading contributor to oncogenic phenotypes.METHODS: In vitro and in vivo assays were used to assess ELF4 impact on cancer phenotypes. We characterized ELF4's mechanism of action via genomic and lipidomic analyses. A MAPK reporter assay verified ELF4's impact on MAPK signaling, and qRT-PCR and western blotting were used to corroborate ELF4 regulatory role on most relevant target genes.
    RESULTS: ELF4 knockdown resulted in significant proliferation delay and apoptosis in GBM cells and long-term growth delay and morphological changes in glioma stem cells (GSCs). Transcriptomic analyses revealed that ELF4 controls two interlinked pathways: 1) Receptor tyrosine kinase signaling, and 2) Lipid dynamics. ELF4 modulation directly affected Receptor Tyrosine Kinase (RTK) signaling, as mitogen-activated protein kinase (MAPK) activity was dependent upon ELF4 levels. Furthermore, shotgun lipidomics revealed that ELF4 depletion disrupted several phospholipid classes, highlighting ELF4's importance in lipid homeostasis.
    CONCLUSIONS: We found that ELF4 is critical for the GBM cell identity by controlling genes of two dependent pathways: RTK signaling (SRC, PTK2B, TNK2) and lipid dynamics (LRP1, APOE, ABCA7, PLA2G6, and PITPNM2). Our data suggests that targeting these two pathways simultaneously may be therapeutically beneficial to GBM patients.
    Keywords:  ELF4; Glioblastoma; Lipid Dynamics; RTK signaling; miRNA-Transcription Factor Networks
  6. JCI Insight. 2022 Jul 19. pii: e148717. [Epub ahead of print]
      Key molecular regulators of acquired radiation resistance in recurrent glioblastoma (GBM) are largely unknown with a dearth of accurate pre-clinical models. To address this, we generated 8 GBM patient-derived xenograft (PDX) models of acquired radiation therapy-selected (RTS) resistance compared with same-patient, treatment naïve (RTU) PDX. These unique models mimic the longitudinal evolution of patient recurrent tumors following serial radiation therapy. Indeed, while whole exome sequencing confirmed retention of major genomic alterations in the RTS lines, we did detect a chromosome 12q14 amplification that is associated with clinical GBM recurrence in two RTS models. A novel bioinformatics pipeline was applied to analyze phenotypic, transcriptomic and kinomic alterations, which identified long non-coding RNAs (lncRNAs) and targetable, PDX-specific kinases. We observed differential transcriptional enrichment of DNA damage repair (DDR) pathways in our RTS models which correlated with several lncRNAs. Global kinomic profiling separated RTU and RTS models, but pairwise analyses indicated that there are multiple molecular routes to acquired radiation-resistance. RTS model-specific kinases were identified and targeted with clinically relevant small molecule inhibitors (SMIs). This unique cohort of in vivo radiation therapy-selected patient-derived models will enable future preclinical therapeutic testing to help overcome the treatment resistance seen in GBM patients.
    Keywords:  Brain cancer; Noncoding RNAs; Oncology; Radiation therapy
  7. Proc Natl Acad Sci U S A. 2022 Jul 19. 119(29): e2202015119
      Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations; however, the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here, we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). Using our autochthonous mouse models, we found that Sox9 suppresses HGG growth and expands associated H3K27ac states, while promoting ZFTA-RELA (ZRFUS) EPN growth and diminishing H3K27ac states. These contrasting roles for Sox9 correspond with protein interactions with histone deacetylating complexes in HGG and an association with the ZRFUS oncofusion in EPN. Mechanistic studies revealed extensive Sox9 and ZRFUS promoter co-occupancy, indicating functional synergy in promoting EPN tumorigenesis. Together, our studies demonstrate how epigenomic states are differentially regulated in distinct subtypes of brain tumors, while revealing divergent roles for Sox9 in HGG and EPN tumorigenesis.
    Keywords:  ependymoma; epigenetics; high-grade glioma; histone; transcription
  8. Nat Commun. 2022 Jul 21. 13(1): 4119
      Here, we report the results of a phase I/II, single-arm study (UMIN-CTR Clinical Trial Registry UMIN000002661) assessing the safety (primary endpoint) of G47∆, a triple-mutated oncolytic herpes simplex virus type 1, in Japanese adults with recurrent/progressive glioblastoma despite radiation and temozolomide therapies. G47Δ was administered intratumorally at 3 × 108 pfu (low dose) or 1 × 109 pfu (set dose), twice to identical coordinates within 5-14 days. Thirteen patients completed treatment (low dose, n = 3; set dose, n = 10). Adverse events occurred in 12/13 patients. The most common G47Δ-related adverse events were fever, headache and vomiting. Secondary endpoint was the efficacy. Median overall survival was 7.3 (95%CI 6.2-15.2) months and the 1-year survival rate was 38.5%, both from the last G47∆ administration. Median progression-free survival was 8 (95%CI 7-34) days from the last G47∆ administration, mainly due to immediate enlargement of the contrast-enhanced area of the target lesion on MRI. Three patients survived >46 months. One complete response (low dose) and one partial response (set dose) were seen at 2 years. Based on biopsies, post-administration MRI features (injection site contrast-enhancement clearing and entire tumor enlargement) likely reflected tumor cell destruction via viral replication and lymphocyte infiltration towards tumor cells, the latter suggesting the mechanism for "immunoprogression" characteristic to this therapy. This study shows that G47Δ is safe for treating recurrent/progressive glioblastoma and warrants further clinical development.
  9. Neuro Oncol. 2022 Jul 15. pii: noac173. [Epub ahead of print]
      BACKGROUND: Approximately 50% of newly diagnosed glioblastomas (GBMs) harbor EGFR gene amplification (EGFR-amp). Preclinical and early phase clinical data suggested efficacy of depatuxizumab mafodotin (depatux-m), an antibody drug conjugate (ADC) comprised of a monoclonal antibody that binds activated EGFR (overexpressed wild-type and EGFRvIII-mutant) linked to a microtubule-inhibitor toxin in EGFR-amp GBMs.METHODS: In this phase III trial, adults with centrally confirmed, EGFR-amp, newly diagnosed GBM were randomized 1:1 to radiotherapy, temozolomide, and depatux-m/placebo. Corneal epitheliopathy (CE) was treated with a combination of protocol-specified prophylactic and supportive measures. There was 85% power to detect a Hazard Ratio (HR) ≤0.75 for survival (OS) at a 2.5% one-sided significance level (i.e., traditional two-sided p ≤0.05) by log-rank testing.
    RESULTS: There were 639 randomized patients (median age 60, range 22-84; 62% men). Pre-specified interim analysis found no improvement in OS for depatux-m over placebo (median 18.9 vs. 18.7 months, HR 1.02, 95% CI 0.82-1.26, one-sided p= 0.63). Progression-free survival was longer for depatux-m than placebo (median 8.0 vs. 6.3 months; HR 0.84, 95% CI 0.70-1.01, p=0.029), particularly among those with EGFRvIII mutant (median 8.3 vs. 5.9 months, HR 0.72, 95% CI 0.56-0.93, p=0.002 one sided) or MGMT unmethylated (HR 0.77, 95% CI 0.61-0.97; p=0.012 one-sided) tumors but without an OS improvement. CE occurred in 94% of depatux-m treated patients (61% grade 3-4), causing 12% to discontinue.
    CONCLUSIONS: Interim analysis demonstrated no OS benefit for depatux-m in treating EGFR-amp newly diagnosed GBM. No new important safety risks were identified.
    Keywords:  EGFR; Glioblastoma; antibody drug conjugate; depatuxizumab-mafodotin; phase III
  10. Sci Transl Med. 2022 Jul 13. 14(653): eabl4106
      Glioblastoma multiforme (GBM) is the most common and lethal brain tumor characterized by a strongly immunosuppressive tumor microenvironment (TME) that represents a barrier also for the development of effective immunotherapies. The possibility to revert this hostile TME by immunoactivating cytokines is hampered by the severe toxicity associated with their systemic administration. Here, we exploited a lentiviral vector-based platform to engineer hematopoietic stem cells ex vivo with the aim of releasing, via their tumor-infiltrating monocyte/macrophage progeny, interferon-α (IFN-α) or interleukin-12 (IL-12) at the tumor site with spatial and temporal selectivity. Taking advantage of a syngeneic GBM mouse model, we showed that inducible release of IFN-α within the TME achieved robust tumor inhibition up to eradication and outperformed systemic treatment with the recombinant protein in terms of efficacy, tolerability, and specificity. Single-cell RNA sequencing of the tumor immune infiltrate revealed reprogramming of the immune microenvironment toward a proinflammatory and antitumoral state associated with loss of a macrophage subpopulation shown to be associated with poor prognosis in human GBM. The spatial and temporal control of IL-12 release was critical to overcome an otherwise lethal hematopoietic toxicity while allowing to fully exploit its antitumor activity. Overall, our findings demonstrate a potential therapeutic approach for GBM and set the bases for a recently launched first-in-human clinical trial in patients with GBM.
  11. Nat Commun. 2022 Jul 19. 13(1): 4178
      Human cerebral cancers are known to contain cell types resembling the varying stages of neural development. However, the basis of this association remains unclear. Here, we map the development of mouse cerebrum across the developmental time-course, from embryonic day 12.5 to postnatal day 365, performing single-cell transcriptomics on >100,000 cells. By comparing this reference atlas to single-cell data from >100 glial tumours of the adult and paediatric human cerebrum, we find that tumour cells have an expression signature that overlaps with temporally restricted, embryonic radial glial precursors (RGPs) and their immediate sublineages. Further, we demonstrate that prenatal transformation of RGPs in a genetic mouse model gives rise to adult cerebral tumours that show an embryonic/juvenile RGP identity. Together, these findings implicate the acquisition of embryonic-like states in the genesis of adult glioma, providing insight into the origins of human glioma, and identifying specific developmental cell types for therapeutic targeting.
  12. Nat Med. 2022 Jul 21.
      This investigator-initiated, phase 2, single-arm trial primarily assessed the efficacy of G47∆, a triple-mutated, third-generation oncolytic herpes simplex virus type 1, in 19 adult patients with residual or recurrent, supratentorial glioblastoma after radiation therapy and temozolomide (UMIN-CTR Clinical Trial Registry UMIN000015995). G47Δ was administered intratumorally and repeatedly for up to six doses. The primary endpoint of 1-yr survival rate after G47∆ initiation was 84.2% (95% confidence interval, 60.4-96.6; 16 of 19). The prespecified endpoint was met and the trial was terminated early. Regarding secondary endpoints, the median overall survival was 20.2 (16.8-23.6) months after G47∆ initiation and 28.8 (20.1-37.5) months from the initial surgery. The most common G47∆-related adverse event was fever (17 of 19) followed by vomiting, nausea, lymphocytopenia and leukopenia. On magnetic resonance imaging, enlargement of and contrast-enhancement clearing within the target lesion repeatedly occurred after each G47∆ administration, which was characteristic to this therapy. Thus, the best overall response in 2 yr was partial response in one patient and stable disease in 18 patients. Biopsies revealed increasing numbers of tumor-infiltrating CD4+/CD8+ lymphocytes and persistent low numbers of Foxp3+ cells. This study showed a survival benefit and good safety profile, which led to the approval of G47∆ as the first oncolytic virus product in Japan.
  13. Clin Cancer Res. 2022 Jul 19. pii: CCR-22-0803. [Epub ahead of print]
      BACKGROUND: PNOC003 is a multi-center precision medicine trial for children and young adults with newly diagnosed diffuse intrinsic pontine glioma (DIPG).METHODS: Patients (3-25 years) were enrolled based on imaging consistent with DIPG. Biopsy tissue was collected for whole exome and mRNA sequencing. After radiation therapy (RT), patients were assigned up to four FDA-approved drugs based on molecular tumor board recommendations. H3K27M-mutant circulating tumor DNA (ctDNA) was longitudinally measured. Tumor tissue and matched primary cell lines were characterized using whole genome sequencing and DNA methylation profiling. When applicable, results were verified in an independent cohort from the Children's Brain Tumor Network (CBTN).
    RESULTS: Of 38 patients enrolled, 28 patients (median 6 years, 10 females) were reviewed by the molecular tumor board. Of those, 19 followed treatment recommendations. Median overall survival (OS) was 13.1 mo (95% CI 11.2, 18.4) with no difference between patients who followed recommendations and those who did not. H3K27M-mutant ctDNA was detected at baseline in 60% of cases tested and associated with response to RT and survival. Eleven cell lines were established, showing 100% fidelity of key somatic driver gene alterations in the primary tumor. In H3K27-altered DIPGs, TP53 mutations were associated with worse OS (TP53mut 11.1 mo [95% CI 8.7, 14]; TP53wt 13.3 mo [95% CI 11.8, NA]; p=3.4e-2), genome instability (p=3.1e-3), and RT resistance (p=6.4e-4). The CBTN cohort confirmed a negative association between TP53 status and clinical outcome.
    CONCLUSION: Upfront treatment-naïve biopsy provides insight into clinically relevant molecular alterations and prognostic biomarkers for H3K27-altered DIPGs.