bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2022‒02‒20
fifteen papers selected by
Oltea Sampetrean
Keio University

  1. Neuro Oncol. 2022 Feb 14. pii: noac042. [Epub ahead of print]
      BACKGROUND: Gliomas are complex tumors with several genetic aberrations and diverse metabolic programs contributing to their aggressive phenotypes and poor prognoses. This study defines key metabolic features that can be used to differentiate between glioma subtypes, with potential for improved diagnostics and subtype targeted therapy.METHODS: Cross-platform global metabolomic profiling coupled with clinical, genetic, and pathological analysis of glioma tissue from 224 tumors - oligodendroglioma (n=31), astrocytoma (n=31) and glioblastoma (n=162) - were performed. Identified metabolic phenotypes were evaluated in accordance with the WHO classification, IDH-mutation, 1p/19q-codeletion, WHO-grading 2-4, and MGMT promoter methylation.
    RESULTS: Distinct metabolic phenotypes separate all six analyzed glioma subtypes. IDH-mutated subtypes, expressing 2-hydroxyglutaric acid, were clearly distinguished from IDH-wildtype subtypes. Considerable metabolic heterogeneity outside of the mutated IDH pathway were also evident, with key metabolites being high expression of glycerophosphates, inositols, monosaccharides and sugar alcohols and low levels of sphingosine and lysoglycerophospholipids in IDH-mutants. Among the IDH-mutated subtypes, we observed high levels of amino acids, especially glycine and 2-aminoadipic acid, in grade 4 glioma, and N-acetyl aspartic acid in low-grade astrocytoma and oligodendroglioma. Both IDH-wildtype and mutated oligodendroglioma and glioblastoma were characterized by high levels of acylcarnitines, likely driven by rapid cell growth and hypoxic features. We found elevated levels of 5-HIAA in gliosarcoma and a subtype of oligodendroglioma not yet defined as a specific entity, indicating a previously not described role for the serotonin pathway linked to glioma with bimorphic tissue.
    CONCLUSION: Key metabolic differences exist across adult glioma subtypes.
    Keywords:  Astrocytoma; Glioblastoma; Metabolic reprogramming; Oligodendroglioma; WHO classification
  2. Int J Pharm. 2022 Feb 10. pii: S0378-5173(22)00117-X. [Epub ahead of print]616 121563
      Glioblastoma is the most common and lethal malignant brain tumor. Despite simvastatin (SVT) showing potential anticancer properties, its antitumoral effect against glioblastoma appears limited when the conventional oral administration route is selected. As a consequence, nose-to-brain delivery has been proposed as an alternative route to deliver SVT into the brain. This study aimed to prepare chitosan-coated simvastatin-loaded lipid-core nanocapsules (LNCSVT-chit) suitable for nose-to-brain delivery and capable of fostering antitumor effects against glioblastoma both in vitro and in vivo. Results showed that the nanocapsules present adequate particle size (mean diameter below 200 nm), narrow particle size distribution (PDI < 0.2), positive zeta potential and high encapsulation efficiency (nearly 100%). In vitro cytotoxicity of LNCSVT-chit was comparable to non-encapsulated SVT in C6 rat glioma cells, whereas LNCSVT-chit were more cytotoxic than non-encapsulated SVT after 72 h of incubation against U-138 MG human glioblastoma cell line. In studies carried out in rats, LNCSVT-chit significantly enhanced the amount of drug in rat brain tissue after intranasal administration (2.4-fold) when compared with free SVT. Moreover, LNCSVT-chit promoted a significant decrease in tumor growth and malignancy in glioma-bearing rats in comparison to control and free SVT groups. Additionally, LNCSVT-chit did not cause any toxicity in treated rats. Considered overall, the results demonstrated that the nose-to-brain administration of LNCSVT-chit represents a novel potential strategy for glioblastoma treatment.
    Keywords:  Chitosan; Glioblastoma; Intranasal administration; Nanocapsules; Nose-to-brain delivery; Simvastatin
  3. Lab Invest. 2022 Feb 12.
      Comprehensive molecular profiling has dramatically transformed the diagnostic neuropathology of brain tumors. Diffuse gliomas, the most common and deadly brain tumor variants, are now classified by highly recurrent biomarkers instead of histomorphological characteristics. Several of the key molecular alterations driving glioma classification involve epigenetic dysregulation at a fundamental level, implicating fields of biology not previously thought to play major roles glioma pathogenesis. This article will review the major epigenetic alterations underlying malignant gliomas, their likely mechanisms of action, and potential strategies for their therapeutic targeting.
  4. Cancers (Basel). 2022 Jan 25. pii: 600. [Epub ahead of print]14(3):
      Despite clinical intervention, glioblastoma (GBM) remains the deadliest brain tumor in adults. Its incurability is partly related to the establishment of drug resistance, both to standard and novel treatments. In fact, even though small kinase inhibitors have changed the standard clinical practice for several solid cancers, in GBM, they did not fulfill this promise. Drug resistance is thought to arise from the heterogeneity of GBM, which leads the development of several different mechanisms. A better understanding of the evolution and characteristics of drug resistance is of utmost importance to improve the current clinical practice. Therefore, the development of clinically relevant preclinical in vitro models which allow careful dissection of these processes is crucial to gain insights that can be translated to improved therapeutic approaches. In this review, we first discuss the heterogeneity of GBM, which is reflected in the development of several resistance mechanisms. In particular, we address the potential role of drug resistance mechanisms in the failure of small kinase inhibitors in clinical trials. Finally, we discuss strategies to overcome therapy resistance, particularly focusing on the importance of developing in vitro models, and the possible approaches that could be applied to the clinic to manage drug resistance.
    Keywords:  cell culture models; drug resistance; glioblastoma; overcoming resistance; small kinase inhibitors
  5. Clin Cancer Res. 2022 Feb 14. pii: clincanres.1933.2021. [Epub ahead of print]
      PURPOSE: Tyrosine kinase inhibitors (TKIs) have poor efficacy in patients with glioblastoma (GBM). Here, we studied whether this is predominantly due to restricted blood-brain barrier penetration or more to biological characteristics of GBM.EXPERIMENTAL DESIGN: Tumor drug concentrations of the TKI sunitinib after 2 weeks of preoperative treatment was determined in 5 patients with GBM and compared with its in vitro inhibitory concentration (IC50) in GBM cell lines. In addition, phosphotyrosine (pTyr) directed mass spectrometry(MS)-based proteomics was performed to evaluate sunitinib-treated versus control GBM tumors.
    RESULTS: The median tumor sunitinib concentration of 1.9 µM (range 1.0 - 3.4) was 10-fold higher than in concurrent plasma, but 3 times lower than sunitinib IC50s in GBM cell lines (median 5.4 µM, 3.0-8.5; p=0.01). pTyr-phosphoproteomic profiles of tumor samples from 4 sunitinib-treated versus 7 control patients revealed 108 significantly up- and 23 downregulated (p<0.05) phosphopeptides for sunitinib-treatment, resulting in an EGFR-centered signaling network. Outlier analysis of kinase activities as a potential strategy to identify drug targets in individual tumors identified 9 kinases, including MAPK10 and INSR/IGF1R.
    CONCLUSIONS: Achieved tumor sunitinib concentrations in patients with GBM are higher than in plasma, but lower than reported for other tumor types and insufficient to significantly inhibit tumor cell growth in vitro Therefore, alternative TKI dosing to increase intratumoral sunitinib concentrations might improve clinical benefit for patients with GBM. In parallel, a complex profile of kinase activity in GBM was found, supporting the potential of (phospho)proteomic analysis to identify targets for (combination) treatment.
  6. Cancers (Basel). 2022 Jan 19. pii: 485. [Epub ahead of print]14(3):
      Glioblastoma is one of the most aggressive brain tumors, characterized by a pronounced redox imbalance, expressed in a high oxidative capacity of cancer cells due to their elevated glycolytic and mitochondrial oxidative metabolism. The assessment and modulation of the redox state of glioblastoma are crucial factors that can provide highly specific targeting and treatment. Our study describes a pharmacological strategy for targeting glioblastoma using a redox-active combination drug. The experiments were conducted in vivo on glioblastoma mice (intracranial model) and in vitro on cell lines (cancer and normal) treated with the redox cycling pair menadione/ascorbate (M/A). The following parameters were analyzed in vivo using MRI or ex vivo on tissue and blood specimens: tumor growth, survival, cerebral perfusion, cellular density, tissue redox state, expression of tumor-associated NADH oxidase (tNOX) and transforming growth factor-beta 1 (TGF-β1). Dose-dependent effects of M/A on cell viability, mitochondrial functionality, and redox homeostasis were evaluated in vitro. M/A treatment suppressed tumor growth and significantly increased survival without adverse side effects. This was accompanied by increased oxidative stress, decreased reducing capacity, and decreased cellular density in the tumor only, as well as increased cerebral perfusion and down-regulation of tNOX and TGF-β1. M/A induced selective cytotoxicity and overproduction of mitochondrial superoxide in isolated glioblastoma cells, but not in normal microglial cells. This was accompanied by a significant decrease in the over-reduced state of cancer cells and impairment of their "pro-oncogenic" functionality, assessed by dose-dependent decreases in: NADH, NAD+, succinate, glutathione, cellular reducing capacity, mitochondrial potential, steady-state ATP, and tNOX expression. The safety of M/A on normal cells was compromised by treatment with cerivastatin, a non-specific prenyltransferase inhibitor. In conclusion, M/A differentiates glioblastoma cells and tissues from normal cells and tissues by redox targeting, causing severe oxidative stress only in the tumor. The mechanism is complex and most likely involves prenylation of menadione in normal cells, but not in cancer cells, modulation of the immune response, a decrease in drug resistance, and a potential role in sensitizing glioblastoma to conventional chemotherapy.
    Keywords:  TGF-β1; ascorbate; glioblastoma; menadione; mitochondrial redox cycling; redox targeting; tumor-associated ENOX2
  7. Antioxid Redox Signal. 2022 Feb 15.
      AIMS: Glioblastoma is one of the most aggressive brain tumors. These tumors modify their metabolism, increasing the expression of glucose transporters, GLUTs, which incorporate glucose and the oxidized form of vitamin C, dehydroascorbic acid (DHA). We hypothesized that glioblastoma cells preferentially take up DHA, which is intracellularly reduced and compartmentalized into the endoplasmic reticulum (ER), promoting collagen biosynthesis and an aggressive phenotype.RESULTS: Our results showed that glioblastoma cells take up DHA using GLUT1, while GLUT3 and sodium-dependent vitamin C transporter 2 (SVCT2), are preferably intracellular. Using a baculoviral system and reticulum-enriched extracts, we determined that SVCT2 is mainly located in the ER and corresponds to a short isoform. AA was compartmentalized, stimulating collagen IV secretion and increasing in vitro and in situ cell migration. Finally, orthotopic xenografts induced in immunocompetent guinea pigs showed that vitamin C deficiency retained collagen, reduced blood vessel invasion, and affected glomeruloid vasculature formation, all pathological conditions associated with malignancy. Innovation and conclusion: We propose a functional role for vitamin C in glioblastoma development and progression. Vitamin C is incorporated into the ER of glioblastoma cells, where it favors the synthesis of collagen, thus impacting tumor development. Collagen secreted by tumor cells favors the formation of the glomeruloid vasculature and enhances perivascular invasion.
  8. Sci Adv. 2022 Feb 18. 8(7): eabl4923
      Malignant tumors will become vulnerable if their uncontrolled biosynthesis and energy consumption engaged in metabolic reprogramming can be cut off. Here, we report finding a glycolytic inhibitor targeting glioblastoma with graphite dots-assisted laser desorption/ionization mass spectrometry as an integrated drug screening and pharmacokinetic platform (GLMSD). We have performed high-throughput virtual screening to narrow an initial library of 240,000 compounds down to the docking of 40 compounds and identified five previously unknown chemical scaffolds as promising hexokinase-2 inhibitors. The best inhibitor (Compd 27) can regulate the reprogrammed metabolic pathway in U87 glioma cells (median inhibitory concentration ~ 11.3 μM) for tumor suppression. Highly effective therapy against glioblastoma has been demonstrated in both subcutaneous and orthotopic brain tumors by synergizing Compd 27 and temozolomide. Our glycolytic inhibitor discovery can inspire personalized medicine targeting reprogrammed metabolisms of malignant tumors. GLMSD enables large, high-quality data for next-generation artificial intelligence-aided drug development.
  9. Cancers (Basel). 2022 Jan 31. pii: 735. [Epub ahead of print]14(3):
      MSC-driven, gene-directed enzyme prodrug therapy (GDEPT) mediated by extracellular vesicles (EV) represents a new paradigm-cell-free GDEPT tumor therapy. In this study, we tested the efficacy of yeast cytosine deaminase::uracilphosphoribosyl transferase (yCD::UPRT-MSC)-exosomes, in the form of conditioned medium (CM) to inhibit the growth of C6 glioblastoma cells both in vitro and in vivo. MSCs isolated from human adipose tissue, umbilical cord, or dental pulp engineered to express the yCD::UPRT gene secreted yCD::UPRT-MSC-exosomes that in the presence of the prodrug 5-fluorocytosine (5-FC), inhibited the growth of rat C6 glioblastoma cells and human primary glioblastoma cells in vitro in a dose-dependent manner. CM from these cells injected repeatedly either intraperitoneally (i.p.) or subcutaneously (s.c.), applied intranasally (i.n.), or infused continuously by an ALZET osmotic pump, inhibited the growth of cerebral C6 glioblastomas in rats. A significant number of rats were cured when CM containing yCD::UPRT-MSC-exosomes conjugated with 5-FC was repeatedly injected i.p. or applied i.n. Cured rats were subsequently resistant to challenges with higher doses of C6 cells. Our data have shown that cell-free GDEPT tumor therapy mediated by the yCD::UPRT-MSC suicide gene EVs for high-grade glioblastomas represents a safer and more practical approach that is worthy of further investigation.
    Keywords:  curative effect; gene-directed enzyme prodrug therapy; intranasal application; mesenchymal stem cells; rat glioblastoma; suicide gene extracellular vesicles; yCD::UPRT-MSC-EVs
  10. Neuro Oncol. 2022 Feb 14. pii: noac041. [Epub ahead of print]
      BACKGROUND: Pediatric diffuse midline gliomas (DMGs) are incurable childhood cancers. The imipridone ONC201 has shown early clinical efficacy in a subset of DMGs. However, the anticancer mechanisms of ONC201 and its derivative ONC206 have not been fully described in DMGs.METHODS: DMG models including primary human in vitro (n=18), and in vivo (murine and zebrafish) models, and patient (n=20) frozen and FFPE specimens were used. Drug-target engagement was evaluated using in silico ChemPLP and in vitro thermal shift assay. Drug toxicity and neurotoxicity were assessed in zebrafish models. Seahorse XF Cell Mito Stress Test, MitoSOX and TMRM assays, and electron microscopy imaging were used to assess metabolic signatures. Cell lineage differentiation and drug-altered pathways were defined using bulk and single cell RNA-seq.
    RESULTS: ONC201 and ONC206 reduce viability of DMG cells in nM concentrations and extend survival of DMG PDX models (ONC201: 117 days, p=0.01; ONC206: 113 days, p=001). ONC206 is 10X more potent than ONC201 in vitro and combination treatment was the most efficacious at prolonging survival in vivo (125 days, p=0.02). Thermal shift assay confirmed that both drugs bind to ClpP, with ONC206 exhibiting a higher binding affinity as assessed by in silico ChemPLP. ClpP activation by both drugs results in impaired tumor cell metabolism, mitochondrial damage, ROS production, activation of integrative stress response and apoptosis in vitro and in vivo. Strikingly, imipridone treatment triggered a lineage shift from a proliferative, oligodendrocyte precursor-like state to a mature, astrocyte-like state.
    CONCLUSION: Targeting mitochondrial metabolism and ISR activation effectively impairs DMG tumorigenicity. These results supported initiation of a phase 1 pediatric clinical trial (PNOC023, NCT04732065).
    Keywords:  ClpP; ONC201; ONC206; diffuse midline glioma (DMG); integrated stress response (ISR)
  11. Nat Commun. 2022 Feb 17. 13(1): 925
      Despite recent advances in cancer immunotherapy, certain tumor types, such as Glioblastomas, are highly resistant due to their tumor microenvironment disabling the anti-tumor immune response. Here we show, by applying an in-silico multidimensional model integrating spatially resolved and single-cell gene expression data of 45,615 immune cells from 12 tumor samples, that a subset of Interleukin-10-releasing HMOX1+ myeloid cells, spatially localizing to mesenchymal-like tumor regions, drive T-cell exhaustion and thus contribute to the immunosuppressive tumor microenvironment. These findings are validated using a human ex-vivo neocortical glioblastoma model inoculated with patient derived peripheral T-cells to simulate the immune compartment. This model recapitulates the dysfunctional transformation of tumor infiltrating T-cells. Inhibition of the JAK/STAT pathway rescues T-cell functionality both in our model and in-vivo, providing further evidence of IL-10 release being an important driving force of tumor immune escape. Our results thus show that integrative modelling of single cell and spatial transcriptomics data is a valuable tool to interrogate the tumor immune microenvironment and might contribute to the development of successful immunotherapies.
  12. Cancers (Basel). 2022 Jan 28. pii: 684. [Epub ahead of print]14(3):
      PURPOSE: To assess the value of whole blood transcriptome data from liquid biopsy (lbx) in recurrent high-grade glioma (rHGG) patients for longitudinal molecular monitoring of tumor evolution under carbon ion irradiation (CIR).METHODS: Whole blood transcriptome (WBT) analysis (Illumina HumanHT-12 Expression BeadChips) was performed in 14 patients with rHGG pre re-irradiation (reRT) with CIR and 3, 6 and 9 weeks post-CIR (reRT grade III:5, 36%, IV:9, 64%). Patients were irradiated with 30, 33, 36 GyRBE (n = 5, 6, 3) in 3GyRBE per fraction.
    RESULTS: WTB analysis showed stable correlation with treatment characteristics and patients tumor grade, indicating a preserved tumor origin specific as well as dynamic transcriptional fingerprints of peripheral blood cells. Initial histopathologic tumor grade was indirectly associated with TMEM173 (STING), DNA-repair (ATM, POLD4) and hypoxia related genes. DNA-repair, chromatin remodeling (LIG1, SMARCD1) and immune response (FLT3LG) pathways were affected post-CIR. Longitudinal WTB fingerprints identified two distinct trajectories of rHGG evolution, characterized by differential and prognostic CRISPLD2 expression pre-CIR.
    CONCLUSIONS: Lbx based WTB analysis holds the potential for molecular stratification of rHGG patients and therapy monitoring. We demonstrate the feasibility of the peripheral blood transcriptome as a sentinel organ for identification of patient, tumor characteristics and CIR specific fingerprints in rHGG.
    Keywords:  biomarker; carbon ion irradiation; liquid biopsy; recurrent high-grade glioma; whole blood transcriptome
  13. Cancers (Basel). 2022 Jan 29. pii: 701. [Epub ahead of print]14(3):
      Radiation therapy is an important part of the standard of care treatment of brain tumors. However, the efficacy of radiation therapy is limited by the radioresistance of tumor cells, a phenomenon held responsible for the dismal prognosis of the most aggressive brain tumor types. A promising approach to radiosensitization of tumors is the inhibition of cell cycle checkpoint control responsible for cell cycle progression and the maintenance of genomic integrity. Inhibition of the kinases involved in these control mechanisms can abolish cell cycle checkpoints and DNA damage repair and thus increase the sensitivity of tumor cells to radiation and chemotherapy. Here, we discuss preclinical progress in molecular targeting of ATM, ATR, CHK1, CHK2, and WEE1, checkpoint kinases in the treatment of brain tumors, and review current clinical phase I-II trials.
    Keywords:  ATM; ATR; CHK1; CHK2; WEE1; brain tumor; cell cycle checkpoints; checkpoint inhibitor; radiation therapy; radiosensitivity
  14. Clin Cancer Res. 2022 Feb 17. pii: clincanres.3324.2021. [Epub ahead of print]
      PURPOSE: Testing safety of Delta24-RGD (DNX-2401), an oncolytic adenovirus, locally delivered by convection enhanced delivery (CED) in tumor and surrounding brain of recurrent glioblastoma patients.EXPERIMENTAL DESIGN: Dose-escalation phase 1 study with 3+3 cohorts, dosing 107 to 1 x 1011 viral particles(vp) in 20 patients. Besides clinical parameters, AE's and radiological findings, blood, cerebrospinal fluid (CSF), brain interstitial fluid (BIF) and excreta were sampled over time and analyzed for presence of immune response, viral replication, distribution and shedding.
    RESULTS: Of 20 enrolled patients, 19 received the oncolytic adenovirus Delta24-RGD, which was found to be safe and feasible. Four patients demonstrated tumor response on MRI, one with complete regression and still alive after 8 years. Most SAEs were attributed to increased intracranial pressure either caused by an inflammatory reaction responding to steroid treatment or viral meningitis being transient and self-limiting. Often viral DNA concentrations in CSF increased over time, peaking after 2-4 weeks and remaining up to 3 months. Concomitantly Th1 and Th2-associated cytokine levels and numbers of CD3+ T- and NK cells increased. Post-treatment tumor specimens revealed increased numbers of macrophages, CD4+ and CD8+ T cells. No evidence of viral shedding in excreta was observed.
    CONCLUSIONS: CED of Delta24-RGD not only in the tumor but also in surrounding brain is safe, induces a local inflammatory reaction and shows promising clinical responses.
  15. Cells. 2022 Jan 21. pii: 362. [Epub ahead of print]11(3):
      Mutually linked expression and methylation dynamics in the brain govern genome regulation over the whole lifetime with an impact on cognition, psychological disorders, and cancer. We performed a joint study of gene expression and DNA methylation of brain tissue originating from the human prefrontal cortex of individuals across the lifespan to describe changes in cellular programs and their regulation by epigenetic mechanisms. The analysis considers previous knowledge in terms of functional gene signatures and chromatin states derived from independent studies, aging profiles of a battery of chromatin modifying enzymes, and data of gliomas and neuropsychological disorders for a holistic view on the development and aging of the brain. Expression and methylation changes from babies to elderly adults decompose into different modes associated with the serial activation of (brain) developmental, learning, metabolic and inflammatory functions, where methylation in gene promoters mostly represses transcription. Expression of genes encoding methylome modifying enzymes is very diverse reflecting complex regulations during lifetime which also associates with the marked remodeling of chromatin between permissive and restrictive states. Data of brain cancer and psychotic disorders reveal footprints of pathophysiologies related to brain development and aging. Comparison of aging brains with gliomas supports the view that glioblastoma-like and astrocytoma-like tumors exhibit higher cellular plasticity activated in the developing healthy brain while oligodendrogliomas have a more stable differentiation hierarchy more resembling the aged brain. The balance and specific shifts between volatile and stable and between more irreversible and more plastic epigenomic networks govern the development and aging of healthy and diseased brain.
    Keywords:  DNA methylation; bioinformatics; chromatin remodeling; development and aging; epigenetics; gene expression; human brain; machine learning