bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2022‒04‒17
fourteen papers selected by
Oltea Sampetrean
Keio University

  1. Cancer Immunol Res. 2022 Apr 12. pii: canimm.0559.2021. [Epub ahead of print]
      The symbiotic interactions between cancer stem cells and the tumor microenvironment (TME) are critical for tumor progression. However, the molecular mechanism underlying this symbiosis in glioblastoma (GBM) remains enigmatic. Here, we show that circadian locomotor output cycles kaput (CLOCK) and its heterodimeric partner brain and muscle ARNT-like 1 (BMAL1) in glioma stem cells (GSCs) drive immunosuppression in GBM. Integrated analyses of the data from transcriptome profiling, single-cell RNA sequencing, and TCGA datasets, coupled with functional studies, identified legumain (LGMN) as a direct transcriptional target of the CLOCK-BMAL1 complex in GSCs. Moreover, CLOCK-directed olfactomedin-like 3 (OLFML3) upregulates LGMN in GSCs via hypoxia-inducible factor 1-alpha (HIF1α) signaling. Consequently, LGMN promotes microglial infiltration into the GBM TME via upregulating CD162 and polarizes infiltrating microglia towards an immune-suppressive phenotype. In GBM mouse models, inhibition of the CLOCK-OLFML3-HIF1α-LGMN-CD162 axis reduces intratumoral immune-suppressive microglia, increases CD8+ T-cell infiltration, activation and cytotoxicity, and synergizes with anti-PD1 therapy. In human GBM, the CLOCK-regulated LGMN signaling correlates positively with microglial abundance and poor prognosis. Together, these findings uncover the CLOCK-OLFML3-HIF1α-LGMN axis as a molecular switch that controls microglial biology and immunosuppression, thus revealing potential new therapeutic targets for GBM patients.
  2. Neuro Oncol. 2022 Apr 11. pii: noac092. [Epub ahead of print]
  3. Am J Cancer Res. 2022 ;12(3): 1129-1142
      Glioblastoma (GBM) is the most common and malignant type of brain cancer in adults with poor prognosis. GBM stem cells (GSCs) reside within niches in GBM tissues and contribute to recurrence and therapy resistance. Previous studies have shown that expression of leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), a Wnt pathway-related stem cell marker, correlates with a poor prognosis in GBM, and its knockdown in GSCs induces apoptosis accompanied with downregulation of signal transducer and activator of transcription 5b (Stat5b). Here, we show that Stat5b co-localizes with Lgr5 in hypoxia-inducible factor 2α (Hif2α)-positive regions in GBM tissues. Functional analyses using GSCs derived from a murine de novo GBM model induced by oncogenic genes transduction using the Sleeping-Beauty transposon system revealed that expression of Stat5b was induced by culturing under hypoxia together with Lgr5, repressed by Hif2α knockdown, and reduced by Lgr5 knockdown or a Wnt/β-catenin signaling inhibitor ICG-001 treatment. Stat5b inhibition in the GSCs induced apoptosis and caused downregulation of Cyclin E2 resulted in blockade of entry into S-phase in the cell cycle. Disruption of Stat5b in an orthotopic transplantation model significantly prolongs event-free survival. These results suggest that Stat5b, regulated by hypoxia and the Wnt pathway, plays an important role in the maintenance and tumorigenicity of GSCs and may be a promising therapeutic molecular target to attack GSCs.
    Keywords:  Hif2α; Lgr5; Stat5b; glioblastoma stem cells; hypoxia
  4. Clin Cancer Res. 2022 Mar 17. OF1-OF15
      PURPOSE: Novel therapeutic targets are critical to unravel for the most common primary brain tumor in adults, glioblastoma (GBM). We have identified a novel synthetic lethal interaction between ClpP activation and HDAC1/2 inhibition that converges on GBM energy metabolism.EXPERIMENTAL DESIGN: Transcriptome, metabolite, and U-13C-glucose tracing analyses were utilized in patient-derived xenograft (PDX) models of GBM. Orthotopic GBM models were used for in vivo studies.
    RESULTS: We showed that activation of the mitochondrial ClpP protease by mutant ClpP (Y118A) or through utilization of second-generation imipridone compounds (ONC206 and ONC212) in combination with genetic interference of HDAC1 and HDAC2 as well as with global (panobinostat) or selective (romidepsin) HDAC inhibitors caused synergistic reduction of viability in GBM model systems, which was mediated by interference with tricarboxylic acid cycle activity and GBM cell respiration. This effect was partially mediated by activation of apoptosis along with activation of caspases regulated chiefly by Bcl-xL and Mcl-1. Knockdown of the ClpP protease or ectopic expression of a ClpP D190A mutant substantially rescued from the inhibition of oxidative energy metabolism as well as from the reduction of cellular viability by ClpP activators and the combination treatment, respectively. Finally, utilizing GBM PDX models, we demonstrated that the combination treatment of HDAC inhibitors and imipridones prolonged host survival more potently than single treatments or vehicle in vivo.
    CONCLUSIONS: Collectively, these observations suggest that the efficacy of HDAC inhibitors might be significantly enhanced through ClpP activators in model systems of human GBM.
  5. Neuro Oncol. 2022 Apr 13. pii: noac085. [Epub ahead of print]
      BACKGROUND: Glioblastoma is a treatment-resistant brain cancer. Its hierarchical cellular nature and its tumour microenvironment (TME) before, during, and after treatments remain unresolved.METHODS: Here, we used single-cell RNA-sequencing to analyze new and recurrent glioblastoma, and the nearby subventricular zone (SVZ).
    RESULTS: We found four glioblastoma neural lineages are present in new and recurrent glioblastoma with an enrichment of the cancer mesenchymal lineage, immune cells, and reactive astrocytes in early recurrences. Cancer lineages were hierarchically organized around cycling oligodendrocytic and astrocytic progenitors that are transcriptomically similar but distinct to SVZ neural stem cells (NSCs). Furthermore, NSCs from the SVZ of glioblastoma patients harbored glioblastoma chromosomal anomalies. Lastly, mesenchymal cancer cells and TME reactive astrocytes shared similar gene signatures which were induced by radiotherapy in a myeloid-dependent fashion in vivo.
    CONCLUSION: These data reveal the dynamic, immune-dependent nature of glioblastoma's response to treatments and identify distant NSCs as likely cells of origin.
  6. Neoplasia. 2022 Apr 07. pii: S1476-5586(22)00019-7. [Epub ahead of print]28 100790
      Mutations in IDH1 and IDH2 drive the development of gliomas. These genetic alterations promote tumor cell renewal, disrupt differentiation states, and induce stem-like properties. Understanding how this phenotypic reprogramming occurs remains an area of high interest in glioma research. Previously, we showed that IDH mutation results in the development of a CD24-positive cell population in gliomas. Here, we demonstrate that this CD24-positive population possesses striking stem-like properties at the molecular and phenotypic levels. We found that CD24 expression is associated with stem-like features in IDH-mutant tumors, a patient-derived gliomasphere model, and a neural stem cell model of IDH1-mutant glioma. In orthotopic models, CD24-positive cells display enhanced tumor initiating potency compared to CD24-negative cells. Furthermore, CD24 knockdown results in changes in cell viability, proliferation rate, and gene expression that closely resemble a CD24-negative phenotype. Our data demonstrate that induction of a CD24-positive population is one mechanism by which IDH-mutant tumors acquire stem-like properties. These findings have significant implications for our understanding of the molecular underpinnings of IDH-mutant gliomas.
    Keywords:  CD24; IDH1 mutation; Low-grade glioma; Neural stem cells; Orthotopic mouse model; cancer stem cells
  7. Neuro Oncol. 2022 Apr 14. pii: noac099. [Epub ahead of print]
      BACKGROUND: Addition of temozolomide (TMZ) to radiotherapy (RT) improves overall survival (OS) in glioblastoma, but previous studies suggest that patients with tumors harboring an unmethylated MGMT promoter derive minimal benefit. The aim of this open-label, phase 3 CheckMate 498 study was to evaluate the efficacy of nivolumab (NIVO)+RT compared with TMZ+RT in newly diagnosed glioblastoma with unmethylated MGMT promoter.METHODS: Patients were randomized 1:1 to standard RT (60 Gy) + NIVO (240 mg every 2 weeks for 8 cycles, then 480 mg every 4 weeks) or RT+TMZ (75 mg/m 2 daily during RT and 150-200 mg/m 2/day 5/28 days during maintenance). The primary endpoint was OS.
    RESULTS: A total of 560 patients were randomized, 280 to each arm. Median OS was 13.4 months (95% CI, 12.6-14.3) with NIVO+RT and 14.9 months (95% CI, 13.3-16.1) with TMZ+RT (hazard ratio [HR], 1.31; 95% CI, 1.09-1.58; P=0.0037). Median progression-free survival was 6.0 months (95% CI, 5.7-6.2) with NIVO+RT and 6.2 months (95% CI, 5.9-6.7) with TMZ+RT (HR, 1.38; 95% CI, 1.15-1.65). Response rates were 7.8% (9/116) with NIVO+RT and 7.2% (8/111) with TMZ+RT; grade 3/4 treatment-related adverse event (TRAE) rates were 21.9% and 25.1%, and any-grade serious TRAE rates were 17.3% and 7.6%, respectively.
    CONCLUSIONS: The study did not meet the primary endpoint of improved OS; TMZ+RT demonstrated a longer median OS than NIVO+RT. No new safety signals were detected with NIVO in this study. The difference between the study treatment arms is consistent with the use of TMZ+RT as standard of care for glioblastoma.
    Keywords:  newly diagnosed glioblastoma; nivolumab; radiotherapy; temozolomide; unmethylated MGMT
  8. Neurooncol Adv. 2022 Jan-Dec;4(1):4(1): vdac012
      Background: GSK3β serine/threonine kinase regulates metabolism and glycogen biosynthesis. GSK3β overexpression promotes progression and resistance through NF-κB and p53 apoptotic pathways. GSK3β inhibits immunomodulation by downregulating PD-L1 and LAG-3 checkpoints and increasing NK and T-cell tumor killing. 9-ING-41, a small-molecule, selective GSK3β inhibitor, showed preclinical activity in chemo-resistant PDX glioblastoma models, including enhanced lomustine antitumor effect.Methods: Refractory malignancies (n = 162) were treated with 9-ING-41 monotherapy (n = 65) or combined with 8 cytotoxic regimens after prior exposure (NCT03678883). Recurrent gliomas (n = 18) were treated with 9-ING-41 IV TIW q21day cycles at 3.3, 5, 9.3, 15 mg/kg, as monotherapy or combined with lomustine 30 mg/m² PO weekly q84day cycles. Primary objective was safety.
    Results: RP2D of 15 mg/kg IV TIW was confirmed across all 9 regimens, no accentuated chemotherapy toxicity noted. Glioma subtypes included: 13 glioblastoma, 2 anaplastic astrocytomas, 1 anaplastic oligodendroglioma, 1 astrocytoma. Median age 52 (30-69) years; 6 female, 12 male; median ECOG 1 (0-2); median recurrences 3 (1-6). All received upfront radiation/temozolomide (18/18), plus salvage nitrosoureas (15/18), bevacizumab (8/18), TTFields (6/18), or immunotherapy (4/18). IDH/mutation(3/18); 1p19q/codeletion(1/18); MGMT/methylated(1/18). Four received 9-ING-41 monotherapy, 14 concurrent with lomustine. No severe toxicities were attributed to 9-ING-41, only mild vision changes (9/18, 50%), or infusion reactions (4/18, 22%). Lomustine-related toxicities: G3/4 thrombocytopenia (3/14, 21%), G1/2 fatigue (4/14, 28%). Median days on therapy was 55 (4-305); 1 partial response (>50%) was noted. Median OS was 5.5 (95% CI: 2.8-11.4) months and PFS-6 was 16.7%.
    Conclusion: 9-ING-41 plus/minus lomustine is safe and warrants further study in glioma patients.
    Keywords:  9-ING-41; GSK-3β; gliomas; lomustine; phase I trial
  9. J Clin Invest. 2022 Apr 15. pii: e159073. [Epub ahead of print]132(8):
      Given its aggressive natural history and immunosuppressive nature, glioblastoma (GBM) remains difficult to treat. Tumor Treating Fields (TTFields) are a promising treatment for GBM patients, yet the entirety of their antitumor action has not been fully elucidated. In a recent issue of the JCI, Chen et al. explored the effect of TTFields in reinvigorating immune responses. By elegant step-by-step approaches, the authors demonstrated that TTFields promote the production of immune-stimulating proinflammatory and interferon type 1 cytokines in tumor cells in a cGAS/STING- and AIM2 inflammasome-dependent mechanism, thereby activating the immune system. The findings show that TTFields not only directly inhibit tumor cell growth, as previously reported, but enhance antitumor immunity, suggesting TTFields can be used as an immune-modulating approach in GBM.
  10. Neurooncol Adv. 2022 Jan-Dec;4(1):4(1): vdac025
      Background: The phase 1 cohorts (1c+1d) of CheckMate 143 (NCT02017717) evaluated the safety/tolerability and efficacy of nivolumab plus radiotherapy (RT) ± temozolomide (TMZ) in newly diagnosed glioblastoma.Methods: In total, 136 patients were enrolled. In part A (safety lead-in), 31 patients (n = 15, methylated/unknown MGMT promoter; n = 16, unmethylated MGMT promoter) received nivolumab and RT+TMZ (NIVO+RT+TMZ) and 30 patients with unmethylated MGMT promoter received NIVO+RT. In part B (expansion), patients with unmethylated MGMT promoter were randomized to NIVO+RT+TMZ (n = 29) or NIVO+RT (n = 30). Primary endpoint was safety/tolerability; secondary endpoint was overall survival (OS).
    Results: NIVO+RT±TMZ was tolerable; grade 3/4 treatment-related adverse events occurred in 51.6% (NIVO+RT+TMZ) and 30.0% (NIVO+RT) of patients in part A and 46.4% (NIVO+RT+TMZ) and 28.6% (NIVO+RT) in part B. No new safety signals were detected. In part A, median OS (mOS) with NIVO+RT+TMZ was 33.38 months (95% CI, 16.2 to not estimable) in patients with methylated MGMT promoter. In patients with unmethylated MGMT promoter, mOS was 16.49 months (12.94-22.08) with NIVO+RT+TMZ and 14.41 months (12.55-17.31) with NIVO+RT. In part B, mOS was 14.75 months (10.01-18.6) with NIVO+RT+TMZ and 13.96 months (10.81-18.14) with NIVO+RT in patients with unmethylated MGMT promoter.
    Conclusions: CheckMate 143 was the first trial evaluating immune checkpoint inhibition with first-line treatment of glioblastoma. Results showed that NIVO can be safely combined with RT±TMZ, with no new safety signals. Toxicities, including lymphopenia, were more frequent with NIVO+RT+TMZ. OS was similar with or without TMZ in patients with unmethylated MGMT promoter, and differences by MGMT methylation status were observed.
    Keywords:  PD-1; newly diagnosed glioblastoma; nivolumab; radiotherapy; temozolomide
  11. Nat Cancer. 2022 Apr 14.
      Diffuse midline gliomas (DMGs) bearing driver mutations of histone 3 lysine 27 (H3K27M) are incurable brain tumors with unique epigenomes. Here, we generated a syngeneic H3K27M mouse model to study the amino acid metabolic dependencies of these tumors. H3K27M mutant cells were highly dependent on methionine. Interrogating the methionine cycle dependency through a short-interfering RNA screen identified the enzyme methionine adenosyltransferase 2A (MAT2A) as a critical vulnerability in these tumors. This vulnerability was not mediated through the canonical mechanism of MTAP deletion; instead, DMG cells have lower levels of MAT2A protein, which is mediated by negative feedback induced by the metabolite decarboxylated S-adenosyl methionine. Depletion of residual MAT2A induces global depletion of H3K36me3, a chromatin mark of transcriptional elongation perturbing oncogenic and developmental transcriptional programs. Moreover, methionine-restricted diets extended survival in multiple models of DMG in vivo. Collectively, our results suggest that MAT2A presents an exploitable therapeutic vulnerability in H3K27M gliomas.
  12. Nature. 2022 Apr 13.
      Chimeric antigen receptor (CAR) therapy has had a transformative effect on the treatment of haematologic malignancies1-6, but it has shown limited efficacy against solid tumours. Solid tumours may have cell-intrinsic resistance mechanisms to CAR T cell cytotoxicity. Here, to systematically identify potential resistance pathways in an unbiased manner, we conducted a genome-wide CRISPR knockout screen in glioblastoma, a disease in which CAR T cells have had limited efficacy7,8. We found that the loss of genes in the interferon-γ receptor (IFNγR) signalling pathway (IFNGR1, JAK1 or JAK2) rendered glioblastoma and other solid tumours more resistant to killing by CAR T cells both in vitro and in vivo. However, loss of this pathway did not render leukaemia or lymphoma cell lines insensitive to CAR T cells. Using transcriptional profiling, we determined that glioblastoma cells lacking IFNγR1 had lower upregulation of cell-adhesion pathways after exposure to CAR T cells. We found that loss of IFNγR1 in glioblastoma cells reduced overall CAR T cell binding duration and avidity. The critical role of IFNγR signalling in susceptibility of solid tumours to CAR T cells is surprising, given that CAR T cells do not require traditional antigen-presentation pathways. Instead, in glioblastoma tumours, IFNγR signalling was required for sufficient adhesion of CAR T cells to mediate productive cytotoxicity. Our work demonstrates that liquid and solid tumours differ in their interactions with CAR T cells and suggests that enhancing binding interactions between T cells and tumour cells may yield improved responses in solid tumours.