bims-malgli 2023-01-29 papers

bims-malgli

Biomed News

on Biology of malignant gliomas

Issue of 2023–01–29
eleven papers selected by
Oltea Sampetrean, Keio University

Pre-clinical models for evaluating glioma targeted immunotherapies.
PGC-1α degradation suppresses mitochondrial biogenesis to confer radiation resistance in glioma.
Telomerase inhibition is an effective therapeutic strategy in TERT promoter mutant-glioblastoma models with low tumor volume.
GBMdeconvoluteR accurately infers proportions of neoplastic and immune cell populations from bulk glioblastoma transcriptomics data.
Natural killer cell therapy potentially enhances the antitumor effects of bevacizumab plus irinotecan in a glioblastoma mouse model.
Cellular senescence in malignant cells promotes tumor progression in mouse and patient Glioblastoma.
Novel Murine Glioblastoma Models That Reflect the Immunotherapy Resistance Profile of Human Disease.
Zinc Finger MYND-Type Containing 8 (ZMYND8) is epigenetically regulated in mutant Isocitrate Dehydrogenase 1 (IDH1) glioma to promote radioresistance.
Radiation-induced circulating myeloid-derived suppressor cells induce systemic lymphopenia after chemoradiotherapy in patients with glioblastoma.
Cancer-associated SMARCAL1 loss-of-function mutations promote alternative lengthening of telomeres and tumorigenesis in telomerase-negative glioblastoma cells.
Reprogramming systemic and local immune function to empower immunotherapy against glioblastoma.

Front Immunol. 2022 ;13 1092399

Pre-clinical models for evaluating glioma targeted immunotherapies.

Stephen C Frederico, Xiaoran Zhang, Baoli Hu, Gary Kohanbash.

  Gliomas have an extremely poor prognosis in both adult and pediatric patient populations as these tumors are known to grow aggressively and respond poorly to standard of care treatment. Currently, treatment for gliomas involves surgical resection followed by chemoradiation therapy. However, some gliomas, such as diffuse midline glioma, have more limited treatment options such as radiotherapy alone. Even with these interventions, the prognosis for those diagnosed with a glioma remains poor. Immunotherapy is highly effective for some cancers and there is great interest in the development of effective immunotherapies for the treatment of gliomas. Clinical trials evaluating the efficacy of immunotherapies targeted to gliomas have largely failed to date, and we believe this is partially due to the poor choice in pre-clinical mouse models that are used to evaluate these immunotherapies. A key consideration in evaluating new immunotherapies is the selection of pre-clinical models that mimic the glioma-immune response in humans. Multiple pre-clinical options are currently available, each one with their own benefits and limitations. Informed selection of pre-clinical models for testing can facilitate translation of more promising immunotherapies in the clinical setting. In this review we plan to present glioma cell lines and mouse models, as well as alternatives to mouse models, that are available for pre-clinical glioma immunotherapy studies. We plan to discuss considerations of model selection that should be made for future studies as we hope this review can serve as a guide for investigators as they choose which model is best suited for their study.

Keywords:  GBM; brain; glioma; immunotherapy; mouse model; pre-clinical; tumor

DOI:  https://doi.org/10.3389/fimmu.2022.1092399
Cancer Res. 2023 Jan 25. pii: CAN-22-3083. [Epub ahead of print]

PGC-1α degradation suppresses mitochondrial biogenesis to confer radiation resistance in glioma.

Mengjie Zhao, Yanhui Li, Chenfei Lu, Fangshu Ding, Miao Xu, Xin Ge, Mengdie Li, Zhen Wang, Jianxing Yin, Junxia Zhang, Xiefeng Wang, Zehe Ge, Hong Xiao, Yong Xiao, Hongyi Liu, Wentao Liu, Yuandong Cao, Qianghu Wang, Yongping You, Xiuxing Wang, Kun Yang, Zhumei Shi, Xu Qian.

Radiotherapy is a major component of standard-of-care treatment for gliomas, the most prevalent type of brain tumor. However, resistance to radiotherapy remains a major concern. Identification of mechanisms governing radioresistance in gliomas could reveal improved therapeutic strategies for treating patients. Here, we report that mitochondrial metabolic pathways are suppressed in radioresistant gliomas through integrated analyses of transcriptomic data from glioma specimens and cell lines. Decreased expression of peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α), the key regulator of mitochondrial biogenesis and metabolism, correlated with glioma recurrence and predicted poor prognosis and response to radiation therapy of glioma patients. The subpopulation of glioma cells with low-mitochondrial-mass exhibited reduced expression of PGC-1α and enhanced resistance to radiation treatment. Mechanistically, PGC-1α was phosphorylated at serine (S) 636 by DNA-dependent protein kinase (DNA-PK) in response to irradiation. Phosphorylation at S636 promoted the degradation of PGC-1α by facilitating its binding to the E3 ligase RNF34. Restoring PGC-1α activity with expression of PGC-1α S636A, a phosphorylation-resistant mutant, or a small molecule PGC-1α activator ZLN005 increased radiosensitivity of resistant glioma cells by reactivating mitochondria-related ROS production and inducing apoptotic effects both in vitro and in vivo. In summary, this study identified a self-protective mechanism in glioma cells in which radiation-induced degradation of PGC-1α and suppression of mitochondrial biogenesis play a central role. Targeted activation of PGC-1α could help improve response to radiation therapy in glioma patients.

DOI: https://doi.org/10.1158/0008-5472.CAN-22-3083
Neuro Oncol. 2023 Jan 24. pii: noad024. [Epub ahead of print]

Telomerase inhibition is an effective therapeutic strategy in TERT promoter mutant-glioblastoma models with low tumor volume.

Elisa Aquilanti, Lauren Kageler, Jacqueline Watson, Duncan M Baird, Rhiannon E Jones, Marie Hodges, Zsofia M Szegletes, John G Doench, Craig A Strathdee, Jose Ricardo McFaline Figueroa, Keith Ligon, Matthew Beck, Patrick Y Wen, Matthew Meyerson.

   BACKGROUND: Glioblastoma is among the deadliest of all cancers, with 5-year survival rates of only 6%. Glioblastoma targeted therapeutics have been challenging to develop due to significant inter- and intra-tumoral heterogeneity. TERT promoter mutations are the most common known clonal oncogenic mutations in glioblastoma. Telomerase is therefore considered to be a promising therapeutic target against this tumor. However, an important limitation of this strategy is that cell death does not occur immediately after telomerase ablation, but rather after several cell divisions required to reach critically short telomeres. We therefore hypothesize that telomerase inhibition would only be effective in low tumor burden glioblastomas.
METHODS: We used CRISPR interference to knock down TERT expression in TERT promoter-mutant glioblastoma cell lines and patient derived models. We then measured viability using serial proliferation assays. We also assessed for features of telomere crisis by measuring telomere length and chromatin bridge formation. Lastly, we used a doxycycline-inducible CRISPR interference system to knock down TERT expression in vivo early and late in the tumor formation process.
RESULTS: Upon TERT inactivation, glioblastoma cells lose their proliferative ability over time and exhibit evidence of telomere crisis with telomere shortening and chromatin bridge formation. In vivo, tumor formation is only inhibited when TERT knockdown is induced shortly after tumor implantation, but not when tumor burden is high.
CONCLUSIONS: Our results support the idea that telomerase inhibition would be most effective at treating glioblastomas with low tumor burden, for example in the adjuvant setting after surgical debulking and chemoradiation.

Keywords:  Telomerase; adjuvant therapy; glioblastoma; target validation; targeted therapy; tumor burden

DOI:  https://doi.org/10.1093/neuonc/noad024
Neuro Oncol. 2023 Jan 23. pii: noad021. [Epub ahead of print]

GBMdeconvoluteR accurately infers proportions of neoplastic and immune cell populations from bulk glioblastoma transcriptomics data.

Shoaib Ajaib, Disha Lodha, Steven Pollock, Gemma Hemmings, Martina A Finetti, Arief Gusnanto, Aruna Chakrabarty, Azzam Ismail, Erica Wilson, Frederick S Varn, Bethany Hunter, Andrew Filby, Asa A Brockman, David McDonald, Roel G W Verhaak, Rebecca A Ihrie, Lucy F Stead.

   BACKGROUND: Characterising and quantifying cell types within glioblastoma (GBM) tumours at scale will facilitate a better understanding of the association between the cellular landscape and tumour phenotypes or clinical correlates. We aimed to develop a tool that deconvolutes immune and neoplastic cells within the GBM tumour microenvironment from bulk RNA sequencing data.
METHODS: We developed an IDH wild-type (IDHwt) GBM-specific single immune cell reference consisting of B cells, T cells, NK cells, microglia, tumour associated macrophages, monocytes, mast and DC cells. We used this alongside an existing neoplastic single cell-type reference for astrocyte-like, oligodendrocyte- and neuronal-progenitor like and mesenchymal GBM cancer cells to create both marker and gene signature matrix-based deconvolution tools. We applied single-cell resolution imaging mass cytometry (IMC) to ten IDHwt GBM samples, five paired primary and recurrent tumours, to determine which deconvolution approach performed best.
RESULTS: Marker based deconvolution using GBM tissue specific markers was most accurate for both immune cells and cancer cells, so we packaged this approach as GBMdeconvoluteR. We applied GBMdeconvoluteR to bulk GBM RNAseq data from The Cancer Genome Atlas and recapitulated recent findings from multi-omics single cell studies with regards associations between mesenchymal GBM cancer cells and both lymphoid and myeloid cells. Furthermore, we expanded upon this to show that these associations are stronger in patients with worse prognosis.
CONCLUSIONS: GBMdeconvoluteR accurately quantifies immune and neoplastic cell proportions in IDHwt GBM bulk RNA sequencing data and is accessible here: https : // gbmdeconvoluter.leeds.ac.uk.

Keywords:  Glioblastoma; deconvolution; immune; neoplastic; transcriptomics

DOI:  https://doi.org/10.1093/neuonc/noad021
Front Immunol. 2022 ;13 1009484

Natural killer cell therapy potentially enhances the antitumor effects of bevacizumab plus irinotecan in a glioblastoma mouse model.

Thi-Anh-Thuy Tran, Young-Hee Kim, Thi-Hoang-Oanh Duong, JayaLakshmi Thangaraj, Tan-Huy Chu, Shin Jung, In-Young Kim, Kyung-Sub Moon, Young-Jin Kim, Tae-Kyu Lee, Chul Won Lee, Hyosuk Yun, Je-Jung Lee, Hyun-Ju Lee, Kyung-Hwa Lee, Tae-Young Jung.

  Various combination treatments have been considered to attain the effective therapy threshold by combining independent antitumor mechanisms against the heterogeneous characteristics of tumor cells in malignant brain tumors. In this study, the natural killer (NK) cells associated with bevacizumab (Bev) plus irinotecan (Iri) against glioblastoma multiforme (GBM) were investigated. For the experimental design, NK cells were expanded and activated by K562 cells expressing the OX40 ligand and membrane-bound IL-18 and IL-21. The effects of Bev and Iri on the proliferation and NK ligand expression of GBM cells were evaluated through MTT assay and flow cytometry. The cytotoxic effects of NK cells against Bev plus Iri-treated GBM cells were also predicted via the LDH assay in vitro. The therapeutic effect of different injected NK cell routes and numbers combined with the different doses of Bev and Iri was confirmed according to tumor size and survival in the subcutaneous (s.c) and intracranial (i.c) U87 xenograft NOD/SCID IL-12Rγnull mouse model. The presence of injected-NK cells in tumors was detected using flow cytometry and immunohistochemistry ex vivo. As a result, Iri was found to affect the proliferation and NK ligand expression of GBM cells, while Bev did not cause differences in these cellular processes. However, the administration of Bev modulated Iri efficacy in the i.c U87 mouse model. NK cells significantly enhanced the cytotoxic effects against Bev plus Iri-treated GBM cells in vitro. Although the intravenous (IV) injection of NK cells in combination with Bev plus Iri significantly reduced the tumor volume in the s.c U87 mouse model, only the direct intratumorally (IT) injection of NK cells in combination with Bev plus Iri elicited delayed tumor growth in the i.c U87 mouse model. Tumor-infiltrating NK cells were detected after IV injection of NK cells in both s.c and i.c U87 mouse models. In conclusion, the potential therapeutic effect of NK cells combined with Bev plus Iri against GBM cells was limited in this study. Accordingly, further research is required to improve the accessibility and strength of NK cell function in this combination treatment.

Keywords:  U87 cell line; bevacizumab; glioblastoma; irinotecan; natural killer cells

DOI:  https://doi.org/10.3389/fimmu.2022.1009484
Nat Commun. 2023 Jan 27. 14(1): 441

Cellular senescence in malignant cells promotes tumor progression in mouse and patient Glioblastoma.

Rana Salam, Alexa Saliou, Franck Bielle, Mathilde Bertrand, Christophe Antoniewski, Catherine Carpentier, Agusti Alentorn, Laurent Capelle, Marc Sanson, Emmanuelle Huillard, Léa Bellenger, Justine Guégan, Isabelle Le Roux.

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, yet it remains refractory to systemic therapy. Elimination of senescent cells has emerged as a promising new treatment approach against cancer. Here, we investigated the contribution of senescent cells to GBM progression. Senescent cells are identified in patient and mouse GBMs. Partial removal of p16Ink4a-expressing malignant senescent cells, which make up less than 7 % of the tumor, modifies the tumor ecosystem and improves the survival of GBM-bearing female mice. By combining single cell and bulk RNA sequencing, immunohistochemistry and genetic knockdowns, we identify the NRF2 transcription factor as a determinant of the senescent phenotype. Remarkably, our mouse senescent transcriptional signature and underlying mechanisms of senescence are conserved in patient GBMs, in whom higher senescence scores correlate with shorter survival times. These findings suggest that senolytic drug therapy may be a beneficial adjuvant therapy for patients with GBM.

DOI: https://doi.org/10.1038/s41467-023-36124-9
Neuro Oncol. 2023 Jan 27. pii: noad025. [Epub ahead of print]

Novel Murine Glioblastoma Models That Reflect the Immunotherapy Resistance Profile of Human Disease.

Chao-Hsien Chen, Renee L Chin, Genevieve P Hartley, Spencer T Lea, Brian J Engel, Cheng-En Hsieh, Rishika Prasad, Jason Roszik, Takashi Shingu, Gregory A Lizee, Amy B Heimberger, Steven W Millward, Jian Hu, David S Hong, Michael A Curran.

   BACKGROUND: The lack of murine glioblastoma models that mimic the immunobiology of human disease has impeded basic and translational immunology research. We therefore developed murine glioblastoma stem cell lines derived from Nestin-CreERT2QkL/L; Trp53L/L; PtenL/L (QPP) mice driven by clinically relevant genetic mutations common in human glioblastoma. This study aims to determine the immune sensitivities of these QPP lines in immunocompetent hosts and underlying mechanisms.
METHODS: The differential responsiveness of QPP lines was assessed in the brain and flank in untreated, anti-PD-1, or anti-CTLA-4 treated mice. The impact of genomic landscape on responsiveness of each tumor was measured through whole exome sequencing. The immune microenvironments of sensitive (QPP7) versus resistant (QPP8) lines were compared in the brain using flow cytometry. Drivers of flank sensitivity versus brain resistance were also measured for QPP8.
RESULTS: QPP lines are syngeneic to C57BL/6J mice and demonstrate varied sensitivities to T cell immune checkpoint blockade ranging from curative responses to complete resistance. Infiltrating tumor immune analysis of QPP8 reveals improved T cell fitness and augmented effector to suppressor ratios when implanted subcutaneously (sensitive), which are absent upon implantation in the brain (resistant). Upregulation of PD-L1 across the myeloid stroma acts to establish this state of immune privilege in the brain. In contrast, QPP7 responds to checkpoint immunotherapy even in the brain likely resulting from its elevated neoantigen burden.
CONCLUSIONS: These syngeneic QPP models of glioblastoma demonstrate clinically-relevant profiles of immunotherapeutic sensitivity and potential utility for both mechanistic discovery and evaluation of immune therapies.

Keywords:  anti-CTLA-4; anti-PD-1; glioblastoma; immunotherapy

DOI:  https://doi.org/10.1093/neuonc/noad025
Clin Cancer Res. 2023 Jan 24. pii: CCR-22-1896. [Epub ahead of print]

Zinc Finger MYND-Type Containing 8 (ZMYND8) is epigenetically regulated in mutant Isocitrate Dehydrogenase 1 (IDH1) glioma to promote radioresistance.

Stephen V Carney, Kaushik Banerjee, Anzar Mujeeb, Brandon Zhu, Santiago Haase, Maria Luisa Varela, Padma Kadiyala, Claire E Tronrud, Ziwen Zhu, Devarshi Mukherji, Preethi Gorla, Yilun Sun, Rebecca Tagett, Felipe J Núñez, Maowu Luo, Weibo Luo, Mats Ljungman, Yayuan Liu, Ziyun Xia, Anna Schwendeman, Tingting Qin, Maureen A Sartor, Joseph F Costello, Daniel P Cahill, Pedro R Lowenstein, Maria G Castro.

PURPOSE: Mutant isocitrate dehydrogenase 1 (mIDH1) alters the epigenetic regulation of chromatin, leading to a hypermethylation phenotype in adult glioma. This work focuses on identifying gene targets epigenetically dysregulated by mIDH1 to confer therapeutic resistance to ionizing radiation (IR).
EXPERIMENTAL DESIGN: We evaluated changes in the transcriptome and epigenome in a radioresistant mIDH1 patient-derived glioma cell culture (GCC) following treatment with an mIDH1 specific inhibitor AGI-5198. We identified Zinc Finger MYND-Type Containing 8 (ZMYND8) as potential target of mIDH1 reprogramming. We suppressed ZMYND8 expression by shRNA knockdown and genetic knockout (KO) in mIDH1 glioma cells then assessed cellular viability to IR. We assessed the sensitivity of mIDH1 GCCS to pharmacological inhibition of ZMYND8-interacting partners: HDAC, BRD4, and PARP.
RESULTS: Inhibition of mIDH1 lead to an upregulation of gene networks involved in replication stress. We found that the expression of ZMYND8, a regulator of DNA damage response was decreased in three patient-derived mIDH1 GCCs after treatment with AGI-5198. Knockdown of ZMYND8 expression sensitized mIDH1 GCCs to radiotherapy marked by decreased cellular viability. Following IR, mIDH1 glioma cells with ZMYND8 knockout (KO) exhibit significant phosphorylation of ATM and sustained γH2AX activation. ZMYND8 KO mIDH1 GCCs were further responsive to IR when treated with either BRD4 or HDAC inhibitors. PARP inhibition further enhanced the efficacy of radiotherapy in ZMYND8 KO mIDH1 glioma cells.
CONCLUSIONS: These findings indicate the impact of ZMYND8 in the maintenance of genomic integrity and repair of IR-induced DNA damage in mIDH1 glioma.

DOI: https://doi.org/10.1158/1078-0432.CCR-22-1896
Sci Transl Med. 2023 Jan 25. 15(680): eabn6758

Radiation-induced circulating myeloid-derived suppressor cells induce systemic lymphopenia after chemoradiotherapy in patients with glioblastoma.

Subhajit Ghosh, Jiayi Huang, Matthew Inkman, Jin Zhang, Sukrutha Thotala, Ekaterina Tikhonova, Natalia Miheecheva, Felix Frenkel, Ravshan Ataullakhanov, Xiaowei Wang, David DeNardo, Dennis Hallahan, Dinesh Thotala.

Severe and prolonged lymphopenia frequently occurs in patients with glioblastoma after standard chemoradiotherapy and has been associated with worse survival, but its underlying biological mechanism is not well understood. To address this, we performed a correlative study in which we collected and analyzed peripheral blood of patients with glioblastoma (n = 20) receiving chemoradiotherapy using genomic and immune monitoring technologies. RNA sequencing analysis of the peripheral blood mononuclear cells (PBMC) showed an elevated concentration of myeloid-derived suppressor cell (MDSC) regulatory genes in patients with lymphopenia when compared with patients without lymphopenia after chemoradiotherapy. Additional analysis including flow cytometry and single-cell RNA sequencing further confirmed increased numbers of circulating MDSC in patients with lymphopenia when compared with patients without lymphopenia after chemoradiotherapy. Preclinical murine models were also established and demonstrated a causal relationship between radiation-induced MDSC and systemic lymphopenia using transfusion and depletion experiments. Pharmacological inhibition of MDSC using an arginase-1 inhibitor (CB1158) or phosphodiesterase-5 inhibitor (tadalafil) during radiation therapy (RT) successfully abrogated radiation-induced lymphopenia and improved survival in the preclinical models. CB1158 and tadalafil are promising drugs in reducing radiation-induced lymphopenia in patients with glioblastoma. These results demonstrate the promise of using these classes of drugs to reduce treatment-related lymphopenia and immunosuppression.

DOI: https://doi.org/10.1126/scitranslmed.abn6758
Neuro Oncol. 2023 Jan 23. pii: noad022. [Epub ahead of print]

Cancer-associated SMARCAL1 loss-of-function mutations promote alternative lengthening of telomeres and tumorigenesis in telomerase-negative glioblastoma cells.

Heng Liu, Cheng Xu, Bill H Diplas, Alexandrea Brown, Laura M Strickland, Haipei Yao, Jinjie Ling, Roger E McLendon, Stephen T Keir, David M Ashley, Yiping He, Matthew S Waitkus.

   BACKGROUND: Telomere maintenance mechanisms are required to enable the replicative immortality of malignant cells. While most cancers activate the enzyme telomerase, a subset of cancers use telomerase-independent mechanisms termed alternative lengthening of telomeres (ALT). ALT occurs via homology directed-repair mechanisms and is frequently associated with ATRX mutations. We previously showed that a subset of adult GBM patients with ATRX-expressing ALT-positive tumors harbored loss-of-function mutations in the SMARCAL1 gene, which encodes an annealing helicase involved in replication fork remodeling and the resolution of replication stress. However, the causative relationship between SMARCAL1 deficiency, tumorigenesis, and de novo telomere synthesis is not understood.
METHODS: We used a patient-derived ALT-positive GBM cell line with native SMARCAL1 deficiency to investigate the role of SMARCAL1 in ALT-mediated de novo telomere synthesis, replication stress, and gliomagenesis in vivo.
RESULTS: Inducible rescue of SMARCAL1 expression suppresses ALT indicators and inhibits de novo telomere synthesis in GBM and osteosarcoma cells, suggesting that SMARCAL1 deficiency plays a functional role in ALT induction in cancers that natively lack SMARCAL1 function. SMARCAL1-deficient ALT-positive cells can be serially propagated in vivo in the absence of detectable telomerase activity, demonstrating that the SMARCAL1-deficient ALT phenotype maintains telomeres in a manner that promotes tumorigenesis.
CONCLUSIONS: SMARCAL1 deficiency is permissive to ALT and promote gliomagenesis. Inducible rescue of SMARCAL1 in ALT-positive cell lines permits the dynamic modulation of ALT activity, which will be valuable for future studies aimed at understanding the mechanisms of ALT and identifying novel anti-cancer therapeutics that target the ALT phenotype.

Keywords:  ATRX; SMARCAL1; adult gliomas; alternative lengthening of telomeres; gliomagenesis; telomere maintenance

DOI:  https://doi.org/10.1093/neuonc/noad022
Nat Commun. 2023 Jan 26. 14(1): 435

Reprogramming systemic and local immune function to empower immunotherapy against glioblastoma.

Songlei Zhou, Yukun Huang, Yu Chen, Yipu Liu, Laozhi Xie, Yang You, Shiqiang Tong, Jianpei Xu, Gan Jiang, Qingxiang Song, Ni Mei, Fenfen Ma, Xiaoling Gao, Hongzhuan Chen, Jun Chen.

The limited benefits of immunotherapy against glioblastoma (GBM) is closely related to the paucity of T cells in brain tumor bed. Both systemic and local immunosuppression contribute to the deficiency of tumor-infiltrating T cells. However, the current studies focus heavily on the local immunosuppressive tumor microenvironment but not on the co-existence of systemic immunosuppression. Here, we develop a nanostructure named Nano-reshaper to co-encapsulate lymphopenia alleviating agent cannabidiol and lymphocyte recruiting cytokine LIGHT. The results show that Nano-reshaper increases the number of systemic T cells and improves local T-cell recruitment condition, thus greatly increasing T-cell infiltration. When combined with immune checkpoint inhibitor, this therapeutic modality achieves 83.3% long-term survivors without recurrence in GBM models in male mice. Collectively, this work unveils that simultaneous reprogramming of systemic and local immune function is critical for T-cell based immunotherapy and provides a clinically translatable option for combating brain tumors.

DOI: https://doi.org/10.1038/s41467-023-35957-8