bims-malgli 2025-02-23 papers

Nature. 2025 Feb 19.

GABAergic neuron-to-glioma synapses in diffuse midline gliomas.

High-grade gliomas (HGGs) are the leading cause of brain cancer-related death. HGGs include clinically, anatomically and molecularly distinct subtypes that stratify into diffuse midline gliomas (DMGs), such as H3K27M-altered diffuse intrinsic pontine glioma, and hemispheric HGGs, such as IDH wild-type glioblastoma. Neuronal activity drives glioma progression through paracrine signalling1,2 and neuron-to-glioma synapses3-6. Glutamatergic AMPA receptor-dependent synapses between neurons and glioma cells have been demonstrated in paediatric3 and adult4 high-grade gliomas, and early work has suggested heterogeneous glioma GABAergic responses7. However, neuron-to-glioma synapses mediated by neurotransmitters other than glutamate remain understudied. Using whole-cell patch-clamp electrophysiology, in vivo optogenetics and patient-derived orthotopic xenograft models, we identified functional, tumour-promoting GABAergic neuron-to-glioma synapses mediated by GABAA receptors in DMGs. GABAergic input has a depolarizing effect on DMG cells due to NKCC1 chloride transporter function and consequently elevated intracellular chloride concentration in DMG malignant cells. As membrane depolarization increases glioma proliferation3,6, we found that the activity of GABAergic interneurons promotes DMG proliferation in vivo. The benzodiazepine lorazepam enhances GABA-mediated signalling, increases glioma proliferation and growth, and shortens survival in DMG patient-derived orthotopic xenograft models. By contrast, only minimal depolarizing GABAergic currents were found in hemispheric HGGs and lorazepam did not influence the growth rate of hemispheric glioblastoma xenografts. Together, these findings uncover growth-promoting GABAergic synaptic communication between GABAergic neurons and H3K27M-altered DMG cells, underscoring a tumour subtype-specific mechanism of brain cancer neurophysiology.

DOI: https://doi.org/10.1038/s41586-024-08579-3

bioRxiv. 2025 Feb 05. pii: 2025.02.03.636330. [Epub ahead of print]

Intratumoral gene delivery of 4-1BBL boosts IL-12-triggered anti-glioblastoma immunity.

The standard of care in high-grade gliomas has remained unchanged in the past 20 years. Efforts to replicate effective immunotherapies in non-cranial tumors have led to only modest therapeutical improvements in glioblastoma (GB). Here, we demonstrate that intratumoral administration of recombinant interleukin-12 (rIL-12) promotes local cytotoxic CD8 POS T cell accumulation and conversion into an effector-like state, resulting in a dose-dependent survival benefit in preclinical GB mouse models. This tumor-reactive CD8 T cell response is further supported by intratumoral rIL-12-sensing dendritic cells (DCs) and is accompanied by the co-stimulatory receptor 4-1BB expression on both cell types. Given that DCs and CD8 POS T cells are functionally suppressed in the tumor microenvironments of de novo and recurrent glioma patients, we tested whether anti-tumor response at the rIL-12-inflamed tumor site could be enhanced with 4-1BBL, the ligand of 4-1BB. 4-1BBL was delivered using an adeno-associated virus (AAV) vector targeting GFAP-expressing cells and resulted in prolonged survival of rIL-12 treated GB-bearing mice. This study establishes that tumor antigen-specific CD8 T cell activity can be directed using an AAV-vector-mediated gene therapy approach, effectively enhancing anti-GB immunity.

DOI: https://doi.org/10.1101/2025.02.03.636330

Nature. 2025 Feb 19.

Tumour-wide RNA splicing aberrations generate actionable public neoantigens.

T cell-based immunotherapies hold promise in treating cancer by leveraging the immune system's recognition of cancer-specific antigens1. However, their efficacy is limited in tumours with few somatic mutations and substantial intratumoural heterogeneity2-4. Here we introduce a previously uncharacterized class of tumour-wide public neoantigens originating from RNA splicing aberrations in diverse cancer types. We identified T cell receptor clones capable of recognizing and targeting neoantigens derived from aberrant splicing in GNAS and RPL22. In cases with multi-site biopsies, we detected the tumour-wide expression of the GNAS neojunction in glioma, mesothelioma, prostate cancer and liver cancer. These neoantigens are endogenously generated and presented by tumour cells under physiologic conditions and are sufficient to trigger cancer cell eradication by neoantigen-specific CD8+ T cells. Moreover, our study highlights a role for dysregulated splicing factor expression in specific cancer types, leading to recurrent patterns of neojunction upregulation. These findings establish a molecular basis for T cell-based immunotherapies addressing the challenges of intratumoural heterogeneity.

DOI: https://doi.org/10.1038/s41586-024-08552-0

Neuro Oncol. 2025 Feb 18. pii: noaf045. [Epub ahead of print]

Targeting PGE2 mediated senescent neuron improves tumour therapy.

Jianyi Zhao, Linshi Wu, Gang Cai, Dan Ou, Keman Liao, Jian Yang, Li Zhou, Renhua Huang, Shukai Lin, Xi Huang, Qi Lv, Juxiang Chen, Lu Cao, Jiayi Chen, Yingying Lin.

BACKGROUND: Recent studies have highlighted bidirectional signalling between tumours and neurons; however, the interactions between tumours and neurons in response to radio-/chemotherapy remain obscure, which hampers the tumour treatment.
METHODS: Glioblastoma organoids (GBOs) and primary neuron coculture, targeted metabonomics, RNA pulldown, mass spectrum, co-immunoprecipitation, RNA-sequencing, transcript/protein validations and multi-electrode arrays were performed to analyse neuron-tumour interaction in response to therapy. In vivo validations were conducted in orthotopic mouse models. Diagnostic and prognostic values were evaluated in serum, tissue-microarray as well as TCGA.
RESULTS: GBOs recruited and induced pro-tumour-survival senescent neurons upon radiation/chemotherapeutic treatment. Targeted metabonomics revealed that significantly increased tumour-derived prostaglandin E2 (PGE2) induced neuronal senescence phenotype. Screening of enzymes involved in PGE2 synthesis identified prostaglandin E synthase 3 (PTGES3) as the key enzyme responsible for PGE2 upregulation. Biochemical studies revealed that irradiation or chemotherapeutic drug-triggered asparagine endopeptidase (AEP) specifically cleaved eIF4A1 to produce teIF4A1-C, which dissociated from DDX6 and recruited eIF4A3 and PABPN1 to promote the mRNA stability of PTGES3. Elevated PGE2 reciprocally enhanced AEP expression. Inhibiting PGE2 or AEP reduced neuronal senescence and delayed tumour progression. Strikingly, single-cell analysis further showed that expressions of AEP/PTGES3/EIF4A1 in tumour cells were consistent with senescent neuronal CDKN1A in high-neuronal-connectivity glioblastoma. The serum PGE2 concentration was elevated after radiation and higher in resistant glioblastoma patients. High expression of PTGES3 was associated with a poor prognosis.
CONCLUSIONS: Our study revealed that the AEP/PGE2 feedback loop modulates tumour-induced neuronal senescence upon radio-/chemotherapy and highlight the therapeutic value to improve tumour therapy.

Keywords: PGE2; neuron; radio-/chemotherapy; senescence; tumour

DOI: https://doi.org/10.1093/neuonc/noaf045