Infiltrating plasma cells maintain glioblastoma stem cells through IgG-Tumor binding.

Glioblastoma is a highly aggressive primary brain tumor with glioblastoma stem cells (GSCs) enforcing the intra-tumoral hierarchy. Plasma cells (PCs) are critical effectors of the B-lineage immune system, but their roles in glioblastoma remain largely unexplored. Here, we leverage single-cell RNA and B cell receptor sequencing of tumor-infiltrating B-lineage cells and reveal that PCs are aberrantly enriched in the glioblastoma-infiltrating B-lineage population, experience low level of somatic hypermutation, and are associated with poor prognosis.

Metabolic regulation of the glioblastoma stem cell epitranscriptome by malate dehydrogenase 2.

Tumors reprogram their metabolism to generate complex neoplastic ecosystems. Here, we demonstrate that glioblastoma (GBM) stem cells (GSCs) display elevated activity of the malate-aspartate shuttle (MAS) and expression of malate dehydrogenase 2 (MDH2). Genetic and pharmacologic targeting of MDH2 attenuated GSC proliferation, self-renewal, and in vivo tumor growth, partially rescued by aspartate.

A peptide encoded by upstream open reading frame of binds to tropomyosin receptor kinase B and promotes glioblastoma growth in mice.

MYC promotes tumor growth through multiple mechanisms. Here, we show that, in human glioblastomas, the variant transcript encodes a 114-amino acid peptide, MYC pre-mRNA encoded protein (MPEP), from the upstream open reading frame (uORF) . Secreted MPEP promotes patient-derived xenograft tumor growth in vivo, independent of MYC through direct binding, and activation of tropomyosin receptor kinase B (TRKB), which induces downstream AKT-mTOR signaling.

The genomic and immunogenomic landscape of mechanics pathway informs clinical prognosis and response to mechanotherapy.

Mechanics shape cell and tissue plasticity and maintain their homeostasis. In cancers, mechanical signals regulate cancer hallmarks via mechanotransduction pathways, such as proliferation, metastasis and metabolic reprogramming. However, comprehensive characterization of mechanotransduction pathway genes and their clinical relevance across different cancer types remains untouched.

IFI35 regulates non-canonical NF-κB signaling to maintain glioblastoma stem cells and recruit tumor-associated macrophages.

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor characterized by a highly heterogeneous and immunosuppressive tumor microenvironment (TME). The symbiotic interactions between glioblastoma stem cells (GSCs) and tumor-associated macrophages (TAM) in the TME are critical for tumor progression. Here, we identified that IFI35, a transcriptional regulatory factor, plays both cell-intrinsic and cell-extrinsic roles in maintaining GSCs and the immunosuppressive TME.

Lymphatic endothelial-like cells promote glioblastoma stem cell growth through cytokine-driven cholesterol metabolism.

Glioblastoma is the most lethal primary brain tumor with glioblastoma stem cells (GSCs) atop a cellular hierarchy. GSCs often reside in a perivascular niche, where they receive maintenance cues from endothelial cells, but the role of heterogeneous endothelial cell populations remains unresolved. Here, we show that lymphatic endothelial-like cells (LECs), while previously unrecognized in brain parenchyma, are present in glioblastomas and promote growth of CCR7-positive GSCs through CCL21 secretion.

LncRNA INHEG promotes glioma stem cell maintenance and tumorigenicity through regulating rRNA 2'-O-methylation.

Glioblastoma (GBM) ranks among the most lethal of human cancers, containing glioma stem cells (GSCs) that display therapeutic resistance. Here, we report that the lncRNA INHEG is highly expressed in GSCs compared to differentiated glioma cells (DGCs) and promotes GSC self-renewal and tumorigenicity through control of rRNA 2'-O-methylation. INHEG induces the interaction between SUMO2 E3 ligase TAF15 and NOP58, a core component of snoRNP that guides rRNA methylation, to regulate NOP58 sumoylation and accelerate the C/D box snoRNP assembly.

Dual Role of CXCL8 in Maintaining the Mesenchymal State of Glioblastoma Stem Cells and M2-Like Tumor-Associated Macrophages.

Purpose: The dynamic interplay between glioblastoma stem cells (GSC) and tumor-associated macrophages (TAM) sculpts the tumor immune microenvironment (TIME) and promotes malignant progression of glioblastoma (GBM). However, the mechanisms underlying this interaction are still incompletely understood. Here, we investigate the role of CXCL8 in the maintenance of the mesenchymal state of GSC populations and reprogramming the TIME to an immunosuppressive state.

Integrative multi-omics approaches to explore immune cell functions: Challenges and opportunities.

As modern biological sciences evolve from investigation of individual molecules and pathways to growing emphasis on global and systems-based processes, increasing efforts have focused on combining the study of genomics with that of the other omics technologies, including epigenomics, transcriptomics, quantitative proteomics, global analyses of post-translational modifications (PTMs) and metabolomics, to characterize specific biological or pathological processes. In addition, emerging genome-wide functional screening technologies further help researchers identify key regulators of immune functions. Derived from these multi-omics technologies, single cell sequencing analysis on multiple layers offers an overview of intra-tissue or intra-organ immune cell heterogeneity.

Sorting nexin 10 sustains PDGF receptor signaling in glioblastoma stem cells via endosomal protein sorting.

Glioblastoma is the most malignant primary brain tumor, the prognosis of which remains dismal even with aggressive surgical, medical, and radiation therapies. Glioblastoma stem cells (GSCs) promote therapeutic resistance and cellular heterogeneity due to their self-renewal properties and capacity for plasticity. To understand the molecular processes essential for maintaining GSCs, we performed an integrative analysis comparing active enhancer landscapes, transcriptional profiles, and functional genomics profiles of GSCs and non-neoplastic neural stem cells (NSCs).

Targeting Microglial Metabolic Rewiring Synergizes with Immune-Checkpoint Blockade Therapy for Glioblastoma.

Unlabelled: Glioblastoma (GBM) constitutes the most lethal primary brain tumor for which immunotherapy has provided limited benefit. The unique brain immune landscape is reflected in a complex tumor immune microenvironment (TIME) in GBM. Here, single-cell sequencing of the GBM TIME revealed that microglia were under severe oxidative stress, which induced nuclear receptor subfamily 4 group A member 2 (NR4A2)-dependent transcriptional activity in microglia.

Superenhancer activation of KLHDC8A drives glioma ciliation and hedgehog signaling.

Glioblastoma ranks among the most aggressive and lethal of all human cancers. Self-renewing, highly tumorigenic glioblastoma stem cells (GSCs) contribute to therapeutic resistance and maintain cellular heterogeneity. Here, we interrogated superenhancer landscapes of primary glioblastoma specimens and patient-derived GSCs, revealing a kelch domain-containing gene, specifically Kelch domain containing 8A (KLHDC8A) with a previously unknown function as an epigenetically driven oncogene.

β2-Microglobulin Maintains Glioblastoma Stem Cells and Induces M2-like Polarization of Tumor-Associated Macrophages.

Unlabelled: Glioblastoma (GBM) is a complex ecosystem that includes a heterogeneous tumor population and the tumor-immune microenvironment (TIME), prominently containing tumor-associated macrophages (TAM) and microglia. Here, we demonstrated that β2-microglobulin (B2M), a subunit of the class I major histocompatibility complex (MHC-I), promotes the maintenance of stem-like neoplastic populations and reprograms the TIME to an anti-inflammatory, tumor-promoting state. B2M activated PI3K/AKT/mTOR signaling by interacting with PIP5K1A in GBM stem cells (GSC) and promoting MYC-induced secretion of transforming growth factor-β1 (TGFβ1).

Brain cancer stem cells: resilience through adaptive plasticity and hierarchical heterogeneity.

Malignant brain tumours are complex ecosystems containing neoplastic and stromal components that generate adaptive and evolutionarily driven aberrant tissues in the central nervous system. Brain cancers are cultivated by a dynamic population of stem-like cells that enforce intratumoural heterogeneity and respond to intrinsic microenvironment or therapeutically guided insults through proliferation, plasticity and restructuring of neoplastic and stromal components. Far from a rigid hierarchy, heterogeneous neoplastic populations transition between cellular states with differential self-renewal capacities, endowing them with powerful resilience.

PDGF signaling inhibits mitophagy in glioblastoma stem cells through N-methyladenosine.

Dysregulated growth factor receptor pathways, RNA modifications, and metabolism each promote tumor heterogeneity. Here, we demonstrate that platelet-derived growth factor (PDGF) signaling induces N-methyladenosine (mA) accumulation in glioblastoma (GBM) stem cells (GSCs) to regulate mitophagy. PDGF ligands stimulate early growth response 1 (EGR1) transcription to induce methyltransferase-like 3 (METTL3) to promote GSC proliferation and self-renewal.

Non-metabolic functions of phosphofructokinase-1 orchestrate tumor cellular invasion and genome maintenance under bevacizumab therapy.

Background: Glioblastoma (GBM) is a highly lethal malignancy for which neoangiogenesis serves as a defining hallmark. The anti-VEGF antibody, bevacizumab, has been approved for the treatment of recurrent GBM, but resistance is universal.

Methods: We analyzed expression data of GBM patients treated with bevacizumab to discover potential resistance mechanisms.

ADAR1-mediated RNA editing links ganglioside catabolism to glioblastoma stem cell maintenance.

Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor, containing GBM stem cells (GSCs) that contribute to therapeutic resistance and relapse. Exposing potential GSC vulnerabilities may provide therapeutic strategies against GBM. Here, we interrogated the role of adenosine-to-inosine (A-to-I) RNA editing mediated by adenosine deaminase acting on RNA 1 (ADAR1) in GSCs and found that both ADAR1 and global RNA editomes were elevated in GSCs compared with normal neural stem cells.

Glioblastoma stem cells reprogram chromatin in vivo to generate selective therapeutic dependencies on DPY30 and phosphodiesterases.

Glioblastomas are universally fatal cancers and contain self-renewing glioblastoma stem cells (GSCs) that initiate tumors. Traditional anticancer drug discovery based on in vitro cultures tends to identify targets with poor therapeutic indices and fails to accurately model the effects of the tumor microenvironment. Here, leveraging in vivo genetic screening, we identified the histone H3 lysine 4 trimethylation (H3K4me3) regulator DPY30 (Dpy-30 histone methyltransferase complex regulatory subunit) as an in vivo–specific glioblastoma dependency.

Leveraging Allele-Specific Expression for Therapeutic Response Gene Discovery in Glioblastoma.

Glioblastoma is the most prevalent primary malignant brain tumor in adults and is characterized by poor prognosis and universal tumor recurrence. Effective glioblastoma treatments are lacking, in part due to somatic mutations and epigenetic reprogramming that alter gene expression and confer drug resistance. To investigate recurrently dysregulated genes in glioblastoma, we interrogated allele-specific expression (ASE), the difference in expression between two alleles of a gene, in glioblastoma stem cells (GSC) derived from 43 patients.

Targeting glioblastoma signaling and metabolism with a re-purposed brain-penetrant drug.

The highly lethal brain cancer glioblastoma (GBM) poses a daunting challenge because the blood-brain barrier renders potentially druggable amplified or mutated oncoproteins relatively inaccessible. Here, we identify sphingomyelin phosphodiesterase 1 (SMPD1), an enzyme that regulates the conversion of sphingomyelin to ceramide, as an actionable drug target in GBM. We show that the highly brain-penetrant antidepressant fluoxetine potently inhibits SMPD1 activity, killing GBMs, through inhibition of epidermal growth factor receptor (EGFR) signaling and via activation of lysosomal stress.

Targeting EYA2 tyrosine phosphatase activity in glioblastoma stem cells induces mitotic catastrophe.

Glioblastoma ranks among the most lethal of primary brain malignancies, with glioblastoma stem cells (GSCs) at the apex of tumor cellular hierarchies. Here, to discover novel therapeutic GSC targets, we interrogated gene expression profiles from GSCs, differentiated glioblastoma cells (DGCs), and neural stem cells (NSCs), revealing EYA2 as preferentially expressed by GSCs. Targeting EYA2 impaired GSC maintenance and induced cell cycle arrest, apoptosis, and loss of self-renewal.

Transcription Elongation Machinery Is a Druggable Dependency and Potentiates Immunotherapy in Glioblastoma Stem Cells.

Glioblastoma (GBM) is the most lethal primary brain cancer characterized by therapeutic resistance, which is promoted by GBM stem cells (GSC). Here, we interrogated gene expression and whole-genome CRISPR/Cas9 screening in a large panel of patient-derived GSCs, differentiated GBM cells (DGC), and neural stem cells (NSC) to identify master regulators of GSC stemness, revealing an essential transcription state with increased RNA polymerase II-mediated transcription. The YY1 and transcriptional CDK9 complex was essential for GSC survival and maintenance and .

Epitranscriptomic editing of the RNA N6-methyladenosine modification by dCasRx conjugated methyltransferase and demethylase.

N6-methyladenosine (m6A) is a common modification on endogenous RNA transcripts in mammalian cells. Technologies to precisely modify the RNA m6A levels at specific transcriptomic loci empower interrogation of biological functions of epitranscriptomic modifications. Here, we developed a bidirectional dCasRx epitranscriptome editing platform composed of a nuclear-localized dCasRx conjugated with either a methyltransferase, METTL3, or a demethylase, ALKBH5, to manipulate methylation events at targeted m6A sites.

Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs.

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs.