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1.
J Exp Med ; 218(11)2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34617969

RESUMO

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. EYA2 displayed novel localization to centrosomes in GSCs, and EYA2 tyrosine (Tyr) phosphatase activity was essential for proper mitotic spindle assembly and survival of GSCs. Inhibition of the EYA2 Tyr phosphatase activity, via genetic or pharmacological means, mimicked EYA2 loss in GSCs in vitro and extended the survival of tumor-bearing mice. Supporting the clinical relevance of these findings, EYA2 portends poor patient prognosis in glioblastoma. Collectively, our data indicate that EYA2 phosphatase function plays selective critical roles in the growth and survival of GSCs, potentially offering a high therapeutic index for EYA2 inhibitors.

2.
Cancer Discov ; 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615656

RESUMO

Glioblastoma (GBM) is the most lethal primary brain cancer characterized by therapeutic resistance, which is promoted by GBM stem cells (GSCs). Here, we interrogated gene expression and whole genome CRISPR/Cas9 screening in a large panel of patient-derived GSCs, differentiated glioblastoma cells (DGCs), and neural stem cells (NSCs) 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 in vitro and in vivo. YY1 interacted with CDK9 to regulate transcription elongation in GSCs. Genetic or pharmacological targeting of YY1-CDK9 complex elicited RNA m6A modification-dependent interferon responses, reduced regulatory T cell infiltration, and augmented efficacy of immune checkpoint therapy in glioblastoma. Collectively, these results suggest that YY1-CDK9 transcription elongation complex defines a targetable cell state with active transcription, suppressed interferon responses, and immunotherapy resistance in glioblastoma.

3.
Nucleic Acids Res ; 49(13): 7361-7374, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34181729

RESUMO

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. Leveraging this platform, we specifically and efficiently edited m6A modifications at targeted sites, reflected in gene expression and cell proliferation. We employed the dCasRx epitranscriptomic editor system to elucidate the molecular function of m6A-binding proteins YTHDF paralogs (YTHDF1, YTHDF2 and YTHDF3), revealing that YTHDFs promote m6A-mediated mRNA degradation. Collectively, our dCasRx epitranscriptome perturbation platform permits site-specific m6A editing for delineating of functional roles of individual m6A modifications in the mammalian epitranscriptome.


Assuntos
Adenosina/análogos & derivados , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Metiltransferases/metabolismo , RNA Mensageiro/metabolismo , Adenosina/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/genética , Proteínas Associadas a CRISPR/genética , Proliferação de Células , Células Cultivadas , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Metiltransferases/genética , Células-Tronco Neoplásicas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/química , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transcriptoma
4.
Proc Natl Acad Sci U S A ; 118(16)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33850013

RESUMO

Sex can be an important determinant of cancer phenotype, and exploring sex-biased tumor biology holds promise for identifying novel therapeutic targets and new approaches to cancer treatment. In an established isogenic murine model of glioblastoma (GBM), we discovered correlated transcriptome-wide sex differences in gene expression, H3K27ac marks, large Brd4-bound enhancer usage, and Brd4 localization to Myc and p53 genomic binding sites. These sex-biased gene expression patterns were also evident in human glioblastoma stem cells (GSCs). These observations led us to hypothesize that Brd4-bound enhancers might underlie sex differences in stem cell function and tumorigenicity in GBM. We found that male and female GBM cells exhibited sex-specific responses to pharmacological or genetic inhibition of Brd4. Brd4 knockdown or pharmacologic inhibition decreased male GBM cell clonogenicity and in vivo tumorigenesis while increasing both in female GBM cells. These results were validated in male and female patient-derived GBM cell lines. Furthermore, analysis of the Cancer Therapeutic Response Portal of human GBM samples segregated by sex revealed that male GBM cells are significantly more sensitive to BET (bromodomain and extraterminal) inhibitors than are female cells. Thus, Brd4 activity is revealed to drive sex differences in stem cell and tumorigenic phenotypes, which can be abrogated by sex-specific responses to BET inhibition. This has important implications for the clinical evaluation and use of BET inhibitors.

5.
Stem Cells ; 39(7): 853-865, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33594762

RESUMO

Glioblastoma (GBM) ranks among the most lethal of human malignancies with GBM stem cells (GSCs) that contribute to tumor growth and therapeutic resistance. Identification and isolation of GSCs continue to be a challenge, as definitive methods to purify these cells for study or targeting are lacking. Here, we leveraged orthogonal in vitro and in vivo phage display biopanning strategies to isolate a single peptide with GSC-specific binding properties. In silico analysis of this peptide led to the isolation of EYA1 (Eyes Absent 1), a tyrosine phosphatase and transcriptional coactivator. Validating the phage discovery methods, EYA1 was preferentially expressed in GSCs compared to differentiated tumor progeny. MYC is a central mediator of GSC maintenance but has been resistant to direct targeting strategies. Based on correlation and colocalization of EYA1 and MYC, we interrogated a possible interaction, revealing binding of EYA1 to MYC and loss of MYC expression upon targeting EYA1. Supporting a functional role for EYA1, targeting EYA1 expression decreased GSC proliferation, migration, and self-renewal in vitro and tumor growth in vivo. Collectively, our results suggest that phage display can identify novel therapeutic targets in stem-like tumor cells and that an EYA1-MYC axis represents a potential therapeutic paradigm for GBM.

6.
Cancer Discov ; 11(2): 480-499, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33023892

RESUMO

Glioblastoma is a universally lethal cancer driven by glioblastoma stem cells (GSC). Here, we interrogated N 6-methyladenosine (m6A) mRNA modifications in GSCs by methyl RNA immunoprecipitation followed by sequencing and transcriptome analysis, finding transcripts marked by m6A often upregulated compared with normal neural stem cells (NSC). Interrogating m6A regulators, GSCs displayed preferential expression, as well as in vitro and in vivo dependency, of the m6A reader YTHDF2, in contrast to NSCs. Although YTHDF2 has been reported to destabilize mRNAs, YTHDF2 stabilized MYC and VEGFA transcripts in GSCs in an m6A-dependent manner. We identified IGFBP3 as a downstream effector of the YTHDF2-MYC axis in GSCs. The IGF1/IGF1R inhibitor linsitinib preferentially targeted YTHDF2-expressing cells, inhibiting GSC viability without affecting NSCs and impairing in vivo glioblastoma growth. Thus, YTHDF2 links RNA epitranscriptomic modifications and GSC growth, laying the foundation for the YTHDF2-MYC-IGFBP3 axis as a specific and novel therapeutic target in glioblastoma. SIGNIFICANCE: Epitranscriptomics promotes cellular heterogeneity in cancer. RNA m6A landscapes of cancer and NSCs identified cell type-specific dependencies and therapeutic vulnerabilities. The m6A reader YTHDF2 stabilized MYC mRNA specifically in cancer stem cells. Given the challenge of targeting MYC, YTHDF2 presents a therapeutic target to perturb MYC signaling in glioblastoma.This article is highlighted in the In This Issue feature, p. 211.

7.
Cancer Discov ; 11(5): 1192-1211, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33328215

RESUMO

Glioblastoma (GBM) contains self-renewing GBM stem cells (GSC) potentially amenable to immunologic targeting, but chimeric antigen receptor (CAR) T-cell therapy has demonstrated limited clinical responses in GBM. Here, we interrogated molecular determinants of CAR-mediated GBM killing through whole-genome CRISPR screens in both CAR T cells and patient-derived GSCs. Screening of CAR T cells identified dependencies for effector functions, including TLE4 and IKZF2. Targeted knockout of these genes enhanced CAR antitumor efficacy. Bulk and single-cell RNA sequencing of edited CAR T cells revealed transcriptional profiles of superior effector function and inhibited exhaustion responses. Reciprocal screening of GSCs identified genes essential for susceptibility to CAR-mediated killing, including RELA and NPLOC4, the knockout of which altered tumor-immune signaling and increased responsiveness of CAR therapy. Overall, CRISPR screening of CAR T cells and GSCs discovered avenues for enhancing CAR therapeutic efficacy against GBM, with the potential to be extended to other solid tumors. SIGNIFICANCE: Reciprocal CRISPR screening identified genes in both CAR T cells and tumor cells regulating the potency of CAR T-cell cytotoxicity, informing molecular targeting strategies to potentiate CAR T-cell antitumor efficacy and elucidate genetic modifications of tumor cells in combination with CAR T cells to advance immuno-oncotherapy.This article is highlighted in the In This Issue feature, p. 995.

8.
EMBO Mol Med ; 12(12): e12291, 2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-33124191

RESUMO

Nuclear matrix-associated proteins (NMPs) play critical roles in regulating chromatin organization and gene transcription by binding to the matrix attachment regions (MARs) of DNA. However, the functional significance of NMPs in glioblastoma (GBM) progression remains unclear. Here, we show that the Special AT-rich Binding Protein-2 (SATB2), one of crucial NMPs, recruits histone acetyltransferase CBP to promote the FOXM1-mediated cell proliferation and tumor growth of GBM. SATB2 is preferentially expressed by glioma stem cells (GSCs) in GBM. Disrupting SATB2 markedly inhibited GSC proliferation and GBM malignant growth by down-regulating expression of key genes involved in cell proliferation program. SATB2 activates FOXM1 expression to promote GSC proliferation through binding to the MAR sequence of FOXM1 gene locus and recruiting CBP to the MAR. Importantly, pharmacological inhibition of SATB2/CBP transcriptional activity by the CBP inhibitor C646 suppressed GSC proliferation in vitro and GBM growth in vivo. Our study uncovers a crucial role of the SATB2/CBP-mediated transcriptional regulation in GBM growth, indicating that targeting SATB2/CBP may effectively improve GBM treatment.

9.
Cancer Discov ; 10(11): 1722-1741, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32703768

RESUMO

Meningiomas are the most common primary intracranial tumor with current classification offering limited therapeutic guidance. Here, we interrogated meningioma enhancer landscapes from 33 tumors to stratify patients based upon prognosis and identify novel meningioma-specific dependencies. Enhancers robustly stratified meningiomas into three biologically distinct groups (adipogenesis/cholesterol, mesodermal, and neural crest) distinguished by distinct hormonal lineage transcriptional regulators. Meningioma landscapes clustered with intrinsic brain tumors and hormonally responsive systemic cancers with meningioma subgroups, reflecting progesterone or androgen hormonal signaling. Enhancer classification identified a subset of tumors with poor prognosis, irrespective of histologic grading. Superenhancer signatures predicted drug dependencies with superior in vitro efficacy to treatment based upon the NF2 genomic profile. Inhibition of DUSP1, a novel and druggable meningioma target, impaired tumor growth in vivo. Collectively, epigenetic landscapes empower meningioma classification and identification of novel therapies. SIGNIFICANCE: Enhancer landscapes inform prognostic classification of aggressive meningiomas, identifying tumors at high risk of recurrence, and reveal previously unknown therapeutic targets. Druggable dependencies discovered through epigenetic profiling potentially guide treatment of intractable meningiomas.This article is highlighted in the In This Issue feature, p. 1611.

10.
Cell Res ; 30(10): 833-853, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32499560

RESUMO

Brain tumors are dynamic complex ecosystems with multiple cell types. To model the brain tumor microenvironment in a reproducible and scalable system, we developed a rapid three-dimensional (3D) bioprinting method to construct clinically relevant biomimetic tissue models. In recurrent glioblastoma, macrophages/microglia prominently contribute to the tumor mass. To parse the function of macrophages in 3D, we compared the growth of glioblastoma stem cells (GSCs) alone or with astrocytes and neural precursor cells in a hyaluronic acid-rich hydrogel, with or without macrophage. Bioprinted constructs integrating macrophage recapitulate patient-derived transcriptional profiles predictive of patient survival, maintenance of stemness, invasion, and drug resistance. Whole-genome CRISPR screening with bioprinted complex systems identified unique molecular dependencies in GSCs, relative to sphere culture. Multicellular bioprinted models serve as a scalable and physiologic platform to interrogate drug sensitivity, cellular crosstalk, invasion, context-specific functional dependencies, as well as immunologic interactions in a species-matched neural environment.

11.
Trends Cancer ; 6(3): 223-235, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32101725

RESUMO

Glioblastoma is an aggressive and heterogeneous tumor in which glioblastoma stem cells (GSCs) are at the apex of an entropic hierarchy and impart devastating therapy resistance. The high entropy of GSCs is driven by a permissive epigenetic landscape and a mutational landscape that revokes crucial cellular checkpoints. The GSC population encompasses a complex array of diverse microstates that are defined and maintained by a wide variety of attractors including the complex tumor ecosystem and therapeutic intervention. Constant dynamic transcriptional fluctuations result in a highly adaptable and heterogeneous entity primed for therapy evasion and survival. Analyzing the transcriptional, epigenetic, and metabolic landscapes of GSC dynamics in the context of a stochastically fluctuating tumor network will provide novel strategies to target resistant populations of GSCs in glioblastoma.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Evolução Clonal , Resistencia a Medicamentos Antineoplásicos , Entropia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/terapia , Humanos , Terapia de Alvo Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Nicho de Células-Tronco , Transcrição Genética , Microambiente Tumoral
12.
Cell Stem Cell ; 26(2): 187-204.e10, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-31956038

RESUMO

Zika virus (ZIKV) causes microcephaly by killing neural precursor cells (NPCs) and other brain cells. ZIKV also displays therapeutic oncolytic activity against glioblastoma (GBM) stem cells (GSCs). Here we demonstrate that ZIKV preferentially infected and killed GSCs and stem-like cells in medulloblastoma and ependymoma in a SOX2-dependent manner. Targeting SOX2 severely attenuated ZIKV infection, in contrast to AXL. As mechanisms of SOX2-mediated ZIKV infection, we identified inverse expression of antiviral interferon response genes (ISGs) and positive correlation with integrin αv (ITGAV). ZIKV infection was disrupted by genetic targeting of ITGAV or its binding partner ITGB5 and by an antibody specific for integrin αvß5. ZIKV selectively eliminated GSCs from species-matched human mature cerebral organoids and GBM surgical specimens, which was reversed by integrin αvß5 inhibition. Collectively, our studies identify integrin αvß5 as a functional cancer stem cell marker essential for GBM maintenance and ZIKV infection, providing potential brain tumor therapy.


Assuntos
Glioblastoma , Células-Tronco Neurais , Infecção por Zika virus , Zika virus , Humanos , Receptores de Vitronectina , Fatores de Transcrição SOXB1/genética
13.
Cancer Discov ; 9(11): 1556-1573, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31455674

RESUMO

Glioblastomas are highly lethal cancers, containing self-renewing glioblastoma stem cells (GSC). Here, we show that GSCs, differentiated glioblastoma cells (DGC), and nonmalignant brain cultures all displayed robust circadian rhythms, yet GSCs alone displayed exquisite dependence on core clock transcription factors, BMAL1 and CLOCK, for optimal cell growth. Downregulation of BMAL1 or CLOCK in GSCs induced cell-cycle arrest and apoptosis. Chromatin immunoprecipitation revealed that BMAL1 preferentially bound metabolic genes and was associated with active chromatin regions in GSCs compared with neural stem cells. Targeting BMAL1 or CLOCK attenuated mitochondrial metabolic function and reduced expression of tricarboxylic acid cycle enzymes. Small-molecule agonists of two independent BMAL1-CLOCK negative regulators, the cryptochromes and REV-ERBs, downregulated stem cell factors and reduced GSC growth. Combination of cryptochrome and REV-ERB agonists induced synergistic antitumor efficacy. Collectively, these findings show that GSCs co-opt circadian regulators beyond canonical circadian circuitry to promote stemness maintenance and metabolism, offering novel therapeutic paradigms. SIGNIFICANCE: Cancer stem cells are highly malignant tumor-cell populations. We demonstrate that GSCs selectively depend on circadian regulators, with increased binding of the regulators in active chromatin regions promoting tumor metabolism. Supporting clinical relevance, pharmacologic targeting of circadian networks specifically disrupted cancer stem cell growth and self-renewal.This article is highlighted in the In This Issue feature, p. 1469.


Assuntos
Fatores de Transcrição ARNTL/genética , Neoplasias Encefálicas/tratamento farmacológico , Proteínas CLOCK/genética , Glioblastoma/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/administração & dosagem , Animais , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Relógios Circadianos/efeitos dos fármacos , Ciclo do Ácido Cítrico/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Humanos , Camundongos , Células-Tronco Neoplásicas/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Sci Transl Med ; 11(504)2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391321

RESUMO

Glioblastoma stem cells (GSCs) reprogram glucose metabolism by hijacking high-affinity glucose uptake to survive in a nutritionally dynamic microenvironment. Here, we trace metabolic aberrations in GSCs to link core genetic mutations in glioblastoma to dependency on de novo pyrimidine synthesis. Targeting the pyrimidine synthetic rate-limiting step enzyme carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, dihydroorotase (CAD) or the critical downstream enzyme dihydroorotate dehydrogenase (DHODH) inhibited GSC survival, self-renewal, and in vivo tumor initiation through the depletion of the pyrimidine nucleotide supply in rodent models. Mutations in EGFR or PTEN generated distinct CAD phosphorylation patterns to activate carbon influx through pyrimidine synthesis. Simultaneous abrogation of tumor-specific driver mutations and DHODH activity with clinically approved inhibitors demonstrated sustained inhibition of metabolic activity of pyrimidine synthesis and GSC tumorigenic capacity in vitro. Higher expression of pyrimidine synthesis genes portends poor prognosis of patients with glioblastoma. Collectively, our results demonstrate a therapeutic approach of precision medicine through targeting the nexus between driver mutations and metabolic reprogramming in cancer stem cells.


Assuntos
Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Terapia de Alvo Molecular , Células-Tronco Neoplásicas/patologia , Pirimidinas/biossíntese , Animais , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Crotonatos/farmacologia , Receptores ErbB/metabolismo , Deleção de Genes , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Toluidinas/farmacologia , Resultado do Tratamento , Regulação para Cima/efeitos dos fármacos
15.
Cancer Discov ; 9(9): 1248-1267, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31201181

RESUMO

Glioblastoma ranks among the most aggressive and lethal of all human cancers. Functionally defined glioma stem cells (GSC) contribute to this poor prognosis by driving therapeutic resistance and maintaining cellular heterogeneity. To understand the molecular processes essential for GSC maintenance and tumorigenicity, we interrogated the superenhancer landscapes of primary glioblastoma specimens and in vitro GSCs. GSCs epigenetically upregulated ELOVL2, a key polyunsaturated fatty-acid synthesis enzyme. Targeting ELOVL2 inhibited glioblastoma cell growth and tumor initiation. ELOVL2 depletion altered cellular membrane phospholipid composition, disrupted membrane structural properties, and diminished EGFR signaling through control of fatty-acid elongation. In support of the translational potential of these findings, dual targeting of polyunsaturated fatty-acid synthesis and EGFR signaling had a combinatorial cytotoxic effect on GSCs. SIGNIFICANCE: Glioblastoma remains a devastating disease despite extensive characterization. We profiled epigenomic landscapes of glioblastoma to pinpoint cell state-specific dependencies and therapeutic vulnerabilities. GSCs utilize polyunsaturated fatty-acid synthesis to support membrane architecture, inhibition of which impairs EGFR signaling and GSC proliferation. Combinatorial targeting of these networks represents a promising therapeutic strategy.See related commentary by Affronti and Wellen, p. 1161.This article is highlighted in the In This Issue feature, p. 1143.


Assuntos
Neoplasias Encefálicas/patologia , Elementos Facilitadores Genéticos , Elongases de Ácidos Graxos/genética , Glioblastoma/patologia , Células-Tronco Neoplásicas/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Epigênese Genética , Receptores ErbB/metabolismo , Ácidos Graxos Insaturados/biossíntese , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Histonas/metabolismo , Humanos , Metilação , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais , Regulação para Cima
16.
J Exp Med ; 216(5): 1071-1090, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-30948495

RESUMO

Glioblastoma is an incurable brain cancer characterized by high genetic and pathological heterogeneity. Here, we mapped active chromatin landscapes with gene expression, whole exomes, copy number profiles, and DNA methylomes across 44 patient-derived glioblastoma stem cells (GSCs), 50 primary tumors, and 10 neural stem cells (NSCs) to identify essential super-enhancer (SE)-associated genes and the core transcription factors that establish SEs and maintain GSC identity. GSCs segregate into two groups dominated by distinct enhancer profiles and unique developmental core transcription factor regulatory programs. Group-specific transcription factors enforce GSC identity; they exhibit higher activity in glioblastomas versus NSCs, are associated with poor clinical outcomes, and are required for glioblastoma growth in vivo. Although transcription factors are commonly considered undruggable, group-specific enhancer regulation of the MAPK/ERK pathway predicts sensitivity to MEK inhibition. These data demonstrate that transcriptional identity can be leveraged to identify novel dependencies and therapeutic approaches.


Assuntos
Neoplasias Encefálicas/genética , Cromatina/genética , Glioblastoma/genética , Transcrição Genética/genética , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Carcinogênese/genética , Linhagem Celular Tumoral , Estudos de Coortes , Regulação Neoplásica da Expressão Gênica , Glioblastoma/patologia , Glioblastoma/cirurgia , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neurais/metabolismo , Fatores de Transcrição/genética , Transcriptoma
17.
JCI Insight ; 4(7)2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30779712

RESUMO

Glioblastomas, which contain stem cell-like glioblastoma stem cells (GSCs), are universally lethal cancers. While neural stem cells (NSCs) are usually quiescent, single-cell studies suggest that proliferating glioblastoma cells reside in the GSC population. Interrogating in silico glioma databases for epigenetic regulators that correlate with cell cycle regulation, we identified the chromatin remodeler HELLS as a potential target in glioblastoma. GSCs preferentially expressed HELLS compared with their differentiated tumor progeny and nonmalignant brain cells. Targeting HELLS disrupted GSC proliferation, survival, and self-renewal with induction of replication stress and DNA damage. Investigating potential molecular mechanisms downstream of HELLS revealed that HELLS interacted with the core oncogenic transcription factors, E2F3 and MYC, to regulate gene expression critical to GSC proliferation and maintenance. Supporting the interaction, HELLS expression strongly correlated with targets of E2F3 and MYC transcriptional activity in glioblastoma patients. The potential clinical significance of HELLS was reinforced by improved survival of tumor-bearing mice upon targeting HELLS and poor prognosis of glioma patients with elevated HELLS expression. Collectively, targeting HELLS may permit the functional disruption of the relatively undruggable MYC and E2F3 transcription factors and serve as a novel therapeutic paradigm for glioblastoma.


Assuntos
Neoplasias Encefálicas/genética , DNA Helicases/metabolismo , Fator de Transcrição E2F3/metabolismo , Glioblastoma/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Encéfalo/patologia , Encéfalo/cirurgia , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/metabolismo , Conjuntos de Dados como Assunto , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioblastoma/mortalidade , Glioblastoma/patologia , Glioblastoma/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Células-Tronco Neoplásicas/metabolismo , Mapeamento de Interação de Proteínas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Cell Stem Cell ; 24(1): 41-53, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30609398

RESUMO

Cancer stem cells (CSCs) proactively remodel their microenvironment to maintain a supportive niche. Viewed through the lens of an ecosystem, numerous tumor components have multi-directional interactions involving CSCs, supporting the complexity of tumors to maintain growth in a dynamic host. In this Perspective, we discuss how CSCs are active architects of their microenvironment and drive interactions with other tumor components, such as immune cells, cancer-associated fibroblasts and differentiated cells, blood vessels, and other extracellular cues to engineer a sustainable niche. We also highlight considerations for modeling this dynamic tumor ecology and discuss potential therapeutic strategies for targeting these multifaceted interactions.


Assuntos
Matriz Extracelular/patologia , Neoplasias/patologia , Células-Tronco Neoplásicas/patologia , Microambiente Tumoral , Animais , Diferenciação Celular , Humanos
19.
Cell ; 175(5): 1228-1243.e20, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30392959

RESUMO

Genetic drivers of cancer can be dysregulated through epigenetic modifications of DNA. Although the critical role of DNA 5-methylcytosine (5mC) in the regulation of transcription is recognized, the functions of other non-canonical DNA modifications remain obscure. Here, we report the identification of novel N6-methyladenine (N6-mA) DNA modifications in human tissues and implicate this epigenetic mark in human disease, specifically the highly malignant brain cancer glioblastoma. Glioblastoma markedly upregulated N6-mA levels, which co-localized with heterochromatic histone modifications, predominantly H3K9me3. N6-mA levels were dynamically regulated by the DNA demethylase ALKBH1, depletion of which led to transcriptional silencing of oncogenic pathways through decreasing chromatin accessibility. Targeting the N6-mA regulator ALKBH1 in patient-derived human glioblastoma models inhibited tumor cell proliferation and extended the survival of tumor-bearing mice, supporting this novel DNA modification as a potential therapeutic target for glioblastoma. Collectively, our results uncover a novel epigenetic node in cancer through the DNA modification N6-mA.


Assuntos
Adenina/análogos & derivados , Neoplasias Encefálicas/patologia , Metilação de DNA , Glioblastoma/patologia , Adenina/análise , Adenina/química , Adulto , Idoso , Homólogo AlkB 1 da Histona H2a Dioxigenase/antagonistas & inibidores , Homólogo AlkB 1 da Histona H2a Dioxigenase/genética , Homólogo AlkB 1 da Histona H2a Dioxigenase/metabolismo , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Hipóxia Celular , Criança , Epigenômica , Feminino , Glioblastoma/metabolismo , Glioblastoma/mortalidade , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína Supressora de Tumor p53/metabolismo
20.
Cell Stem Cell ; 22(4): 514-528.e5, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29625067

RESUMO

Glioblastoma is the most lethal primary brain tumor; however, the crosstalk between glioblastoma stem cells (GSCs) and their supportive niche is not well understood. Here, we interrogated reciprocal signaling between GSCs and their differentiated glioblastoma cell (DGC) progeny. We found that DGCs accelerated GSC tumor growth. DGCs preferentially expressed brain-derived neurotrophic factor (BDNF), whereas GSCs expressed the BDNF receptor NTRK2. Forced BDNF expression in DGCs augmented GSC tumor growth. To determine molecular mediators of BDNF-NTRK2 paracrine signaling, we leveraged transcriptional and epigenetic profiles of matched GSCs and DGCs, revealing preferential VGF expression by GSCs, which patient-derived tumor models confirmed. VGF serves a dual role in the glioblastoma hierarchy by promoting GSC survival and stemness in vitro and in vivo while also supporting DGC survival and inducing DGC secretion of BDNF. Collectively, these data demonstrate that differentiated glioblastoma cells cooperate with stem-like tumor cells through BDNF-NTRK2-VGF paracrine signaling to promote tumor growth.


Assuntos
Neoplasias Encefálicas/metabolismo , Progressão da Doença , Glioblastoma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Transdução de Sinais , Neoplasias Encefálicas/patologia , Diferenciação Celular , Glioblastoma/patologia , Humanos , Células-Tronco Neoplásicas/patologia
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