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1.
Cell ; 161(4): 803-16, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25913192

RESUMO

Active neurons exert a mitogenic effect on normal neural precursor and oligodendroglial precursor cells, the putative cellular origins of high-grade glioma (HGG). By using optogenetic control of cortical neuronal activity in a patient-derived pediatric glioblastoma xenograft model, we demonstrate that active neurons similarly promote HGG proliferation and growth in vivo. Conditioned medium from optogenetically stimulated cortical slices promoted proliferation of pediatric and adult patient-derived HGG cultures, indicating secretion of activity-regulated mitogen(s). The synaptic protein neuroligin-3 (NLGN3) was identified as the leading candidate mitogen, and soluble NLGN3 was sufficient and necessary to promote robust HGG cell proliferation. NLGN3 induced PI3K-mTOR pathway activity and feedforward expression of NLGN3 in glioma cells. NLGN3 expression levels in human HGG negatively correlated with patient overall survival. These findings indicate the important role of active neurons in the brain tumor microenvironment and identify secreted NLGN3 as an unexpected mechanism promoting neuronal activity-regulated cancer growth.


Assuntos
Neoplasias Encefálicas/patologia , Moléculas de Adesão Celular Neuronais/metabolismo , Proliferação de Células , Glioma/patologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Adolescente , Sequência de Aminoácidos , Animais , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Xenoenxertos , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Transplante de Neoplasias , Neurônios/metabolismo
3.
Proc Natl Acad Sci U S A ; 116(3): 997-1006, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30602457

RESUMO

Glioblastoma multiforme (GBM) is a highly aggressive malignant brain tumor with fatal outcome. Tumor-associated macrophages and microglia (TAMs) have been found to be major tumor-promoting immune cells in the tumor microenvironment. Hence, modulation and reeducation of tumor-associated macrophages and microglia in GBM is considered a promising antitumor strategy. Resident microglia and invading macrophages have been shown to have distinct origin and function. Whereas yolk sac-derived microglia reside in the brain, blood-derived monocytes invade the central nervous system only under pathological conditions like tumor formation. We recently showed that disruption of the SIRPα-CD47 signaling axis is efficacious against various brain tumors including GBM primarily by inducing tumor phagocytosis. However, most effects are attributed to macrophages recruited from the periphery but the role of the brain resident microglia is unknown. Here, we sought to utilize a model to distinguish resident microglia and peripheral macrophages within the GBM-TAM pool, using orthotopically xenografted, immunodeficient, and syngeneic mouse models with genetically color-coded macrophages (Ccr2RFP) and microglia (Cx3cr1GFP). We show that even in the absence of phagocytizing macrophages (Ccr2RFP/RFP), microglia are effector cells of tumor cell phagocytosis in response to anti-CD47 blockade. Additionally, macrophages and microglia show distinct morphological and transcriptional changes. Importantly, the transcriptional profile of microglia shows less of an inflammatory response which makes them a promising target for clinical applications.


Assuntos
Neoplasias Encefálicas/imunologia , Antígeno CD47/imunologia , Glioblastoma/imunologia , Microglia/imunologia , Proteínas de Neoplasias/imunologia , Neoplasias Experimentais/imunologia , Fagocitose , Receptores Imunológicos/imunologia , Transdução de Sinais/imunologia , Animais , Neoplasias Encefálicas/patologia , Antígeno CD47/genética , Glioblastoma/genética , Glioblastoma/patologia , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Microglia/patologia , Monócitos/imunologia , Monócitos/patologia , Proteínas de Neoplasias/genética , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , Receptores Imunológicos/genética , Transdução de Sinais/genética
4.
Genes Dev ; 27(24): 2642-7, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24352421

RESUMO

The self-renewal versus differentiation choice of Drosophila and mammalian neural stem cells (NSCs) requires Notch (N) signaling. How N regulates NSC behavior is not well understood. Here we show that canonical N signaling cooperates with a noncanonical N signaling pathway to mediate N-directed NSC regulation. In the noncanonical pathway, N interacts with PTEN-induced kinase 1 (PINK1) to influence mitochondrial function, activating mechanistic target of rapamycin complex 2 (mTORC2)/AKT signaling. Importantly, attenuating noncanonical N signaling preferentially impaired the maintenance of Drosophila and human cancer stem cell-like tumor-forming cells. Our results emphasize the importance of mitochondria to N and NSC biology, with important implications for diseases associated with aberrant N signaling.


Assuntos
Mitocôndrias/metabolismo , Complexos Multiproteicos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas Quinases/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Animais , Neoplasias Encefálicas/fisiopatologia , Linhagem Celular Tumoral , Proliferação de Células , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina , Microscopia Eletrônica de Transmissão , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Complexos Multiproteicos/genética , Mutação , Proteínas Quinases/genética , Interferência de RNA , Serina-Treonina Quinases TOR/genética
5.
Adv Exp Med Biol ; 1273: 197-208, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33119883

RESUMO

Microglia are the brain resident phagocytes that act as the primary form of the immune defense in the central nervous system. These cells originate from primitive macrophages that arise from the yolk sac. Advances in imaging and single-cell RNA-seq technologies provided new insights into the complexity of microglia biology.Microglia play an essential role in the brain development and maintenance of brain homeostasis. They are also crucial in injury repair in the central nervous system. The tumor microenvironment is complex and includes neoplastic cells as well as varieties of host and infiltrating immune cells. Microglia are part of the glioma microenvironment and play a critical part in initiating and maintaining tumor growth and spread. Microglia can also act as effector cells in treatments against gliomas. In this chapter, we summarize the current knowledge of how and where microglia are generated. We also discuss their functions during brain development, injury repair, and homeostasis. Moreover, we discuss the role of microglia in the tumor microenvironment of gliomas and highlight their therapeutic implications.


Assuntos
Neoplasias Encefálicas/imunologia , Glioma/imunologia , Microglia/citologia , Microambiente Tumoral/imunologia , Encéfalo/imunologia , Neoplasias Encefálicas/terapia , Glioma/terapia , Humanos , Microglia/imunologia
6.
Nature ; 501(7467): 380-4, 2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-24025767

RESUMO

Down's syndrome results from full or partial trisomy of chromosome 21. However, the consequences of the underlying gene-dosage imbalance on adult tissues remain poorly understood. Here we show that in Ts65Dn mice, which are trisomic for 132 genes homologous to genes on human chromosome 21, triplication of Usp16 reduces the self-renewal of haematopoietic stem cells and the expansion of mammary epithelial cells, neural progenitors and fibroblasts. In addition, Usp16 is associated with decreased ubiquitination of Cdkn2a and accelerated senescence in Ts65Dn fibroblasts. Usp16 can remove ubiquitin from histone H2A on lysine 119, a critical mark for the maintenance of multiple somatic tissues. Downregulation of Usp16, either by mutation of a single normal Usp16 allele or by short interfering RNAs, largely rescues all of these defects. Furthermore, in human tissues overexpression of USP16 reduces the expansion of normal fibroblasts and postnatal neural progenitors, whereas downregulation of USP16 partially rescues the proliferation defects of Down's syndrome fibroblasts. Taken together, these results suggest that USP16 has an important role in antagonizing the self-renewal and/or senescence pathways in Down's syndrome and could serve as an attractive target to ameliorate some of the associated pathologies.


Assuntos
Síndrome de Down/metabolismo , Síndrome de Down/patologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Ubiquitina Tiolesterase/metabolismo , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/patologia , Animais , Proliferação de Células , Senescência Celular , Cromossomos Humanos Par 21/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Modelos Animais de Doenças , Síndrome de Down/genética , Epitélio/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Dosagem de Genes , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/patologia , Humanos , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Camundongos , Terapia de Alvo Molecular , Trissomia/genética , Ubiquitina Tiolesterase/genética , Ubiquitinação
7.
Proc Natl Acad Sci U S A ; 112(7): 2145-50, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25646432

RESUMO

Macrophage-mediated programmed cell removal (PrCR) is an important mechanism of eliminating diseased and damaged cells before programmed cell death. The induction of PrCR by eat-me signals on tumor cells is countered by don't-eat-me signals such as CD47, which binds macrophage signal-regulatory protein α to inhibit phagocytosis. Blockade of CD47 on tumor cells leads to phagocytosis by macrophages. Here we demonstrate that the activation of Toll-like receptor (TLR) signaling pathways in macrophages synergizes with blocking CD47 on tumor cells to enhance PrCR. Bruton's tyrosine kinase (Btk) mediates TLR signaling in macrophages. Calreticulin, previously shown to be an eat-me signal on cancer cells, is activated in macrophages for secretion and cell-surface exposure by TLR and Btk to target cancer cells for phagocytosis, even if the cancer cells themselves do not express calreticulin.


Assuntos
Calreticulina/fisiologia , Macrófagos/imunologia , Neoplasias/patologia , Proteínas Tirosina Quinases/metabolismo , Receptores Toll-Like/fisiologia , Tirosina Quinase da Agamaglobulinemia , Humanos , Neoplasias/enzimologia , Neoplasias/metabolismo
8.
J Neurooncol ; 123(3): 449-57, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25682090

RESUMO

Advancements in immunotherapeutics promise new possibilities for the creation of glioblastoma (GBM) treatment options. Ongoing work in cancer stem cell biology has progressively elucidated the role of this tumor sub-population in oncogenesis and has distinguished them as prime therapeutic targets. Current clinical trials take a multifaceted approach with the intention of harnessing the intrinsic cytotoxic capabilities of the immune system to directly target glioblastoma cancer stem cells (gCSC) or indirectly disrupt their stromal microenvironment. Monoclonal antibodies (mAbs), dendritic cell (DC) vaccines, and chimeric antigen receptor (CAR) T cell therapies have emerged as the most common approaches, with particular iterations incorporating cancer stem cell antigenic markers in their treatment designs. Ongoing work to determine the comprehensive antigenic profile of the gCSC in conjunction with efforts to counter the immunosuppressive tumor microenvironment holds much promise in future immunotherapeutic strategies against GBM. Given recent advancements in these fields, we believe there is tremendous potential to improve outcomes of GBM patients in the continuing evolution of immunotherapies targeted to cancer stem cell populations in GBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Imunoterapia/métodos , Células-Tronco Neoplásicas/fisiologia , Animais , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Glioblastoma/imunologia , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Terapia de Imunossupressão
9.
Proc Natl Acad Sci U S A ; 109(17): 6662-7, 2012 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-22451913

RESUMO

CD47, a "don't eat me" signal for phagocytic cells, is expressed on the surface of all human solid tumor cells. Analysis of patient tumor and matched adjacent normal (nontumor) tissue revealed that CD47 is overexpressed on cancer cells. CD47 mRNA expression levels correlated with a decreased probability of survival for multiple types of cancer. CD47 is a ligand for SIRPα, a protein expressed on macrophages and dendritic cells. In vitro, blockade of CD47 signaling using targeted monoclonal antibodies enabled macrophage phagocytosis of tumor cells that were otherwise protected. Administration of anti-CD47 antibodies inhibited tumor growth in orthotopic immunodeficient mouse xenotransplantation models established with patient tumor cells and increased the survival of the mice over time. Anti-CD47 antibody therapy initiated on larger tumors inhibited tumor growth and prevented or treated metastasis, but initiation of the therapy on smaller tumors was potentially curative. The safety and efficacy of targeting CD47 was further tested and validated in immune competent hosts using an orthotopic mouse breast cancer model. These results suggest all human solid tumor cells require CD47 expression to suppress phagocytic innate immune surveillance and elimination. These data, taken together with similar findings with other human neoplasms, show that CD47 is a commonly expressed molecule on all cancers, its function to block phagocytosis is known, and blockade of its function leads to tumor cell phagocytosis and elimination. CD47 is therefore a validated target for cancer therapies.


Assuntos
Antígenos de Diferenciação/metabolismo , Antígeno CD47/imunologia , Neoplasias/imunologia , RNA Mensageiro/genética , Receptores Imunológicos/metabolismo , Anticorpos/imunologia , Antígeno CD47/genética , Divisão Celular/imunologia , Citometria de Fluxo , Humanos , Neoplasias/patologia , Neoplasias/terapia , Fagocitose/imunologia , Prognóstico , Análise de Sobrevida
10.
Proc Natl Acad Sci U S A ; 108(11): 4453-8, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21368213

RESUMO

Diffuse intrinsic pontine gliomas (DIPGs) are highly aggressive tumors of childhood that are almost universally fatal. Our understanding of this devastating cancer is limited by a dearth of available tissue for study and by the lack of a faithful animal model. Intriguingly, DIPGs are restricted to the ventral pons and occur during a narrow window of middle childhood, suggesting dysregulation of a postnatal neurodevelopmental process. Here, we report the identification of a previously undescribed population of immunophenotypic neural precursor cells in the human and murine brainstem whose temporal and spatial distributions correlate closely with the incidence of DIPG and highlight a candidate cell of origin. Using early postmortem DIPG tumor tissue, we have established in vitro and xenograft models and find that the Hedgehog (Hh) signaling pathway implicated in many developmental and oncogenic processes is active in DIPG tumor cells. Modulation of Hh pathway activity has functional consequences for DIPG self-renewal capacity in neurosphere culture. The Hh pathway also appears to be active in normal ventral pontine precursor-like cells of the mouse, and unregulated pathway activity results in hypertrophy of the ventral pons. Together, these findings provide a foundation for understanding the cellular and molecular origins of DIPG, and suggest that the Hh pathway represents a potential therapeutic target in this devastating pediatric tumor.


Assuntos
Neoplasias do Tronco Encefálico/metabolismo , Neoplasias do Tronco Encefálico/patologia , Linhagem da Célula , Proteínas Hedgehog/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Agregação Celular , Proliferação de Células , Humanos , Proteínas de Filamentos Intermediários/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Nestina , Fator de Transcrição 2 de Oligodendrócitos , Ponte/crescimento & desenvolvimento , Ponte/patologia , Transdução de Sinais , Fatores de Tempo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Cancer Res Commun ; 4(8): 1919-1932, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38984891

RESUMO

Chromobox 2 (CBX2), an epigenetic reader and component of polycomb repressor complex 1, is highly expressed in >75% of high-grade serous carcinoma. Increased CBX2 expression is associated with poorer survival, whereas CBX2 knockdown leads to improved chemotherapy sensitivity. In a high-grade serous carcinoma immune-competent murine model, knockdown of CBX2 decreased tumor progression. We sought to explore the impact of modulation of CBX2 on the tumor immune microenvironment (TIME), understanding that the TIME plays a critical role in disease progression and development of therapy resistance. Exploration of existing datasets demonstrated that elevated CBX2 expression significantly correlated with specific immune cell types in the TIME. RNA sequencing and pathway analysis of differentially expressed genes demonstrated immune signature enrichment. Confocal microscopy and co-culture experiments found that modulation of CBX2 leads to increased recruitment and infiltration of macrophages. Flow cytometry of macrophages cultured with CBX2-overexpressing cells showed increased M2-like macrophages and decreased phagocytosis activity. Cbx2 knockdown in the Trp53-null, Brca2-null ID8 syngeneic murine model (ID8 Trp53-/-Brca2-/-) led to decreased tumor progression compared with the control. NanoString immuno-oncology panel analysis suggested that knockdown in Cbx2 shifts immune cell composition, with an increase in macrophages. Multispectral immunohistochemistry (mIHC) further confirmed an increase in macrophage infiltration. Increased CBX2 expression leads to recruitment and polarization of protumor macrophages, and targeting CBX2 may serve to modulate the TIME to enhance the efficacy of immune therapies. SIGNIFICANCE: CBX2 expression correlates with the TIME. CBX2 modulation shifts the macrophage population, potentially leading to an immunosuppressive microenvironment, highlighting CBX2 as a target to improve efficacy of immunotherapy.


Assuntos
Microambiente Tumoral , Animais , Camundongos , Humanos , Feminino , Cistadenocarcinoma Seroso/patologia , Cistadenocarcinoma Seroso/metabolismo , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/imunologia , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/imunologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Macrófagos/metabolismo , Macrófagos/imunologia , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética
12.
Neuro Oncol ; 26(6): 1109-1123, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38334125

RESUMO

BACKGROUND: Cellular senescence can have positive and negative effects on the body, including aiding in damage repair and facilitating tumor growth. Adamantinomatous craniopharyngioma (ACP), the most common pediatric sellar/suprasellar brain tumor, poses significant treatment challenges. Recent studies suggest that senescent cells in ACP tumors may contribute to tumor growth and invasion by releasing a senesecence-associated secretory phenotype. However, a detailed analysis of these characteristics has yet to be completed. METHODS: We analyzed primary tissue samples from ACP patients using single-cell, single-nuclei, and spatial RNA sequencing. We performed various analyses, including gene expression clustering, inferred senescence cells from gene expression, and conducted cytokine signaling inference. We utilized LASSO to select essential gene expression pathways associated with senescence. Finally, we validated our findings through immunostaining. RESULTS: We observed significant diversity in gene expression and tissue structure. Key factors such as NFKB, RELA, and SP1 are essential in regulating gene expression, while senescence markers are present throughout the tissue. SPP1 is the most significant cytokine signaling network among ACP cells, while the Wnt signaling pathway predominantly occurs between epithelial and glial cells. Our research has identified links between senescence-associated features and pathways, such as PI3K/Akt/mTOR, MYC, FZD, and Hedgehog, with increased P53 expression associated with senescence in these cells. CONCLUSIONS: A complex interplay between cellular senescence, cytokine signaling, and gene expression pathways underlies ACP development. Further research is crucial to understand how these elements interact to create novel therapeutic approaches for patients with ACP.


Assuntos
Senescência Celular , Craniofaringioma , Aprendizado de Máquina , Neoplasias Hipofisárias , Humanos , Craniofaringioma/metabolismo , Craniofaringioma/patologia , Craniofaringioma/genética , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/genética , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/genética , Fenótipo , Regulação Neoplásica da Expressão Gênica , Criança , Masculino , Feminino
13.
J Membr Biol ; 245(8): 495-506, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22965738

RESUMO

Attenuation in gap junctional coupling has consistently been associated with induction of rapid or synchronous cell division in normal and pathological conditions. In the case of the v-src oncogene, gating of Cx43 gap junction channels has been linked to both direct phosphorylation of tyrosines (Y247 and 265) and phosphorylation of the serine targets of Erk1/2 (S255, 279 and 282) on the cytoplasmic C-terminal domain of Cx43. However, only the latter has been associated with acute, rather than chronic, gating of the channels immediately after v-src expression, a process that is mediated through a "ball-and-chain" mechanism. In this study we show that, while ERK1/2 is necessary for acute closure of gap junction channels, it is not sufficient. Rather, multiple pathways converge to regulate Cx43 coupling in response to expression of v-src, including parallel signaling through PKC and MEK1/2, with additional positive and negative regulatory effects mediated by PI3 kinase, distinguished by the involvement of Akt.


Assuntos
Conexina 43/metabolismo , Junções Comunicantes/fisiologia , Regulação da Expressão Gênica/fisiologia , Ativação do Canal Iônico/fisiologia , Proteína Oncogênica pp60(v-src)/metabolismo , Oócitos/fisiologia , Transdução de Sinais/fisiologia , Animais , Células Cultivadas , Relação Estrutura-Atividade , Xenopus laevis
14.
J Neurooncol ; 108(3): 395-402, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22382786

RESUMO

Despite numerous clinical trials over the past 2 decades, the overall survival for children diagnosed with diffuse intrinsic pontine glioma (DIPG) remains 9-10 months. Radiation therapy is the only treatment with proven effect and novel therapies are needed. Epidermal growth factor receptor variant III (EGFRvIII) is the most common variant of the epidermal growth factor receptor and is expressed in many tumor types but is rarely found in normal tissue. A peptide vaccine targeting EGFRvIII is currently undergoing investigation in phase 3 clinical trials for the treatment of newly diagnosed glioblastoma (GBM), the tumor in which this variant receptor was first discovered. In this study, we evaluated EGFRvIII expression in pediatric DIPG samples using immunohistochemistry with a double affinity purified antibody raised against the EGFRvIII peptide. Staining of pediatric DIPG histological samples revealed expression in 4 of 9 cases and the pattern of staining was consistent with what has been seen in EGFRvIII transfected cells as well as GBMs from adult trials. In addition, analysis of tumor samples collected immediately post mortem and of DIPG cells in culture by RT-PCR, western blot analysis, and flow cytometry confirmed EGFRvIII expression. We were therefore able to detect EGFRvIII expression in 6 of 11 DIPG cases. These data suggest that EGFRvIII warrants investigation as a target for these deadly pediatric tumors.


Assuntos
Neoplasias do Tronco Encefálico/genética , Receptores ErbB/genética , Adulto , Western Blotting , Neoplasias do Tronco Encefálico/metabolismo , Pré-Escolar , Receptores ErbB/metabolismo , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Fragmentos de Peptídeos/imunologia , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Clin Cancer Res ; 28(11): 2409-2424, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35344040

RESUMO

PURPOSE: Tumor relapse after radiotherapy is a major hurdle in treating pediatric H3K27M-mutant diffuse midline gliomas (DMG). Radiotherapy-induced stress increases association of BCL2 family of proteins with BH3 pro-apoptotic activators preventing apoptosis. We hypothesized that inhibition of radiotherapy-induced BCL2 with a clinically relevant inhibitor, venetoclax, will block BCL2 activity leading to increased apoptosis. BCL2 has never been implicated in DMG as a radiotherapy-induced resistant mechanism. EXPERIMENTAL DESIGN: We performed an integrated genomic analysis to determine genes responsible for radioresistance and a targeted drug screen to identify drugs that synergize with radiation in DMG. Effect of venetoclax on radiation-naïve and 6 Gy radiation on cells was evaluated by studying cell death, changes in BCL2 phosphorylation, reactive oxygen species (ROS), and apoptosis, as well as BCL2 association with BH3 apoptosis initiators. The efficacy of combining venetoclax with radiation was evaluated in vivo using orthotopic xenograft models. RESULTS: BCL2 was identified as a key regulator of tumor growth after radiation in DMGs. Radiation sensitizes DMGs to venetoclax treatment independent of p53 status. Venetoclax as a monotherapy was not cytotoxic to DMG cells. Postradiation venetoclax treatment significantly increased cell death, reduced BCL2-BIM association, and augmented mitochondrial ROS leading to increased apoptosis. Combining venetoclax with radiotherapy significantly enhanced the survival of mice with DMG tumors. CONCLUSIONS: This study shows that venetoclax impedes the antiapoptotic function of radiation-induced BCL2 in DMG, leading to increased apoptosis. Results from these preclinical studies demonstrate the potential use of the BCL2 inhibitor venetoclax combined with radiotherapy for pediatric DMG.


Assuntos
Antineoplásicos , Glioma , Animais , Antineoplásicos/farmacologia , Apoptose , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Linhagem Celular Tumoral , Glioma/tratamento farmacológico , Glioma/genética , Glioma/radioterapia , Humanos , Camundongos , Recidiva Local de Neoplasia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2 , Radiação Ionizante , Espécies Reativas de Oxigênio , Sulfonamidas
16.
Mol Cancer Ther ; 20(6): 961-974, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33850005

RESUMO

While immunotherapy has revolutionized the treatment of many types of advanced cancer, most patients still do not derive benefit. The currently available immune checkpoint inhibitors target the adaptive immune system, generating a T-cell antitumor response. However, an antitumor immune response depends on a complex interplay of both innate and adaptive immune cells. The innate immune system is a promising new target, and innate immune checkpoint inhibitors can disrupt inhibitory interactions ("don't eat me" signals) between tumor and both phagocytes and natural killer cells. The checkpoint inhibitor may also provide a stimulatory interaction ("eat me" signal), or this can be achieved through use of combination therapy. This generates antitumor effector functions including phagocytosis, natural cytotoxicity, antibody-dependent effects, and synergistic activation of the adaptive immune system via antigen presentation. This is a rapidly expanding area of drug development, either alone or in combination (with anticancer antibodies or adaptive immune checkpoint inhibitors). Here, we comprehensively review the mechanism of action and up-to-date solid tumor clinical trial data of the drugs targeting phagocytosis checkpoints (SIRPα/CD47, LILRB1/MHC-I, and LILRB2/MHC-I) and natural killer-cell checkpoints (TIGIT/CD112 + CD155, PVRIG/CD112, KIRs/MHC-I, and NKG2A-CD94/HLA-E). Innate immune checkpoint inhibitors could once again revolutionize immune-based cancer therapies.


Assuntos
Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/métodos , Neoplasias/tratamento farmacológico , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Oncologia
17.
Cells ; 10(4)2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919732

RESUMO

Cancer cells "hijack" host immune cells to promote growth, survival, and metastasis. The immune microenvironment of high-grade gliomas (HGG) is a complex and heterogeneous system, consisting of diverse cell types such as microglia, bone marrow-derived macrophages (BMDMs), myeloid-derived suppressor cells (MDSCs), dendritic cells, natural killer (NK) cells, and T-cells. Of these, MDSCs are one of the major tumor-infiltrating immune cells and are correlated not only with overall worse prognosis but also poor clinical outcomes. Upon entry from the bone marrow into the peripheral blood, spleen, as well as in tumor microenvironment (TME) in HGG patients, MDSCs deploy an array of mechanisms to perform their immune and non-immune suppressive functions. Here, we highlight the origin, function, and characterization of MDSCs and how they are recruited and metabolically reprogrammed in HGG. Furthermore, we discuss the mechanisms by which MDSCs contribute to immunosuppression and resistance to current therapies. Finally, we conclude by summarizing the emerging approaches for targeting MDSCs alone as a monotherapy or in combination with other standard-of-care therapies to improve the current treatment of high-grade glioma patients.


Assuntos
Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Resistencia a Medicamentos Antineoplásicos , Glioma/imunologia , Glioma/metabolismo , Terapia de Imunossupressão , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Neoplasias Encefálicas/patologia , Glioma/patologia , Humanos , Células Supressoras Mieloides/patologia , Gradação de Tumores
18.
BMC Biotechnol ; 10: 72, 2010 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-20925961

RESUMO

BACKGROUND: EGF receptor variant III (EGFRvIII) is the most common variant of the EGF receptor observed in human tumors. It results from the in frame deletion of exons 2-7 and the generation of a novel glycine residue at the junction of exons 1 and 8. This novel juxtaposition of amino acids within the extra-cellular domain of the EGF receptor creates a tumor specific and immunogenic epitope. EGFRvIII expression has been seen in many tumor types including glioblastoma multiforme (GBM), breast adenocarcinoma, non-small cell lung carcinoma, ovarian adenocarcinoma and prostate cancer, but has been rarely observed in normal tissue. Because this variant is tumor specific and highly immunogenic, it can be used for both a diagnostic marker as well as a target for immunotherapy. Unfortunately many of the monoclonal and polyclonal antibodies directed against EGFRvIII have cross reactivity to wild type EGFR or other non-specific proteins. Furthermore, a monoclonal antibody to EGFRvIII is not readily available to the scientific community. RESULTS: In this study, we have developed a recombinant antibody that is specific for EGFRvIII, has little cross reactivity for the wild type receptor, and which can be easily produced. We initially designed a recombinant antibody with two anti-EGFRvIII single chain Fv's linked together and a human IgG1 Fc component. To enhance the specificity of this antibody for EGFRvIII, we mutated tyrosine H59 of the CDRH2 domain and tyrosine H105 of the CDRH3 domain to phenylalanine for both the anti-EGFRvIII sequence inserts. This mutated recombinant antibody, called RAb(DMvIII), specifically detects EGFRvIII expression in EGFRvIII expressing cell lines as well as in EGFRvIII expressing GBM primary tissue by western blot, immunohistochemistry (IHC) and immunofluorescence (IF) and FACS analysis. It does not recognize wild type EGFR in any of these assays. The affinity of this antibody for EGFRvIII peptide is 1.7 × 107 M⁻¹ as determined by enzyme-linked immunosorbent assay (ELISA). CONCLUSION: This recombinant antibody thus holds great potential to be used as a research reagent and diagnostic tool in research laboratories and clinics because of its high quality, easy viability and unique versatility. This antibody is also a strong candidate to be investigated for further in vivo therapeutic studies.


Assuntos
Especificidade de Anticorpos , Receptores ErbB/imunologia , Proteínas Recombinantes/biossíntese , Anticorpos de Cadeia Única/biossíntese , Animais , Afinidade de Anticorpos , Linhagem Celular Tumoral , Reações Cruzadas , Epitopos/imunologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mutagênese Sítio-Dirigida , Neoplasias Experimentais/imunologia , Proteínas Recombinantes/genética , Anticorpos de Cadeia Única/genética
19.
Clin Cancer Res ; 26(12): 2810-2818, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32156743

RESUMO

PURPOSE: Bruton tyrosine kinase (BTK) inhibition alone leads to incomplete responses in chronic lymphocytic leukemia (CLL). Combination therapy may reduce activation of escape pathways and deepen responses. This open-label, phase Ib, sequential dose-escalation and dose-expansion study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the selective BTK inhibitor tirabrutinib alone, in combination with the PI3K delta (PI3Kδ) inhibitor idelalisib, or with the spleen tyrosine kinase (SYK) inhibitor entospletinib in patients with relapsed/refractory CLL. PATIENTS AND METHODS: Patients received either tirabrutinib monotherapy (80 mg every day) or tirabrutinib 20-150 mg every day in combination with either idelalisib (50 mg twice a day or 100 mg every day) or entospletinib (200 mg or 400 mg every day). RESULTS: Fifty-three patients were included. Systemic tirabrutinib exposure was comparable between monotherapy and combination therapy. No MTD was identified. Across all treatment groups, the most common adverse event was diarrhea (43%, 1 patient grade ≥3); discontinuation due to adverse events was uncommon (13%). Objective response rates were 83%, 93%, and 100%, and complete responses were 7%, 7%, and 10% in patients receiving tirabrutinib, tirabrutinib/idelalisib, and tirabrutinib/entospletinib, respectively. As of February 21, 2019, 46 of 53 patients continue to receive treatment on study. CONCLUSIONS: Tirabrutinib in combination with idelalisib or entospletinib was well tolerated in patients with CLL, establishing an acceptable safety profile for concurrent selective inhibition of BTK with either PI3Kδ or SYK. This small study did not establish a superior efficacy of the combinations over tirabrutinib alone. This trial is registered at www.clinicaltrials.gov (NCT02457598).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Terapia de Salvação , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Feminino , Seguimentos , Humanos , Imidazóis/administração & dosagem , Indazóis/administração & dosagem , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Purinas/administração & dosagem , Pirazinas/administração & dosagem , Pirimidinas/administração & dosagem , Quinazolinonas/administração & dosagem , Distribuição Tecidual
20.
Nat Med ; 26(5): 712-719, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32341579

RESUMO

Atypical teratoid/rhabdoid tumors (ATRTs) typically arise in the central nervous system (CNS) of children under 3 years of age. Despite intensive multimodal therapy (surgery, chemotherapy and, if age permits, radiotherapy), median survival is 17 months1,2. We show that ATRTs robustly express B7-H3/CD276 that does not result from the inactivating mutations in SMARCB1 (refs. 3,4), which drive oncogenesis in ATRT, but requires residual SWItch/Sucrose Non-Fermentable (SWI/SNF) activity mediated by BRG1/SMARCA4. Consistent with the embryonic origin of ATRT5,6, B7-H3 is highly expressed on the prenatal, but not postnatal, brain. B7-H3.BB.z-chimeric antigen receptor (CAR) T cells administered intracerebroventricularly or intratumorally mediate potent antitumor effects against cerebral ATRT xenografts in mice, with faster kinetics, greater potency and reduced systemic levels of inflammatory cytokines compared to CAR T cells administered intravenously. CAR T cells administered ICV also traffic from the CNS into the periphery; following clearance of ATRT xenografts, B7-H3.BB.z-CAR T cells administered intracerebroventricularly or intravenously mediate antigen-specific protection from tumor rechallenge, both in the brain and periphery. These results identify B7-H3 as a compelling therapeutic target for this largely incurable pediatric tumor and demonstrate important advantages of locoregional compared to systemic delivery of CAR T cells for the treatment of CNS malignancies.


Assuntos
Antígenos B7/imunologia , Neoplasias Encefálicas/terapia , Vacinas Anticâncer/administração & dosagem , Imunoterapia Adotiva/métodos , Tumor Rabdoide/terapia , Teratoma/terapia , Adulto , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Células Cultivadas , Pré-Escolar , Feminino , Feto/patologia , Humanos , Lactente , Injeções Intraventriculares , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptores de Antígenos Quiméricos/administração & dosagem , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Tumor Rabdoide/imunologia , Tumor Rabdoide/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Teratoma/imunologia , Teratoma/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
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