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1.
Cancer Cell ; 40(4): 379-392.e9, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35303420

RESUMO

Glioblastomas (GBMs) are aggressive brain tumors characterized by extensive inter- and intratumor heterogeneity. Patient-derived models, such as organoids and explants, have recently emerged as useful models to study such heterogeneity, although the extent to which they can recapitulate GBM genomic features remains unclear. Here, we analyze bulk exome and single-cell genome and transcriptome profiles of 12 IDH wild-type GBMs, including two recurrent tumors, and of patient-derived explants (PDEs) and gliomasphere (GS) lines derived from these tumors. We find that PDEs are genetically similar to, and variably retain gene expression characteristics of, their parent tumors. Notably, PDEs appear to exhibit similar levels of transcriptional heterogeneity compared with their parent tumors, whereas GS lines tend to be enriched for cells in a more uniform transcriptional state. The approaches and datasets introduced here will provide a valuable resource to help guide experiments using GBM-derived models, especially in the context of studying cellular heterogeneity.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular , Genômica , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Recidiva Local de Neoplasia
2.
Neuro Oncol ; 24(4): 624-638, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34498069

RESUMO

BACKGROUND: The role of surgery for incidentally discovered diffuse incidental low-grade gliomas (iLGGs) is debatable and poorly documented in current literature. OBJECTIVE: The aim was to identify factors that influence survival for patients that underwent surgical resection of iLGGs in a large multicenter population. METHODS: Clinical, radiological, and surgical data were retrospectively analyzed in 267 patients operated for iLGG from 4 neurosurgical Centers. Univariate and multivariate analyses were performed to identify predictors of overall survival (OS) and tumor recurrence (TR). RESULTS: The OS rate was 92.41%. The 5- and 10-year estimated OS rates were 98.09% and 93.2%, respectively. OS was significantly longer for patients with a lower preoperative tumor volume (P = .001) and higher extent of resection (EOR) (P = .037), regardless the WHO-defined molecular class (P = .2). In the final model, OS was influenced only by the preoperative tumor volume (P = .006), while TR by early surgery (P = .028). A negative association was found between preoperative tumor volumes and EOR (rs = -0.44, P < .001). The median preoperative tumor volume was 15 cm3. The median EOR was 95%. Total or supratotal resection of T2-FLAIR abnormality was achieved in 61.62% of cases. Second surgery was performed in 26.22%. The median time between surgeries was 5.5 years. Histological evolution to high-grade glioma was detected in 22.85% of cases (16/70). Permanent mild deficits were observed in 3.08% of cases. CONCLUSIONS: This multicenter study confirms the results of previous studies investigating surgical management of iLGGs and thereby strengthens the evidence in favor of early surgery for these lesions.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/patologia , Glioma/patologia , Humanos , Procedimentos Neurocirúrgicos/métodos , Estudos Retrospectivos , Resultado do Tratamento
3.
Front Neurol ; 11: 593950, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329346

RESUMO

Background: Transcranial direct current stimulation (tDCS) has been used extensively in patient populations to facilitate motor network plasticity. However, it has not been studied in patients with brain tumors. We aimed to determine the feasibility of a preoperative motor training and tDCS intervention in patients with glioma. In an exploratory manner, we assessed changes in motor network connectivity following this intervention and related these changes to predicted electrical field strength from the stimulated motor cortex. Methods: Patients with left-sided glioma (n=8) were recruited in an open label proof of concept pilot trial and participated in four consecutive days of motor training combined with tDCS. The motor training consisted of a 60-min period where the subject learned to play the piano with their right hand. Concurrently, they received 40 min of 2 mA anodal tDCS of the left motor cortex. Patients underwent task and resting state fMRI before and after this intervention. Changes in both the connectivity of primary motor cortex (M1) and general connectivity across the brain were assessed. Patient specific finite element models were created and the predicted electrical field (EF) resulting from stimulation was computed. The magnitude of the EF was extracted from left M1 and correlated to the observed changes in functional connectivity. Results: There were no adverse events and all subjects successfully completed the study protocol. Left M1 increased both local and global connectivity. Voxel-wide measures, not constrained by a specific region, revealed increased global connectivity of the frontal pole and decreased global connectivity of the supplementary motor area. The magnitude of EF applied to the left M1 correlated with changes in global connectivity of the right M1. Conclusion: In this proof of concept pilot study, we demonstrate for the first time that tDCS appears to be feasible in glioma patients. In our exploratory analysis, we show preoperative motor training combined with tDCS may alter sensorimotor network connectivity. Patient specific modeling of EF in the presence of tumor may contribute to understanding the dose-response relationship of this intervention. Overall, this suggests the possibility of modulating neural networks in glioma patients.

4.
IEEE Trans Biomed Eng ; 67(12): 3327-3338, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32286953

RESUMO

BACKGROUND: Tumor treatment fields (TTFie-lds) are an approved adjuvant therapy for glioblastoma (GBM). The magnitude of applied electrical field has been shown to be related to the anti-tumoral response. However, peritumoral edema may result in shunting of electrical current around the tumor, thereby reducing the intra-tumoral electric field. In this study, we systematically address this issue with computational simulations. METHODS: Finite element models are created of a human head with varying amounts of peritumoral edema surrounding a virtual tumor. The electric field distribution was simulated using the standard TTFields electrode montage. Electric field magnitude was extracted from the tumor and related to edema thickness. Two patient specific models were created to confirm these results. RESULTS: The inclusion of peritumoral edema decreased the average magnitude of the electric field within the tumor. In the model considering a frontal tumor and an anterior-posterior electrode configuration, ≥6 mm of peritumoral edema decreased the electric field by 52%. In the patient specific models, peritumoral edema decreased the electric field magnitude within the tumor by an average of 26%. The effect of peritumoral edema on the electric field distribution was spatially heterogenous, being most significant at the tissue interface between edema and tumor. CONCLUSIONS: The inclusion of peritumoral edema during TTFields modelling may have a dramatic effect on the predicted electric field magnitude within the tumor. Given the importance of electric field magnitude for the anti-tumoral effects of TTFields, the presence of edema should be considered both in future modelling studies and when planning TTField therapy.


Assuntos
Neoplasias Encefálicas , Terapia por Estimulação Elétrica , Glioblastoma , Neoplasias Encefálicas/terapia , Edema/terapia , Eletrodos , Glioblastoma/complicações , Glioblastoma/terapia , Cabeça , Humanos
5.
World Neurosurg ; 132: e133-e139, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31505287

RESUMO

BACKGROUND: Incidentally discovered diffusely infiltrating low-grade gliomas (iDLGGs) are rare findings on neuroimaging that pose a challenge to neurosurgeons. There is a paucity of data regarding the natural history of these lesions, and thus management is controversial. We characterize the growth rates and patterns of iDLGGs in a cohort of patients who underwent serial magnetic resonance imaging before surgical treatment. METHODS: We performed a retrospective review of all adult patients (≥18 years old) with diffuse low-grade glioma diagnosed at our institution between April 2004 and April 2016. iDLGG was defined as any lesion discovered on computed tomography or magnetic resonance imaging performed for reasons and/or symptoms not attributable to the lesion and confirmed on histopathology as low-grade glioma. Tumor growth rates and patterns of growth were analyzed in patients who had serial imaging available. RESULTS: Inclusion criteria were met by 15 patients. Mean velocity of diametric expansion was 2.93 mm/year. Of 15 patients, 11 (73.3%) had tumors with an exponential growth pattern, and 4 (26.7%) had a linear growth pattern. Initial tumor volume was positively correlated (r = 0.78) with velocity of diametric expansion. CONCLUSIONS: iDLGGs grow over time, and most exhibit an exponential pattern of growth. Tumor volume at the time of diagnosis is predictive of a faster growth rate, but not the pattern of growth.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Adulto , Fatores Etários , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Achados Incidentais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neuroimagem , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X , Adulto Jovem
6.
Oncotarget ; 10(33): 3129-3143, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31139325

RESUMO

Microglia and macrophages are the largest component of the inflammatory infiltrate in glioblastoma (GBM). However, whether there are differences in their representation and activity in the prognostically-favorable isocitrate dehydrogenase (IDH)-mutated compared to -wild type GBMs is unknown. Studies on human specimens of untreated IDH-mutant GBMs are rare given they comprise 10% of all GBMs and often present at lower grades, receiving treatments prior to dedifferentiation that can drastically alter microglia and macrophage phenotypes. We were able to obtain large samples of four previously untreated IDH-mutant GBM. Using flow cytometry, immunofluorescence techniques with automated segmentation protocols that quantify at the individual-cell level, and comparison between single-cell RNA-sequencing (scRNA-seq) databases of human GBM, we discerned dissimilarities between GBM-associated microglia and macrophages (GAMMs) in IDH-mutant and -wild type GBMs. We found there are significantly fewer GAMM in IDH-mutant GBMs, but they are more pro-inflammatory, suggesting this contributes to the better prognosis of these tumors. Our pro-inflammatory score which combines the expression of inflammatory markers (CD68/HLA-A, -B, -C/TNF/CD163/IL10/TGFB2), Iba1 intensity, and GAMM surface area also indicates that more pro-inflammatory GAMMs are associated with longer overall survival independent of IDH status. Interrogation of scRNA-seq databases demonstrates microglia in IDH-mutants are mainly pro-inflammatory, while anti-inflammatory macrophages that upregulate genes such as FCER1G and TYROBP predominate in IDH-wild type GBM. Taken together, these observations are the first head-to-head comparison of GAMMs in treatment-naïve IDH-mutant versus -wild type GBMs. Our findings highlight biological disparities in the innate immune microenvironment related to IDH prognosis that can be exploited for therapeutic purposes.

7.
J Neurosurg ; 129(1): 19-26, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-28984519

RESUMO

OBJECTIVE Occasionally, diffusely infiltrating low-grade gliomas (LGGs) are identified as incidental findings in patients who have no signs or symptoms that can be ascribed to the tumors. The diagnosis of incidental, asymptomatic LGGs has become more frequent due to the vast increase in access to medical imaging technology. While management of these lesions remains controversial, early surgery has been suggested to improve outcome. The authors set out to identify and review the characteristics and surgical outcomes of patients who underwent surgical intervention for incidental LGG. METHODS All cases of LGG surgically treated between 2004 and 2016 at the authors' institution were analyzed to identify those that were discovered incidentally. Patients with incidentally discovered LGGs were identified, and their cases were retrospectively reviewed. An "incidental" finding was defined as an abnormality on imaging that was obtained for a reason not attributable to the glioma, such as trauma, headache, screening, or research participation. Kaplan-Meier analysis was performed to determine actuarial rates of overall survival, progression-free survival, and malignant progression-free survival. RESULTS In 34 (6.8%) of 501 adult patients who underwent surgery for LGG, the tumors were discovered incidentally. Headache (26%, n = 9) and screening (21%, n = 7) were the most common indications for brain imaging in this group. Four of these 34 patients had initial biopsy after the tumor was identified on imaging. In 5 cases, the patients opted for immediate resection; the remaining cases were managed with a "watch-and-wait" approach, with intervention undertaken only after radiological or clinical evidence of disease progression. The mean duration of follow-up for all 34 cases was 5 years. Twelve patients (35.3%) had disease progression, with an average time to progression of 43.8 months (range 3-105 months). There were 5 cases (14.7%) of malignant progression and 4 deaths (11.8%). Oligodendroglioma was diagnosed in 16 cases (47%) and astrocytoma in 15 (44%). Twenty-five patients (74%) had IDH1 mutation and demonstrated prolonged survival. Only 2 patients had mild surgery-related complications, and 16 patients (47%) developed epilepsy during the course of the disease. CONCLUSIONS In this retrospective analysis of cases of incidentally discovered LGGs, the tumors were surgically removed with minimal surgical risk. In patients with incidental LGGs there is improved overall survival relative to median survival for patients with symptomatic LGGS, which is likely attributable to the underlying favorable biology of the disease indicated by the presence of IDH1 mutation in 74% of the cases.


Assuntos
Neoplasias Encefálicas/cirurgia , Glioma/cirurgia , Adulto , Neoplasias Encefálicas/patologia , Feminino , Glioma/patologia , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
8.
World Neurosurg ; 110: e612-e620, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29162526

RESUMO

BACKGROUND: Evidence suggests a survival benefit for patients with glioblastoma who undergo maximal safe surgical resection. Not all glioblastomas are amenable to surgical resection and anatomic location is one potentially limiting factor. Glioblastomas that invade the corpus callosum and cross midline to the contralateral hemisphere-butterfly glioblastomas (bGBMs)-are one subgroup of tumors traditionally deemed inoperable. METHODS: We evaluate the management of bGBMs at our institution to assess whether surgical resection is feasible, safe, and more effective than biopsy. We retrospectively reviewed our institutional brain tumor registry for all adult patients treated for glioblastoma (World Health Organization grade IV) between 2004 and 2016 to identify all bGBMs. RESULTS: Survival between biopsy and resection was assessed using the Kaplan-Meier model. Twenty-nine (3.8%) of 764 newly diagnosed GBMs were identified as bGBM. Of these, 9 patients (31.0%) underwent surgical resection and 20 patients (69.0%) underwent biopsy. Five patients (55.6%) in the surgical resection group had 98% extent of resection or greater. Median survival of our entire cohort of patients was 3.3 months. Median survival was higher in the surgical resection groups (7.8 vs. 2.8 months; P = 0.0019). Increased age is independently associated with increased risk of death, and adjuvant therapy is independently associated with prolonged survival. CONCLUSIONS: Surgical resection of butterfly glioblastoma prolongs survival without increased risk of permanent neurologic deficit. Both anterior and posterior bGBMs can be resected safely.


Assuntos
Biópsia , Neoplasias Encefálicas/cirurgia , Corpo Caloso , Glioblastoma/cirurgia , Procedimentos Neurocirúrgicos , Fatores Etários , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/patologia , Corpo Caloso/cirurgia , Feminino , Seguimentos , Glioblastoma/genética , Glioblastoma/mortalidade , Glioblastoma/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Retrospectivos , Carga Tumoral
9.
World Neurosurg ; 105: 913-922.e2, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28583454

RESUMO

BACKGROUND: Patients with diffuse glioma are known to have impaired cognitive functions preoperatively. However, the mechanism of these cognitive deficits remains unclear. Resting-state functional connectivity in the frontoparietal network (FPN) is associated with cognitive performance in healthy subjects. For this reason, it was hypothesized that functional connectivity of the FPN would be related to cognitive functioning in patients with glioma. To assess this relationship, preoperative cognitive status was correlated to patient-specific connectivity within the FPN. Further, we assessed whether connectivity could predict neuropsychologic outcome following surgery. METHODS: Sixteen patients with diffuse glioma underwent neuropsychologic assessment and preoperative functional magnetic resonance imaging using task (n-back) and resting-state scans. Thirteen patients had postoperative cognitive assessment. An index of patient-specific functional connectivity in the FPN was derived by averaging connectivity values between 2 prefrontal and 2 parietal cortex regions defined by activation during the n-back task. The relationship of these indices with cognitive performance was assessed. RESULTS: Higher average connectivity within the FPN is associated with lower composite cognitive scores. Higher connectivity of the parietal region of the tumor-affected hemisphere is associated specifically with lower fluid cognition. Lower connectivity of the parietal region of the nontumor hemisphere is associated with worse neuropsychologic outcome 1 month after surgery. CONCLUSION: Resting-state functional connectivity between key regions of the FPN is associated with cognitive performance in patients with glioma and is related to cognitive outcome following surgery.


Assuntos
Mapeamento Encefálico , Transtornos Cognitivos/fisiopatologia , Cognição/fisiologia , Glioma/cirurgia , Vias Neurais/fisiopatologia , Adulto , Transtornos Cognitivos/etiologia , Feminino , Glioma/patologia , Glioma/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Vias Neurais/patologia , Lobo Parietal/patologia , Período Perioperatório , Resultado do Tratamento , Adulto Jovem
10.
Brain ; 140(6): 1548-1560, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28334886

RESUMO

Glioblastoma is the most common and most malignant primary adult human brain tumour. Diagnosis of glioblastoma carries a dismal prognosis. Treatment resistance and tumour recurrence are the result of both cancer cell proliferation and their interaction with the tumour microenvironment. A large proportion of the tumour microenvironment consists of an inflammatory infiltrate predominated by microglia and macrophages, which are thought to be subverted by glioblastoma cells for tumour growth. Thus, glioblastoma-associated microglia and macrophages are logical therapeutic targets. Their emerging roles in glioblastoma progression are reflected in the burgeoning research into therapeutics directed at their modification or elimination. Here, we review the biology of glioblastoma-associated microglia and macrophages, and model systems used to study these cells in vitro and in vivo. We discuss translation of results using these model systems and review recent advances in immunotherapies targeting microglia and macrophages in glioblastoma. Significant challenges remain but medications that affect glioblastoma-associated microglia and macrophages hold considerable promise to improve the prognosis for patients with this disease.


Assuntos
Neoplasias Encefálicas/imunologia , Glioblastoma/imunologia , Imunoterapia/métodos , Macrófagos/imunologia , Microglia/imunologia , Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Humanos
11.
Neuro Oncol ; 15(7): 904-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23585629

RESUMO

BACKGROUND: Intratumoral heterogeneity in glioblastoma multiforme (GBM) poses a significant barrier to therapy in certain subpopulation such as the tumor-initiating cell population, being shown to be refractory to conventional therapies. Oncolytic virotherapy has the potential to target multiple compartments within the tumor and thus circumvent some of the barriers facing conventional therapies. In this study, we investigate the oncolytic potential of myxoma virus (MYXV) alone and in combination with rapamycin in vitro and in vivo using human brain tumor-initiating cells (BTICs). METHODS: We cultured fresh GBM specimens as neurospheres and assayed their growth characteristics in vivo. We then tested the susceptibility of BTICs to MYXV infection with or without rapamycin in vitro and assessed viral biodistribution/survival in vivo in orthotopic xenografts. RESULTS: The cultured neurospheres were found to retain stem cell markers in vivo, and they closely resembled human infiltrative GBM. In this study we determined that (i) all patient-derived BTICs tested, including those resistant to temozolomide, were susceptible to MYXV replication and killing in vitro; (ii) MYXV replicated within BTICs in vivo, and intratumoral administration of MYXV significantly prolonged survival of BTIC-bearing mice; (iii) combination therapy with MYXV and rapamycin improved antitumor activity, even in mice bearing "advanced" BTIC tumors; (iv) MYXV treatment decreased expression of stem cell markers in vitro and in vivo. CONCLUSIONS: Our study suggests that MYXV in combination with rapamycin infects and kills both the BTICs and the differentiated compartments of GBM and may be an effective treatment even in TMZ-resistant patients.


Assuntos
Neoplasias Encefálicas/prevenção & controle , Glioblastoma/prevenção & controle , Células-Tronco Neoplásicas/patologia , Terapia Viral Oncolítica , Infecções por Poxviridae/prevenção & controle , Sirolimo/uso terapêutico , Infecções Tumorais por Vírus/prevenção & controle , Animais , Antibióticos Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/virologia , Proliferação de Células/efeitos dos fármacos , Terapia Combinada , Feminino , Citometria de Fluxo , Imunofluorescência , Glioblastoma/patologia , Glioblastoma/virologia , Proteínas de Fluorescência Verde/metabolismo , Humanos , Técnicas Imunoenzimáticas , Luciferases/metabolismo , Camundongos , Camundongos SCID , Myxoma virus/fisiologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/virologia , Infecções por Poxviridae/patologia , Infecções por Poxviridae/virologia , Células Tumorais Cultivadas , Infecções Tumorais por Vírus/patologia , Infecções Tumorais por Vírus/virologia , Replicação Viral , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Mol Ther ; 18(11): 1927-36, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20808290

RESUMO

The purpose of this study was to investigate the oncolytic potential of the recombinant, granulocyte macrophage colony-stimulating factor (GM-CSF)-expressing vaccinia virus (VV) JX-594 in experimental malignant glioma (MGs) in vitro and in immunocompetent rodent models. We have found that JX-594 killed all MG cell lines tested in vitro. Intratumoral (i.t.) administration of JX-594 significantly inhibited tumor growth and prolonged survival in rats-bearing RG2 intracranial (i.c.) tumors and mice-bearing GL261 brain tumors. Combination therapy with JX-594 and rapamycin significantly increased viral replication and further prolonged survival in both immunocompetent i.c. MG models with several animals considered "cured" (three out of seven rats >120 days, terminated experiment). JX-594 infected and killed brain tumor-initiating cells (BTICs) from patient samples grown ex vivo, and did so more efficiently than other oncolytic viruses MYXV, Reovirus type-3, and VSV(ΔM51). Additional safety/toxicity studies in nontumor-bearing rodents treated with a supratherapeutic dose of JX-594 demonstrated GM-CSF-dependent inflammation and necrosis. These results suggest that i.c. administered JX-594 triggers a predictable GM-CSF-mediated inflammation in murine models. Before proceeding to clinical trials, JX-594 should be evaluated in the brains of nonhuman primates and optimized for the viral doses, delivery routes as well as the combination agents (e.g., mTOR inhibitors).


Assuntos
Neoplasias Encefálicas/terapia , Modelos Animais de Doenças , Glioma/terapia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Terapia Viral Oncolítica , Sirolimo/uso terapêutico , Vaccinia virus/genética , Animais , Antibióticos Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/genética , Terapia Combinada , Feminino , Vetores Genéticos/uso terapêutico , Glioma/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/análise , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Ratos Endogâmicos F344 , Taxa de Sobrevida , Transgenes/fisiologia , Células Tumorais Cultivadas , Vacinas Sintéticas/uso terapêutico , Replicação Viral
14.
Neuro Oncol ; 12(7): 745-55, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20388696

RESUMO

Investigating the biology of oligodendroglioma and its characteristic combined deletion of chromosomal arms 1p and 19q, mediated by an unbalanced translocation, t(1;19)(q10;p10), has been hampered by the lack of cell lines that harbor these traits. We grew cells from 2 anaplastic oligodendrogliomas in serum-free conditions. Serial propagation and expansion led to the establishment of permanent cell lines that maintained the genetic signature of the parent oligodendrogliomas and displayed features of brain tumor stem cells in vitro. One line was established from a treatment-naïve tumor and the other from a temozolomide resistant recurrent tumor. These lines may be important tools for understanding the biology of oligodendrogliomas and the function of their defining genetic traits.


Assuntos
Neoplasias Encefálicas/genética , Cromossomos Humanos Par 19/genética , Cromossomos Humanos Par 1/genética , Oligodendroglioma/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Humanos , Oligodendroglioma/patologia , Translocação Genética/genética
15.
Stem Cells ; 27(8): 1722-33, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19544433

RESUMO

Primary glial tumors of the central nervous system, most commonly glioblastoma multiforme (GBM), are aggressive lesions with a dismal prognosis. Despite identification and isolation of human brain tumor stem cells (BTSCs), characteristics that distinguish BTSCs from neural stem cells remain to be elucidated. We cultured cells isolated from gliomas, using the neurosphere culture system, to understand their growth requirements. Both CD133(+) and CD133(-) adult GBM BTSCs proliferated in the absence of exogenous mitogenic stimulation and gave rise to multipotent GBM spheres that were capable of self-renewal. Epidermal growth factor (EGF) and fibroblast growth factor-2 enhanced GBM BTSC survival, proliferation, and subsequent sphere size. Blockade of EGF receptor (EGFR) signaling reduced exogenous mitogen-independent GBM sphere growth. Implantation of as few as 10 exogenous mitogen-independent GBM BTSCs led to the formation of highly invasive intracranial tumors, which closely resembled human GBMs, in immunocompromised mice. These results demonstrate that exogenous mitogen independence, mediated in part through EGFR signaling, is one characteristic that distinguishes CD133(+) and CD133(-) GBM BTSCs from neural stem cells. This novel experimental system will permit the elucidation of additional constitutively activated mechanisms that promote GBM BTSC survival, self-renewal, and proliferation.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Mitógenos/farmacologia , Células-Tronco Neoplásicas/patologia , Antígeno AC133 , Adolescente , Adulto , Animais , Antígenos CD/metabolismo , Neoplasias Encefálicas/metabolismo , Processos de Crescimento Celular/efeitos dos fármacos , Citometria de Fluxo , Glioblastoma/metabolismo , Glicoproteínas/metabolismo , Humanos , Camundongos , Células-Tronco Neoplásicas/metabolismo , Peptídeos/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas , Adulto Jovem
16.
PLoS Biol ; 6(11): e289, 2008 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-19067488

RESUMO

The multifunctional signaling protein p75 neurotrophin receptor (p75(NTR)) is a central regulator and major contributor to the highly invasive nature of malignant gliomas. Here, we show that neurotrophin-dependent regulated intramembrane proteolysis (RIP) of p75(NTR) is required for p75(NTR)-mediated glioma invasion, and identify a previously unnamed process for targeted glioma therapy. Expression of cleavage-resistant chimeras of p75(NTR) or treatment of animals bearing p75(NTR)-positive intracranial tumors with clinically applicable gamma-secretase inhibitors resulted in dramatically decreased glioma invasion and prolonged survival. Importantly, proteolytic processing of p75(NTR) was observed in p75(NTR)-positive patient tumor specimens and brain tumor initiating cells. This work highlights the importance of p75(NTR) as a therapeutic target, suggesting that gamma-secretase inhibitors may have direct clinical application for the treatment of malignant glioma.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Neoplasias Encefálicas/metabolismo , Inibidores Enzimáticos/uso terapêutico , Glioma/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Encéfalo/metabolismo , Neoplasias Encefálicas/terapia , Glioma/terapia , Humanos , Invasividade Neoplásica/fisiopatologia , Fatores de Crescimento Neural/metabolismo , Proteínas Recombinantes de Fusão
17.
Ann Neurol ; 64(2): 127-42, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18756507

RESUMO

OBJECTIVE: Platelet-derived growth factor (PDGF)-responsive neural precursors (PRPs; also known as oligodendrocyte progenitor cells) are one of the best characterized precursor cell populations of the rodent central nervous system. Yet little is known about the biology of human PRPs because of an apparent inability to culture and expand them in large numbers. This study was designed to establish an approach that allows direct comparisons between the biology of fetal and adult human PRPs, as a means to address potential differences in intrinsic myelin-production capabilities. METHODS: We used the neurosphere culture system, under low plating density, to isolate, culture, and compare the properties of fetal and adult human PRPs. RESULTS: PDGF stimulated fetal human PRPs to generate neurospheres that differentiated primarily into oligodendrocytes, which acquired myelin basic protein expression, as well as neurons and a small number of astrocytes. Together with PDGF, fibroblast growth factor 2 promoted fetal human PRP expansion. In contrast, adult human PRPs isolated from the corpus callosum required twice the culture period to generate neurospheres, which contained oligodendrocytes, as well as astrocytes, but not neurons. Strikingly, fibroblast growth factor 2 did not promote adult human PRP self-renewal. INTERPRETATION: Differences in the intrinsic proliferation, phenotype, and self-renewal properties of fetal and adult human PRPs suggest they are distinct populations, which may result in distinct myelin-production capabilities.


Assuntos
Neurônios/citologia , Neurônios/fisiologia , Fator de Crescimento Derivado de Plaquetas/fisiologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Adolescente , Adulto , Técnicas de Cultura de Células/métodos , Diferenciação Celular/fisiologia , Células Cultivadas , Criança , Feto , Humanos , Oligodendroglia/citologia , Oligodendroglia/fisiologia
18.
Neurosurgery ; 62(5 Suppl 2): ONS400-5; discussion ONS405-6, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18596521

RESUMO

OBJECTIVE: To design and manufacture an aneurysm clip that incorporates ceramic jaws and a titanium spring, thereby decreasing susceptibility artifact at the aneurysm neck and allowing intra- and/or postoperative magnetic resonance (MR) evaluation. METHODS: A series of aneurysm clips were developed using ceramic jaws and a titanium spring. A corresponding clip applicator with a novel clip-applicator interface was developed to improve ergonomics and visibility during clip placement or removal. Ceramic clips were imaged at 3.0 T in a kiwi fruit phantom model and compared with MR-compatible Yasargil aneurysm clips (Aesculap, AG & Co., Tuttlingen, Germany). Ceramic clips were subsequently evaluated in a human cadaveric model at 1.5 T. RESULTS: Ceramic clips were developed initially using silicon nitride ceramic and subsequently with yttria-stabilized zirconia ceramic. The ceramic clip jaws showed reduced susceptibility artifact compared with MR-compatible Yasargil clips. Closing pressure was maintained over the course of 50 cycles of clip opening and closing. Aneurysm clip jaw crossing was not observed. The novel clip applicator and enhanced applicator-clip interface improved visibility during clip application and reduced the potential for torque during clip removal. CONCLUSION: The use of ceramic material limited MR imaging susceptibility artifact and image distortion in the area immediately surrounding the ceramic jaws. As expected, image distortion occurred around the titanium spring and pivot. However, in the unique design of this new aneurysm clip, the spring is located far enough from the distal end of the jaws to provide an undistorted image of the clipped area.


Assuntos
Cerâmica , Desenho Assistido por Computador , Aneurisma Intracraniano/cirurgia , Procedimentos Neurocirúrgicos/instrumentação , Procedimentos Cirúrgicos Vasculares/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento
19.
Med J Aust ; 182(5): 224-7, 2005 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-15748132

RESUMO

Lack of donors has led to a worldwide increase in commercial kidney transplantation programs where recipients acquire kidneys either from executed prisoners or live non-related donors. Commercial transplantation is prohibited by legislation in Australia. Our centres have had 16 patients who have travelled overseas to receive a commercial kidney transplant; five have subsequently died. As has been found previously, patients who received commercial transplants were more likely to develop infections such as HIV, hepatitis B virus, cytomegalovirus and fungal infections. Previous reports have found that patient and graft survival were comparable to local results, whereas we found that patient and graft survival were worse than transplantation within Australia. Patients considering the option of overseas commercial donation should be advised that heightened risks to life and graft survival exist.


Assuntos
Transplante de Rim , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Adulto , Idoso , Aspergilose/etiologia , Austrália , Infecções por Citomegalovirus/etiologia , Feminino , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Hepatite B/etiologia , Humanos , Internacionalidade , Transplante de Rim/efeitos adversos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , New South Wales , Complicações Pós-Operatórias , Taxa de Sobrevida , Viagem , Resultado do Tratamento
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