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1.
Exp Cell Res ; 431(1): 113743, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37591452

RESUMO

A critical challenge in the treatment of glioblastoma (GBM) is its highly invasive nature which promotes cell migration throughout the brain and hinders surgical resection and effective drug delivery. GBM cells demonstrate augmented invasive capabilities following exposure to the current gold standard treatment of radiotherapy (RT) and concomitant and adjuvant temozolomide (TMZ), resulting in rapid disease recurrence. Elucidating the mechanisms employed by post-treatment invasive GBM cells is critical to the development of more effective therapies. In this study, we utilized a Nanostring® Cancer Progression gene expression panel to identify candidate genes that may be involved in enhanced GBM cell invasion after treatment with clinically relevant doses of RT/TMZ. Our findings identified thrombospondin-1 (THBS1) as a pro-invasive gene that is upregulated in these cells. Immunofluorescence staining revealed that THBS1 localised within functional matrix-degrading invadopodia that formed on the surface of GBM cells. Furthermore, overexpression of THBS1 resulted in enhanced GBM cell migration and secretion of MMP-2, which was reduced with silencing of THBS1. The preliminary data demonstrates that THBS1 is associated with invadopodia in GBM cells and is likely involved in the invadopodia-mediated invasive process in GBM cells exposed to RT/TMZ treatment. Therapeutic inhibition of THBS1-mediated invadopodia activity, which facilitates GBM cell invasion, should be further investigated as a treatment for GBM.


Assuntos
Glioblastoma , Podossomos , Humanos , Glioblastoma/genética , Glioblastoma/terapia , Recidiva Local de Neoplasia , Temozolomida/farmacologia , Encéfalo
2.
Mol Cell Biochem ; 478(6): 1251-1267, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36302993

RESUMO

Glioblastoma (GBM) is the most prevalent primary central nervous system tumour in adults. The lethality of GBM lies in its highly invasive, infiltrative, and neurologically destructive nature resulting in treatment failure, tumour recurrence and death. Even with current standard of care treatment with surgery, radiotherapy and chemotherapy, surviving tumour cells invade throughout the brain. We have previously shown that this invasive phenotype is facilitated by actin-rich, membrane-based structures known as invadopodia. The formation and matrix degrading activity of invadopodia is enhanced in GBM cells that survive treatment. Drug repurposing provides a means of identifying new therapeutic applications for existing drugs without the need for discovery or development and the associated time for clinical implementation. We investigate several FDA-approved agents for their ability to act as both cytotoxic agents in reducing cell viability and as 'anti-invadopodia' agents in GBM cell lines. Based on their cytotoxicity profile, three agents were selected, bortezomib, everolimus and fludarabine, to test their effect on GBM cell invasion. All three drugs reduced radiation/temozolomide-induced invadopodia activity, in addition to reducing GBM cell viability. These drugs demonstrate efficacious properties warranting further investigation with the potential to be implemented as part of the treatment regime for GBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/metabolismo , Reposicionamento de Medicamentos , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Temozolomida/farmacologia
3.
Int J Mol Sci ; 24(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38139284

RESUMO

Multiple sclerosis (MS) is a neurodegenerative disease marked by chronic neuroinflammation thought to be mediated by the inflammasome pathway. Connexin 43 (Cx43) hemichannels contribute to the activation of the inflammasome through the release of adenosine triphosphate (ATP) inflammasome activation signals. The objective of the study was to evaluate if the Cx43 hemichannel blocker, tonabersat, is effective in modulating the inflammatory response and reducing disability in the myelin oligodendrocyte glycoprotein 35-55-induced experimental autoimmune encephalomyelitis (MOG35-55 EAE) model of MS. Here, we show that the Cx43 hemichannel blocking drug, tonabersat, significantly reduced expression of neuroinflammatory markers for microglial activation (ionized calcium-binding adapter molecule 1 (Iba1)) and astrogliosis (glial fibrillary acidic protein (GFAP)) while preserving myelin basic protein (MBP) expression levels in the corpus callosum, motor cortex, and striatum regions of the brain in MOG35-55 EAE mice. Reduced NOD-like receptor protein 3 (NLRP3) inflammasome complex assembly and Caspase-1 activation confirmed the drug's mode of action. MOG35-55 EAE mice showed clinical signs of MS, but MOG35-55 EAE mice treated with tonabersat retained behavior closer to normal. These data suggest that clinical trial phase IIb-ready tonabersat may merit further investigation as a promising candidate for MS treatment.


Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Doenças Neurodegenerativas , Camundongos , Animais , Esclerose Múltipla/tratamento farmacológico , Conexina 43/metabolismo , Inflamassomos/metabolismo , Progressão da Doença , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
4.
Epilepsia ; 63(5): 1081-1092, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35266138

RESUMO

OBJECTIVES: Around 30% of patients undergoing surgical resection for drug-resistant mesial temporal lobe epilepsy (MTLE) do not obtain seizure freedom. Success of anterior temporal lobe resection (ATLR) critically depends on the careful selection of surgical candidates, aiming at optimizing seizure freedom while minimizing postoperative morbidity. Structural MRI and FDG-PET neuroimaging are routinely used in presurgical assessment and guide the decision to proceed to surgery. In this study, we evaluate the potential of machine learning techniques applied to standard presurgical MRI and PET imaging features to provide enhanced prognostic value relative to current practice. METHODS: Eighty two patients with drug resistant MTLE were scanned with FDG-PET pre-surgery and T1-weighted MRI pre- and postsurgery. From these images the following features of interest were derived: volume of temporal lobe (TL) hypometabolism, % of extratemporal hypometabolism, presence of contralateral TL hypometabolism, presence of hippocampal sclerosis, laterality of seizure onset volume of tissue resected and % of temporal lobe hypometabolism resected. These measures were used as predictor variables in logistic regression, support vector machines, random forests and artificial neural networks. RESULTS: In the study cohort, 24 of 82 (28.3%) who underwent an ATLR for drug-resistant MTLE did not achieve Engel Class I (i.e., free of disabling seizures) outcome at a minimum of 2 years of postoperative follow-up. We found that machine learning approaches were able to predict up to 73% of the 24 ATLR surgical patients who did not achieve a Class I outcome, at the expense of incorrect prediction for up to 31% of patients who did achieve a Class I outcome. Overall accuracies ranged from 70% to 80%, with an area under the receiver operating characteristic curve (AUC) of .75-.81. We additionally found that information regarding overall extent of both total and significantly hypometabolic tissue resected was crucial to predictive performance, with AUC dropping to .59-.62 using presurgical information alone. Incorporating the laterality of seizure onset and the choice of machine learning algorithm did not significantly change predictive performance. SIGNIFICANCE: Collectively, these results indicate that "acceptable" to "good" patient-specific prognostication for drug-resistant MTLE surgery is feasible with machine learning approaches utilizing commonly collected imaging modalities, but that information on the surgical resection region is critical for optimal prognostication.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/cirurgia , Fluordesoxiglucose F18 , Humanos , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Convulsões , Resultado do Tratamento
5.
Pituitary ; 25(4): 563-572, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35552990

RESUMO

PURPOSE: The prognostic value of optical coherence tomography (OCT) of the macular ganglion cell layer (mGGL) versus peripapillary retinal nerve fibre layers (pRNFL) following chiasmal decompression is unclear. This study is the largest comparison of the two parameters to date and aims to clarify how their performance as covariates compare in predictive models of long-term visual outcomes following pituitary or parasellar tumour surgical resection. METHODS: This was a prospective, two-year, longitudinal cohort study in a single centre tertiary hospital setting. Participants with MRI evidence of pituitary or parasellar tumour compression of the optic chiasm who underwent surgical decompression, were enrolled. Associations between pre-operative OCT parameters and long-term visual outcomes were assessed using multivariable generalised linear mixed models and an age matched normative database. RESULTS: Final analysis included 216 eyes of 108 participants with a mean age (standard deviation) of 51.6 (17.04) years, of whom 58 (49%) were female. The superior inner mGCL was the best predictor of long-term visual field recovery, with an area under the curve of 0.90, a sensitivity of 80%, specificity of 88%, positive predictive value of 86%, and negative predictive value of 83%. CONCLUSION: mGCL performed better in predicting long-term visual field recovery post-pituitary or parasellar surgical resection. The superior inner mGCL was the best specific measure which may provide clinical utility in pre-operative counselling. In this study we clarify previously variable comparisons of mGCL and pRNFL parameters in post-operative predictive modelling.


Assuntos
Neoplasias Hipofisárias , Tomografia de Coerência Óptica , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Neoplasias Hipofisárias/diagnóstico por imagem , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/cirurgia , Estudos Prospectivos , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica/métodos
6.
Acta Neurochir (Wien) ; 164(5): 1357-1364, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33811520

RESUMO

BACKGROUND: Hemangioblastomas (HGBs) are highly vascular benign tumors, commonly located in the posterior fossa, and 80% of them are sporadic. Patients usually present with features of raised intracranial pressure and cerebellar symptoms. HGB can be classified as either mostly cystic or solids. Although the solid component is highly vascularized, aneurysm or hemorrhagic presentation is rarely described, having catastrophic results. METHODS: We identified 32 consecutive patients with posterior fossa HBG who underwent surgery from 2008 through 2020 at our medical center. Tumors were classified as predominantly cystic or solid according to radiological features. Resection was defined as gross total (GTR) or subtotal (STR). RESULTS: During the study period, 32 posterior fossa HGBs were resected. There were 26 cerebellar lesions and 4 medullar lesions, and in 2 patients, both structures were affected. Predominant cystic tumors were seen in 15 patients and solids in 17. Preoperative digital subtraction angiography (DSA) was performed in 8 patients with solid tumors, and 4 showed tumor-related aneurysms. Embolization of the tumors was performed in 6 patients, including the four tumor-related aneurysms. GTR was achieved in 29 tumors (91%), and subtotal resection in 3 (9%). Three patients had postoperative lower cranial nerve palsy. Functional status was stable in 5 patients (16%), improved in 24 (75%), and 3 patients (9%) deteriorated. One patient died 2 months after the surgery. Two tumors recurred and underwent a second surgery achieving GTR. The mean follow-up was 42.7 months (SD ± 51.0 months). CONCLUSIONS: Predominant cystic HGB is usually easily treated as the surgery is straightforward. Those with a solid predominance present a more complex challenge sharing features similar to arteriovenous malformations. Given the important vascular association of solid predominance HGB with these added risk factors, the preoperative assessment should include DSA, as in arteriovenous malformations, and endovascular intervention should be considered before surgery.


Assuntos
Malformações Arteriovenosas , Neoplasias Cerebelares , Hemangioblastoma , Doença de von Hippel-Lindau , Neoplasias Cerebelares/diagnóstico por imagem , Neoplasias Cerebelares/cirurgia , Hemangioblastoma/diagnóstico por imagem , Hemangioblastoma/cirurgia , Humanos , Recidiva Local de Neoplasia/patologia , Estudos Retrospectivos , Resultado do Tratamento , Doença de von Hippel-Lindau/complicações
7.
Int J Mol Sci ; 23(5)2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35269915

RESUMO

Glioblastoma is the most aggressive brain tumour with short survival, partly due to resistance to conventional therapy. Glioma stem cells (GSC) are likely to be involved in treatment resistance, by releasing extracellular vesicles (EVs) containing specific molecular cargoes. Here, we studied the EVs secreted by glioma stem cells (GSC-EVs) and their effects on radiation resistance and glioma progression. EVs were isolated from 3 GSCs by serial centrifugation. NanoSight measurement, cryo-electron microscopy and live imaging were used to study the EVs size, morphology and uptake, respectively. The non-GSC glioma cell lines LN229 and U118 were utilised as a recipient cell model. Wound healing assays were performed to detect cell migration. Colony formation, cell viability and invadopodium assays were conducted to detect cell survival of irradiated recipient cells and cell invasion post GSC-EV treatment. NanoString miRNA global profiling was used to select for the GSC-EVs' specific miRNAs. All three GSC cell lines secreted different amounts of EVs, and all expressed consistent levels of CD9 but different level of Alix, TSG101 and CD81. EVs were taken up by both LN229 and U118 recipient cells. In the presence of GSC-EVs, these recipient cells survived radiation exposure and initiated colony formation. After GSC-EVs exposure, LN229 and U118 cells exhibited an invasive phenotype, as indicated by an increase in cell migration. We also identified 25 highly expressed miRNAs in the GSC-EVs examined, and 8 of these miRNAs can target PTEN. It is likely that GSC-EVs and their specific miRNAs induced the phenotypic changes in the recipient cells due to the activation of the PTEN/Akt pathway. This study demonstrated that GSC-EVs have the potential to induce radiation resistance and modulate the tumour microenvironment to promote glioma progression. Future therapeutic studies should be designed to interfere with these GSC-EVs and their specific miRNAs.


Assuntos
Vesículas Extracelulares , Glioma , MicroRNAs , Microscopia Crioeletrônica , Vesículas Extracelulares/metabolismo , Glioma/genética , Glioma/metabolismo , Glioma/radioterapia , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , Microambiente Tumoral
8.
Acta Neurochir (Wien) ; 163(3): 699-709, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389125

RESUMO

PURPOSE: Meningiomas are a common tumor within the cranial cavity. They may be a target for metastatic spread of cancer elsewhere in the body. We analyzed all the data in the literature about tumor-to-meningioma metastasis (TTMM). METHODS: We performed a meta-analysis using the PRISMA checklist to locate all cases of TTMM in the PubMed and Medline databases. We collected patient and cancer parameters, meningioma parameters, and clinical factors. RESULTS: We located 124 articles, describing 152 cases of patients with TTMM. The mean (± SD) age of all patients was 62.21 ± 10.8 years, with even distribution above and below the mean. Of the cases, 65.9% were reported in women. The most common cancer origins of TTMM were breast and lung carcinoma, followed by kidney, prostate, and GI tract carcinoma. Cancer status is not a good marker of TTMM when managing a meningioma. In 36.69% of cases, TTMM was the presentation of an unknown cancer. In nearly 60% of the known cases, cancer was considered in remission for at least 1 year. Meningioma parameters are unhelpful when considering a TTMM. The distribution of meningioma location is similar to other series of meningioma reported in the literature. Meningioma grade is similar to meningiomas without TTMM. In 57.89%, the patient presented with a focal deficit. Presenting factors were seizures, elevated ICP, and others. Over 95% of cases were symptomatic at presentation. CONCLUSION: TTMM should be suspected in cases of meningioma in a patient with background cancer, regardless of meningioma parameters or cancer status.


Assuntos
Neoplasias da Mama/patologia , Carcinoma/patologia , Neoplasias Renais/patologia , Neoplasias Pulmonares/patologia , Neoplasias Meníngeas/secundário , Meningioma/secundário , Neoplasias da Próstata/patologia , Idoso , Neoplasias da Mama/epidemiologia , Carcinoma/epidemiologia , Feminino , Humanos , Neoplasias Renais/epidemiologia , Neoplasias Pulmonares/epidemiologia , Masculino , Neoplasias Meníngeas/epidemiologia , Meningioma/epidemiologia , Pessoa de Meia-Idade , Neoplasias da Próstata/epidemiologia
9.
Ann Neurol ; 85(2): 241-250, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30609109

RESUMO

OBJECTIVE: We investigated the relationship between the interictal metabolic patterns, the extent of resection of 18 F-fluorodeoxyglucose positron emission tomography (18 FDG-PET) hypometabolism, and seizure outcomes in patients with unilateral drug-resistant mesial temporal lobe epilepsy (MTLE) following anterior temporal lobe (TL) resection. METHODS: Eighty-two patients with hippocampal sclerosis or normal magnetic resonance imaging (MRI) findings, concordant 18 FDG-PET hypometabolism, and at least 2 years of postoperative follow-up were included in this 2-center study. The hypometabolic regions in each patient were identified with reference to 20 healthy controls (p < 0.005). The resected TL volume and the volume of resected TL PET hypometabolism (TLH) were calculated from the pre- and postoperative MRI scans coregistered with interictal 18 FDG-PET. RESULTS: Striking differences in metabolic patterns were observed depending on the lateralization of the epileptogenic TL. The extent of the ipsilateral TLH was significantly greater in left MTLE patients (p < 0.001), whereas right MTLE patients had significantly higher rates of contralateral (CTL) TLH (p = 0.016). In right MTLE patients, CTL hypometabolism was the strongest predictor of an unfavorable seizure outcome, associated with a 5-fold increase in the likelihood of seizure recurrence (odds ratio [OR] = 4.90, 95% confidence interval [CI] = 1.07-22.39, p = 0.04). In left MTLE patients, greater extent of resection of ipsilateral TLH was associated with lower rates of seizure recurrence (p = 0.004) in univariate analysis; however, its predictive value did not reach statistical significance (OR = 0.96, 95% CI = 0.90-1.02, p = 0.19). INTERPRETATION: The difference in metabolic patterns depending on the lateralization of MTLE may represent distinct epileptic networks in patients with right versus left MTLE, and can guide preoperative counseling and surgical planning. Ann Neurol 2019; 1-10 ANN NEUROL 2019;85:241-250.


Assuntos
Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia do Lobo Temporal/metabolismo , Adulto , Lobectomia Temporal Anterior , Estudos de Casos e Controles , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/cirurgia , Feminino , Fluordesoxiglucose F18 , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Esclerose , Resultado do Tratamento
10.
J Neurooncol ; 149(3): 401, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33026635

RESUMO

For the reference citation '[57]' in the second paragraph of the Results section of the original article there was no corresponding entry in the References section. It should have referred to the below mentioned article by Ebrahimkhani et al. (2018).

11.
J Neurooncol ; 149(3): 391-400, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32915353

RESUMO

PURPOSE: A circulating biomarker has potential to provide more accurate information for glioma progression post treatment, however no such biomarker is currently available. We aimed to discover a microRNA serum biomarker for longitudinal monitoring of glioma patients. METHODS: A prospectively collected cohort of 91 glioma patients and 17 healthy controls underwent pre and post-operative serum miRNA profiling using Nanostring®. Differentially expressed miRNAs were discovered using a machine learning random forest analysis. Candidate miRNAs were then assessed by droplet digital PCR in 11 patients with multiple follow up samples and compared to tumor volume based on magnetic resonance imaging. RESULTS: A 9-gene miRNA signature was identified that could distinguish between glioma and healthy controls with 99.8% accuracy. Two miRNAs miR-223 and miR-320e, best demonstrated dynamic changes that correlated closely with tumor volume in LGG and GBM respectively. Importantly, miRNA levels did not increase in two cases of pseudo-progression, indicating the potential utility of this test in guiding treatment decisions. CONCLUSIONS: We identified a highly accurate 9-miRNA signature associated with glioma serum. Additionally, we observed dynamic changes in specific miRNAs correlating with tumor volume over long-term follow up. These results support a large prospective validation study of serum miRNA biomarkers in glioma.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/sangue , Glioma/sangue , MicroRNAs/genética , Recidiva Local de Neoplasia/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Feminino , Seguimentos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/patologia , Glioma/cirurgia , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Estudos Prospectivos , Adulto Jovem
12.
Exp Cell Res ; 374(2): 353-364, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30562483

RESUMO

Glioblastoma (GBM) tumor cells exhibit drug resistance and are highly infiltrative. GBM stem cells (GSCs), which have low proliferative capacity are thought to be one of the sources of resistant cells which result in relapse/recurrence. However, the molecular mechanisms regulating quiescent-specific tumor cell biology are not well understood. Using human GBM cell lines and patient-derived GBM cells, Oregon Green dye retention was used to identify and isolate the slow-cycling, quiescent-like cell subpopulation from the more proliferative cells in culture. Sensitivity of cell subpopulations to temozolomide and radiation, as well as the migration and invasive potential were measured. Differential expression analysis following RNAseq identified genes enriched in the quiescent cell subpopulation. Orthotopic transplantation of cells into mice was used to compare the in vivo malignancy and invasive capacity of the cells. Proliferative quiescence correlated with better TMZ resistance and enhanced cell invasion, in vitro and in vivo. RNAseq expression analysis identified genes involved in the regulation cell invasion/migration and a three-gene signature, TGFBI, IGFBP3, CHI3L1, overexpressed in quiescent cells which correlates with poor GBM patient survival.


Assuntos
Neoplasias Encefálicas/patologia , Divisão Celular/fisiologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Glioblastoma/patologia , Animais , Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
13.
Crit Rev Clin Lab Sci ; 57(4): 227-252, 2019 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-31865806

RESUMO

Research on the role of extracellular vesicles (EVs) in disease pathogenesis has been rapidly growing over the last two decades. As EVs can mediate intercellular communication, they can ultimately facilitate both normal and pathological processes through the delivery of their bioactive cargo, which may include nucleic acids, proteins and lipids. EVs have emerged as important regulators of brain tumors, capable of transferring oncogenic proteins, receptors, and small RNAs that may support brain tumor progression, including in the most common type of brain cancer, glioma. Investigating the role of EVs in glioma is crucial, as the most malignant glioma, glioblastoma (GBM), is incurable with a dismal median survival of 12-15 months. EV research in GBM has primarily focused on circulating brain tumor-derived vesicles in biofluids, such as blood and cerebrospinal fluid (CSF), investigating their potential as diagnostic and prognostic biomarkers. Gaining a greater understanding of the role of EVs and their cargo in brain tumor progression may contribute to the discovery of novel diagnostics and therapeutics. In this review, we summarize the known and emerging functions of EVs in glioma biology and pathogenesis, as well as their emerging biomarker potential.

14.
Adv Exp Med Biol ; 1139: 1-21, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31134492

RESUMO

Glioblastoma is a primary tumor of the brain with a poor prognosis. Pathological examination shows that this disease is characterized by intra-tumor morphological heterogeneity, while numerous and ongoing genomic analysis reveals multiple layers of heterogeneity. Intra-tumor and patient-to-patient heterogeneity is underpinned by cellular, genetic, and molecular heterogeneity, which is thought to be key determinants of time to tumor recurrence and resistance to therapy. The key cell type believed to contribute to the establishment and ongoing evolution of tumor heterogeneity is a glioma stem cell (GSC) subpopulation. In this chapter, we review, highlight, and discuss controversies and clinical relevance of glioblastoma heterogeneity and its cellular basis. Characterization of how cancer stem cells (CSCs) behave is important in understanding how tumors are initiated and how they recur following initial treatment.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Células-Tronco Neoplásicas , Glioma , Humanos , Recidiva Local de Neoplasia
15.
Exp Mol Pathol ; 105(1): 23-31, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29852183

RESUMO

Limitations in discovering useful tumor biomarkers and drug targets is not only due to patient-to-patient differences but also due to intratumor heterogeneity. Heterogeneity arises due to the genetic and epigenetic variation of tumor cells in response to microenvironmental interactions and cytotoxic therapy. We explored specific signaling pathway activation in glioblastoma (GBM) by investigating the intratumor activation of the MAPK and PI3K pathways. We present data demonstrating a striking preponderance for mutual exclusivity of MAPK and PI3K activation in GBM tissue, where MAPK activation correlates with proliferation and transcription factor CREB activation and PI3K activation correlates with CD44 expression. Bioinformatic analysis of signaling and CREB-regulated target genes supports the immunohistochemical data, showing that the MAPK-CREB activation correlates with proliferative regions. In-silico analysis suggests that MAPK-CREB signaling activates a pro-inflammatory molecular signature and correlates with a mesenchymal GBM subtype profile, while PI3K-CREB activation correlates with the proneural GBM subtype and a tumor cell invasive gene signature. Overall, the data suggests the existence of intratumor subtype heterogeneity in GBM and that using combinations of both MAPK and PI3K drug inhibitors is necessary for effective targeted therapy.


Assuntos
Neoplasias Encefálicas/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Heterogeneidade Genética , Glioblastoma/genética , Sistema de Sinalização das MAP Quinases , Fosfatidilinositol 3-Quinases/metabolismo , Transcriptoma , Neoplasias Encefálicas/metabolismo , Proliferação de Células , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Humanos , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Fosfatidilinositol 3-Quinases/genética
16.
J Neurooncol ; 131(2): 321-329, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27896520

RESUMO

Bevacizumab, an anti-angiogenic agent, is FDA-approved for use in patients with recurrent glioblastoma multiforme (rGBM). The radiologic evaluation of tumor response to bevacizumab is complex and there is no validated method of monitoring tumor vascularity during therapy. We evaluated perfusion-weighted MR imaging (PWI) in our cohort of patients enrolled in the CABARET trial, which examined the effectiveness of bevacizumab with or without carboplatin in patients with rGBM. Pre-treatment and early follow-up (4- and 8-week) PWI were used to calculate relative cerebral blood volume (rCBV) histogram statistics of the contrast-enhancing and FLAIR hyperintense tumor volumes. A novel rCBV measurement (load) was developed to estimate the total volume of perfused tumor blood vessels. Changes in all rCBV measures were examined for correlations with progression-free (PFS) and overall survival (OS). All of our 15 patients enrolled in the CABARET trial were included. Median PFS and OS were 23 and 45 weeks respectively. Kaplan-Meier analysis of pre-treatment PWI revealed an 18 week reduction in median OS in patients with high tumor rCBV (p = 0.031). Changes in rCBV measures, especially load, correlated significantly with PFS and OS at both follow-up time-points. Patients with the greatest reduction in rCBVload by 8-weeks of therapy had a significantly increased median OS (30 weeks; p = 0.013). PWI may be of significant clinical utility in managing patients with rGBM, particularly those treated with anti-angiogenic agents such as bevacizumab. These findings need to be confirmed prospectively in larger studies.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Antineoplásicos/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Carboplatina/uso terapêutico , Glioblastoma/tratamento farmacológico , Angiografia por Ressonância Magnética , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Encefálicas/diagnóstico por imagem , Feminino , Glioblastoma/diagnóstico por imagem , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
17.
J Neurooncol ; 125(2): 237-48, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26391593

RESUMO

Glioblastoma is the most aggressive and lethal tumour of the central nervous system and as such the identification of reliable prognostic and predictive biomarkers for patient survival and tumour recurrence is paramount. MicroRNA detection has rapidly emerged as potential biomarkers, in patients with glioblastoma. Over the last decade, analysis of miRNA in laboratory based studies have yielded several candidates as potential biomarkers however, the accepted use of these candidates in the clinic is yet to be validated. Here we will examine the use of miRNA signatures to improve glioblastoma stratification into subgroups and summarise recent advances made in miRNA examination as potential biomarkers for glioblastoma progression and recurrence.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas , Glioblastoma , MicroRNAs , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Glioblastoma/diagnóstico , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos
18.
Epilepsia ; 55(9): 1438-43, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24903073

RESUMO

OBJECTIVE: The isocitrate dehydrogenase 1 (IDH1) R132H mutation is the most common mutation in World Health Organization (WHO) grade II gliomas, reported to be expressed in 70-80%, but only 5-10% of high grade gliomas. Low grade tumors, especially the protoplasmic subtype, have the highest incidence of tumor associated epilepsy (TAE). The IDH1 mutation leads to the accumulation of 2-hydroxyglutarate (2HG), a metabolite that bears a close structural similarity to glutamate, an excitatory neurotransmitter that has been implicated in the pathogenesis of TAE. We hypothesized that expression of mutated IDH1 may play a role in the pathogenesis of TAE in low grade gliomas. METHODS: Thirty consecutive patients with WHO grade II gliomas were analyzed for the presence of the IDH1-R132H mutation using immunohistochemistry. The expression of IDH1 mutation was semiquantified using open-source biologic-imaging analysis software. RESULTS: The percentage of cells positive for the IDH1-R132H mutation was found to be higher in patients with TAE compared to those without TAE (median and interquartile range (IQR) 25.3% [8.6-53.5] vs. 5.2% [0.6-13.4], p = 0.03). In addition, we found a significantly higher median IDH1 mutation expression level in the protoplasmic subtype of low grade glioma (52.2% [IQR 19.9-58.6] vs. 13.8% [IQR 3.9-29.4], p = 0.04). SIGNIFICANCE: Increased expression of the IDH1-R132H mutation is associated with seizures in low grade gliomas and also with the protoplasmic subtype. This supports the hypothesis that this mutation may play a role in the pathogenesis of both TAE and low grade gliomas.


Assuntos
Astrocitoma/complicações , Astrocitoma/genética , Neoplasias Encefálicas/genética , Isocitrato Desidrogenase/genética , Mutação/genética , Adolescente , Adulto , Idoso , Arginina/genética , Estudos de Coortes , Epilepsia/etiologia , Feminino , Estudos de Associação Genética , Histidina/genética , Humanos , Masculino , Pessoa de Meia-Idade , Convulsões/complicações , Convulsões/genética , Adulto Jovem
19.
Commun Dis Intell Q Rep ; 38(4): E273-8, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25631587

RESUMO

In 2013, an outbreak of gastrointestinal illness occurred following a buffet lunch at a restaurant in Canberra. An investigation was conducted to identify the cause of illness and to implement appropriate public health measures to prevent further disease. We conducted a retrospective cohort study via telephone interviews, using a structured questionnaire developed from the restaurant buffet menu. A case was defined as someone who ate the buffet lunch at the restaurant on the implicated date and developed any symptoms of gastrointestinal illness (such as diarrhoea, abdominal pain and nausea) following the consumption of food. A total of 74% (225/303) of known attendees were interviewed, of whom 56% (125/225) had become ill. The median incubation period and duration of illness were 13 and 19 hours respectively. The most commonly reported symptoms were diarrhoea (94%, 118/125) and abdominal pain (82%, 103/125). A toxin-mediated gastrointestinal illness was suspected based on the incubation period, duration of illness and the symptoms. The environmental health investigation identified a lack of designated hand washing facilities in the kitchen, an absence of thermometers for measuring food temperatures and several maintenance and minor cleaning issues. A number of food samples were taken for microbiological analysis. Multivariable analysis showed that illness was significantly associated with consuming curried prawns (OR 18.4, 95% CI 8.6-39.3, P < 0.001) and Caesar salad (OR 3.6, 95% CI 1.8-7.5, P 0.001). Enterotoxin-producing Staphylococcus aureus and Bacillus cereus were identified in leftover samples of cooked buffet food, but this food was not epidemiologically implicated. The investigation suggested that a breakdown in cleanliness, temperature control and food handling practices may have resulted in contamination of the buffet food. In order to prevent such outbreaks in the future, caterers and restaurateurs need to ensure they have the appropriate facilities and procedures in place if planning to cater for large groups.


Assuntos
Diarreia/diagnóstico , Surtos de Doenças , Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/diagnóstico , Gastroenterite/diagnóstico , Intoxicação por Frutos do Mar/diagnóstico , Adolescente , Adulto , Austrália/epidemiologia , Bacillus cereus/isolamento & purificação , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/microbiologia , Feminino , Manipulação de Alimentos/ética , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Higiene das Mãos , Humanos , Lactente , Almoço , Masculino , Pessoa de Meia-Idade , Restaurantes , Intoxicação por Frutos do Mar/epidemiologia , Intoxicação por Frutos do Mar/microbiologia , Staphylococcus aureus/isolamento & purificação , Inquéritos e Questionários
20.
J Clin Neurosci ; 129: 110837, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39288543

RESUMO

BACKGROUND: Spheno-orbital meningiomas (SOM) are known to invaded critical skull base areas. The authors report a series of WHO I SOM, propose a subclassification of this tumor according to its extension to critical positions and analyze the impact of extent of resection and the role of stereotactic radiotherapy in tumor recurrence. METHODS: A prospective maintained university medical center registry was utilized to undertake a retrospective review of patients operated with WHO I SOM. Details related to critical skull base region's extension (superior orbital fissure, cavernous sinus, orbital apex), extent of resection and adjuvant radiosurgery were collected. Statistical calculations were preformed using IBM SPSS Statistics version 25. A p value < 0.05 was considered significant. Survival analysis was performed using Kaplan-Meier survival analysis and the log rank test. RESULTS: A total of 77 patients operated from 2002 to 2021 were included. There were 65 women (84.4 %) and 12 men (15.6 %). Mean age at surgery was 54.8 years (median 53 years, range 23 - 88). Tumors were defined as local in 28 (35.4 %) and with extension into the skull base critical structures in 51 (64.6 %). GTR was achieved in 35 (44.3 %), STR in 40 (50.6 %), and PR in four (5.1 %). Surgical morbidity was 10 %. There was no surgical mortality. 28 patients with STR or PR were treated with adjuvant radiotherapy. The total length of follow up was a mean of 172.3 months. There were 14 recurrences/progressive growth (17.7 %), 63 patients (79.7 %) had no recurrence/progressive growth, and two patients (2.5 %) were lost to follow-up. PFS was significant statistically different in patients with invasive tumors in whom the extent of resection was subtotal, with a longer PFS in patients that were treated with adjuvant radiotherapy. (P value < 0.001). CONCLUSIONS: SOM could be divided in two groups according to its skull base extension facilitating decision management and outcome prediction. Patients with local WHO I SOM had higher rate of GTR and better PFS than tumors extending to involve critical regions. When STR or PR is achieved postoperative adjuvant radiotherapy is advised if there is evidence of previous tumor growth.

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