Advances in diffuse glial tumors diagnosis.

In recent decades, there have been significant advances in the diagnosis of diffuse gliomas, driven by the integration of novel technologies. These advancements have deepened our understanding of tumor oncogenesis, enabling a more refined stratification of the biological behavior of these neoplasms. This progress culminated in the fifth edition of the WHO classification of central nervous system (CNS) tumors in 2021. This comprehensive review article aims to elucidate these advances within a multidisciplinary framework, contextualized within the backdrop of the new classification. This article will explore morphologic pathology and molecular/genetics techniques (immunohistochemistry, genetic sequencing, and methylation profiling), which are pivotal in diagnosis, besides the correlation of structural neuroimaging radiophenotypes to pathology and genetics. It briefly reviews the usefulness of tractography and functional neuroimaging in surgical planning. Additionally, the article addresses the value of other functional imaging techniques such as perfusion MRI, spectroscopy, and nuclear medicine in distinguishing tumor progression from treatment-related changes. Furthermore, it discusses the advantages of evolving diagnostic techniques in classifying these tumors, as well as their limitations in terms of availability and utilization. Moreover, the expanding domains of data processing, artificial intelligence, radiomics, and radiogenomics hold great promise and may soon exert a substantial influence on glioma diagnosis. These innovative technologies have the potential to revolutionize our approach to these tumors. Ultimately, this review underscores the fundamental importance of multidisciplinary collaboration in employing recent diagnostic advancements, thereby hoping to translate them into improved quality of life and extended survival for glioma patients.

Nas últimas décadas, houve avanços significativos no diagnóstico de gliomas difusos, impulsionados pela integração de novas tecnologias. Esses avanços aprofundaram nossa compreensão da oncogênese tumoral, permitindo uma estratificação mais refinada do comportamento biológico dessas neoplasias. Esse progresso culminou na quinta edição da classificação da OMS de tumores do sistema nervoso central (SNC) em 2021. Esta revisão abrangente tem como objetivo elucidar esses avanços de forma multidisciplinar, no contexto da nova classificação. Este artigo irá explorar a patologia morfológica e as técnicas moleculares/genéticas (imuno-histoquímica, sequenciamento genético e perfil de metilação), que são fundamentais no diagnóstico, além da correlação dos radiofenótipos da neuroimagem estrutural com a patologia e a genética. Aborda sucintamente a utilidade da tractografia e da neuroimagem funcional no planejamento cirúrgico. Destacaremos o valor de outras técnicas de imagem funcional, como ressonância magnética de perfusão, espectroscopia e medicina nuclear, na distinção entre a progressão do tumor e as alterações relacionadas ao tratamento. Discutiremos as vantagens das diferentes técnicas de diagnóstico na classificação desses tumores, bem como suas limitações em termos de disponibilidade e utilização. Além disso, os crescentes avanços no processamento de dados, inteligência artificial, radiômica e radiogenômica têm grande potencial e podem em breve exercer uma influência substancial no diagnóstico de gliomas. Essas tecnologias inovadoras têm o potencial de revolucionar nossa abordagem a esses tumores. Em última análise, esta revisão destaca a importância fundamental da colaboração multidisciplinar na utilização dos recentes avanços diagnósticos, com a esperança de traduzi-los em uma melhor qualidade de vida e uma maior sobrevida.

Advances in diffuse glial tumors diagnosis / Avanços no diagnóstico dos gliomas difusos

Abstract In recent decades, there have been significant advances in the diagnosis of diffuse gliomas, driven by the integration of novel technologies. These advancements have deepened our understanding of tumor oncogenesis, enabling a more refined stratification of the biological behavior of these neoplasms. This progress culminated in the fifth edition of the WHO classification of central nervous system (CNS) tumors in 2021. This comprehensive review article aims to elucidate these advances within a multidisciplinary framework, contextualized within the backdrop of the new classification. This article will explore morphologic pathology and molecular/genetics techniques (immunohistochemistry, genetic sequencing, and methylation profiling), which are pivotal in diagnosis, besides the correlation of structural neuroimaging radiophenotypes to pathology and genetics. It briefly reviews the usefulness of tractography and functional neuroimaging in surgical planning. Additionally, the article addresses the value of other functional imaging techniques such as perfusion MRI, spectroscopy, and nuclear medicine in distinguishing tumor progression from treatment-related changes. Furthermore, it discusses the advantages of evolving diagnostic techniques in classifying these tumors, as well as their limitations in terms of availability and utilization. Moreover, the expanding domains of data processing, artificial intelligence, radiomics, and radiogenomics hold great promise and may soon exert a substantial influence on glioma diagnosis. These innovative technologies have the potential to revolutionize our approach to these tumors. Ultimately, this review underscores the fundamental importance of multidisciplinary collaboration in employing recent diagnostic advancements, thereby hoping to translate them into improved quality of life and extended survival for glioma patients.

Resumo Nas últimas décadas, houve avanços significativos no diagnóstico de gliomas difusos, impulsionados pela integração de novas tecnologias. Esses avanços aprofundaram nossa compreensão da oncogênese tumoral, permitindo uma estratificação mais refinada do comportamento biológico dessas neoplasias. Esse progresso culminou na quinta edição da classificação da OMS de tumores do sistema nervoso central (SNC) em 2021. Esta revisão abrangente tem como objetivo elucidar esses avanços de forma multidisciplinar, no contexto da nova classificação. Este artigo irá explorar a patologia morfológica e as técnicas moleculares/genéticas (imuno-histoquímica, sequenciamento genético e perfil de metilação), que são fundamentais no diagnóstico, além da correlação dos radiofenótipos da neuroimagem estrutural com a patologia e a genética. Aborda sucintamente a utilidade da tractografia e da neuroimagem funcional no planejamento cirúrgico. Destacaremos o valor de outras técnicas de imagem funcional, como ressonância magnética de perfusão, espectroscopia e medicina nuclear, na distinção entre a progressão do tumor e as alterações relacionadas ao tratamento. Discutiremos as vantagens das diferentes técnicas de diagnóstico na classificação desses tumores, bem como suas limitações em termos de disponibilidade e utilização. Além disso, os crescentes avanços no processamento de dados, inteligência artificial, radiômica e radiogenômica têm grande potencial e podem em breve exercer uma influência substancial no diagnóstico de gliomas. Essas tecnologias inovadoras têm o potencial de revolucionar nossa abordagem a esses tumores. Em última análise, esta revisão destaca a importância fundamental da colaboração multidisciplinar na utilização dos recentes avanços diagnósticos, com a esperança de traduzi-los em uma melhor qualidade de vida e uma maior sobrevida.

High frequency of WNT-activated medulloblastomas with CTNNB1 wild type suggests a higher proportion of hereditary cases in a Latin-Iberian population.

Purpose: Medulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%-90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics. Methods: A total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively. Results: WNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants. Conclusion: We observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.

Comparative analysis of somatostatin analog uptake between successfully irradiated and non-irradiated meningiomas.

OBJECTIVE: To evaluate whether there is a significant difference in somatostatin analog uptake in meningiomas treated or not with radiation therapy. METHODS: A cross-sectional study was performed comparing measurements of somatostatin analog (68Ga-DOTATATE) uptake in two independent groups of ten patients each - one consisting of patients with meningiomas previously treated with radiation therapy and another comprising patients who had never been submitted to radiation therapy. All patients underwent PET/CT and MRI scans in an interval shorter than 24 hours between exams. RESULTS: A total of 32 meningiomas from 20 patients were analyzed, all presenting significant somatostatin analog uptake in different degrees. The uptake levels of somatostatin analog were similar between the lesions treated or not with radiation therapy, and the mean values of SUVmax were 27.62 and 24.82, respectively (p=0.722). For SUVmean, the values were 16.20 and 14.82, respectively (p=0.822). CONCLUSION: Comparative analysis between the groups showed no significant differences in degree of somatostatin analog uptake in successfully irradiated and non-irradiated meningiomas.

Single nCounter assay for prediction of MYCN amplification and molecular classification of medulloblastomas: a multicentric study.

PURPOSE: Medulloblastoma is the most frequent pediatric malignant brain tumor, and is divided into four main subgroups: WNT, SHH, group 3, and group 4. MYCN amplification is an important medulloblastoma prognostic biomarker. We aimed to molecular classify and predict MYCN amplification in a single assay. METHODS: It was included 209 medulloblastomas from 205 patients (Brazil, Argentina, and Portugal), divided into training (n = 50) and validation (n = 159) sets. A nCounter assay was carried out using a custom panel for molecular classification, with additional genes, including MYCN. nSolver 4.0 software and the R environment were used for profiling and MYCN mRNA analysis. MYCN amplification by FISH was performed in 64 cases. RESULTS: The 205 medulloblastomas were classified in SHH (44.9%), WNT (15.6%), group 3 (18.1%) and group 4 (21.4%). In the training set, MYCN amplification was detected in three SHH medulloblastomas by FISH, which showed significantly higher MYCN mRNA counts than non-FISH amplified cases, and a cutoff for MYCN amplification was established ([Formula: see text] + 4σ = 11,124.3). Applying this threshold value in the validation set, we identified MYCN mRNA counts above the cutoff in three cases, which were FISH validated. CONCLUSION: We successfully stratified medulloblastoma molecular subgroups and predicted MYCN amplification using a single nCounter assay without the requirement of additional biological tissue, costs, or bench time.

Comparative analysis of somatostatin analog uptake between successfully irradiated and non-irradiated meningiomas

Abstract Objective To evaluate whether there is a significant difference in somatostatin analog uptake in meningiomas treated or not with radiation therapy. Methods A cross-sectional study was performed comparing measurements of somatostatin analog (68Ga-DOTATATE) uptake in two independent groups of ten patients each - one consisting of patients with meningiomas previously treated with radiation therapy and another comprising patients who had never been submitted to radiation therapy. All patients underwent PET/CT and MRI scans in an interval shorter than 24 hours between exams. Results A total of 32 meningiomas from 20 patients were analyzed, all presenting significant somatostatin analog uptake in different degrees. The uptake levels of somatostatin analog were similar between the lesions treated or not with radiation therapy, and the mean values of SUVmax were 27.62 and 24.82, respectively (p=0.722). For SUVmean, the values were 16.20 and 14.82, respectively (p=0.822). Conclusion Comparative analysis between the groups showed no significant differences in degree of somatostatin analog uptake in successfully irradiated and non-irradiated meningiomas.

RIPK3 is a novel prognostic marker for lower grade glioma and further enriches IDH mutational status subgrouping.

PURPOSE: Necroptosis is a necrotic-like cell death pathway in which Receptor-interacting serine/threonine-protein kinase 3 (RIPK3) plays a central role and may induce inflammation and immunity. Lower RIPK3 levels have been correlated with a poor prognosis in breast and colorectal cancer patients. Instead, in gliomas, the most prevalent among central nervous system cancers, necrosis concurs with a more aggressive and lethal outcome, suggesting that, in these cases, necrotic-like pathways may be linked to worse prognoses. Lower-grade gliomas (LGG) exhibit highly diverse clinical behaviors, ranging from slow-paced growth to fast progression to glioblastoma yet patient outcomes cannot be fully predicted through the available markers. To date, IDH mutational status is the most broadly used prognostic marker, albeit several candidates have been proposed to refine LGG subgrouping. Here, we aimed to assess RIPK3 role as a prognostic marker for LGG patients, independently of or in combination with IDH. METHODS: Using publicly available discovery (513 patients) and validation (134 patients) cohorts, we performed Kaplan Meier survival analysis and uni- and multivariate Cox regression models. RESULTS: RIPK3 is an independent prognostic marker in LGG patients, even when controlled by age and molecular or histological diagnostic criteria. Contrary to what was previously reported for other cancers, high RIPK3 expression levels correlates with an increased risk of death. Importantly, RIPK3 expression levels further split both the mutant and wild-type IDH patients into distinct risk groups. CONCLUSION: RIPK3 expression levels can be used in combination with IDH mutational status to better subgroup LGG patients regarding overall survival.

Minimizing the uncertainties regarding the effects of delaying radiotherapy for Glioblastoma: A systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Previous studies have provided no clear conclusions regarding the effects of delaying radiotherapy (RT) in GBM patients. We present a systematic review and meta-analysis to address the effect of delayed RT on the overall survival (OS) of GBM patients. METHODS: A systematic search retrieved 19 retrospective studies published between 1975 and 2014 reporting on the waiting time (WT) to RT for GBM patients. The meta-analysis was performed by converting WT to RT studies intervals into a regression coefficient (ß) and standard error expressing the effect size on OS per week of delay. RESULTS: Data required to calculate the effect size on OS per week of delay were available for 12 studies (5212 patients). A non-adjusted model and a meta-regression model based on well-recognized prognostic factors were performed. No association between WT to RT, per week of delay, and OS was found (HR=0.98; 95% CI 0.90-1.08; p=0.70). The meta-regression adjusted for prognostic factors weighted by the inverse-variance (1/SE(2)) showed no clear evidence of the effect of WT to RT, per week of delay, on OS. CONCLUSIONS: This meta-analysis, despite limitations, provided no evidence of a true effect on OS by delaying RT in GBM patients.

Waiting time to radiotherapy as a prognostic factor for glioblastoma patients in a scenario of medical disparities.

OBJECTIVE: To evaluate the effect of waiting time (WT) to radiotherapy (RT) on overall survival (OS) of glioblastoma (GBM) patients as a reliable prognostic variable in Brazil, a scenario of medical disparities. METHOD: Retrospective study of 115 GBM patients from two different health-care institutions (one public and one private) in Brazil who underwent post-operative RT. RESULTS: Median WT to RT was 6 weeks (range, 1.3-17.6). The median OS for WT ≤ 6 weeks was 13.5 months (95%CI , 9.1-17.9) and for WT > 6 weeks was 14.2 months (95%CI, 11.2-17.2) (HR 1.165, 95%CI 0.770-1.762; p = 0.470). In the multivariate analysis, the variables associated with survival were KPS (p < 0.001), extent of resection (p = 0.009) and the adjuvant treatment (p = 0.001). The KPS interacted with WT to RT (HR 0.128, 95%CI 0.034-0.476; p = 0.002), showing that the benefit of KPS on OS depends on the WT to RT. CONCLUSION: No prognostic impact of WT to RT could be detected on the OS. Although there are no data to ensure that delays to RT are tolerable, we may reassure patients that the time-length to initiate treatment does not seem to influence the control of the disease, particularly in face of other prognostic factors.

Waiting time to radiotherapy as a prognostic factor for glioblastoma patients in a scenario of medical disparities / Tempo de espera para a radioterapia como um fator prognóstico em pacientes com glioblastoma em um cenário de disparidades médicas

Objective To evaluate the effect of waiting time (WT) to radiotherapy (RT) on overall survival (OS) of glioblastoma (GBM) patients as a reliable prognostic variable in Brazil, a scenario of medical disparities. Method Retrospective study of 115 GBM patients from two different health-care institutions (one public and one private) in Brazil who underwent post-operative RT. Results Median WT to RT was 6 weeks (range, 1.3-17.6). The median OS for WT ≤ 6 weeks was 13.5 months (95%CI , 9.1-17.9) and for WT > 6 weeks was 14.2 months (95%CI, 11.2-17.2) (HR 1.165, 95%CI 0.770-1.762; p = 0.470). In the multivariate analysis, the variables associated with survival were KPS (p < 0.001), extent of resection (p = 0.009) and the adjuvant treatment (p = 0.001). The KPS interacted with WT to RT (HR 0.128, 95%CI 0.034-0.476; p = 0.002), showing that the benefit of KPS on OS depends on the WT to RT. Conclusion No prognostic impact of WT to RT could be detected on the OS. Although there are no data to ensure that delays to RT are tolerable, we may reassure patients that the time-length to initiate treatment does not seem to influence the control of the disease, particularly in face of other prognostic factors. .

Objetivo Avaliar o efeito do tempo de espera (TE) até radioterapia na sobrevida global de pacientes com glioblastoma como um fator prognóstico confiável. Método Estudo retrospectivo de 115 pacientes com glioblastoma, que foram submetidos à radioterapia pós-operatória, em dois serviços diferentes no Brasil (um público e outro privado). Resultados Mediana de TE para radioterapia foi de 6 semanas (variação, 1,3-17,6). A mediana de sobrevida para TE ≤ 6 semanas foi de 13,5 meses (IC95%, 9,1-17,9) e para TE > 6 semanas foi de 14,2 meses (IC95%, 11,2-17,2) (HR 1,165, 0,770-1,762; p = 0,470). Na análise multivariada, as variáveis associadas à sobrevida foram perfomance status (p < 0,001), extensão da ressecção (p = 0,009) e tratamento adjuvante (p = 0,001). Conclusão Não se observou impacto prognóstico para TE até a radioterapia na sobrevida. Diante de outros fatores prognósticos, é possível assegurar de que o espaço de tempo até a radioterapia não parece influenciar o controle da doença. .

Initial care and outcome of glioblastoma multiforme patients in 2 diverse health care scenarios in Brazil: does public versus private health care matter?.

BACKGROUND: The aim of this study was to describe the epidemiological and survival features of patients with glioblastoma multiforme treated in 2 health care scenarios--public and private--in Brazil. METHODS: We retrospectively analyzed clinical, treatment, and outcome characteristics of glioblastoma multiforme patients from 2003 to 2011 at 2 institutions. RESULTS: The median age of the 171 patients (117 public and 54 private) was 59.3 years (range, 18-84). The median survival for patients treated in private institutions was 17.4 months (95% confidence interval, 11.1-23.7) compared with 7.1 months (95% confidence interval, 3.8-10.4) for patients treated in public institutions (P < .001). The time from the first symptom to surgery was longer in the public setting (median of 64 days for the public hospital and 31 days for the private institution; P = .003). The patients at the private hospital received radiotherapy concurrent with chemotherapy in 59.3% of cases; at the public hospital, only 21.4% (P < .001). Despite these differences, the institution of treatment was not found to be an independent predictor of outcome (hazard ratio, 1.675; 95% confidence interval, 0.951-2.949; P = .074). The Karnofsky performance status and any additional treatment after surgery were predictors of survival. A hazard ratio of 0.010 (95% confidence interval, 0.003-0.033; P < .001) was observed for gross total tumor resection followed by radiotherapy concurrent with chemotherapy. CONCLUSIONS: Despite obvious disparities between the hospitals, the medical assistance scenario was not an independent predictor of survival. However, survival was directly influenced by additional treatment after surgery. Therefore, increasing access to resources in developing countries like Brazil is critical.

Patterns of care and outcomes in elderly patients with glioblastoma in Sao Paulo, Brazil: a retrospective study.

OBJECTIVE: To analyze how elderly patients with glioblastoma are managed in Brazil. MATERIAL AND METHODS: We identified 30 patients aged ≥ 65 years treated between 2003 and 2011 at Albert Einstein Hospital in Sao Paulo. We retrospectively reviewed medical records to obtain data on clinical variables, treatment and outcomes. Overall survival (OS) was evaluated using Kaplan-Meier methods and compared using a Wilcoxon log-rank test. RESULTS: The median age was 73 years. The majority of patients (73.2%) underwent surgical intervention. Following surgery, 80% received radiotherapy (RT), and of those, 79.2% were treated with concurrent temozolomide (TMZ). The median progression free survival and OS were 5 and 10.6 months, respectively. Patients with a KPS ≥ 70 had a median OS of 16.2 months, compared to 6.4 months for those with a KPS <70 (p=0.032). For those patients in whom biopsy only was performed, the median OS was 5.3 months, as compared to 7.8 months for those who underwent partial resection and 18.6 months for those treated with gross total resection (p=0.021). A longer survival was found among patients who received RT versus those who did not (11 months vs. 1 month, p=0.003), as well as for those treated with chemoradiation (13.6 months vs. 6.4 months, p<0.0001). CONCLUSIONS: This study brings new information about the management of elderly patients with glioblastoma in Brazil. Our data may suggest that elderly patients who undergo cytoreductive surgery and adjuvant RT with concurrent TMZ can do better than those with less aggressive treatment.

Glioblastoma: approach to treat elderly patients / Glioblastoma: enfoque no tratamento de pacientes idosos

Treating elderly cancer patients is a challenge for oncologists, especially considering the several therapeutic modalities in glioblastoma. Extensive tumor resection offers the best chance of local control. Adequate radiotherapy should always be given to elderly patients if they have undergone gross total resection and have maintained a good performance status. Rather than being ruled out, chemotherapy should be considered, and temozolomide is the chosen drug. A comprehensive geriatric assessment is a valuable tool to help guiding treatment decisions in elderly patients with glioblastoma.

O tratamento de idosos com câncer é um desafio para a prática oncológica, especialmente no que se refere à terapêutica multimodal do glioblastoma. Nessa população, a ressecção ampla do tumor oferece a melhor chance de controle local e, naqueles pacientes que mantenham um bom performance status, a radioterapia complementar deve sempre ser levada em consideração. A quimioterapia também tem um papel no tratamento, sendo a temozolomida a droga de eleição. Frente à heterogeneidade desses pacientes, uma avaliação geriátrica ampla é um instrumento valioso no auxílio da decisão terapêutica em idosos com glioblastoma.

Tumor growth analysis by magnetic resonance imaging of the C6 glioblastoma model with prospects for the assessment of magnetohyperthermia therapy.

OBJECTIVE: The objective was to establish a pattern of tumor growth of the C6 model of glioblastoma multiform in Wistar rats via magnetic resonance imaging (MRI) for the subsequent verification of tumor volume reduction due to magnetic hyperthermia therapy. METHODS: Young male Wistar rats weighing between 250 and 300 g were used for the C6 model. After the rats were anesthetized (55 mg/ kg ketamine and 11 mg/kg xylazine), C6 lineage tumorigenic cells suspended in culture medium (10(5) cells in 10 microl) were stereotaxically injected into the right frontal cortex (bregma coordinates: 2.0 mm anteroposterior, 3.0 mm laterolateral, and 2.5 mm depth) of the rats using a Hamilton syringe. For the control group, the rats were injected with culture medium without cells. MRI scans were performed at 14, 21, and 28 d after the injection using a 2.0 T MRI scanner (Bruker BioSpec, Germany). The animals were anesthetized with 55 mg/kg ketamine and 11 mg/kg xylazine before being examined. Coronal multilayers were acquired using a standard spin echo sequence with the following parameters: repetition/echo time = 4.000 ms/67.1 ms, field of view = 3.50, matrix = 192, slice thickness = 0.4 mm, and slice separation = 0 mm. RESULTS: The MRI analysis enabled a clear visualization of the tumor mass, and it was possible to establish the tumor volume parameters on the various days that were examined. The volume at 14 d after induction was 13.7 +/- 2.5 mm3. On days 21 and 28, the tumor volumes were 31.7 +/- 6.5 mm3 and 122.1 +/- 11.8 mm3, respectively. CONCLUSION: These results demonstrated that it is possible to evaluate the C6 model tumor volume in rats, which will allow for the future implementation and verification of magnetic hyperthermia therapy.

Isolation, cultivation and characterization of CD133+ stem cells from human glioblastoma.

OBJECTIVE: To establish the method of isolation and culture of human glioblastoma neurospheres, and the purification of their stem cells, followed by the process of obtaining tumor subspheres, immunophenotypically characterizing this clonogenic set. METHODS: Through the processing of glioblastoma samples (n=3), the following strategy of action was adopted: (i) establish primary culture of glioblastoma; (ii) isolation and culture of tumor neurospheres; (iii) purify cells that initiate tumors (CD133+) by magnetic separation system (MACS); (iv) obtain tumor subspheres; (v) study the expression of the markers nestin, CD133, and GFAP. RESULTS: The study successfully described the process of isolation and culture of glioblastoma subspheres, which consist of a number of clonogenic cells immunophenotypically characterized as neural, which are able to initiate tumor formation. CONCLUSION: These findings may contribute to a better understanding of the process of gliomagenesis.

Isolation, cultivation and characterization of CD133+ stem cells from human glioblastoma / Isolamento, cultivo e caracterização de células-tronco CD133+ de glioblastoma humano

Objetivo: Estabelecer o método de isolamento e cultivo das neuroesferas de glioblastoma humano, bem como purificação de suas células-tronco, seguido do processo de obtenção de subesferas tumorais, caracterizando imunofenotipicamente esse conjunto clonogênico. Métodos: Por meio do processamento de amostras de glioblastomas (n=3), cumpriu-se a seguinte estratégia de ação: (i) estabelecimento da cultura primária de glioblastoma; (ii) isolamento e cultura de neuroesferas tumorais; (iii) purificação das células que iniciam os tumores (CD133+) por sistema de separação magnética (MACS); (iv) obtenção subesferas tumorais; (v) estudo da expressão de marcadores GFAP, CD133 e nestina. Resultados: Este estudo descreveu com sucesso o processo de isolamento e cultivo de subesferas de glioblastoma, as quais são constituídas por um conjunto clonogênico de células caracterizadas imunofenotipicamente como neurais, capazes de iniciar a formação tumoral. Conclusão: Estes achados poderão contribuir para a compreensão do processo de gliomagênese.