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1.
Acta Neuropathol ; 147(1): 3, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38079020

RESUMO

Glioblastoma is a clinically and molecularly heterogeneous disease, and new predictive biomarkers are needed to identify those patients most likely to respond to specific treatments. Through prospective genomic profiling of 459 consecutive primary treatment-naïve IDH-wildtype glioblastomas in adults, we identified a unique subgroup (2%, 9/459) defined by somatic hypermutation and DNA replication repair deficiency due to biallelic inactivation of a canonical mismatch repair gene. The deleterious mutations in mismatch repair genes were often present in the germline in the heterozygous state with somatic inactivation of the remaining allele, consistent with glioblastomas arising due to underlying Lynch syndrome. A subset of tumors had accompanying proofreading domain mutations in the DNA polymerase POLE and resultant "ultrahypermutation". The median age at diagnosis was 50 years (range 27-78), compared with 63 years for the other 450 patients with conventional glioblastoma (p < 0.01). All tumors had histologic features of the giant cell variant of glioblastoma. They lacked EGFR amplification, lacked combined trisomy of chromosome 7 plus monosomy of chromosome 10, and only rarely had TERT promoter mutation or CDKN2A homozygous deletion, which are hallmarks of conventional IDH-wildtype glioblastoma. Instead, they harbored frequent inactivating mutations in TP53, NF1, PTEN, ATRX, and SETD2 and recurrent activating mutations in PDGFRA. DNA methylation profiling revealed they did not align with known reference adult glioblastoma methylation classes, but instead had unique globally hypomethylated epigenomes and mostly classified as "Diffuse pediatric-type high grade glioma, RTK1 subtype, subclass A". Five patients were treated with immune checkpoint blockade, four of whom survived greater than 3 years. The median overall survival was 36.8 months, compared to 15.5 months for the other 450 patients (p < 0.001). We conclude that "De novo replication repair deficient glioblastoma, IDH-wildtype" represents a biologically distinct subtype in the adult population that may benefit from prospective identification and treatment with immune checkpoint blockade.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Adulto , Humanos , Criança , Pessoa de Meia-Idade , Idoso , Glioblastoma/genética , Glioblastoma/patologia , Inibidores de Checkpoint Imunológico , Homozigoto , Estudos Prospectivos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Deleção de Sequência , Mutação/genética , Isocitrato Desidrogenase/genética
2.
Virol J ; 20(1): 49, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949545

RESUMO

BACKGROUND: The human skin contains a diverse microbiome that provides protective functions against environmental pathogens. Studies have demonstrated that bacteriophages modulate bacterial community composition and facilitate the transfer of host-specific genes, potentially influencing host cellular functions. However, little is known about the human skin virome and its role in human health. Especially, how viral-host relationships influence skin microbiome structure and function is poorly understood. RESULTS: Population dynamics and genetic diversity of bacteriophage communities in viral metagenomic data collected from three anatomical skin locations from 60 subjects at five different time points revealed that cutaneous bacteriophage populations are mainly composed of tailed Caudovirales phages that carry auxiliary genes to help improve metabolic remodeling to increase bacterial host fitness through antimicrobial resistance. Sequence variation in the MRSA associated antimicrobial resistance gene, erm(C) was evaluated using targeted sequencing to further confirm the presence of antimicrobial resistance genes in the human virome and to demonstrate how functionality of such genes may influence persistence and in turn stabilization of bacterial host and their functions. CONCLUSIONS: This large temporal study of human skin associated viruses indicates that the human skin virome is associated with auxiliary metabolic genes and antimicrobial resistance genes to help increase bacterial host fitness.


Assuntos
Bacteriófagos , Microbiota , Vírus , Humanos , Viroma , Bacteriófagos/genética , Vírus/genética , Metagenoma , Bactérias/genética
3.
J Neurooncol ; 165(1): 101-112, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37864646

RESUMO

INTRODUCTION: Hypoxia inducible factor 2-alpha (HIF2α) mediates cellular responses to hypoxia and is over-expressed in glioblastoma (GBM). PT2385 is an oral HIF2α inhibitor with in vivo activity against GBM. METHODS: A two-stage single-arm open-label phase II study of adults with GBM at first recurrence following chemoradiation with measurable disease was conducted through the Adult Brain Tumor Consortium. PT2385 was administered at the phase II dose (800 mg b.i.d.). The primary outcome was objective radiographic response (ORR = complete response + partial response, CR + PR); secondary outcomes were safety, overall survival (OS), and progression free survival (PFS). Exploratory objectives included pharmacokinetics (day 15 Cmin), pharmacodynamics (erythropoietin, vascular endothelial growth factor), and pH-weighted amine- chemical exchange saturation transfer (CEST) MRI to quantify tumor acidity at baseline and explore associations with drug response. Stage 1 enrolled 24 patients with early stoppage for ≤ 1 ORR. RESULTS: Of the 24 enrolled patients, median age was 62.1 (38.7-76.7) years, median KPS 80, MGMT promoter was methylated in 46% of tumors. PT2385 was well tolerated. Grade ≥ 3 drug-related adverse events were hypoxia (n = 2), hyponatremia (2), lymphopenia (1), anemia (1), and hyperglycemia (1). No objective radiographic responses were observed; median PFS was 1.8 months (95% CI 1.6-2.5) and OS was 7.7 months (95% CI 4.9-12.6). Drug exposure varied widely and did not differ by corticosteroid use (p = 0.12), antiepileptics (p = 0.09), or sex (p = 0.37). Patients with high systemic exposure had significantly longer PFS (6.7 vs 1.8 months, p = 0.009). Baseline acidity by pH-weighted CEST MRI correlated significantly with treatment duration (R2 = 0.49, p = 0.017). Non-enhancing infiltrative disease with high acidity gave rise to recurrence. CONCLUSIONS: PT2385 monotherapy had limited activity in first recurrent GBM. Drug exposure was variable. Signals of activity were observed in GBM patients with high systemic exposure and acidic lesions on CEST imaging. A second-generation HIF2α inhibitor is being studied.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Adulto , Humanos , Pessoa de Meia-Idade , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/diagnóstico por imagem , Glioblastoma/tratamento farmacológico , Hipóxia , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/tratamento farmacológico , Fator A de Crescimento do Endotélio Vascular , Idoso
4.
Mol Carcinog ; 61(3): 281-287, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34758158

RESUMO

Persistent and symptomatic reflux of gastric and duodenal contents, known as gastroesophageal reflux disease (GERD), is the strongest risk factor for esophageal adenocarcinoma (EAC). Despite similar rates of GERD and other risk factors across racial groups, EAC progression disproportionately impacts Caucasians. We recently reported that elevated tissue levels of the detoxification enzyme GSTT2 in the esophagi of Blacks compared to Caucasians may contribute protection. Herein, we extend our research to investigate whether cranberry proanthocyanidins (C-PAC) mitigate bile acid-induced damage and GSTT2 levels utilizing a racially diverse panel of patient-derived primary esophageal cultures. We have shown that C-PACs mitigate reflux-induced DNA damage through GSTT2 upregulation in a rat esophageal reflux model, but whether effects are recapitulated in humans or differentially based on race remains unknown. We isolated normal primary esophageal cells from Black and Caucasian patients and assessed GSTT2 protein levels and cellular viability following exposure to a bile acid cocktail with and without C-PAC treatment. Constitutive GSTT2 levels were significantly elevated in Black (2.9-fold) compared to Caucasian patients, as were GSTT2 levels in Black patients with GERD. C-PAC treatment induced GSTT2 levels 1.6-fold in primary normal esophageal cells. GSTT2 induction by C-PAC was greatest in cells with constitutively low GSTT2 expression. Overall, C-PAC mitigated bile-induced reductions of GSTT2 and subsequent loss of cell viability regardless of basal GSTT2 expression or race. These data support that C-PAC may be a safe efficacious agent to promote epithelial fitness through GSTT2 induction and in turn protect against bile acid-induced esophageal injury.


Assuntos
Neoplasias Esofágicas , Refluxo Gastroesofágico , Proantocianidinas , Vaccinium macrocarpon , Adenocarcinoma , Animais , Ácidos e Sais Biliares , Técnicas de Cultura de Células , Neoplasias Esofágicas/genética , Refluxo Gastroesofágico/tratamento farmacológico , Refluxo Gastroesofágico/genética , Refluxo Gastroesofágico/metabolismo , Glutationa Transferase , Humanos , Extratos Vegetais/farmacologia , Proantocianidinas/farmacologia , Ratos
5.
Acta Neuropathol ; 144(4): 747-765, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35945463

RESUMO

Gliomas arising in the setting of neurofibromatosis type 1 (NF1) are heterogeneous, occurring from childhood through adulthood, can be histologically low-grade or high-grade, and follow an indolent or aggressive clinical course. Comprehensive profiling of genetic alterations beyond NF1 inactivation and epigenetic classification of these tumors remain limited. Through next-generation sequencing, copy number analysis, and DNA methylation profiling of gliomas from 47 NF1 patients, we identified 2 molecular subgroups of NF1-associated gliomas. The first harbored biallelic NF1 inactivation only, occurred primarily during childhood, followed a more indolent clinical course, and had a unique epigenetic signature for which we propose the terminology "pilocytic astrocytoma, arising in the setting of NF1". The second subgroup harbored additional oncogenic alterations including CDKN2A homozygous deletion and ATRX mutation, occurred primarily during adulthood, followed a more aggressive clinical course, and was epigenetically diverse, with most tumors aligning with either high-grade astrocytoma with piloid features or various subclasses of IDH-wildtype glioblastoma. Several patients were treated with small molecule MEK inhibitors that resulted in stable disease or tumor regression when used as a single agent, but only in the context of those tumors with NF1 inactivation lacking additional oncogenic alterations. Together, these findings highlight recurrently altered pathways in NF1-associated gliomas and help inform targeted therapeutic strategies for this patient population.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioma , Neurofibromatose 1 , Adulto , Astrocitoma/genética , Neoplasias Encefálicas/genética , Glioma/genética , Glioma/patologia , Homozigoto , Humanos , Neurofibromatose 1/complicações , Neurofibromatose 1/genética , Deleção de Sequência
6.
J Neurooncol ; 159(1): 103-115, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35716311

RESUMO

INTRODUCTION: Although immunosuppression is a known characteristic of glioma, no previous large studies have reported peripheral blood immune cell profiles prior to patient surgery and chemoradiation. This report describes blood immune cell characteristics and associated variables prior to surgery among typical glioma patients seen at a large University practice. METHODS: We analyzed pre-surgery blood samples from 139 glioma patients diagnosed with a new or recurrent grade II/III glioma (LrGG, n = 64) or new glioblastoma (GBM, n = 75) and 454 control participants without glioma. Relative cell fractions of CD4, CD8, B-cells, Natural Killer cells, monocytes, and neutrophils, were estimated via a validated deconvolution algorithm from blood DNA methylation measures from Illumina EPIC arrays. RESULTS: Dexamethasone use at time of blood draw varied by glioma type being highest among patients with IDH wild-type (wt) GBM (75%) and lowest for those with oligodendroglioma (14%). Compared to controls, glioma patients showed statistically significant lower cell fractions for all immune cell subsets except for neutrophils which were higher (all p-values < 0.001), in part because of the higher prevalence of dexamethasone use at time of blood draw for IDHwt GBM. Patients who were taking dexamethasone were more likely to have a low CD4 count (< 200, < 500), increased neutrophils, low absolute lymphocyte counts, higher total cell count and higher NLR. CONCLUSION: We show that pre-surgery blood immune profiles vary by glioma subtype, age, and more critically, by use of dexamethasone. Our results highlight the importance of considering dexamethasone exposures in all studies of immune profiles and of obtaining immune measures prior to use of dexamethasone, if possible.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Adulto , Neoplasias Encefálicas/genética , Dexametasona/uso terapêutico , Glioma/genética , Humanos , Isocitrato Desidrogenase/genética , Recidiva Local de Neoplasia
7.
Curr Oncol Rep ; 23(2): 21, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33496872

RESUMO

PURPOSE OF REVIEW: This review seeks to inform oncology clinicians and researchers about the development of novel immunotherapies for the treatment of glioblastoma. An enumeration of ongoing and recently completed clinical trials will be discussed with special attention given to current technologies implemented to overcome central nervous system-specific challenges including barriers to the peripheral immune system, impaired antigen presentation, and T cell dysfunction. RECENT FINDINGS: The success of immunotherapy in other solid cancers has served as a catalyst to explore its application in glioblastoma, which has limited response to other treatments. Recent developments include multi-antigen vaccines that seek to overcome the heterogeneity of glioblastoma, as well as immune checkpoint inhibitors, which could amplify the adaptive immune response and may have promise in combinatorial approaches. Additionally, oncolytic and retroviruses have opened the door to a plethora of combinatorial approaches aiming to leverage their immunogenicity and/or ability to carry therapeutic transgenes. Treatment of glioblastoma remains a serious challenge both with regard to immune-based as well as other therapeutic strategies. The disease has proven to be highly resistant to treatment due to a combination of tumor heterogeneity, adaptive expansion of resistant cellular subclones, evasion of immune surveillance, and manipulation of various signaling pathways involved in tumor progression and immune response. Immunotherapeutics that are efficacious in other cancer types have unfortunately not enjoyed the same success in glioblastoma, illustrating the challenging and complex nature of this disease and demonstrating the need for development of multimodal treatment regimens utilizing the synergistic qualities of immune-mediated therapies.


Assuntos
Neoplasias Encefálicas/terapia , Vacinas Anticâncer/uso terapêutico , Glioblastoma/terapia , Imunoterapia/métodos , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Terapia Combinada , Glioblastoma/imunologia , Glioblastoma/patologia , Humanos , Terapia Viral Oncolítica/métodos
8.
J Neurooncol ; 146(1): 71-78, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31728884

RESUMO

OBJECTIVES: Treatment-induced lesions represent a great challenge in neuro-oncology. The aims of this study were (i) to characterize treatment induced lesions in glioblastoma patients treated with chemoradiotherapy and heat-shock protein (HSP) vaccine and (ii) to evaluate the diagnostic accuracy of diffusion weighted imaging for differentiation between treatment-induced lesions and tumor progression. METHODS: Twenty-seven patients with newly diagnosed glioblastoma treated with HSP vaccine and chemoradiotherapy were included. Serial magnetic resonance imaging evaluation was performed to detect treatment-induced lesions and assess their growth. Quantitative analysis of the apparent diffusion coefficient (ADC) was performed to discriminate treatment-induced lesions from tumor progression. Mann-Whitney U-test and receiver operating characteristic (ROC) curves were used for analysis. RESULTS: Thirty-three percent of patients developed treatment-induced lesions. Five treatment-related lesions appeared between end of radiotherapy and the first vaccine administration; 4 lesions within the first 4 months from vaccine initiation and 1 at 3.5 years. Three patients with pathology proven treatment-induced lesions showed a biphasic growth pattern progressed shortly after. ADC ratio between the peripheral enhancing rim and central necrosis showed an accuracy of 0.84 (95% CI 0.63-1) for differentiation between progression and treatment-induced lesions. CONCLUSION: Our findings do not support the iRANO recommendation of a 6-month time window in which progressive disease should not be declared after immunotherapy initiation. A biphasic growth pattern of pathologically proven treatment-induced lesions was associated with a dismal prognosis. The presence of lower ADC values in the central necrotic portion of the lesions compared to the enhancing rim shows high specificity for detection of treatment-induced lesions.


Assuntos
Neoplasias Encefálicas/patologia , Quimiorradioterapia/efeitos adversos , Imagem de Difusão por Ressonância Magnética/métodos , Glioblastoma/patologia , Proteínas de Choque Térmico/imunologia , Imunoterapia Ativa/efeitos adversos , Segunda Neoplasia Primária/patologia , Adulto , Idoso , Neoplasias Encefálicas/terapia , Terapia Combinada , Progressão da Doença , Feminino , Seguimentos , Glioblastoma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Segunda Neoplasia Primária/etiologia , Prognóstico , Curva ROC , Estudos Retrospectivos , Taxa de Sobrevida
9.
J Magn Reson Imaging ; 50(3): 868-877, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30663150

RESUMO

BACKGROUND: Although radiation therapy (RT) contributes to survival benefit in many brain tumor patients, it has also been associated with long-term brain injury. Cerebral microbleeds (CMBs) represent an important manifestation of radiation-related injury. PURPOSE: To characterize the change in size and number of CMBs over time and to evaluate their relationship to white matter structural integrity as measured using diffusion MRI indices. STUDY TYPE: Longitudinal, retrospective, human cohort. POPULATION: In all, 113 brain tumor patients including patients treated with focal RT (n = 91, 80.5%) and a subset of nonirradiated controls (n = 22, 19.5%). FIELD STRENGTH/SEQUENCE: Single and multiecho susceptibility-weighted imaging (SWI) and multiband, shell, and direction diffusion tensor imaging (DTI) at 7 T. ASSESSMENT: Patients were scanned either once or serially. CMBs were detected and quantified on SWI images using a semiautomated approach. Local and global fractional anisotropy (FA) were measured from DTI data for a subset of 35 patients. STATISTICAL TESTS: Potential risk factors for CMB development were determined by multivariate linear regression and using linear mixed-effect models. Longitudinal FA was quantitatively and qualitatively evaluated for trends. RESULTS: All patients scanned at 1 or more years post-RT had CMBs. A history of multiple surgical resections was a risk factor for development of CMBs. The total number and volume of CMBs increased by 18% and 11% per year, respectively, although individual CMBs decreased in volume over time. Simultaneous to these microvascular changes, FA decreased by a median of 6.5% per year. While the majority of nonirradiated controls had no CMBs, four control patients presented with fewer than five CMBs. DATA CONCLUSION: Identifying patients who are at the greatest risk for CMB development, with its likely associated long-term cognitive impairment, is an important step towards developing and piloting preventative and/or rehabilitative measures for patients undergoing RT. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;50:868-877.


Assuntos
Neoplasias Encefálicas/radioterapia , Hemorragia Cerebral/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Lesões por Radiação/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Substância Branca/patologia
10.
J Neurooncol ; 140(2): 477-483, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30151703

RESUMO

INTRODUCTION: Alterations in the CDK4/6-RB signaling pathway are common causes of cell cycle dysregulation in many cancers, including glioblastoma. Palbociclib is an oral inhibitor of CDK4/6, which leads to phosphorylation of RB1 and cell-cycle arrest. We conducted a two-arm study evaluating efficacy and tissue pharmacokinetics/pharmacodynamics of palbociclib in patients with recurrent glioblastoma. METHODS: Eligibility criteria included confirmation of RB1 proficiency by IHC; ≤ 3 relapses; KPS ≥ 60; no limit on prior treatments. Arm 1 received palbociclib for 7 days prior to indicated resection followed by adjuvant palbociclib. Arm 2 received palbociclib without resection. Primary objective was PFS6; secondary included toxicity, OS, and ORR. Exploratory aims included biomarker assessment and pharmacokinetic/pharmacodynamic effects in surgical patients. RESULTS: Total of 22 patients were enrolled; 6 on Arm 1 and 16 on Arm 2. Trial was stopped early secondary to lack of efficacy, with 95% of evaluable patients progressing within 6 months. Median PFS was 5.14 weeks (range 5 days-142 weeks) and median OS was 15.4 weeks (range 2-274 weeks). Two patients (10%) had related grade ≥ 3 AEs. In Arm 1, 5 patients had tissue concentrations of palbociclib felt to be sufficient for biological effect and paired samples available for RB1 IHC. There were no consistent changes in RB1 expression or cell proliferation in the paired tissue. CONCLUSION: In this trial, despite adequate tissue PK, palbociclib monotherapy was not an effective treatment for recurrent glioblastoma. However, these were heavily pretreated patients and targeting the CDK4/6 pathway may still deserve further exploration.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Piperazinas/uso terapêutico , Piridinas/uso terapêutico , Adulto , Idoso , Antineoplásicos/farmacocinética , Antineoplásicos/toxicidade , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/cirurgia , Terapia Combinada , Feminino , Glioblastoma/metabolismo , Glioblastoma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/cirurgia , Piperazinas/farmacocinética , Piperazinas/toxicidade , Piridinas/farmacocinética , Piridinas/toxicidade , Adulto Jovem
12.
Cancer ; 123(23): 4631-4639, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28759109

RESUMO

BACKGROUND: Activation of the phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway is common in patients with low-grade gliomas (LGGs), but agents that inhibit this pathway, including mTOR inhibitors, have not been studied in this population. METHODS: Fifty-eight patients with pathologic evidence of recurrence after they had initially been diagnosed with World Health Organization (WHO) grade II gliomas were enrolled into a prospective phase 2 clinical trial and received daily everolimus (RAD001) for 1 year or until progression. Tissue at the time of enrollment was analyzed for markers of PI3K/mTOR pathway activation. Thirty-eight patients underwent serial multiparametric magnetic resonance imaging, with the tumor volume and the perfusion metrics (the fractional blood volume [fBV] for capillary density and the transfer coefficient [Kps ] for vascular permeability) measured during treatment. The primary endpoint was progression-free survival at 6 months (PFS-6) in patients with WHO II disease at enrollment. RESULTS: For patients with WHO II gliomas at enrollment, the PFS-6 rate was 84%, and this met the primary endpoint (P < .001 for an improvement from the historical rate of 17%). Evidence of PI3K/mTOR activation by immunohistochemistry for phosphorylated ribosomal S6Ser240/244 (p-S6Ser240/244 ) was associated with worse progression-free survival (PFS; hazard ratio [HR], 3.03; P = .004) and overall survival (HR, 12.7; P = .01). Tumor perfusion decreased after 6 months (median decrease in fBV, 15%; P = .03; median decrease in Kps , 12%; P = .09), with greater decreases associated with improved PFS (HR for each 10% fBV decrease, 0.71; P = .01; HR for each 10% Kps decrease, 0.82; P = .04). CONCLUSIONS: Patients with recurrent LGGs demonstrated a high degree of disease stability during treatment with everolimus. PI3K/mTOR activation, as measured by immunohistochemistry for p-S6, was associated with a worse prognosis. Tumor vascular changes were observed that were consistent with the antiangiogenic effects of mTOR inhibitors. These results support further study of everolimus for LGGs. Cancer 2017;123:4631-4639. © 2017 American Cancer Society.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Everolimo/uso terapêutico , Glioma/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Inibidores de Fosfoinositídeo-3 Quinase , Serina-Treonina Quinases TOR/antagonistas & inibidores , Adulto , Idoso , Neoplasias Encefálicas/patologia , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Estudos Prospectivos , Taxa de Sobrevida
14.
BMC Bioinformatics ; 17(1): 380, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27634377

RESUMO

BACKGROUND: Clustering is a widely used collection of unsupervised learning techniques for identifying natural classes within a data set. It is often used in bioinformatics to infer population substructure. Genomic data are often categorical and high dimensional, e.g., long sequences of nucleotides. This makes inference challenging: The distance metric is often not well-defined on categorical data; running time for computations using high dimensional data can be considerable; and the Curse of Dimensionality often impedes the interpretation of the results. Up to the present, however, the literature and software addressing clustering for categorical data has not yet led to a standard approach. RESULTS: We present software for an ensemble method that performs well in comparison with other methods regardless of the dimensionality of the data. In an ensemble method a variety of instantiations of a statistical object are found and then combined into a consensus value. It has been known for decades that ensembling generally outperforms the components that comprise it in many settings. Here, we apply this ensembling principle to clustering. We begin by generating many hierarchical clusterings with different clustering sizes. When the dimension of the data is high, we also randomly select subspaces also of variable size, to generate clusterings. Then, we combine these clusterings into a single membership matrix and use this to obtain a new, ensembled dissimilarity matrix using Hamming distance. CONCLUSIONS: Ensemble clustering, as implemented in R and called EnsCat, gives more clearly separated clusters than other clustering techniques for categorical data. The latest version with manual and examples is available at https://github.com/jlp2duke/EnsCat .


Assuntos
Biologia Computacional/métodos , Software , Algoritmos , Análise por Conglomerados , Genômica/métodos
16.
J Neurooncol ; 126(1): 193-200, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26493740

RESUMO

Central neurocytomas are uncommon intraventricular neoplasms whose optimal management remains controversial due to their rarity. We assessed outcomes for a historical cohort of neurocytoma patients and evaluated effects of tumor atypia, size, resection extent, and adjuvant radiotherapy. Progression-free survival (PFS) was measured by Kaplan-Meier and Cox proportional hazards methods. A total of 28 patients (15 males, 13 females) were treated between 1995 and 2014, with a median age at diagnosis of 26 years (range 5-61). Median follow-up was 62.2 months and 3 patients were lost to follow-up postoperatively. Thirteen patients experienced recurrent/progressive disease and 2-year PFS was 75% (95% CI 53-88%). Two-year PFS was 48% for MIB-1 labeling >4% versus 90% for ≤4% (HR 5.4, CI 2.2-27.8, p = 0.0026). Nine patients (32%) had gross total resections (GTR) and 19 (68%) had subtotal resections (STR). PFS for >80% resection was 83 versus 67% for ≤80% resection (HR 0.67, CI 0.23-2.0, p = 0.47). Three STR patients (16%) received adjuvant radiation which significantly improved overall PFS (p = 0.049). Estimated 5-year PFS was 67% for STR with radiotherapy versus 53% for STR without radiotherapy. Salvage therapy regimens were diverse and resulted in stable disease for 54% of patients and additional progression for 38 %. Two patients with neuropathology-confirmed atypical neurocytomas died at 4.3 and 113.4 months after initial surgery. For central neurocytomas, MIB-1 labeling index >4% is predictive of poorer outcome and our data suggest that adjuvant radiotherapy after STR may improve PFS. Most patients requiring salvage therapy will be stabilized and multiple modalities can be effectively utilized.


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/terapia , Neurocitoma/diagnóstico , Neurocitoma/terapia , Resultado do Tratamento , Adolescente , Adulto , Institutos de Câncer/estatística & dados numéricos , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
17.
J Neurooncol ; 121(1): 135-40, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25208478

RESUMO

The majority of gliomas are sporadic in origin. Familial gliomas have been reported, though they are exceptionally rare. Several familial cancer syndromes are associated with autosomal dominant glioma risk, typically with incomplete penetrance. When two siblings are affected in the absence of a known dominantly inherited cancer syndrome, an autosomal recessive condition may be suspected (e.g. constitutional mismatch repair syndrome). We present two separate sets of siblings, one set with low grade gliomas, and the other with high grade gliomas. Histology for all tumors were either oligodendroglioma or had features of oligodendroglioma. Interestingly, there is a nearly identical histopathology and anatomical localization noted in these clinical presentations. For one family, genetic testing and family inquiry have resulted in no identifiable genetic pattern of disease. High-penetrance familial mutations and common low-penetrance susceptibility loci (e.g. single-nucleotide polymorphism (SNPs)) may contribute to familial glioma risk. We present two instances of familial glioma without an identifiable genetic cause. These cases implicate a potential heritable etiology for glioma families in which Mendelian disorders have not been identified. Further investigation should focus on identifying the potential genetic links involved with cases such as the ones presented here.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , Irmãos , Adolescente , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Neoplasias Encefálicas/terapia , Glioma/patologia , Glioma/fisiopatologia , Glioma/terapia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Adulto Jovem
19.
Cancers (Basel) ; 16(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38672606

RESUMO

This study aimed to develop a rapid, 1 mm3 isotropic resolution, whole-brain MRI technique for automatic lesion segmentation and multi-parametric mapping without using contrast by continuously applying balanced steady-state free precession with inversion pulses throughout incomplete inversion recovery in a single 6 min scan. Modified k-means clustering was performed for automatic brain tissue and lesion segmentation using distinct signal evolutions that contained mixed T1/T2/magnetization transfer properties. Multi-compartment modeling was used to derive quantitative multi-parametric maps for tissue characterization. Fourteen patients with contrast-enhancing gliomas were scanned with this sequence prior to the injection of a contrast agent, and their segmented lesions were compared to conventionally defined manual segmentations of T2-hyperintense and contrast-enhancing lesions. Simultaneous T1, T2, and macromolecular proton fraction maps were generated and compared to conventional 2D T1 and T2 mapping and myelination water fraction mapping acquired with MAGiC. The lesion volumes defined with the new method were comparable to the manual segmentations (r = 0.70, p < 0.01; t-test p > 0.05). The T1, T2, and macromolecular proton fraction mapping values of the whole brain were comparable to the reference values and could distinguish different brain tissues and lesion types (p < 0.05), including infiltrating tumor regions within the T2-lesion. Highly efficient, whole-brain, multi-contrast imaging facilitated automatic lesion segmentation and quantitative multi-parametric mapping without contrast, highlighting its potential value in the clinic when gadolinium is contraindicated.

20.
JCI Insight ; 9(6)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329812

RESUMO

The gut and local esophageal microbiome progressively shift from healthy commensal bacteria to inflammation-linked pathogenic bacteria in patients with gastroesophageal reflux disease, Barrett's esophagus, and esophageal adenocarcinoma (EAC). However, mechanisms by which microbial communities and metabolites contribute to reflux-driven EAC remain incompletely understood and challenging to target. Herein, we utilized a rat reflux-induced EAC model to investigate targeting the gut microbiome-esophageal metabolome axis with cranberry proanthocyanidins (C-PAC) to inhibit EAC progression. Sprague-Dawley rats, with or without reflux induction, received water or C-PAC ad libitum (700 µg/rat/day) for 25 or 40 weeks. C-PAC exerted prebiotic activity abrogating reflux-induced dysbiosis and mitigating bile acid metabolism and transport, culminating in significant inhibition of EAC through TLR/NF-κB/TP53 signaling cascades. At the species level, C-PAC mitigated reflux-induced pathogenic bacteria (Streptococcus parasanguinis, Escherichia coli, and Proteus mirabilis). C-PAC specifically reversed reflux-induced bacterial, inflammatory, and immune-implicated proteins and genes, including Ccl4, Cd14, Crp, Cxcl1, Il6, Il1b, Lbp, Lcn2, Myd88, Nfkb1, Tlr2, and Tlr4, aligning with changes in human EAC progression, as confirmed through public databases. C-PAC is a safe, promising dietary constituent that may be utilized alone or potentially as an adjuvant to current therapies to prevent EAC progression through ameliorating reflux-induced dysbiosis, inflammation, and cellular damage.


Assuntos
Adenocarcinoma , Refluxo Biliar , Neoplasias Esofágicas , Refluxo Gastroesofágico , Microbioma Gastrointestinal , Proantocianidinas , Humanos , Ratos , Animais , Proantocianidinas/farmacologia , Proantocianidinas/uso terapêutico , Proantocianidinas/metabolismo , Microbioma Gastrointestinal/fisiologia , Disbiose/tratamento farmacológico , Ratos Sprague-Dawley , Adenocarcinoma/genética , Refluxo Gastroesofágico/tratamento farmacológico , Refluxo Gastroesofágico/genética , Inflamação/tratamento farmacológico , Metaboloma
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