Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
Mol Cancer ; 23(1): 121, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38853277

RESUMO

BACKGROUND: Platinum resistance is the primary cause of poor survival in ovarian cancer (OC) patients. Targeted therapies and biomarkers of chemoresistance are critical for the treatment of OC patients. Our previous studies identified cell surface CD55, a member of the complement regulatory proteins, drives chemoresistance and maintenance of cancer stem cells (CSCs). CSCs are implicated in tumor recurrence and metastasis in multiple cancers. METHODS: Protein localization assays including immunofluorescence and subcellular fractionation were used to identify CD55 at the cell surface and nucleus of cancer cells. Protein half-life determinations were used to compare cell surface and nuclear CD55 stability. CD55 deletion mutants were generated and introduced into cancer cells to identify the nuclear trafficking code, cisplatin sensitivity, and stem cell frequency that were assayed using in vitro and in vivo models. Detection of CD55 binding proteins was analyzed by immunoprecipitation followed by mass spectrometry. Target pathways activated by CD55 were identified by RNA sequencing. RESULTS: CD55 localizes to the nucleus of a subset of OC specimens, ascites from chemoresistant patients, and enriched in chemoresistant OC cells. We determined that nuclear CD55 is glycosylated and derived from the cell surface pool of CD55. Nuclear localization is driven by a trafficking code containing the serine/threonine (S/T) domain of CD55. Nuclear CD55 is necessary for cisplatin resistance, stemness, and cell proliferation in OC cells. CD55 S/T domain is necessary for nuclear entry and inducing chemoresistance to cisplatin in both in vitro and in vivo models. Deletion of the CD55 S/T domain is sufficient to sensitize chemoresistant OC cells to cisplatin. In the nucleus, CD55 binds and attenuates the epigenetic regulator and tumor suppressor ZMYND8 with a parallel increase in H3K27 trimethylation and members of the Polycomb Repressive Complex 2. CONCLUSIONS: For the first time, we show CD55 localizes to the nucleus in OC and promotes CSC and chemoresistance. Our studies identify a therapeutic mechanism for treating platinum resistant ovarian cancer by blocking CD55 nuclear entry.


Assuntos
Antígenos CD55 , Núcleo Celular , Cromatina , Cisplatino , Resistencia a Medicamentos Antineoplásicos , Histonas , Células-Tronco Neoplásicas , Neoplasias Ovarianas , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/genética , Feminino , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Animais , Camundongos , Antígenos CD55/metabolismo , Antígenos CD55/genética , Linhagem Celular Tumoral , Histonas/metabolismo , Núcleo Celular/metabolismo , Cromatina/metabolismo , Metilação , Ensaios Antitumorais Modelo de Xenoenxerto , Antineoplásicos/farmacologia , Transporte Proteico
2.
J Neurooncol ; 163(3): 647-655, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37341842

RESUMO

PURPOSE: Distinguishing radiation necrosis from tumor progression among patients with brain metastases previously treated with stereotactic radiosurgery represents a common diagnostic challenge. We performed a prospective pilot study to determine whether PET/CT with 18F-fluciclovine, a widely available amino acid PET radiotracer, repurposed intracranially, can accurately diagnose equivocal lesions. METHODS: Adults with brain metastases previously treated with radiosurgery presenting with a follow-up tumor-protocol MRI brain equivocal for radiation necrosis versus tumor progression underwent an 18F-fluciclovine PET/CT of the brain within 30 days. The reference standard for final diagnosis consisted of clinical follow-up until multidisciplinary consensus or tissue confirmation. RESULTS: Of 16 patients imaged from 7/2019 to 11/2020, 15 subjects were evaluable with 20 lesions (radiation necrosis, n = 16; tumor progression, n = 4). Higher SUVmax statistically significantly predicted tumor progression (AUC = 0.875; p = 0.011). Lesion SUVmean (AUC = 0.875; p = 0.018), SUVpeak (AUC = 0.813; p = 0.007), and SUVpeak-to-normal-brain (AUC = 0.859; p = 0.002) also predicted tumor progression, whereas SUVmax-to-normal-brain (p = 0.1) and SUVmean-to-normal-brain (p = 0.5) did not. Qualitative visual scores were significant predictors for readers 1 (AUC = 0.750; p < 0.001) and 3 (AUC = 0.781; p = 0.045), but not for reader 2 (p = 0.3). Visual interpretations were significant predictors for reader 1 (AUC = 0.898; p = 0.012) but not for reader 2 (p = 0.3) or 3 (p = 0.2). CONCLUSIONS: In this prospective pilot study of patients with brain metastases previously treated with radiosurgery presenting with a contemporary MRI brain with a lesion equivocal for radiation necrosis versus tumor progression, 18F-fluciclovine PET/CT repurposed intracranially demonstrated encouraging diagnostic accuracy, supporting the pursuit of larger clinical trials which will be necessary to establish diagnostic criteria and performance.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Adulto , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Radiocirurgia/efeitos adversos , Projetos Piloto , Estudos Prospectivos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/etiologia , Necrose/diagnóstico por imagem , Necrose/etiologia
3.
J Biol Chem ; 297(2): 100965, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34270956

RESUMO

Signaling of semaphorin ligands via their plexin-neuropilin receptors is involved in tissue patterning in the developing embryo. These proteins play roles in cell migration and adhesion but are also important in disease etiology, including in cancer angiogenesis and metastasis. While some structures of the soluble domains of these receptors have been determined, the conformations of the full-length receptor complexes are just beginning to be elucidated, especially within the context of the plasma membrane. Pulsed-interleaved excitation fluorescence cross-correlation spectroscopy allows direct insight into the formation of protein-protein interactions in the membranes of live cells. Here, we investigated the homodimerization of neuropilin-1 (Nrp1), plexin A2, plexin A4, and plexin D1 using pulsed-interleaved excitation fluorescence cross-correlation spectroscopy. Consistent with previous studies, we found that Nrp1, plexin A2, and plexin A4 are present as dimers in the absence of exogenous ligand. Plexin D1, on the other hand, was monomeric under similar conditions, which had not been previously reported. We also found that plexin A2 and A4 assemble into a heteromeric complex. Stimulation with semaphorin 3A or semaphorin 3C neither disrupts nor enhances the dimerization of the receptors when expressed alone, suggesting that activation involves a conformational change rather than a shift in the monomer-dimer equilibrium. However, upon stimulation with semaphorin 3C, plexin D1 and Nrp1 form a heteromeric complex. This analysis of interactions provides a complementary approach to the existing structural and biochemical data that will aid in the development of new therapeutic strategies to target these receptors in cancer.


Assuntos
Moléculas de Adesão Celular , Proteínas do Tecido Nervoso , Semaforinas , Membrana Celular/metabolismo , Movimento Celular , Humanos , Transdução de Sinais
4.
J Neurooncol ; 158(3): 341-348, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35486307

RESUMO

PURPOSE: We sought to evaluate the effects of concurrent temozolomide-based chemoradiation therapy on neurocognitive function in patients with low-grade glioma (LGG). MATERIALS/METHODS: We included adult patients with LGG who were treated postoperatively with radiotherapy (RT) with concurrent and adjuvant temozolomide (TMZ). Patients were evaluated with comprehensive psychometric tests at baseline (prior to RT + TMZ) and at various time intervals following RT + TMZ. Baseline cognitive performance was analyzed by sex, age, education history, history of seizures, IDH mutation status, and 1p/19q codeletion status. Changes in neurocognitive performance were evaluated over time. RESULTS: Thirty-seven LGG patients (mean age 43.6, 59.5% male) had baseline neurocognitive evaluation. Patients with an age > 40 years old at diagnosis and those with an education > 16 years demonstrated superior baseline verbal memory as assessed by HVLT. No other cognitive domains showed differences when stratified by the variables mentioned above. A total of 22 LGG patients had baseline and post RT + TMZ neurocognitive evaluation. Overall, patients showed no statistical difference between group mean test scores prior to and following RT + TMZ on all psychometric measures (with the exception of HVLT Discrimination). CONCLUSION: Cognitive function remained stable following RT + TMZ in LGG patients evaluated prospectively up to 2 years. The anticipated analysis of RTOG 0424 will provide valuable neurocognitive outcomes specifically for high risk LGG patients treated with RT + TMZ.


Assuntos
Neoplasias Encefálicas , Glioma , Adulto , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/genética , Cognição , Feminino , Glioma/genética , Humanos , Masculino , Temozolomida/uso terapêutico
5.
J Neurooncol ; 156(3): 499-507, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35064450

RESUMO

PURPOSE: Low-grade glioma (LGG) exhibits longer median survival than high-grade brain tumors, and thus impact of our therapies on patient quality of life remains a crucial consideration. This study evaluated the effects of concurrent temozolomide-based chemoradiation (RT + TMZ) or observation on quality of life (QOL) in patients with low-grade glioma. METHODS: We completed a retrospective cross-sectional study of adults with LGG who underwent surgery with known molecular classification from 1980 to 2018. Postoperatively, patients were either observed or received adjuvant concurrent temozolomide-based chemoradiation. EQ-5D and PHQ-9 depression screen were completed before outpatient visits every 2-3 months. Baseline score was defined as ± 30 days within initial operation. RESULTS: Of the 63 patients (mean age 44 ± 17 years, 51% female) with baseline EQ-5D or PHQ-9 depression screen data and at least one follow-up measure, 30 (48%) were observed and 33 (52%) received RT + TMZ. No significant decline was seen in EQ-5D or PHQ-9 scores at 3, 6, 9, 12, and 24 months compared to baseline scores for all patients. At each time point, there was no significant difference between those who were observed or received adjuvant therapy. The linear mixed model estimating PHQ-9 value or EQ-5D index demonstrated that there was no significant difference in PHQ-9 or EQ-5D index between treatment groups (p = 0.42 and p = 0.54, respectively) or time points (p = 0.24 and p = 0.99, respectively). CONCLUSION: Our study found no significant decline in patient QOL or depression scores as assessed by patient- reported outcome measures for patients with low-grade glioma up to 2 years following surgery. We found no difference between RT + TMZ compared to observation during this time frame. Additional follow-up can help identify the longer-term impact of treatment strategy on patient experience.


Assuntos
Neoplasias Encefálicas , Quimiorradioterapia , Glioma , Qualidade de Vida , Temozolomida , Conduta Expectante , Adulto , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Estudos Transversais , Feminino , Glioma/patologia , Glioma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estudos Retrospectivos , Temozolomida/uso terapêutico , Resultado do Tratamento
6.
Genes Dev ; 27(6): 670-82, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23512660

RESUMO

Epithelial-mesenchymal transition (EMT) is thought to be an important, possibly essential, component of the process of tumor dissemination and metastasis. About 20%-30% of Hras mutant mouse skin carcinomas induced by chemical initiation/promotion protocols have undergone EMT. Reduced exposure to TPA-induced chronic inflammation causes a dramatic reduction in classical papillomas and squamous cell carcinomas (SCCs), but the mice still develop highly invasive carcinomas with EMT properties, reduced levels of Hras and Egfr signaling, and frequent Ink4/Arf deletions. Deletion of Hras from the mouse germline also leads to a strong reduction in squamous tumor development, but tumors now acquire activating Kras mutations and exhibit more aggressive metastatic properties. We propose that invasive carcinomas can arise by different genetic and biological routes dependent on exposure to chronic inflammation and possibly from different target cell populations within the skin. Our data have implications for the use of inhibitors of inflammation or of Ras/Egfr pathway signaling for prevention or treatment of invasive cancers.


Assuntos
Carcinoma de Células Escamosas/patologia , Inflamação/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/patologia , Animais , Carcinoma de Células Escamosas/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Transição Epitelial-Mesenquimal , Receptores ErbB/metabolismo , Dosagem de Genes , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Marcadores Genéticos/genética , Camundongos , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Cutâneas/genética
7.
Int J Hyperthermia ; 36(1): 986-992, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31544546

RESUMO

Background: Treatment for locally recurrent breast cancer poses a significant challenge because the benefits in local control must be weighed against the increased risk of side effects of the treatment. Frequently, patients have been heavily pre-treated with radiation and several types of chemotherapy. Moreover, they often present with large volumes of bulky disease, further complicating management. Hyperthermia can be used to improve the efficacy of radiation, particularly in the setting of recurrent disease. Methods: We reviewed our clinical and dosimetric experience of breast cancer patients who received hyperthermia and radiation for recurrent breast cancer from 2011 to 2017. Thirty-six patients were treated with hyperthermia and radiation. Median follow-up was 11 months. Thirty patients (83.3%) received prior radiotherapy. The most commonly used radiation fraction scheme was 32 Gy in 8 fractions. The median radiation dose at the time of recurrence was 35.5 Gy (range 20-64 Gy). Mild temperature hyperthermia was delivered two times per week. Results: The median repeat radiation volume was 574 cc (range 11-3620 cc). Electrons, conventional photons, and IMRT radiation techniques were used. IMRT was used for large and complex treatment volumes and showed acceptable doses to organs at risk. The overall response rate was 61.1%. Complete response was observed in 17 patients (47.2%), partial response in 5 patients (13.9%), stable disease in 11 patients (30.6%), and progressive disease in 3 patients (8.3%). Twenty-six patients experienced acute grade 1 and 2 toxicities, primarily pain and erythema; and 26 experienced long-term grade 1 and 2 toxicities, mainly hyperpigmentation and lymphedema. Three patients developed new ulcerations that healed with conservative management. One patient developed pulmonary fibrosis resulting in mild dyspnea on exertion. Conclusion: Hyperthermia and radiation provide good local control with a favorable side effect profile. Thermoradiotherapy may be offered to patients with recurrent breast cancer, including those with extensive volumes of disease.


Assuntos
Neoplasias da Mama/radioterapia , Hipertermia Induzida/métodos , Radiometria/métodos , Neoplasias da Mama/patologia , Feminino , Humanos , Recidiva Local de Neoplasia , Dosagem Radioterapêutica
8.
Mol Carcinog ; 55(9): 1387-96, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26310697

RESUMO

The tumor suppressor TP53 can initiate a plethora of anti-proliferative effects to maintain genomic integrity under conditions of genotoxic stress. The N-terminal proline-rich domain (PRD) of TP53 is important in the regulation of TP53 activity and stability. A common polymorphism at codon 72 in this region has been associated with altered cancer risk in humans. The Trp53ΔP mouse, which carries a germline homozygous deletion of a region of the PRD, does not develop spontaneous tumors in a mixed 129/Sv and C57BL/6 genetic background, but is highly susceptible to a broad range of tumor types following total body exposure to 4 Gy gamma (γ) radiation. This contrasts with the tumor spectrum in Trp53 null (-/-) mice, which mainly develop thymic lymphomas and osteosarcomas. Analysis of genomic instability in tissues and cells from Trp53ΔP mice demonstrated elevated basal levels of aneuploidy, but this is not sufficient to drive spontaneous tumorigenesis, which requires an additional DNA damage stimulus. Levels of genomic instability did not increase significantly in Trp53ΔP mice following irradiation exposure, suggesting that other radiation effects including tissue inflammation, altered metabolism or autophagy, may play an important role. The Trp53ΔP mouse is a novel model to dissect the mechanisms of tumor development induced by radiation exposure. © 2015 Wiley Periodicals, Inc.


Assuntos
Carcinogênese/genética , Instabilidade Genômica , Neoplasias Induzidas por Radiação/genética , Proteína Supressora de Tumor p53/genética , Sequência de Aminoácidos , Animais , Autofagia , Feminino , Raios gama , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Poliploidia , Prolina/química , Prolina/genética , Deleção de Sequência , Proteína Supressora de Tumor p53/química
9.
Stem Cells ; 32(8): 2033-47, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24831540

RESUMO

Glioblastomas are highly lethal brain tumors containing tumor-propagating glioma stem cells (GSCs). The molecular mechanisms underlying the maintenance of the GSC phenotype are not fully defined. Here we demonstrate that the zinc finger and X-linked transcription factor (ZFX) maintains GSC self-renewal and tumorigenic potential by upregulating c-Myc expression. ZFX is differentially expressed in GSCs relative to non-stem glioma cells and neural progenitor cells. Disrupting ZFX by shRNA reduced c-Myc expression and potently inhibited GSC self-renewal and tumor growth. Ectopic expression of c-Myc to its endogenous level rescued the effects caused by ZFX disruption, supporting that ZFX controls GSC properties through c-Myc. Furthermore, ZFX binds to a specific sequence (GGGCCCCG) on the human c-Myc promoter to upregulate c-Myc expression. These data demonstrate that ZFX functions as a critical upstream regulator of c-Myc and plays essential roles in the maintenance of the GSC phenotype. This study also supports that c-Myc is a dominant driver linking self-renewal to malignancy.


Assuntos
Glioblastoma/patologia , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Neoplásicas/patologia , Proliferação de Células/fisiologia , Células Cultivadas , Imunoprecipitação da Cromatina , Imunofluorescência , Glioblastoma/metabolismo , Humanos , Immunoblotting , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Células-Tronco Neoplásicas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
J Neurooncol ; 122(3): 421-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25670390

RESUMO

Cranial radiation can impact the cerebral vasculature in many ways, with a wide range of clinical manifestations. The incidence of these late effects including cerebrovascular accidents (CVAs), lacunar lesions, vascular occlusive disease including moyamoya syndrome, vascular malformations, and hemorrhage is not well known. This article reviews the preclinical findings regarding the pathophysiology of late radiation-induced vascular damage, and discusses the clinical incidence and risk factors for each type of vasculopathy. The pathophysiology is complex and dependent on the targeted blood vessels, and upregulation of pro-inflammatory and hypoxia-related genes. The risk factors for adult CVAs are similar to those for patients not exposed to cranial radiotherapy. For children, risks for late vascular complications include young age at radiotherapy, radiotherapy dose, NF1, tumor location, chemotherapy, and endocrine abnormalities. The incidence of late vascular complications of radiotherapy may be impacted by improved technology, therapeutic interventions, and appropriate follow up.


Assuntos
Transtornos Cerebrovasculares/etiologia , Lesões por Radiação/etiologia , Radioterapia/efeitos adversos , Adulto , Neoplasias Encefálicas/radioterapia , Transtornos Cerebrovasculares/epidemiologia , Criança , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Fatores de Risco
12.
Adv Exp Med Biol ; 853: 85-110, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25895709

RESUMO

Radiation therapy is the most effective adjuvant treatment modality for virtually all patients with high-grade glioma. Its ability to improve patient survival has been recognized for decades. Cancer stem cells provide new insights into how tumor biology is affected by radiation and the role that this cell population can play in disease recurrence. Glioma stem cells possess a variety of intracellular mechanisms to resist and even flourish in spite of radiation, and their proliferation and maintenance appear tied to supportive stimuli from the tumor microenvironment. This chapter reviews the basis for our current use of radiation to treat high-grade gliomas, and addresses this model in the context of therapeutically resistant stem cells. We discuss the available evidence highlighting current clinical efforts to improve radiosensitivity, and newer targets worthy of further development.


Assuntos
Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Células-Tronco Neoplásicas/efeitos da radiação , Animais , Neoplasias Encefálicas/patologia , Glioma/patologia , Humanos , Células-Tronco Neoplásicas/patologia , Tolerância a Radiação , Microambiente Tumoral/efeitos da radiação
13.
J Appl Clin Med Phys ; 16(4): 31­39, 2015 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-26218994

RESUMO

The purpose of this study was to compare the single-isocenter, four-field hybrid IMRT with the two-isocenter techniques to treat the whole breast and supraclavicular fields and to investigate the intrafraction motions in both techniques in the superior direction. Fifteen breast cancer patients who underwent lumpectomy and adjuvant radiation to the whole breast and supraclavicular (SCV) fossa at our institution were selected for this study. Two planning techniques were compared for the treatment of the breast and SCV lymph nodes. The patients were divided into three subgroups according to the whole breast volume. For the two-isocenter technique, conventional wedged or field-within-a-field tangents (FIF) were used to match with the same anterior field for the SCV region. For the single-isocenter technique, four-field hybrid IMRT was used for the tangent fields matched with a half blocked anterior field for the SCV region. To simulate the intrafraction uncertainties in the longitudinal direction for both techniques, the treatment isocenters were shifted by 1 mm and 2 mm in the superior direction. The average breast clinical tumor volume (CTV) receiving 100% (V(100%)) of the prescription dose (50 Gy) was 99.3% ± 0.5% and 96.4% ± 1.2% for the for two-isocenter and single-isocenter plans (р < 0.05), respectively. The breast CTV receiving 95% of the prescription dose (V(95%)) was close to 100% in both techniques. The average breast CTV receiving 105% (V(105%)) of the prescription dose was 32.4% ± 19.3% and 23.8% ± 13.3% (р = 0.08). The percentage volume of the breast CTV receiving 110% of the dose was 0.4% ± 1.2% in the two-isocentric technique vs. 0.1% ± 0.2% in the single-isocentric technique. The average uniformity index was 0.91 ± 0.02 vs. 0.91 ± 0.01 in both techniques (p = 0.04), but had no clinical impact. The percentage volume of the contralateral breast receiving a dose of 1 Gy was less than 2.3% in small breast patients and insignificant for medium and large breast sizes. The percentage of the total lung volume receiving > 20 Gy (V(20Gy)) and the heart receiving > 30 Gy (V(30Gy)) were 13.6% vs. 14.3% (р = 0.03) and 1.25% vs. 1.2% (р = 0.62), respectively. Shifting the treatment isocenter by 1 mm and 2 mm superiorly showed that the average maximum dose to 1 cc of the breast volume was 55.5 ± 1.8 Gy and 58.6 ± 4.3 Gy in the two-isocentric technique vs. 56.4 ± 2.1 Gy and 59.1 ± 5.1 Gy in the single-isocentric technique (р = 0.46, 0.87), respectively. The single-isocenter technique using four-field hybrid IMRT approach resulted in comparable plan quality as the two-isocentric technique. The single-isocenter technique is more sensitive to intra-fraction motion in the superior direction compared to the two-isocentric technique. The advantages of the single-isocenter include elimination of isocentric errors due to couch and collimator rotations and reduction in treatment time. This study supports consideration of a single-isocenter four-field hybrid IMRT technique for patients undergoing breast and supraclavicular nodal irradiation.


Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Linfonodos/patologia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Feminino , Humanos , Linfonodos/efeitos da radiação , Dosagem Radioterapêutica , Estudos Retrospectivos
14.
Pac Symp Biocomput ; 29: 521-533, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38160304

RESUMO

Advances in molecular characterization have reshaped our understanding of low-grade glioma (LGG) subtypes, emphasizing the need for comprehensive classification beyond histology. Lever-aging this, we present a novel approach, network-based Subnetwork Enumeration, and Analysis (nSEA), to identify distinct LGG patient groups based on dysregulated molecular pathways. Using gene expression profiles from 516 patients and a protein-protein interaction network we generated 25 million sub-networks. Through our unsupervised bottom-up approach, we selected 92 subnetworks that categorized LGG patients into five groups. Notably, a new LGG patient group with a lack of mutations in EGFR, NF1, and PTEN emerged as a previously unidentified patient subgroup with unique clinical features and subnetwork states. Validation of the patient groups on an independent dataset demonstrated the robustness of our approach and revealed consistent survival traits across different patient populations. This study offers a comprehensive molecular classification of LGG, providing insights beyond traditional genetic markers. By integrating network analysis with patient clustering, we unveil a previously overlooked patient subgroup with potential implications for prognosis and treatment strategies. Our approach sheds light on the synergistic nature of driver genes and highlights the biological relevance of the identified subnetworks. With broad implications for glioma research, our findings pave the way for further investigations into the mechanistic underpinnings of LGG subtypes and their clinical relevance.Availability: Source code and supplementary data are available at https://github.com/bebeklab/nSEA.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Prognóstico , Biologia Computacional , Glioma/genética , Glioma/patologia , Algoritmos , Mapas de Interação de Proteínas , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia
15.
Neuro Oncol ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38456228

RESUMO

BACKGROUND: Hypoxia is associated with poor prognosis in many cancers including glioblastoma (GBM). Glioma stem-like cells (GSCs) often reside in hypoxic regions and serve as reservoirs for disease progression. Long non-coding RNAs (lncRNAs) have been implicated in GBM. However, the lncRNAs that modulate GSC adaptations to hypoxia are poorly understood. Identification of these lncRNAs may provide new therapeutic strategies to target GSCs under hypoxia. METHODS: lncRNAs induced by hypoxia in GSCs were identified by RNAseq. LUCAT1 expression was assessed by qPCR, RNAseq, Northern blot, single molecule FISH in GSCs, and interrogated in IvyGAP, TCGA, and CGGA databases. LUCAT1 was depleted by shRNA, CRISPR/Cas9, and CRISPR/Cas13d. RNAseq, Western blot, immunohistochemistry, co-IP, ChIP, ChIPseq, RNA immunoprecipitation, and proximity ligation assay were performed to investigate mechanisms of action of LUCAT1. GSC viability, limiting dilution assay, and tumorigenic potential in orthotopic GBM xenograft models were performed to assess the functional consequences of depleting LUCAT1. RESULTS: A new isoform of Lucat1 is induced by HIF1α and NRF2 in GSCs under hypoxia. LUCAT1 is highly expressed in hypoxic regions in GBM. Mechanistically, LUCAT1 formed a complex with HIF1α and its co-activator CBP to regulate HIF1α target gene expression and GSC adaptation to hypoxia. Depletion of LUCAT1 impaired GSC self-renewal. Silencing LUCAT1 decreased tumor growth and prolonged mouse survival in GBM xenograft models. CONCLUSIONS: A HIF1α-LUCAT1 axis forms a positive feedback loop to amplify HIF1α signaling in GSCs under hypoxia. LUCAT1 promotes GSC self-renewal and GBM tumor growth. LUCAT1 is a potential therapeutic target in GBM.

16.
Neuro Oncol ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38656347

RESUMO

BACKGROUND: Single session stereotactic radiosurgery (SRS) or surgical resection alone for brain metastases larger than 2 cm results in unsatisfactory local control. We conducted a phase I trial for brain metastases(>2cm) to determine the safety of preoperative SRS at escalating doses. METHODS: Radiosurgery dose was escalated at 3 Gy increments for 3 cohorts based on maximum tumor dimension starting at: 18 Gy for >2-3 cm, 15 Gy for >3-4 cm, and 12 Gy for >4-6 cm. Dose limiting toxicity (DLT) was defined as grade III or greater acute toxicity. RESULTS: A total of 35 patients/36 lesions were enrolled. For tumor size >2-3 cm, patients were enrolled up to the second dose level (21 Gy); for >3-4 cm and >4-6 cm cohorts the third dose level (21 Gy and 18 Gy, respectively) was reached. There were 2 DLTs in the >3-4 cm arm at 21Gy. The maximum tolerated dose (MTD) of SRS for >2-3 cm was not reached; and was 18 Gy for both >3-4 cm arm and >4-6 cm arm. With a median follow-up of 64.0 months, the 6- and 12-month local control rates were 85.9% and 76.6%, respectively. One patient developed grade 3 radiation necrosis at 5 months. The 2-year rate of leptomeningeal disease (LMD) was 0%. CONCLUSION: Preoperative SRS with dose escalation followed by surgical resection for brain metastases greater than 2 cm in size demonstrates acceptable acute toxicity. The phase II portion of the trial will be conducted at the maximum tolerated SRS doses.

17.
Front Oncol ; 13: 1110473, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007113

RESUMO

In the United States, an individual's access to resources, insurance status, and wealth are critical social determinants that affect both the risk and outcomes of many diseases. One disease for which the correlation with socioeconomic status (SES) is less well-characterized is glioblastoma (GBM), a devastating brain malignancy. The aim of this study was to review the current literature characterizing the relationship between area-level SES and both GBM incidence and prognosis in the United States. A query of multiple databases was performed to identify the existing data on SES and GBM incidence or prognosis. Papers were filtered by relevant terms and topics. A narrative review was then constructed to summarize the current body of knowledge on this topic. We obtained a total of three papers that analyze SES and GBM incidence, which all report a positive correlation between area-level SES and GBM incidence. In addition, we found 14 papers that focus on SES and GBM prognosis, either overall survival or GBM-specific survival. Those studies that analyze data from greater than 1,530 patients report a positive correlation between area-level SES and individual prognosis, while those with smaller study populations report no significant relationship. Our report underlines the strong association between SES and GBM incidence and highlights the need for large study populations to assess SES and GBM prognosis to ideally guide interventions that improve outcomes. Further studies are needed to determine underlying socio-economic stresses on GBM risk and outcomes to identify opportunities for intervention.

18.
Front Oncol ; 13: 1110440, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36910642

RESUMO

Brain metastases are a significant source of morbidity and mortality in patients with non-small cell lung cancer. Historically, surgery and radiation therapy have been essential to maintaining disease control within the central nervous system due to poorly penetrant conventional chemotherapy. With the advent of targeted therapy against actionable driver mutations, there is potential to control limited and asymptomatic intracranial disease and delay local therapy until progression. In this review paper, intracranial response rates and clinical outcomes to biological and immune therapies are summarized from the literature and appraised to assist clinical decision making and identify areas for further research. Future clinical trials ought to prioritize patient-centered quality of life and neurocognitive measures as major outcomes and specifically stratify patients based on mutational marker status, disease burden, and symptom acuity.

19.
Nat Commun ; 14(1): 2262, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-37080989

RESUMO

The Wnt pathway is frequently dysregulated in many cancers, underscoring it as a therapeutic target. Wnt inhibitors have uniformly failed in clinical trials. Here, we report a mechanism of WNT pathway activation through the Semaphorin 3 C neurodevelopmental program in glioma stem-like cells. Sema3C directs ß-catenin nuclear accumulation in a Rac1-dependent process, leading to transactivation of Wnt target genes. Sema3C-driven Wnt signaling occurred despite suppression of Wnt ligand secretion, suggesting that Sema3C drives canonical Wnt signaling independent of Wnt ligand binding. In a mouse model of glioblastoma, combined depletion of Sema3C and ß-catenin partner TCF1 extended animal survival more than single target inhibition alone. In human glioblastoma, Sema3C expression and Wnt pathway activation were highly concordant. Since Sema3C is frequently overexpressed in glioblastoma, Sema3C signaling may be a significant mechanism of resistance to upstream Wnt pathway inhibitors. Dual targeting of Sema3C and Wnt pathways may achieve clinically significant Wnt pathway inhibition.


Assuntos
Glioblastoma , Semaforinas , Animais , Humanos , Camundongos , beta Catenina/genética , beta Catenina/metabolismo , Linhagem Celular Tumoral , Glioblastoma/genética , Glioblastoma/metabolismo , Ligantes , Semaforinas/genética , Via de Sinalização Wnt/genética
20.
bioRxiv ; 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38014234

RESUMO

The glioblastoma microenvironment is enriched in immunosuppressive factors that potently interfere with the function of cytotoxic T lymphocytes. Cancer cells can directly impact the immune system, but the mechanisms driving these interactions are not completely clear. Here we demonstrate that the polyamine metabolite spermidine is elevated in the glioblastoma tumor microenvironment. Exogenous administration of spermidine drives tumor aggressiveness in an immune-dependent manner in pre-clinical mouse models via reduction of CD8+ T cell frequency and phenotype. Knockdown of ornithine decarboxylase, the rate-limiting enzyme in spermidine synthesis, did not impact cancer cell growth in vitro but did result in extended survival. Furthermore, glioblastoma patients with a more favorable outcome had a significant reduction in spermidine compared to patients with a poor prognosis. Our results demonstrate that spermidine functions as a cancer cell-derived metabolite that drives tumor progression by reducing CD8+T cell number and function.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA