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1.
Am J Med Genet A ; : e63604, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38511879

RESUMO

Orthodenticle homeobox 2 (OTX2) is a known oncogenic driver of medulloblastoma. Germline duplication of 14q22.3 including OTX2 is a rare condition reported in patients with combined pituitary hormone deficiency, oculo-auriculo-vertebral spectrum, and hemifacial microsomia. There has been one previously published case of a patient carrying a 14q22.3 duplication that included OTX2 with hemifacial microsomia who also developed medulloblastoma. Here, we present a case of a 6-year-old girl with a history of delayed development who was diagnosed with medulloblastoma. Genetic evaluations revealed that she inherited a germline duplication of 14q22.3, which included OTX2. This genetic alteration was passed down from her mother, who also had a history of delayed development. Results from other genetic testing, including exome sequencing, fragile X syndrome, and mtDNA testing, were negative/normal. This is the second report of a 14q22.3 duplication that included OTX2 in a patient with medulloblastoma. Further studies are necessary to establish a clear association.

2.
J Pediatr Hematol Oncol ; 46(3): e227-e232, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38447113

RESUMO

Surveillance magnetic resonance imaging (MRI) is routinely used to detect recurrence in pediatric central nervous system (CNS) tumors. The frequency of neuroimaging surveillance varies without a standardized approach. A single-institutional retrospective cohort study evaluated the frequency of recurrences. This study included 476 patients with the majority diagnosed with low-grade glioma (LGG) (n=138, 29%), high-grade glioma (HGG) (n=77, 16%), ependymoma (n=70, 15%), or medulloblastoma (n=61, 13%). LGG, HGG, and ependymoma patients more commonly had multiply recurrent disease ( P =0.08), with ependymoma patients demonstrating ≥2 relapses in 47% of cases. Recurrent disease was identified by imaging more often than clinical symptoms (65% vs. 32%; P =<0.01). Patients diagnosed with meningioma demonstrated the longest mean time to first relapse (74.7 mo) whereas those with atypical teratoid rhabdoid tumor and choroid plexus carcinoma tended to have the shortest time to relapse (8.9 and 9 mo, respectively). Overall, 22 patients sustained first relapse >10 years from initial diagnosis. With a higher tendency toward detection of tumor recurrence/progression on MRI surveillance in comparison to clinical progression, surveillance imaging is necessary in routine follow up of pediatric CNS tumor survivors. With some relapses >10 years from initial diagnosis, imaging beyond this time point may be useful in particular tumor types. While the study is limited in outcome analysis, earlier detection of recurrence would lead to earlier initiation of treatment and implementation of salvage treatment regimens which can impact survival and quality of life.


Assuntos
Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Neoplasias Cerebelares , Ependimoma , Glioma , Criança , Humanos , Estudos Retrospectivos , Qualidade de Vida , Recidiva Local de Neoplasia/diagnóstico , Neoplasias Encefálicas/patologia , Glioma/patologia , Ependimoma/diagnóstico por imagem , Ependimoma/terapia , Imageamento por Ressonância Magnética , Recidiva
3.
Neurooncol Pract ; 10(5): 418-428, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37720398

RESUMO

Background: Pediatric brain tumor survivors (PBTS) are at risk of worse quality of life (QOL) due to the impact of neurotoxic treatments on the developing nervous system. Parenting factors such as protectiveness have been linked to worse QOL in childhood cancer survivors generally, but have yet to be explored for PBTS. We examined whether parenting behaviors moderated the association between neurotoxic treatment and QOL for PBTS. Methods: PBTS (n = 40; ages 10-25) and their caregivers (n = 47) completed measures of parenting behaviors including warmth (support/connectedness) and psychological control (protectiveness) and QOL. We divided the sample into moderate/high and low neurotoxicity groups based on chart review using the Pediatric Neuro-Oncology Rating of Treatment Intensity and examined moderator effects. Results: Survivor-reported primary caregiver warmth moderated the relationship between neurotoxicity and caregiver-reported QOL. Moderate/high neurotoxicity was associated with lower caregiver-reported QOL only when survivor-reported primary caregiver warmth was low, P = .02. Similar results were found for survivor-reported QOL. Caregiver-reported psychological control moderated the association between neurotoxicity and caregiver-reported QOL such that neurotoxicity only affected QOL at high levels of psychological control, P = .01. Conclusions: Heightened associations between parenting and QOL in the context of neurotoxic treatments underscore the need to better support PBTS. Findings are consistent with research suggesting that family factors may be particularly important for children with other neurological insults. Limitations include cross-sectional design and a small/heterogeneous clinical sample with low ethnic/racial diversity. Prospective studies are needed to refine evidence-based screening and develop psychosocial intervention strategies to optimize QOL for PBTS and their families.

4.
Pediatr Clin North Am ; 70(5): 937-950, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37704352

RESUMO

Neurofibromatosis type I (NF1) is a common dominantly inherited disorder, and one of the most common of the RASopathies. Most individuals with NF1 develop plexiform neurofibromas and cutaneous neurofibromas, nerve tumors caused by NF1 loss of function in Schwann cells. Cell culture models and mouse models of NF1 are being used to test drug efficacy in preclinical trials, which led to Food and Drug Administration approval for use of MEK inhibitors to shrink most inoperable plexiform neurofibromas. This article details methods used for testing in preclinical models, and outlines newer models that may identify additional, curative, strategies.


Assuntos
Neurofibroma Plexiforme , Neurofibromatose 1 , Estados Unidos , Humanos , Animais , Camundongos , Criança , Neurofibromatose 1/complicações , Neurofibromatose 1/diagnóstico , Neurofibromatose 1/tratamento farmacológico , Neurofibroma Plexiforme/complicações , Neurofibroma Plexiforme/tratamento farmacológico
5.
Clin Pediatr (Phila) ; : 99228231191957, 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37542412

RESUMO

For pediatric patients with cancer, a healthy lifestyle is important for treatment outcomes and beyond. General pediatricians play a major role in the care of these patients, particularly given the improved rates of survival. Pediatric obesity has many negative consequences, but it is an area where primary care providers can make an impact and provide support to childhood cancer survivors. To provide the best quality of care for this population, there must be collaboration between primary care and oncology providers. Additionally, general practioners should feel empowered to offer standard nutrition and physical activity recommendations to all childhood cancer survivors. For pediatric patients who carry a cancer diagnosis, cure is no longer the only goal. Pediatric providers across specialties need to work as a team to improve long-term quality of life for these patients, starting with modifiable healthy habits.

6.
Cancers (Basel) ; 15(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37046770

RESUMO

BACKGROUND: Understanding the effect of selumetinib on FASI may help elucidate the biology, proliferative potential, and role in neurocognitive changes for these NF1-associated lesions. METHODS: Patients with NF1-associated LGG and FASI treated with selumetinib on PBTC-029B were age-matched to untreated patients with NF1-associated FASI at Cincinnati Children's Hospital Medical Center. Paired bidirectional measurements were compared over time using nonparametric tests. RESULTS: Sixteen age-matched pairs were assessed (age range: 2.8-16.9 years, 60% male). Initial FASI burden was not different between groups (median range 138.7 cm2 [88.4-182.0] for the treated subjects vs. 121.6 cm2 [79.6-181.9] for the untreated subjects; p = 0.98). Over a mean follow-up of 18.9 (±5.9) months, the LGG size consistently decreased with treatment while no consistent change among the treated or untreated FASI size was seen. At the paired time points, the median treated LGG decreased significantly more than the treated FASI (-41.3% (LGG) versus -10.7% (FASI), p = 0.006). However, there was no difference in the median size change in the treated versus untreated FASI (-10.7% (treated FASI) versus -17.9% (untreated FASI), p = 0.08). Among the treated subjects, there was no correlation between the change in LGG and FASI (r = -0.04, p = 0.88). CONCLUSIONS: Treatment with selumetinib did not affect the overall FASI size in children with NF1 treated for progressive low-grade glioma.

7.
Neurooncol Pract ; 9(4): 338-343, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35859541

RESUMO

Background: Medulloblastoma is an aggressive central nervous system (CNS) tumor that occurs mostly in the pediatric population. Treatment often includes a combination of surgical resection, craniospinal irradiation (CSI), and chemotherapy. Children who receive standard photon CSI are at risk for cardiac toxicities including coronary artery disease, left ventricular scarring and dysfunction, valvular damage, and atherosclerosis. Current survivorship guidelines recommend routine echocardiogram (ECHO) surveillance. In this multi-institutional study, we describe markers of cardiac dysfunction in medulloblastoma survivors. Methods: A retrospective chart review of medulloblastoma patients who had photon beam CSI was followed by ECHO between 1980 and 2010 at Lurie Children's Hospital and Dana-Farber/Boston Children's Hospital. Results: During the 30-year study period, 168 medulloblastoma patient records were identified. Included in this study were the 75 patients who received CSI or spinal radiation and ECHO follow-up. The mean age at CSI was 8.6 years (range, 2.9-20), and the mean number of years between radiation therapy (RT) completion and first ECHO was 7.4 (range, 2-16). Mean ejection fraction (EF) was 60.0% and shortening fraction (SF) was 33.8%. Five patients (7%) had abnormal ECHO results: three with EF <50% and two with SF <28%. Conclusion: The majority of medulloblastoma patients who received CSI have relatively normal ECHOs post-treatment; however, 7% of patients had abnormal ECHOs. The implication of our study for medulloblastoma survivors is that further investigations are needed in this population with a more systematic, longitudinal assessment to determine predictors and screenings.

8.
Neurooncol Adv ; 4(1): vdac055, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35611273

RESUMO

Background: Genomic aberrations in the cell cycle and PI3K/Akt/mTOR pathways have been reported in diffuse intrinsic pontine glioma (DIPG) and high-grade glioma (HGG). Dual inhibition of CDK4/6 and mTOR has biologic rationale and minimal overlapping toxicities. This study determined the recommended phase 2 dose (RP2D) of ribociclib and everolimus following radiotherapy in children with DIPG and HGG. Methods: Patients were enrolled according to a Rolling-6 design and received ribociclib and everolimus once daily for 21 and 28 days, respectively. All patients with HGG and biopsied DIPG were screened for retinoblastoma protein presence by immunohistochemistry. Pharmacokinetics were analyzed. Results: Nineteen patients enrolled (median age: 8 years [range: 2-18]). Three patients enrolled at each dose level 1 and 2 without dose-limiting toxicities (DLT). Thirteen patients were enrolled at dose level 3, with one patient experiencing a DLT (grade 3 infection). One patient came off therapy before cycle 9 due to cardiac toxicity. The most common grade 3/4 toxicities were neutropenia (33%), leucopenia (17%), and lymphopenia (11%). Steady-state everolimus exposures in combination were 1.9 ± 0.9-fold higher than single-agent administration. Median overall survival for 15 patients with DIPG was 13.9 months; median event-free survival for four patients with HGG was 10.5 months. Two longer survivors had tumor molecular profiling identifying CDKN2A/B deletion and CDK4 overexpression. Conclusion: The combination of ribociclib and everolimus following radiotherapy in children with newly diagnosed DIPG and HGG was well tolerated, with a RP2D of ribociclib 170 mg/m2 and everolimus 1.5 mg/m2. Results will inform a molecularly guided phase II study underway to evaluate efficacy.

9.
J Neurooncol ; 152(1): 107-114, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33502679

RESUMO

BACKGROUND: While autopsy-repository programs with a variety of pediatric central nervous system (CNS) tumor types are a critical resource for preclinical neuro-oncology research, few exist and there is no published guidance on how to develop one. The goal of this prospective Pediatric Brain Tumor Repository (PBTR) study was to develop such a program at Cincinnati Children's Hospital Medical Center (CCHMC) and then publish the quantitative and experiential data as a guide to support the development of similar programs. METHODS: Protocols and infrastructure were established-to educate oncologists and families, establish eligibility, obtain consent, address pre- and post-autopsy logistics (e.g., patient and tissue transportation), process and authenticate tissue samples, and collect and analyze data. RESULTS: Of the 129 pediatric CNS tumor patients at CCHMC who died between 2013 and 2018, 109 were eligible for our study. Of these, 74% (81 of 109) were approached for PBTR donation, and 68% (55 of 81) consented. In the final year of the study, approach and consent rates were 93% and 85%, respectively. Median time from death to autopsy (postmortem interval, PMI) was 10 h (range, 1.5-30). In the outpatient setting, PMI increased with distance (from the hospice/home where the patient died to CCHMC). In all patients, PMI appeared to be lower, when consent was obtained more than 24 h before death. CONCLUSIONS: Procurement of autopsy specimens need not be a barrier in neuro-oncology research. Regional centers, strict timing-of-consent, patient education, and dedicated staff are all needed to minimize PMI and, thereby, increase the value of the procured tissue for an array of basic and translational research applications.


Assuntos
Autopsia , Neoplasias do Sistema Nervoso Central , Obtenção de Tecidos e Órgãos/organização & administração , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Adulto Jovem
10.
J Genet Couns ; 30(2): 533-543, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33073438

RESUMO

Pediatric brain tumor survivorship populations have not been typically offered genetic services as part of routine care. Genetic services can be defined as family history collection, genetic risk assessment for a patient and family members, and coordination of genetic testing. Prior research has focused on the integration of genetic services in the general pediatric oncology survivorship population and found a need for these services to be implemented. Gathering a family history and providing a genetic risk assessment have previously been determined to be an integral step in determining if an individual's cancer was due to a hereditary predisposition. The purpose of this study was to examine parental attitudes regarding the need for genetic services in their child's pediatric brain tumor survivorship clinic. Twelve semi-structured interviews were conducted with parents participating in the Brain STAR (Survivors Taking Action and Responsibility) program at Ann and Robert H. Lurie Children's Hospital of Chicago. A grounded theory approach was used to code and analyze the results thematically. Five key themes were identified: participants' perceived benefits and barriers regarding receiving genetic services, desirable time for implementation of these services, relevance of family history, and their thoughts regarding reproductive risk. These results provide insight for genetics professionals regarding the need for genetic services in this population, and how to best implement them.


Assuntos
Neoplasias Encefálicas , Sobrevivência , Atitude , Neoplasias Encefálicas/genética , Criança , Serviços em Genética , Humanos , Pais
11.
J Pediatr Hematol Oncol ; 43(4): e550-e553, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32520842

RESUMO

Molecularly targeted therapy with MEK inhibitors has been increasingly incorporated into the treatment of pediatric low-grade gliomas, but this promising therapy is associated with distinctive and specific toxicities. Understanding life-threatening MEK inhibitor toxicities and their management is critical to MEK inhibitor safety, especially among young children. This report describes severe hyponatremia associated with trametinib in an infant with progressive low-grade glioma without underlying endocrine dysfunction, which recurred despite significant dose reduction. Therapy with an alternative MEK inhibitor, binimetinib, provided excellent tumor response without hyponatremia, suggesting that some toxicities may be avoided by changing MEK inhibitor agents within the same class.


Assuntos
Antineoplásicos/efeitos adversos , Glioma/tratamento farmacológico , Hiponatremia/induzido quimicamente , Inibidores de Proteínas Quinases/efeitos adversos , Piridonas/efeitos adversos , Pirimidinonas/efeitos adversos , Antineoplásicos/uso terapêutico , Benzimidazóis/uso terapêutico , Glioma/diagnóstico , Humanos , Lactente , Masculino , Inibidores de Proteínas Quinases/uso terapêutico , Piridonas/uso terapêutico , Pirimidinonas/uso terapêutico
12.
Acta Neuropathol Commun ; 8(1): 182, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33153497

RESUMO

Recent discoveries have provided valuable insight into the genomic landscape of pediatric low-grade gliomas (LGGs) at diagnosis, facilitating molecularly targeted treatment. However, little is known about their temporal and therapy-related genomic heterogeneity. An adequate understanding of the evolution of pediatric LGGs' genomic profiles over time is critically important in guiding decisions about targeted therapeutics and diagnostic biopsy at recurrence. Fluorescence in situ hybridization, mutation-specific immunohistochemistry, and/or targeted sequencing were performed on paired tumor samples from primary diagnostic and subsequent surgeries. Ninety-four tumor samples from 45 patients (41 with two specimens, four with three specimens) from three institutions underwent testing. Conservation of BRAF fusion, BRAFV600E mutation, and FGFR1 rearrangement status was observed in 100%, 98%, and 96% of paired specimens, respectively. No loss or gain of IDH1 mutations or NTRK2, MYB, or MYBL1 rearrangements were detected over time. Histologic diagnosis remained the same in all tumors, with no acquired H3K27M mutations or malignant transformation. Changes in CDKN2A deletion status at recurrence occurred in 11 patients (42%), with acquisition of hemizygous CDKN2A deletion in seven and loss in four. Shorter time to progression and shorter time to subsequent surgery were observed among patients with acquired CDKN2A deletions compared to patients without acquisition of this alteration [median time to progression: 5.5 versus 16.0 months (p = 0.048); median time to next surgery: 17.0 months versus 29.0 months (p = 0.031)]. Most targetable genetic aberrations in pediatric LGGs, including BRAF alterations, are conserved at recurrence and following chemotherapy or irradiation. However, changes in CDKN2A deletion status over time were demonstrated. Acquisition of CDKN2A deletion may define a higher risk subgroup of pediatric LGGs with a poorer prognosis. Given the potential for targeted therapies for tumors harboring CDKN2A deletions, biopsy at recurrence may be indicated in certain patients, especially those with rapid progression.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , Recidiva Local de Neoplasia/genética , Adolescente , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Criança , Pré-Escolar , Inibidor p16 de Quinase Dependente de Ciclina/genética , Progressão da Doença , Feminino , Deleção de Genes , Genoma , Genômica , Glioma/patologia , Glioma/terapia , Humanos , Lactente , Isocitrato Desidrogenase/genética , Masculino , Glicoproteínas de Membrana/genética , Gradação de Tumores , Recidiva Local de Neoplasia/terapia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-myb/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor trkB/genética , Transativadores/genética
13.
Pediatr Dev Pathol ; 22(2): 123-127, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30301444

RESUMO

Delta-granule platelet storage pool deficiency (δ-PSPD) is a qualitative platelet function defect associated with variable bleeding phenotypes. Platelet electron microscopy (EM) is commonly utilized to evaluate for δ-PSPD, but intrapatient variability in platelet δ-granule numbers by EM is currently unknown. Fifteen young women aged 11 to 17 years presenting to a young women's hematology clinic for the evaluation of heavy menstrual bleeding underwent platelet EM testing at their initial hematology clinic visit and at 1 and 3 months later. Platelet aggregation of platelet-rich plasma by light transmission was also performed on all patients at their initial visit. Eight patients had average δ-granules per platelet consistently ≥2. Three patients were found to have average δ-granules per platelet <2 on initial testing, 2 of which reverted to ≥2 on subsequent testing. When initial average δ-granules per platelet was ≥2, initial repeat testing remained so in 83% (95% confidence interval [CI], 52%-98%) of cases and subsequent repeat testing remained so in 75% (95% CI, 43%-95%) of the cases. Platelet aggregation testing was abnormal in 53% of patients, and there was no apparent correlation between platelet EM findings and platelet aggregation testing. In this small group of young women presenting for the evaluation of bleeding symptoms, we found that almost half of the patients had substantial variability in platelet EM results. Given other identified limitations in platelet EM testing, and the intrapatient variability identified in this study, providers should use caution in utilizing EM in isolation to diagnose δ-PSPD.


Assuntos
Plaquetas/patologia , Menorragia/etiologia , Microscopia Eletrônica , Deficiência do Pool Plaquetário/diagnóstico , Adolescente , Criança , Feminino , Seguimentos , Humanos , Deficiência do Pool Plaquetário/complicações , Deficiência do Pool Plaquetário/patologia , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Tempo
14.
Bioengineering (Basel) ; 5(4)2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30544889

RESUMO

Pediatric Neuro-Oncology is a highly specialized field encompassing molecular biology, clinical acumen, evidence based medicine, cancer genetics and neuropsychological care for the diagnosis and treatment of children with central nervous system (CNS) tumors. [...].

15.
Bioengineering (Basel) ; 5(3)2018 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-30208602

RESUMO

The late neurocognitive and psychosocial effects of treatment for pediatric brain tumor (PBT) represent important areas of clinical focus and ongoing research. Neurocognitive sequelae and associated problems with learning and socioemotional development negatively impact PBT survivors' overall health-related quality of life, educational attainment and employment rates. Multiple factors including tumor features and associated complications, treatment methods, individual protective and vulnerability factors and accessibility of environmental supports contribute to the neurocognitive and psychosocial outcomes in PBT survivors. Declines in overall measured intelligence are common and may persist years after treatment. Core deficits in attention, processing speed and working memory are postulated to underlie problems with overall intellectual development, academic achievement and career attainment. Additionally, psychological problems after PBT can include depression, anxiety and psychosocial adjustment issues. Several intervention paradigms are briefly described, though to date research on innovative, specific and effective interventions for neurocognitive late effects is still in its early stages. This article reviews the existing research for understanding PBT late effects and highlights the need for innovative research to enhance neurocognitive and psychosocial outcomes in PBT survivors.

16.
J Pediatr Hematol Oncol ; 40(8): 616-619, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29401100

RESUMO

We describe 2 cases of rapidly progressive primary central nervous system malignant melanoma, and summarize 18 previously reported cases of this extremely rare tumor in children. Both patients presented with focal neurologic symptoms, with no evidence of skin or other organ system involvement. One patient was treated with temozolomide and etoposide, whereas the other was treated with multiple surgical resections, radiation therapy, and a trial of ipilimumab. New molecularly targeted and immune-based therapies used in metastatic melanoma in adults are potential new treatment options, but their efficacy and safety in pediatric patients needs to be established.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias do Sistema Nervoso Central , Quimiorradioterapia , Melanoma , Adolescente , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/terapia , Pré-Escolar , Etoposídeo/administração & dosagem , Humanos , Ipilimumab/administração & dosagem , Masculino , Melanoma/metabolismo , Melanoma/patologia , Melanoma/terapia , Temozolomida/administração & dosagem
17.
Physiol Rep ; 5(6)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28330951

RESUMO

Solid tumors can often be hypoxic in regions, and cancer cells can respond to hypoxia with an increase in proliferation and a decrease in apoptosis, leading to a net increase in viable cell numbers. We have recently found that in an osteosarcoma cell line, hypoxia-induced proliferation depends on arginase II induction. Epidermal growth factor receptor (EGFR) has been shown to mediate the hypoxia-induced cellular proliferation in some cancer cell lines. We hypothesized that hypoxia-induced proliferation of HeLa cells would depend on arginase II induction and that this induction of arginase II would occur through EGFR activation. Exposure of HeLa cells to hypoxia resulted in an upregulation of arginase II mRNA and protein levels, with no effect on arginase I expression. Hypoxia also resulted in significantly greater viable cell numbers than did normoxia. The hypoxia-induced increase in viable cell numbers was prevented by either a small molecule inhibitor of arginase or siRNA targeting arginase II Overexpression of arginase II resulted in an increase in viable cell numbers both in normoxia and hypoxia. Hypoxia caused a substantial induction of both epidermal growth factor (EGF) and EGFR Preventing hypoxia-induced EGFR expression using siRNA abolished hypoxia-induced arginase II expression and the increase in viable cell numbers. Treatment with EGF in normoxia not only induced arginase II expression but also resulted in an increase in viable cell numbers. Blocking EGF interactions with EGFR using either an EGF neutralizing antibody or an EGFR antibody prevented the hypoxia-induced increase in viable cell numbers. These results demonstrate an EGF/EGFR/arginase II pathway that is necessary for hypoxic proliferation in HeLa cells.


Assuntos
Arginase/metabolismo , Hipóxia Celular/fisiologia , Proliferação de Células/fisiologia , Receptores ErbB/metabolismo , Arginase/genética , Contagem de Células , Células HeLa , Humanos , RNA Interferente Pequeno , Transdução de Sinais/fisiologia , Regulação para Cima
18.
Pediatr Blood Cancer ; 63(9): 1671-3, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27187113

RESUMO

We present a unique case of radiation necrosis in a child with brain stem low-grade glioma (LGG) presenting with trigeminal neuralgia. Despite extensive therapies, severe pain persisted. She received proton beam radiation with significant improvement. However, she developed radiation necrosis and hydrocephalus. Despite surgical correction of hydrocephalus, the patient remained critically ill. She was treated with dexamethasone and bevacizumab with rapid clinical improvement. Subsequent MRIs revealed almost complete resolution of the necrosis. This case illustrates the successful treatment of trigeminal neuralgia with radiation and a rare case of radiation necrosis in an LGG successfully treated with bevacizumab and dexamethasone.


Assuntos
Bevacizumab/uso terapêutico , Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Terapia com Prótons/efeitos adversos , Lesões por Radiação/tratamento farmacológico , Neuralgia do Trigêmeo/radioterapia , Neoplasias Encefálicas/complicações , Feminino , Glioma/complicações , Humanos , Hidrocefalia/etiologia , Lactente , Necrose
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