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1.
J Neurooncol ; 167(3): 509-514, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38441840

RESUMO

PURPOSE: Treatment decisions for leptomeningeal disease (LMD) rely on patient risk stratification, since clinicians lack objective prognostic tools. The introduction of rare cell capture technology for identification of cerebrospinal fluid tumor cells (CSF-TCs), such as CNSide assay, improved the sensitivity of LMD diagnosis, but prognostic value is unknown. This study assesses the prognostic value of CSF-TC density in patients with LMD from solid tumors. METHODS: We conducted a retrospective cohort study of patients with newly diagnosed or previously treated LMD from a single institution who had CNSide assay testing for CSF-TCs from 2020 to 2023. Univariable and multivariable survival analyses were conducted with Cox proportional-hazards modeling. Maximally-selected rank statistics were used to determine an optimal cutpoint for CSF-TC density and survival. RESULTS: Of 31 patients, 29 had CSF-TCs detected on CNSide. Median (interquartile range [IQR]) CSF-TC density was 67.8 (4.7-639) TCs/mL. CSF cytology was positive in 16 of 29 patients with positive CNSide (CNSide diagnostic sensitivity = 93.5%, negative predictive value = 85.7%). Median (IQR) survival from time of CSF-TC detection was 176 (89-481) days. On univariable and multivariable analysis, CSF-TC density was significantly associated with survival. An optimal cutpoint for dichotomizing survival by CSF-TC density was 19.34 TCs/mL. The time-dependent sensitivity and specificity for survival using this stratification were 76% and 67% at 6 months and 65% and 67% at 1 year, respectively. CONCLUSIONS: CSF-TC density may carry prognostic value in patients with LMD from solid tumors. Integrating CSF-TC density into LMD patient risk-stratification may help guide treatment decisions.


Assuntos
Neoplasias Meníngeas , Humanos , Estudos Retrospectivos , Feminino , Masculino , Prognóstico , Pessoa de Meia-Idade , Neoplasias Meníngeas/líquido cefalorraquidiano , Neoplasias Meníngeas/mortalidade , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/patologia , Idoso , Adulto , Taxa de Sobrevida , Seguimentos , Neoplasias/líquido cefalorraquidiano , Neoplasias/mortalidade , Neoplasias/diagnóstico , Neoplasias/patologia , Carcinomatose Meníngea/líquido cefalorraquidiano , Carcinomatose Meníngea/diagnóstico , Carcinomatose Meníngea/mortalidade , Contagem de Células
2.
Semin Neurol ; 44(1): 90-101, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38183974

RESUMO

Over the past decade, the improvement in cancer diagnostics and therapeutics has extended the overall survival of patients diagnosed with cancer including brain cancer. However, despite these unprecedented medical successes, patients continue to experience numerous neurologic complications after treatment that interfere with their independence, functionality, and overall quality of life. These include, among others, cognitive impairment, endocrinopathies, peripheral and cranial neuropathies, and vasculopathy. This article describes the long-term neurologic complications cancer survivors commonly experience to increase awareness of these complications and discuss treatments when available. Further research is necessary to understanding of mechanisms of neurologic injury and advance diagnosis and treatment. Effective patient education, monitoring, and managing neurologic issues after cancer treatment may improve independence, functionality, and quality of life during survivorship.


Assuntos
Neoplasias Encefálicas , Sobreviventes de Câncer , Neoplasias , Adulto , Humanos , Qualidade de Vida , Sobreviventes/psicologia , Neoplasias/complicações , Neoplasias/terapia
4.
Ann Palliat Med ; 12(6): 1447-1462, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37817502

RESUMO

BACKGROUND AND OBJECTIVE: Malignant epidural spinal cord compression (MESCC), often presenting with back pain and motor/sensory deficits, is associated with poor survival, particularly when there is loss of ambulation. The purpose of this review is to evaluate the literature and discuss appropriate workup and management of MESCC, specifically in the emergent setting. METHODS: A PubMed search was conducted on "spinal cord compression" and "radiation therapy." Articles were analyzed for the purpose of this narrative review. KEY CONTENT AND FINDINGS: If MESCC is suspected, neurologic examination and complete spine imaging are recommended. Emergent treatment is indicated if there is radiographic evidence of high-grade compression and/or clinically significant motor deficits. Treatment involves a combination of medical management, surgical decompression, radiation therapy (RT), and rehabilitation. For motor deficits, emergent initiation of high dose steroids is recommended. Circumferential surgical decompression ± stabilization followed by RT provides superior clinical outcomes than RT alone. For patients whom surgery is not reasonable, RT alone may provide significant treatment response which depends on radioresponsiveness of the pathology. Systemic therapy, if indicated, is typically reserved till after primary treatment of MESCC, but patients with chemoresponsive tumors may receive primary chemotherapy. The selected RT schedule should be personalized to each patient and commonly is 30 Gy in 10 fractions (fx), 20 Gy in 5 fx, or 8 Gy in 1 fx. MESCC recurrence may be treated with additional RT, if within the spinal cord tolerance, or surgery. Stereotactic body radiation therapy (SBRT) has been used for high grade MESCC in patients with relatively intact neurologic function at a few centers with a very robust infrastructure to support rapid initiation of treatment within a short period of time, but is generally not feasible for most clinical practices. SBRT may be advantageous for low grade MESCC, recurrence, or in the post-operative setting. Detection of MESCC prior to development of high-grade compression or deterioration of neurologic function may allow patients to benefit more from advanced therapies and improve prognosis. CONCLUSIONS: MESCC is a devastating condition; optimal treatment should be personalized to each patient and approached collaboratively by a multidisciplinary team.


Assuntos
Radiocirurgia , Compressão da Medula Espinal , Neoplasias da Coluna Vertebral , Humanos , Compressão da Medula Espinal/diagnóstico , Neoplasias da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/radioterapia , Prognóstico , Descompressão Cirúrgica/métodos
5.
Ann Palliat Med ; 12(6): 1405-1419, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37431225

RESUMO

BACKGROUND AND OBJECTIVE: As novel systemic therapies allow patients to live longer with cancer, the risk of developing central nervous system (CNS) metastases increases and providers will more frequently encounter emergent presentation of brain metastases (BM) and leptomeningeal metastases (LM). Management of these metastases requires appropriate work-up and well-coordinated multidisciplinary care. We set out to perform a review of emergent radiotherapy (RT) for CNS metastases, specifically focusing on BM and LM. METHODS: We review the appropriate pathways for workup and initial management of BM and LM, while reviewing the literature supporting emergent treatment of these entities with surgery, systemic anti-cancer therapy, and RT. To inform this narrative review, literature searches in PubMed and Google Scholar were conducted, with preference given to articles employing modern RT techniques, when applicable. Due to the paucity of high-quality evidence for management of BM and LM in the emergent setting, discussion was supplemented by the authors' expert commentary. KEY CONTENT AND FINDINGS: This work highlights the importance of surgical evaluation, particularly for patients presenting with significant mass effect, hemorrhagic metastases, or increased intracranial pressure. We review the rare situations where emergent initiation of systemic anti-cancer therapy is indicated. When defining the role of RT, we review factors guiding selection of appropriate modality, treatment volume, and dose-fractionation. Generally, 2D- or 3D-conformal treatment techniques prescribed as 30 Gy in 10 fractions or 20 Gy in 5 fractions, should be employed in the emergent setting. CONCLUSIONS: Patients with BM and LM present from a diverse array of clinical situations, requiring well-coordinated multidisciplinary management, and there is a paucity of high-quality evidence guiding such management decisions. This narrative review aims to more thoroughly prepare providers for the challenging situation of emergent management of BM and LM.


Assuntos
Neoplasias Encefálicas , Carcinomatose Meníngea , Humanos , Carcinomatose Meníngea/secundário , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Encéfalo
6.
Neurooncol Pract ; 9(6): 475-486, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36388419

RESUMO

As a result of treatment and diagnosis, adults with primary or metastatic brain tumors experience comorbidities that impacts their health and well-being. The Children's Oncology Group has guideline recommendations for childhood survivors of brain tumors; however, guidelines for monitoring long-term sequela among adult brain tumor survivors are lacking. The purpose of this review is to present the screening recommendations for the long-term complications after brain tumor treatment from a multidisciplinary panel of healthcare professionals. Chronic complications identified include cognitive dysfunction, vasculopathy, endocrinopathy, ophthalmic, ototoxicity, physical disability, sleep disturbance, mood disorder, unemployment, financial toxicity, and secondary malignancy. We invited specialists across disciplines to perform a literature search and provide expert recommendations for surveillance for long-term complications for adult brain tumor survivors. The Brain Tumor Center Survivorship Committee recommends routine screening using laboratory testing, subjective assessment of symptoms, and objective evaluations to appropriately monitor the complications of brain tumor treatments. Effective monitoring and treatment should involve collaboration with primary care providers and may require referral to other specialties and support services to provide patient-centered care during neuro-oncology survivorship. Further research is necessary to document the incidence and prevalence of medical complications as well as evaluate the efficacy of screening and neuro-oncology survivorship programs.

7.
Cancers (Basel) ; 14(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36291922

RESUMO

In the past 5 years, the treatment options available to patients with HER2+ breast cancer brain metastasis (BCBM) have expanded. The longer survival of patients with HER2+ BCBM renders understanding the toxicities of local therapies even more important to consider. After reviewing the available literature for HER2 targeted systemic therapies as well as local therapies, we present a simplified algorithm for when to prioritize systemic therapies over local therapies in patients with HER2+ BCBM.

8.
Clin Lung Cancer ; 23(5): 446-455, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35610115

RESUMO

INTRODUCTION: Leptomeningeal (LM) disease occurs in 9% to 10% of EGFR mutated non-small cell lung cancer (NSCLC) cases. The natural history and optimal systemic treatment strategies for this disease are not well-characterized, particularly in the era of osimertinib. MATERIALS AND METHODS: We identified 54 patients with EGFR mutated NSCLC and LM disease diagnosed between January 3, 2000 to March 31, 2020 and treated at an academic oncology practice in Seattle, Washington. We abstracted demographic, tumor, treatment, and outcome data from the electronic medical record. Univariate Cox models were run to evaluate the association between post-LM disease systemic therapy and overall survival. Differences in LM disease natural history and healthcare utilization between groups were assessed using Student's t test or a chi-squared test. RESULTS: Patients that received osimertinib prior to LM disease had a longer median time to LM disease diagnosis and trended toward better performance status than those that did not. Patients that received any post-LM disease systemic therapy had a lower risk of death relative to those that did not (HR 0.17, P < .001), with a suggestion that osimertinib-containing regimens result in longer median overall survival. Emergency department, hospital and hospice utilization were not associated with receipt of post-LM disease systemic therapy. CONCLUSION: Prior exposure to osimertinib appears to favorably influence the natural history of LM disease. Any systemic therapy after LM disease diagnosis is associated with longer survival and does not increase healthcare utilization. Additional research is needed to assess whether an osimertinib-containing regimen confers a survival benefit after LM disease diagnosis among patients who received prior osimertinib.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinomatose Meníngea , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/genética , Mutação/genética , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos
9.
Expert Rev Anticancer Ther ; 22(3): 307-315, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35114862

RESUMO

INTRODUCTION: Gestational trophoblastic diseases and neoplasias (GTDs and GTNs) comprise a spectrum of diseases arising from abnormally proliferating placental/trophoblastic tissue following an antecedent molar or non-molar pregnancy. These can spread to the brain hematogenously in about 10% of patients, mostly in high-risk disease. The optimal management of patients with brain metastases from GTN is unclear, with multiple systemic regimens under use and an uncertain role for radiotherapy. AREAS COVERED: Here, we review the epidemiology, workup, and treatment of GTN with central nervous system (CNS) involvement. Literature searches in PubMed and Google Scholar were conducted using combinations of keywords such as 'gestational trophoblastic disease,' 'gestational trophoblastic neoplasia,' 'choriocarcinoma,' and 'brain metastases.' EXPERT OPINION: Systemic therapy is the frontline treatment for GTN with brain metastases, and radiotherapy should only be considered in the context of a clinical trial or for resistant/recurrent disease. Surgery has a limited role in palliating symptoms or relieving intracranial pressure/bleeding. Given the highly specialized care these patients require, treatment at a high-volume referral center with multidisciplinary collaboration likely leads to better outcomes. Randomized trials should be conducted to determine the best systemic therapy option for GTN.


Assuntos
Neoplasias Encefálicas , Doença Trofoblástica Gestacional , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/terapia , Feminino , Doença Trofoblástica Gestacional/diagnóstico , Doença Trofoblástica Gestacional/tratamento farmacológico , Humanos , Placenta/patologia , Gravidez
10.
Curr Treat Options Oncol ; 22(7): 57, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34097171

RESUMO

OPINION STATEMENT: Intracranial stereotactic radiosurgery (SRS) is an effective and convenient treatment for many brain conditions. Data regarding safety come mostly from retrospective single institutional studies and a small number of prospective studies. Variations in target delineation, treatment delivery, imaging follow-up protocols and dose prescription limit the interpretation of this data. There has been much clinical focus on radiation necrosis (RN) in particular, as it is being increasingly recognized on follow-up imaging. Symptomatic RN may be treated with medical therapy (such as corticosteroids and bevacizumab) with surgical resection being reserved for refractory patients. Nevertheless, RN remains a challenging condition to manage, and therefore upfront patient selection for SRS remains critical to provide complication-free control. Mitigation strategies need to be considered in situations where the baseline risk of RN is expected to be high-such as large target volume or re-irradiation. These may involve reduction in the prescribed dose or hypofractionated stereotactic radiation therapy (HSRT). Recently published guidelines and international meta-analysis report the benefit of HSRT in larger lesions, without compromising control rates. However, careful attention to planning parameters and SRS techniques still need to be adhered, even with HSRT. In cases where the risk is deemed to be high despite mitigation, a combination approach of surgery with or without post-operative radiation should be considered.


Assuntos
Neoplasias Encefálicas/radioterapia , Lesões por Radiação/prevenção & controle , Radiocirurgia/efeitos adversos , Neoplasias Encefálicas/patologia , Humanos , Necrose , Lesões por Radiação/diagnóstico , Lesões por Radiação/etiologia , Lesões por Radiação/terapia , Carga Tumoral
11.
J Neurooncol ; 151(2): 193-200, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33398532

RESUMO

BACKGROUND: Relapsed or refractory primary CNS lymphoma (rrPCNSL) is a rare and challenging malignancy for which better evidence is needed to guide management. METHODS: We present a retrospective cohort of 66 consecutive patients with rrPCNSL treated at the University of Washington between 2000 and 2020. Immunosuppressed and secondary CNS lymphoma patients were excluded. RESULTS: During a median follow-up of 40.5 months from initial diagnosis, median OS for relapsed disease was 14.1 (0.2-88.5) months and median PFS was 11.0 (0.2-73.9) months. At diagnosis (r2 = 0.85, p < 0.001), first relapse (r2 = 0.69, p < 0.001), multiple relapses (r2 = 0.97, p < 0.001) PFS was highly correlated with OS. In contrast, there was no correlation between the duration of subsequent progression-free intervals. No difference in PFS or OS was seen between CSF or intraocular relapse and parenchymal relapse. Patients reinduced with high-dose methotrexate-based (HD-MTX) regimens had an overall response rate (ORR) of 86.7%. Consolidation with autologous stem cell transplant (ASCT) was associated with longer PFS compared to either no consolidation (p = 0.01) and trended to longer PFS when compared to other consolidation strategies (p = 0.06). OS was similarly improved in patients consolidated with ASCT compared with no consolidation (p = 0.04), but not compared with other consolidation (p = 0.22). Although patients receiving ASCT were younger, KPS, sex, and number of recurrences were similar between consolidation groups. A multivariate analysis confirmed an independent effect of consolidation group on PFS (p = 0.01), but not OS. CONCLUSIONS: PFS may be a useful surrogate endpoint which predicts OS in PCNSL. Consolidation with ASCT was associated with improved PFS in rrPCNSL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/mortalidade , Quimioterapia de Consolidação/mortalidade , Transplante de Células-Tronco Hematopoéticas/mortalidade , Linfoma/mortalidade , Recidiva Local de Neoplasia/mortalidade , Terapia de Salvação , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/terapia , Terapia Combinada , Resistencia a Medicamentos Antineoplásicos , Feminino , Seguimentos , Humanos , Linfoma/patologia , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Transplante Autólogo
12.
Curr Treat Options Oncol ; 20(3): 24, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30790064

RESUMO

OPINION STATEMENT: At this time, there are no FDA-approved immune therapies for glioblastoma (GBM) despite many unique therapies currently in clinical trials. GBM is a highly immunosuppressive tumor and there are limitations to a safe immune response in the central nervous system. To date, there have been several failures of phase 3 immune therapy clinical trials in GBM. These trials have targeted single components of an antitumor immune response. Learning from these failures, the future of immunotherapy for GBM appears most hopeful for combination of immune therapies to overcome the profound immunosuppression of this disease. Understanding biomarkers for appropriate patient selection as well as tumor progression are necessary for implementation of immunotherapy for GBM.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Imunoterapia , Terapia de Alvo Molecular , Biomarcadores Tumorais , Neoplasias Encefálicas/patologia , Vacinas Anticâncer , Ensaios Clínicos como Assunto , Glioblastoma/patologia , Humanos , Imunoterapia/tendências , Terapia de Alvo Molecular/tendências , Seleção de Pacientes , Prognóstico , Resultado do Tratamento
13.
Neurohospitalist ; 9(1): 37-40, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30671163

RESUMO

The occurrence of amyotrophic lateral sclerosis (ALS) and neuromyelitis optica (NMO) in a single patient is exceedingly rare. We report a case of a 54-year-old woman of East Asian descent with a prior diagnosis of ALS who developed an episode of unexplained hiccups and nausea and vomiting consistent with area postrema syndrome 3 months prior to the onset of acute transverse myelitis. Magnetic resonance imaging revealed abnormal T2 hyperintensity and gadolinium enhancement at the cervicomedullary junction with extension to C3. Imaging was also notable for nonenhancing central cord T2 hyperintensity from T6 to T8 suggesting previous demyelination. The patient's cerebrospinal fluid analysis was mildly inflammatory. She was found to have a positive NMO/aquaporin-4 immunoglobulin G titer (cell-based assay) greater than 1:100 000, consistent with a diagnosis of NMO. The unusual coexistence of ALS and NMO prompts consideration of potential common pathological neuroinflammatory processes.

14.
Ther Adv Med Oncol ; 9(5): 347-368, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28529551

RESUMO

Malignant brain tumors such as glioblastoma (GBM) and brain metastasis have poor prognosis despite conventional therapies. Successful use of vaccines and checkpoint inhibitors in systemic malignancy has increased the hope that immune therapies could improve survival in patients with brain tumors. Manipulating the immune system to fight malignancy has a long history of both modest breakthroughs and pitfalls that should be considered when applying the current immunotherapy approaches to patients with brain tumors. Therapeutic vaccine trials for GBM date back to the mid 1900s and have taken many forms; from irradiated tumor lysate to cell transfer therapies and peptide vaccines. These therapies were generally well tolerated without significant autoimmune toxicity, however also did not demonstrate significant clinical benefit. In contrast, the newer checkpoint inhibitors have demonstrated durable benefit in some metastatic malignancies, accompanied by significant autoimmune toxicity. While this toxicity was not unexpected, it exceeded what was predicted from pre-clinical studies and in many ways was similar to the prior trials of immunostimulants. This review will discuss the history of these studies and demonstrate that the future use of immune therapy for brain tumors will likely need a personalized approach that balances autoimmune toxicity with the opportunity for significant survival benefit.

15.
Curr Treat Options Oncol ; 18(4): 22, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28391420

RESUMO

OPINION STATEMENT: Management of non-small cell lung cancer (NSCLC) with brain metastasis (BrM) has been revolutionized by identification of molecular subsets that have targetable oncogenes. Historically, survival for NSCLC with symptomatic BrM was weeks to months. Now, many patients are surviving years with limited data to guide treatment decisions. Tumors with activating mutations in epidermal growth factor receptor (EGFRact+) have a higher incidence of BrM, but a longer overall survival. The high response rate of both systemic and BrM EGFRact+ NSCLC to tyrosine kinase inhibitors (TKIs) has led to the rapid incorporation of new therapies but is outpacing evidence-based decisions for BrM in NSCLC. While whole brain radiation therapy (WBRT) was the foundation of management of BrM, extended survival raises concerns for the subacute and late effects radiotherapy. We favor the use of TKIs and delaying the use of WBRT when able. At inevitable disease progression, we consider alternative dosing schedules to increase CNS penetration (such as pulse dosing of erlotinib) or advance to next generation TKI if available. We utilize local control options of surgery or stereotactic radiosurgery (SRS) for symptomatic accessible lesions based on size and edema. At progression despite available TKIs, we use pemetrexed-based platinum doublet chemotherapy or immunotherapy if the tumor has high expression of PDL-1. We reserve the use of WBRT for patients with more than 10 BrM and progression despite TKI and conventional chemotherapy, if performance status is appropriate.


Assuntos
Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/terapia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Neoplasias Encefálicas/diagnóstico , Ensaios Clínicos como Assunto , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Gerenciamento Clínico , Receptores ErbB/antagonistas & inibidores , Humanos , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Resultado do Tratamento
16.
J Neurosci ; 31(30): 10891-902, 2011 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-21795541

RESUMO

Nicotine is the primary psychoactive substance in tobacco, and it exerts its effects by interaction with various subtypes of nicotinic acetylcholine receptors (nAChRs) in the brain. One of the major subtypes expressed in brain, the α4ß2-nAChR, endogenously modulates neuronal excitability and thereby, modifies certain normal as well as nicotine-induced behaviors. Although α4-containing nAChRs are widely expressed across the brain, a major focus has been on their roles within midbrain dopaminergic regions involved in drug addiction, mental illness, and movement control in humans. We developed a unique model system to examine the role of α4-nAChRs within dopaminergic neurons by a targeted genetic deletion of the α4 subunit from dopaminergic neurons in mice. The loss α4 mRNA and α4ß2-nAChRs from dopaminergic neurons was confirmed, as well as selective loss of α4ß2-nAChR function from dopaminergic but not GABAergic neurons. Two behaviors central to nicotine dependence, reward and anxiety relief, were examined. α4-nAChRs specifically on dopaminergic neurons were demonstrated to be necessary for nicotine reward as measured by nicotine place preference, but not for another drug of addiction, cocaine. α4-nAChRs are necessary for the anxiolytic effects of nicotine in the elevated plus maze, and elimination of α4ß2-nAChRs specifically from dopaminergic neurons decreased sensitivity to the anxiolytic effects of nicotine. Deletion of α4-nAChRs specifically from dopaminergic neurons also increased sensitivity to nicotine-induced locomotor depression; however, nicotine-induced hypothermia was unaffected. This is the first work to develop a dopaminergic specific deletion of a nAChR subunit and examine resulting changes in nicotine-related behaviors.


Assuntos
Ansiedade/tratamento farmacológico , Dopamina/metabolismo , Neurônios/fisiologia , Nicotina/administração & dosagem , Agonistas Nicotínicos/administração & dosagem , Receptores Nicotínicos/metabolismo , Recompensa , Análise de Variância , Animais , Ansiedade/patologia , Comportamento Animal , Temperatura Corporal/efeitos dos fármacos , Temperatura Corporal/genética , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Condicionamento Operante/efeitos dos fármacos , Condicionamento Operante/fisiologia , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Feminino , Glutamato Descarboxilase/metabolismo , Masculino , Mesencéfalo/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Agonistas Nicotínicos/farmacocinética , Ligação Proteica/efeitos dos fármacos , Piridinas/farmacocinética , Receptores Nicotínicos/deficiência , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Trítio/metabolismo , Ácido gama-Aminobutírico/metabolismo
17.
Biol Psychiatry ; 63(2): 152-7, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17570346

RESUMO

BACKGROUND: There has been a recent upsurge of interest in the role of hypothalamic feeding peptides, in particular, orexin (hypocretin), in drug-seeking behavior. However, the potential role of other hypothalamic feeding peptides, such as cocaine- and amphetamine-regulated transcript (CART), in conditioned reinstatement has yet to be explored. METHODS: Animals were exposed to environmental stimuli previously associated with ethanol availability (EtOH S+), and sections from the hypothalamus and paraventricular thalamus (PVT), a recipient of CART and orexin innervation, were dual labeled for Fos-protein and either CART or orexin. RESULTS: Significantly larger numbers of Fos-positive arcuate nucleus CART and hypothalamic orexin neurons were seen in animals exposed to the EtOH S+ compared with nonreward S- animals. Presentation of the EtOH S+ also increased numbers of Fos-positive PVT neurons. Fos-positive PVT neurons were observed to be closely associated with orexin and CART terminal fields. CONCLUSIONS: Taken together, these findings suggest that activation of hypothalamic neuropeptide systems may be a common mechanism underlying drug-seeking behavior.


Assuntos
Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Hipotálamo/citologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Análise de Variância , Animais , Condicionamento Operante/efeitos dos fármacos , Masculino , Neurônios/metabolismo , Orexinas , Ratos , Ratos Wistar
18.
Artigo em Inglês | MEDLINE | ID: mdl-17271428

RESUMO

Tools of systems engineering and signal dynamics were employed to develop a quantitative model of the intracellular signaling systems involved in adult neural stem cell proliferation, based on pathways elucidated in our experimental systems. Neural progenitors isolated from the adult rat hippocampus are dependent on the basic fibroblast growth factor (FGF-2) and extracellular matrix (ECM) proteins. However, the intracellular effects of these stimuli were previously undetermined. We employed chemical inhibitors of known signal transduction molecules to identify important players in the FGF-2/ECM signal cascade, such as the cyclic AMP responsive element binding protein (CREB), protein kinase B/Akt, and several related molecules. Genetic mutants of these proteins were used to confirm their role in adult neural progenitor proliferation. Proliferation was assayed using the incorporation of a thymidine analog to determine cell doubling rate under various stimuli. Such assays have also uncovered novel synergistic signaling between FGF-2 and ECM components. This research is, to our knowledge, the first to elucidate intracellular signaling pathways for adult neural stem cell proliferation. Upon determination of the pertinent intracellular signaling pathways, quantitative immunoblots were employed to examine the dynamics of these systems. These data, as well as enzyme kinetics information from the literature, are being used to parameterize a dynamic mathematical model of progenitor proliferation events induced by FGF-2. This computational model will be used to predict the biochemical and mechanical signaling inputs necessary to achieve a desired proliferative output from the cells, based on specific extracellular stimuli. It is our hope that this essential quantitative understanding will facilitate the use of adult neural stem cells in medical applications.

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