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1.
Lancet Oncol ; 22(1): 118-131, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33387490

RESUMO

BACKGROUND: Standard chemotherapy remains inadequate in metastatic pancreatic adenocarcinoma. Combining an agonistic CD40 monoclonal antibody with chemotherapy induces T-cell-dependent tumour regression in mice and improves survival. In this study, we aimed to evaluate the safety of combining APX005M (sotigalimab) with gemcitabine plus nab-paclitaxel, with and without nivolumab, in patients with pancreatic adenocarcinoma to establish the recommended phase 2 dose. METHODS: This non-randomised, open-label, multicentre, four-cohort, phase 1b study was done at seven academic hospitals in the USA. Eligible patients were adults aged 18 years and older with untreated metastatic pancreatic adenocarcinoma, Eastern Cooperative Oncology Group performance status score of 0-1, and measurable disease by Response Evaluation Criteria in Solid Tumors version 1.1. All patients were treated with 1000 mg/m2 intravenous gemcitabine and 125 mg/m2 intravenous nab-paclitaxel. Patients received 0·1 mg/kg intravenous APX005M in cohorts B1 and C1 and 0·3 mg/kg in cohorts B2 and C2. In cohorts C1 and C2, patients also received 240 mg intravenous nivolumab. Primary endpoints comprised incidence of adverse events in all patients who received at least one dose of any study drug, incidence of dose-limiting toxicities (DLTs) in all patients who had a DLT or received at least two doses of gemcitabine plus nab-paclitaxel and one dose of APX005M during cycle 1, and establishing the recommended phase 2 dose of intravenous APX005M. Objective response rate in the DLT-evaluable population was a key secondary endpoint. This trial (PRINCE, PICI0002) is registered with ClinicalTrials.gov, NCT03214250 and is ongoing. FINDINGS: Between Aug 22, 2017, and July 10, 2018, of 42 patients screened, 30 patients were enrolled and received at least one dose of any study drug; 24 were DLT-evaluable with median follow-up 17·8 months (IQR 16·0-19·4; cohort B1 22·0 months [21·4-22·7], cohort B2 18·2 months [17·0-18·9], cohort C1 17·9 months [14·3-19·7], cohort C2 15·9 months [12·7-16·1]). Two DLTs, both febrile neutropenia, were observed, occurring in one patient each for cohorts B2 (grade 3) and C1 (grade 4). The most common grade 3-4 treatment-related adverse events were lymphocyte count decreased (20 [67%]; five in B1, seven in B2, four in C1, four in C2), anaemia (11 [37%]; two in B1, four in B2, four in C1, one in C2), and neutrophil count decreased (nine [30%]; three in B1, three in B2, one in C1, two in C2). 14 (47%) of 30 patients (four each in B1, B2, C1; two in C2) had a treatment-related serious adverse event. The most common serious adverse event was pyrexia (six [20%] of 30; one in B2, three in C1, two in C2). There were two chemotherapy-related deaths due to adverse events: one sepsis in B1 and one septic shock in C1. The recommended phase 2 dose of APX005M was 0·3 mg/kg. Responses were observed in 14 (58%) of 24 DLT-evaluable patients (four each in B1, C1, C2; two in B2). INTERPRETATION: APX005M and gemcitabine plus nab-paclitaxel, with or without nivolumab, is tolerable in metastatic pancreatic adenocarcinoma and shows clinical activity. If confirmed in later phase trials, this treatment regimen could replace chemotherapy-only standard of care in this population. FUNDING: Parker Institute for Cancer Immunotherapy, Cancer Research Institute, and Bristol Myers Squibb.


Assuntos
Adenocarcinoma/tratamento farmacológico , Albuminas/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígenos CD40/antagonistas & inibidores , Desoxicitidina/análogos & derivados , Nivolumabe/administração & dosagem , Paclitaxel/administração & dosagem , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma/imunologia , Adenocarcinoma/secundário , Idoso , Albuminas/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antígenos CD40/imunologia , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nivolumabe/efeitos adversos , Paclitaxel/efeitos adversos , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Gencitabina
2.
Nature ; 543(7647): 670-675, 2017 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-28329757

RESUMO

The brain's ability to associate different stimuli is vital for long-term memory, but how neural ensembles encode associative memories is unknown. Here we studied how cell ensembles in the basal and lateral amygdala encode associations between conditioned and unconditioned stimuli (CS and US, respectively). Using a miniature fluorescence microscope, we tracked the Ca2+ dynamics of ensembles of amygdalar neurons during fear learning and extinction over 6 days in behaving mice. Fear conditioning induced both up- and down-regulation of individual cells' CS-evoked responses. This bi-directional plasticity mainly occurred after conditioning, and reshaped the neural ensemble representation of the CS to become more similar to the US representation. During extinction training with repetitive CS presentations, the CS representation became more distinctive without reverting to its original form. Throughout the experiments, the strength of the ensemble-encoded CS-US association predicted the level of behavioural conditioning in each mouse. These findings support a supervised learning model in which activation of the US representation guides the transformation of the CS representation.


Assuntos
Memória de Longo Prazo/fisiologia , Plasticidade Neuronal , Neurônios/fisiologia , Tonsila do Cerebelo/citologia , Tonsila do Cerebelo/fisiologia , Animais , Cálcio/metabolismo , Sinalização do Cálcio , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Medo/psicologia , Masculino , Camundongos , Microscopia de Fluorescência
3.
Neuron ; 87(6): 1317-1331, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26402611

RESUMO

Forming distinct representations and memories of multiple contexts and episodes is thought to be a crucial function of the hippocampal-entorhinal cortical network. The hippocampal dentate gyrus (DG) and CA3 are known to contribute to these functions, but the role of the entorhinal cortex (EC) is poorly understood. Here, we show that Ocean cells, excitatory stellate neurons in the medial EC layer II projecting into DG and CA3, rapidly form a distinct representation of a novel context and drive context-specific activation of downstream CA3 cells as well as context-specific fear memory. In contrast, Island cells, excitatory pyramidal neurons in the medial EC layer II projecting into CA1, are indifferent to context-specific encoding or memory. On the other hand, Ocean cells are dispensable for temporal association learning, for which Island cells are crucial. Together, the two excitatory medial EC layer II inputs to the hippocampus have complementary roles in episodic memory.


Assuntos
Córtex Entorrinal/citologia , Córtex Entorrinal/fisiologia , Medo/fisiologia , Memória/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Vias Neurais/citologia , Vias Neurais/fisiologia
4.
Proc Natl Acad Sci U S A ; 112(30): 9466-71, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26170279

RESUMO

Entorhinal-hippocampal circuits in the mammalian brain are crucial for an animal's spatial and episodic experience, but the neural basis for different spatial computations remain unknown. Medial entorhinal cortex layer II contains pyramidal island and stellate ocean cells. Here, we performed cell type-specific Ca(2+) imaging in freely exploring mice using cellular markers and a miniature head-mounted fluorescence microscope. We found that both oceans and islands contain grid cells in similar proportions, but island cell activity, including activity in a proportion of grid cells, is significantly more speed modulated than ocean cell activity. We speculate that this differential property reflects island cells' and ocean cells' contribution to different downstream functions: island cells may contribute more to spatial path integration, whereas ocean cells may facilitate contextual representation in downstream circuits.


Assuntos
Córtex Entorrinal/citologia , Hipocampo/metabolismo , Potenciais de Ação , Animais , Mapeamento Encefálico/métodos , Cálcio/metabolismo , Dependovirus , Corantes Fluorescentes , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência , Modelos Neurológicos , Vias Neurais/citologia , Neurônios/citologia
5.
Nat Neurosci ; 17(12): 1825-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25402858

RESUMO

Fluorescence Ca(2+) imaging enables large-scale recordings of neural activity, but collective dynamics across mammalian brain regions are generally inaccessible within single fields of view. Here we introduce a two-photon microscope possessing two articulated arms that can simultaneously image two brain areas (∼0.38 mm(2) each), either nearby or distal, using microendoscopes. Concurrent Ca(2+) imaging of ∼100-300 neurons in primary visual cortex (V1) and lateromedial (LM) visual area in behaving mice revealed that the variability in LM neurons' visual responses was strongly dependent on that in V1, suggesting that fluctuations in sensory responses propagate through extended cortical networks.


Assuntos
Potenciais de Ação/fisiologia , Cálcio/metabolismo , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Estimulação Luminosa/métodos , Córtex Visual/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Córtex Visual/química , Vias Visuais/química , Vias Visuais/fisiologia
6.
Nat Neurosci ; 16(3): 264-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23396101

RESUMO

Using Ca(2+) imaging in freely behaving mice that repeatedly explored a familiar environment, we tracked thousands of CA1 pyramidal cells' place fields over weeks. Place coding was dynamic, as each day the ensemble representation of this environment involved a unique subset of cells. However, cells in the ∼15-25% overlap between any two of these subsets retained the same place fields, which sufficed to preserve an accurate spatial representation across weeks.


Assuntos
Potenciais de Ação/fisiologia , Região CA1 Hipocampal/fisiologia , Cálcio/metabolismo , Células Piramidais/fisiologia , Animais , Meio Ambiente , Memória/fisiologia , Camundongos
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