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1.
Biol Psychiatry ; 94(3): 239-248, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36925415

RESUMO

BACKGROUND: The ability to correctly associate cues and contexts with threat is critical for survival, and the inability to do so can result in threat-related disorders such as posttraumatic stress disorder. The prefrontal cortex (PFC) and hippocampus are well known to play critical roles in cued and contextual threat memory processing. However, the circuits that mediate prefrontal-hippocampal modulation of context discrimination during cued threat processing are less understood. Here, we demonstrate the role of a previously unexplored projection from the ventromedial region of PFC (vmPFC) to the lateral entorhinal cortex (LEC) in modulating the gain of behavior in response to contextual information during threat retrieval and encoding. METHODS: We used optogenetics followed by in vivo calcium imaging in male C57/B6J mice to manipulate and monitor vmPFC-LEC activity in response to threat-associated cues in different contexts. We then investigated the inputs to, and outputs from, vmPFC-LEC cells using Rabies tracing and channelrhodopsin-assisted electrophysiology. RESULTS: vmPFC-LEC cells flexibly and bidirectionally shaped behavior during threat expression, shaping sensitivity to contextual information to increase or decrease the gain of behavioral output in response to a threatening or neutral context, respectively. CONCLUSIONS: Glutamatergic vmPFC-LEC cells are key players in behavioral gain control in response to contextual information during threat processing and may provide a future target for intervention in threat-based disorders.


Assuntos
Comportamento , Medo , Vias Neurais , Córtex Olfatório , Córtex Pré-Frontal , Animais , Masculino , Camundongos , Comportamento/fisiologia , Sinalização do Cálcio , Channelrhodopsins/metabolismo , Sinais (Psicologia) , Ácido Glutâmico/metabolismo , Camundongos Endogâmicos C57BL , Córtex Olfatório/citologia , Córtex Olfatório/fisiologia , Optogenética , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/fisiologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Técnicas de Patch-Clamp
2.
Front Synaptic Neurosci ; 14: 1004154, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36186623

RESUMO

A-kinase anchoring protein 79-human/150-rodent (AKAP79/150) organizes signaling proteins to control synaptic plasticity. AKAP79/150 associates with the plasma membrane and endosomes through its N-terminal domain that contains three polybasic regions and two Cys residues that are reversibly palmitoylated. Mutations abolishing palmitoylation (AKAP79/150 CS) reduce its endosomal localization and association with the postsynaptic density (PSD). Here we combined advanced light and electron microscopy (EM) to characterize the effects of AKAP79/150 palmitoylation on its postsynaptic nanoscale organization, trafficking, and mobility in hippocampal neurons. Immunogold EM revealed prominent extrasynaptic membrane AKAP150 labeling with less labeling at the PSD. The label was at greater distances from the spine membrane for AKAP150 CS than WT in the PSD but not in extra-synaptic locations. Immunogold EM of GFP-tagged AKAP79 WT showed that AKAP79 adopts a vertical, extended conformation at the PSD with its N-terminus at the membrane, in contrast to extrasynaptic locations where it adopts a compact or open configurations of its N- and C-termini with parallel orientation to the membrane. In contrast, GFP-tagged AKAP79 CS was displaced from the PSD coincident with disruption of its vertical orientation, while proximity and orientation with respect to the extra-synaptic membrane was less impacted. Single-molecule localization microscopy (SMLM) revealed a heterogeneous distribution of AKAP150 with distinct high-density, nano-scale regions (HDRs) overlapping the PSD but more prominently located in the extrasynaptic membrane for WT and the CS mutant. Thick section scanning transmission electron microscopy (STEM) tomography revealed AKAP150 immunogold clusters similar in size to HDRs seen by SMLM and more AKAP150 labeled endosomes in spines for WT than for CS, consistent with the requirement for AKAP palmitoylation in endosomal trafficking. Hidden Markov modeling of single molecule tracking data revealed a bound/immobile fraction and two mobile fractions for AKAP79 in spines, with the CS mutant having shorter dwell times and faster transition rates between states than WT, suggesting that palmitoylation stabilizes individual AKAP molecules in various spine subpopulations. These data demonstrate that palmitoylation fine tunes the nanoscale localization, mobility, and trafficking of AKAP79/150 in dendritic spines, which might have profound effects on its regulation of synaptic plasticity.

3.
J Neurosci ; 41(46): 9633-9649, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34580165

RESUMO

Epilepsy Aphasia Syndromes (EAS) are a spectrum of childhood epileptic, cognitive, and language disorders of unknown etiology. CNKSR2 is a strong X-linked candidate gene implicated in EAS; however, there have been no studies of genetic models to dissect how its absence may lead to EAS. Here we develop a novel Cnksr2 KO mouse line and show that male mice exhibit increased neural activity and have spontaneous electrographic seizures. Cnksr2 KO mice also display significantly increased anxiety, impaired learning and memory, and a progressive and dramatic loss of ultrasonic vocalizations. We find that Cnksr2 is expressed in cortical, striatal, and cerebellar regions and is localized at both excitatory and inhibitory postsynapses. Proteomics analysis reveals Cnksr2 anchors key binding partners at synapses, and its loss results in significant alterations of the synaptic proteome, including proteins implicated in epilepsy disorders. Our results validate that loss of CNKSR2 leads to EAS and highlights the roles of Cnksr2 in synaptic organization and neuronal network activity.SIGNIFICANCE STATEMENT Epilepsy Aphasia Syndromes (EAS) are at the severe end of a spectrum of cognitive-behavioral symptoms seen in childhood epilepsies, and they remain an inadequately understood disorder. The prognosis of EAS is frequently poor, and patients have life-long language and cognitive disturbances. Here we describe a genetic mouse model of EAS, based on the KO of the EAS risk gene Cnksr2 We show that these mice exhibit electrophysiological and behavioral phenotypes similar to those of patients, providing an important new model for future studies of EAS. We also provide insights into the molecular disturbances downstream of Cnksr2 loss by using in vivo quantitative proteomics tools.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/deficiência , Modelos Animais de Doenças , Síndrome de Landau-Kleffner , Proteínas do Tecido Nervoso/deficiência , Animais , Comportamento Animal , Camundongos , Camundongos Knockout , Fenótipo , Síndrome
4.
Nature ; 588(7837): 296-302, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33177716

RESUMO

Perisynaptic astrocytic processes are an integral part of central nervous system synapses1,2; however, the molecular mechanisms that govern astrocyte-synapse adhesions and how astrocyte contacts control synapse formation and function are largely unknown. Here we use an in vivo chemico-genetic approach that applies a cell-surface fragment complementation strategy, Split-TurboID, and identify a proteome that is enriched at astrocyte-neuron junctions in vivo, which includes neuronal cell adhesion molecule (NRCAM). We find that NRCAM is expressed in cortical astrocytes, localizes to perisynaptic contacts and is required to restrict neuropil infiltration by astrocytic processes. Furthermore, we show that astrocytic NRCAM interacts transcellularly with neuronal NRCAM coupled to gephyrin at inhibitory postsynapses. Depletion of astrocytic NRCAM reduces numbers of inhibitory synapses without altering glutamatergic synaptic density. Moreover, loss of astrocytic NRCAM markedly decreases inhibitory synaptic function, with minor effects on excitation. Thus, our results present a proteomic framework for how astrocytes interface with neurons and reveal how astrocytes control GABAergic synapse formation and function.


Assuntos
Astrócitos/química , Astrócitos/metabolismo , Neurônios/metabolismo , Proteoma/metabolismo , Proteômica , Sinapses/química , Sinapses/metabolismo , Animais , Astrócitos/citologia , Moléculas de Adesão Celular Neuronais/metabolismo , Forma Celular , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Teste de Complementação Genética , Células HEK293 , Humanos , Masculino , Camundongos , Inibição Neural , Neurônios/citologia , Ácido gama-Aminobutírico/metabolismo
5.
Cell Rep ; 31(12): 107785, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32579917

RESUMO

Molecular mechanisms underlying plasticity at brain inhibitory synapses remain poorly characterized. Increased postsynaptic clustering of GABAA receptors (GABAARs) rapidly strengthens inhibition during inhibitory long-term potentiation (iLTP). However, it is unclear how synaptic GABAAR clustering is maintained to sustain iLTP. Here, we identify a role for miR376c in regulating the translation of mRNAs encoding the synaptic α1 and γ2 GABAAR subunits, GABRA1 and GABRG2, respectively. Following iLTP induction, transcriptional repression of miR376c is induced through a calcineurin-NFAT-HDAC signaling pathway and promotes increased translation and clustering of synaptic GABAARs. This pathway is essential for the long-term expression of iLTP and is blocked by miR376c overexpression, specifically impairing inhibitory synaptic strength. Finally, we show that local de novo synthesis of synaptic GABAARs occurs exclusively in dendrites and in a miR376c-dependent manner following iLTP. Together, this work describes a local post-transcriptional mechanism that regulates inhibitory synaptic plasticity via miRNA control of dendritic protein synthesis.


Assuntos
Potenciação de Longa Duração/genética , MicroRNAs/genética , Biossíntese de Proteínas/genética , Receptores de GABA-A/genética , Animais , Sequência de Bases , Calcineurina/metabolismo , Dendritos/metabolismo , Regulação da Expressão Gênica , Inativação Gênica , Células HEK293 , Humanos , MicroRNAs/metabolismo , Fatores de Transcrição NFATC/metabolismo , Inibição Neural , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Transcrição Gênica
6.
Artigo em Inglês | MEDLINE | ID: mdl-32292336

RESUMO

Experience-dependent learning and memory require multiple forms of plasticity at hippocampal and cortical synapses that are regulated by N-methyl-D-aspartate receptors (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors (NMDAR, AMPAR). These plasticity mechanisms include long-term potentiation (LTP) and depression (LTD), which are Hebbian input-specific mechanisms that rapidly increase or decrease AMPAR synaptic strength at specific inputs, and homeostatic plasticity that globally scales-up or -down AMPAR synaptic strength across many or even all inputs. Frequently, these changes in synaptic strength are also accompanied by a change in the subunit composition of AMPARs at the synapse due to the trafficking to and from the synapse of receptors lacking GluA2 subunits. These GluA2-lacking receptors are most often GluA1 homomeric receptors that exhibit higher single-channel conductance and are Ca2+-permeable (CP-AMPAR). This review article will focus on the role of protein phosphorylation in regulation of GluA1 CP-AMPAR recruitment and removal from hippocampal synapses during synaptic plasticity with an emphasis on the crucial role of local signaling by the cAMP-dependent protein kinase (PKA) and the Ca2+calmodulin-dependent protein phosphatase 2B/calcineurin (CaN) that is coordinated by the postsynaptic scaffold protein A-kinase anchoring protein 79/150 (AKAP79/150).

7.
Cell Rep ; 25(4): 974-987.e4, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30355502

RESUMO

Ca2+-permeable AMPA-type glutamate receptors (CP-AMPARs) containing GluA1 but lacking GluA2 subunits contribute to multiple forms of synaptic plasticity, including long-term potentiation (LTP), but mechanisms regulating CP-AMPARs are poorly understood. A-kinase anchoring protein (AKAP) 150 scaffolds kinases and phosphatases to regulate GluA1 phosphorylation and trafficking, and trafficking of AKAP150 itself is modulated by palmitoylation on two Cys residues. Here, we developed a palmitoylation-deficient knockin mouse to show that AKAP150 palmitoylation regulates CP-AMPAR incorporation at hippocampal synapses. Using biochemical, super-resolution imaging, and electrophysiological approaches, we found that palmitoylation promotes AKAP150 localization to recycling endosomes and the postsynaptic density (PSD) to limit CP-AMPAR basal synaptic incorporation. In addition, we found that AKAP150 palmitoylation is required for LTP induced by weaker stimulation that recruits CP-AMPARs to synapses but not stronger stimulation that recruits GluA2-containing AMPARs. Thus, AKAP150 palmitoylation controls its subcellular localization to maintain proper basal and activity-dependent regulation of synaptic AMPAR subunit composition.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Cálcio/metabolismo , Permeabilidade da Membrana Celular , Lipoilação , Potenciação de Longa Duração , Receptores de AMPA/metabolismo , Sinapses/metabolismo , Animais , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Espinhas Dendríticas/metabolismo , Endossomos/metabolismo , Camundongos Endogâmicos C57BL , Transmissão Sináptica
8.
BMC Cancer ; 18(1): 136, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402316

RESUMO

BACKGROUND: Polo-like kinase 1 (Plk1) is a serine/threonine kinase that is a key regulator of multiple stages of mitotic progression. Plk1 is upregulated in many tumor types including colorectal cancer (CRC) and portends a poor prognosis. TAK-960 is an ATP-competitive Plk1 inhibitor that has demonstrated efficacy across a broad range of cancer cell lines, including CRC. In this study, we investigated the activity of TAK-960 against a large collection of CRC models including 55 cell lines and 18 patient-derived xenografts. METHODS: Fifty-five CRC cell lines and 18 PDX models were exposed to TAK-960 and evaluated for proliferation (IC50) and Tumor Growth Inhibition Index, respectively. Additionally, 2 KRAS wild type and 2 KRAS mutant PDX models were treated with TAK-960 as single agent or in combination with cetuximab or irinotecan. TAK-960 mechanism of action was elucidated through immunoblotting and cell cycle analysis. RESULTS: CRC cell lines demonstrated a variable anti-proliferative response to TAK-960 with IC50 values ranging from 0.001 to > 0.75 µmol/L. Anti-proliferative effects were sustained after removal of drug. Following TAK-960 treatment a highly variable accumulation of mitotic (indicating cell cycle arrest) and apoptotic markers was observed. Cell cycle analysis demonstrated that TAK-960 treatment induced G2/M arrest and polyploidy. Six out of the eighteen PDX models responded to single agent TAK-960 therapy (TGII< 20). The addition of TAK-960 to standard of care chemotherapy resulted in largely additive antitumor effects. CONCLUSION: TAK-960 is an active anti-proliferative agent against CRC cell lines and PDX models. Collectively, these data suggest that TAK-960 may be of therapeutic benefit alone or in combination with other agents, although future work should focus on the development of predictive biomarkers and hypothesis-driven rational combinations.


Assuntos
Azepinas/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Neoplasias Colorretais/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto , Ácido 4-Aminobenzoico/farmacologia , Animais , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Camundongos Nus , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Carga Tumoral/efeitos dos fármacos , Quinase 1 Polo-Like
9.
PLoS One ; 12(11): e0187173, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29091939

RESUMO

BACKGROUND: Dysregulation of the Src pathway has been shown to be important at various stages of cancer. Dasatinib is a potent Src/Abl inhibitor and has demonstrated to have anti-proliferative and anti-invasive activity in many preclinical models. The objective of this study was to determine the anti-tumor activity of dasatinib using in vitro and in vivo preclinical colorectal (CRC) models. METHODS: CRC cell lines and patient-derived tumor explant (PDX) models were used to investigate the efficacy of dasatinib. We treated 50 CRC cell lines with dasatinib for 72 hours and proliferation was assayed by a sulforhodamine B (SRB) assay; an IC50 ≤ 0.08 µmol/L was considered sensitive. We treated 17 patient-derived CRC explants with dasatinib (50 mg/kg/day, administered once-daily) for 28 days to determine in vivo efficacy. Tumor growth inhibition (TGI) ≥ 50% was considered sensitive. RESULTS: We found that 8 out of 50 CRC cell lines reached an IC50 ≤ 0.08 µmol/L with dasatinib treatment. In addition, of 17 CRC explants grown in the xenograft mouse model, 2 showed sensitivity to dasatinib. The anti-tumor effects observed in this study were a result of G1 cell cycle arrest as the dasatinib sensitive CRC cell lines exhibited G1 inhibition. Moreover, those CRC cell lines that were responsive (0.08 µmol/L) to treatment demonstrated a significant baseline increase in Src and FAK gene expression. CONCLUSION: Dasatinib demonstrated significant anti-proliferative activity in a subset of CRC cell lines in vitro, especially in those with increased Src expression at baseline, but only showed modest efficacy in CRC explants. Dasatinib is currently being studied in combination with chemotherapy in patients with advanced CRC, as its use as a single agent appears limited.


Assuntos
Antineoplásicos/farmacologia , Dasatinibe/farmacologia , Proteínas Oncogênicas v-abl/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinases da Família src/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Oncotarget ; 7(31): 50290-50301, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-27385211

RESUMO

BACKGROUND: The Aurora kinases are a family of serine/threonine kinases comprised of Aurora A, B, and C which execute critical steps in mitotic and meiotic progression. Alisertib (MLN8237) is an investigational Aurora A selective inhibitor that has demonstrated activity against a wide variety of tumor types in vitro and in vivo, including CRC. RESULTS: CRC cell lines demonstrated varying sensitivity to alisertib with IC50 values ranging from 0.06 to > 5 umol/L. Following exposure to alisertib we observed a decrease in pAurora A, B and C in four CRC cell lines. We also observed an increase in p53 and p21 in a sensitive p53 wildtype cell line in contrast to the p53 mutant cell line or the resistant cell lines. The addition of alisertib to standard CRC treatments demonstrated improvement over single agent arms; however, the benefit was largely less than additive, but not antagonistic. METHODS: Forty-seven CRC cell lines were exposed to alisertib and IC50s were calculated. Twenty-one PDX models were treated with alisertib and the Tumor Growth Inhibition Index was assessed. Additionally, 5 KRAS wildtype and mutant PDX models were treated with alisertib as single agent or in combination with cetuximab or irinotecan, respectively. CONCLUSION: Alisertib demonstrated anti-proliferative effects against CRC cell lines and PDX models. Our data suggest that the addition of alisertib to standard therapies in colorectal cancer if pursued clinically, will require further investigation of patient selection strategies and these combinations may facilitate future clinical studies.


Assuntos
Antineoplásicos/farmacologia , Aurora Quinase A/antagonistas & inibidores , Azepinas/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Apoptose , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cetuximab/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Concentração Inibidora 50 , Irinotecano , Camundongos , Camundongos Nus , Transplante de Neoplasias , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Oncotarget ; 7(19): 28273-85, 2016 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-27070088

RESUMO

BACKGROUND: Dysregulation of the canonical Wnt signaling pathway has been implicated in colorectal cancer (CRC) development as well as incipient stages of malignant transformation. In this study, we investigated the antitumor effects of AZ1366 (a novel tankyrase inhibitor) as a single agent and in combination with irinotecan in our patient derived CRC explant xenograft models. RESULTS: Six out of 18 CRC explants displayed a significant growth reduction to AZ1366. There was one CRC explant (CRC040) that reached the threshold of sensitivity (TGII ≤ 20%) in this study. In addition, the combination of AZ1366 + irinotecan demonstrated efficacy in 4 out of 18 CRC explants. Treatment effects on the WNT pathway revealed that tankyrase inhibition was ineffective at reducing WNT dependent signaling. However, the anti-tumor effects observed in this study were likely a result of alternative tankyrase effects whereby tankyrase inhibition reduced NuMA levels. MATERIALS AND METHODS: Eighteen CRC explants were treated with AZ1366 single agent or in combination for 28 days and treatment responses were assessed. Pharmacokinetic (AZ1366 drug concentrations) and pharmacodynamic effects (Axin2 levels) were investigated over 48 hours. Immunohistochemistry of nuclear ß-catenin levels as well as western blot was employed to examine the treatment effects on the WNT pathway as well as NuMA. CONCLUSIONS: Combination AZ1366 and irinotecan achieved greater anti-tumor effects compared to monotherapy. Activity was limited to CRC explants that displayed irinotecan resistance and increased protein levels of tankyrase and NuMA.


Assuntos
Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Tanquirases/antagonistas & inibidores , Adulto , Idoso , Animais , Proteína Axina/biossíntese , Proteína Axina/efeitos dos fármacos , Camptotecina/farmacologia , Neoplasias Colorretais/enzimologia , Feminino , Humanos , Irinotecano , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Pancreas ; 45(1): 117-22, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26566217

RESUMO

OBJECTIVES: The aim of the current study was to examine expression and the role, if any, of aldehyde dehydrogenase (ALDH)1B1 in pancreatic adenocarcinoma. METHODS: A tissue microarray of 61 pancreatic cancer patients were evaluated for protein expression of ALDH1B1 by immunohistochemistry. The ALDH1B1 small interfering (RNA) was used to assess the contribution of ALDH1B1 on proliferation of pancreatic cancer cells. RESULTS: In normal human pancreas, ALDH1B1 is abundantly expressed in glandular cells, but sparsely in the ducts (ALDH1B1 immunopositivity = 16.7 ± 1.7). In pancreatic ductal carcinoma, we found high ALDH1B1 expression in ductal cancerous tissues (ALDH1B1 immunopositivity = 197.2 ± 29.4). Analysis of ALDH1B1 expression in a human pancreatic adenocarcinoma tissue microarray showed the greatest expression in tumors that were more invasive. A variation in ALDH1B1 expression was also observed in 16 human pancreatic cancer cell lines. Knockdown of ALDH1B1 caused a 35% reduction in cell growth in the high ALDH1B1-expressing cell lines. CONCLUSIONS: Our data show for the first time that ALDH1B1 is expressed at very high levels in human pancreatic cancer, and it contributes to proliferation in these tumor cells. These data suggest a potential modulatory role for ALDH1B1 in pancreatic cancer.


Assuntos
Aldeído Desidrogenase/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/enzimologia , Neoplasias Pancreáticas/enzimologia , Aldeído Desidrogenase/genética , Família Aldeído Desidrogenase 1 , Aldeído-Desidrogenase Mitocondrial , Animais , Biomarcadores Tumorais/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Camundongos Nus , Invasividade Neoplásica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Interferência de RNA , Transdução de Sinais , Análise Serial de Tecidos , Transfecção , Carga Tumoral , Regulação para Cima
13.
Int J Cancer ; 138(1): 195-205, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26152787

RESUMO

Dysregulation of the Notch1 receptor has been shown to facilitate the development and progression of colorectal cancer (CRC) and has been identified as an independent predictor of disease progression and worse survival. Although mutations in the NOTCH1 receptor have not been described in CRC, we have previously discovered a NOTCH1 gene copy number gain in a portion of CRC tumor samples. Here, we demonstrated that a NOTCH1 gene copy number gain is significantly associated with worse survival and a high percentage of gene duplication in a cohort of patients with advanced CRC. In our CRC patient-derived tumor xenograft (PDTX) model, tumors harboring a NOTCH1 gain exhibited significant elevation of the Notch1 receptor, JAG1 ligand and cleaved Notch1 activity. In addition, a significant association was identified between a gain in NOTCH1 gene copy number and sensitivity to a Notch1-targeting antibody. These findings suggest that patients with metastatic CRC that harbor a gain in NOTCH1 gene copy number have worse survival and that targeting this patient population with a Notch1 antibody may yield improved outcomes.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Variações do Número de Cópias de DNA , Dosagem de Genes , Receptor Notch1/genética , Animais , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Biomarcadores Tumorais , Proteínas de Ligação ao Cálcio/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Duplicação Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Jagged-1 , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Metástase Neoplásica , Prognóstico , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/metabolismo , Proteínas Serrate-Jagged , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Biol Chem ; 290(22): 14107-19, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-25882844

RESUMO

Anchoring proteins direct protein kinases and phosphoprotein phosphatases toward selected substrates to control the efficacy, context, and duration of neuronal phosphorylation events. The A-kinase anchoring protein AKAP79/150 interacts with protein kinase A (PKA), protein kinase C (PKC), and protein phosphatase 2B (calcineurin) to modulate second messenger signaling events. In a mass spectrometry-based screen for additional AKAP79/150 binding partners, we have identified the Roundabout axonal guidance receptor Robo2 and its ligands Slit2 and Slit3. Biochemical and cellular approaches confirm that a linear sequence located in the cytoplasmic tail of Robo2 (residues 991-1070) interfaces directly with sites on the anchoring protein. Parallel studies show that AKAP79/150 interacts with the Robo3 receptor in a similar manner. Immunofluorescent staining detects overlapping expression patterns for murine AKAP150, Robo2, and Robo3 in a variety of brain regions, including hippocampal region CA1 and the islands of Calleja. In vitro kinase assays, peptide spot array mapping, and proximity ligation assay staining approaches establish that human AKAP79-anchored PKC selectively phosphorylates the Robo3.1 receptor subtype on serine 1330. These findings imply that anchored PKC locally modulates the phosphorylation status of Robo3.1 in brain regions governing learning and memory and reward.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Proteína Quinase C/metabolismo , Receptores Imunológicos/metabolismo , Animais , Encéfalo/metabolismo , Citoplasma/metabolismo , Inativação Gênica , Glutationa Transferase/metabolismo , Células HEK293 , Hipocampo/metabolismo , Humanos , Ligantes , Substâncias Macromoleculares , Espectrometria de Massas , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Microscopia de Fluorescência , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Fosforilação , Mapeamento de Interação de Proteínas , Isoformas de Proteínas , RNA Interferente Pequeno/metabolismo , Receptores de Superfície Celular , Transdução de Sinais
15.
Int J Cancer ; 136(8): 1967-75, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25242168

RESUMO

Antiangiogenic therapy is commonly used for the treatment of colorectal cancer (CRC). Although patients derive some clinical benefit, treatment resistance inevitably occurs. The MET signaling pathway has been proposed to be a major contributor of resistance to antiangiogenic therapy. MET is upregulated in response to vascular endothelial growth factor pathway inhibition and plays an essential role in tumorigenesis and progression of tumors. In this study, we set out to determine the efficacy of cabozantinib in a preclinical CRC patient-derived tumor xenograft model. We demonstrate potent inhibitory effects on tumor growth in 80% of tumors treated. The greatest antitumor effects were observed in tumors that possess a mutation in the PIK3CA gene. The underlying antitumor mechanisms of cabozantinib consisted of inhibition of angiogenesis and Akt activation and significantly decreased expression of genes involved in the PI3K pathway. These findings support further evaluation of cabozantinib in patients with CRC. PIK3CA mutation as a predictive biomarker of sensitivity is intriguing and warrants further elucidation. A clinical trial of cabozantinib in refractory metastatic CRC is being activated.


Assuntos
Anilidas/farmacologia , Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Piridinas/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Adulto , Idoso , Inibidores da Angiogênese/farmacologia , Animais , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Classe I de Fosfatidilinositol 3-Quinases , Neoplasias Colorretais/metabolismo , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
16.
PLoS One ; 9(11): e113037, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25401499

RESUMO

BACKGROUND: The activation of the MAPK and PI3K/AKT/mTOR pathways is implicated in the majority of cancers. Activating mutations in both of these pathways has been described in colorectal cancer (CRC), thus indicating their potential as therapeutic targets. This study evaluated the combination of a PI3K/mTOR inhibitor (PF-04691502/PF-502) in combination with a MEK inhibitor (PD-0325901/PD-901) in CRC cell lines and patient-derived CRC tumor xenograft models (PDTX). MATERIALS AND METHODS: The anti-proliferative effects of PF-502 and PD-901 were assessed as single agents and in combination against a panel of CRC cell lines with various molecular backgrounds. Synergy was evaluated using the Bliss Additivity method. In selected cell lines, we investigated the combination effects on downstream effectors by immunoblotting. The combination was then evaluated in several fully genetically annotated CRC PDTX models. RESULTS: The in vitro experiments demonstrated a wide range of IC50 values for both agents against a cell line panel. The combination of PF-502 and PD-901 demonstrated synergistic anti-proliferative activity with Bliss values in the additive range. As expected, p-AKT and p-ERK were downregulated by PF-502 and PD-901, respectively. In PDTX models, following a 30-day exposure to PF-502, PD-901 or the combination, the combination demonstrated enhanced reduction in tumor growth as compared to either single agent regardless of KRAS or PI3K mutational status. CONCLUSIONS: The combination of a PI3K/mTOR and a MEK inhibitor demonstrated enhanced anti-proliferative effects against CRC cell lines and PDTX models.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Sinergismo Farmacológico , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Benzamidas/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Difenilamina/análogos & derivados , Difenilamina/farmacologia , Feminino , Humanos , Immunoblotting , Camundongos , Camundongos Nus , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Behav Genet ; 44(3): 270-81, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24213680

RESUMO

Human facial attractiveness and facial sexual dimorphism (masculinity-femininity) are important facets of mate choice and are hypothesized to honestly advertise genetic quality. However, it is unclear whether genes influencing facial attractiveness and masculinity-femininity have similar, opposing, or independent effects across sex, and the heritability of these phenotypes is poorly characterized. To investigate these issues, we assessed facial attractiveness and facial masculinity-femininity in the largest genetically informative sample (n = 1,580 same- and opposite-sex twin pairs and siblings) to assess these questions to date. The heritability was ~0.50-0.70 for attractiveness and ~0.40-0.50 for facial masculinity-femininity, indicating that, despite ostensible selection on genes influencing these traits, substantial genetic variation persists in both. Importantly, we found evidence for intralocus sexual conflict, whereby alleles that increase masculinity in males have the same effect in females. Additionally, genetic influences on attractiveness were shared across the sexes, suggesting that attractive fathers tend to have attractive daughters and attractive mothers tend to have attractive sons.


Assuntos
Beleza , Modelos Genéticos , Caracteres Sexuais , Comportamento de Escolha , Face , Feminino , Humanos , Masculino , Comportamento Sexual
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