RESUMO
(-)-5,9-Dimethyl-6,7-benzomorphan (normetazocine) derivatives with a para-OH or ortho-F substituent in the aromatic ring of the N-phenethyl moiety were synthesized and found to have subnanomolar potency at MOR, and both were fully efficacious in vitro. These new compounds, (1R,5R,9R)-6,11-dimethyl-3-(2-fluorophenethyl)-1,2,3,4,5,6-hexahydro-2,6-methanobenzo[d]azocin-8-ol and (1R,5R,9R)-6,11-dimethyl-3-(4-hydroxyphenethyl)-1,2,3,4,5,6-hexahydro-2,6-methanobenzo[d]azocin-8-ol, were more potent than the unsubstituted compound N-phenethylnormetazocine and about 30 or 40 times more potent than morphine, respectively. A variety of substituents in the ortho, meta, or para position in the aromatic ring of the N-phenethyl moiety were synthesized, 25 of these compounds, and found to have varying effects on potency and efficacy as determined by the forskolin-induced cAMP accumulation assay. The N-phenethyl moiety was also modified by increasing chain length to form a N-phenylpropyl side chain with and without a para-nitro moiety, and by an N-cinnamyl side chain. Also, an indole ethylamine normetazocine was synthesized to replace the N-phenethylamine side chain in normetazocine. The phenylpropylamine, propenylamine (cinnamyl) and the para-nitropropylamine had little or no MOR potency. The indole-ethylamine on the normetazocine nucleus, however, had moderate potency (MOR EC50 = 12 nM), and was fully efficacious (%Emax = 102%) in the cAMP assay. Retention of the N-phenethyl moiety and the addition of alkyl and alkenyl moieties on C8 in (-)-N-phenethylnormetazocine gave a C8-methylene derivative that had subnanomolar potency at MOR and a C8-methyl analog that had nanomolar potency. Five C8-substituted compounds were synthesized.
Assuntos
Benzomorfanos , Morfina , Benzomorfanos/química , Etilaminas , Indóis , Relação Estrutura-AtividadeRESUMO
The diester derivative of dihydroxyfumaric acid (DHF) has been used exclusively as an electrophile in organic synthesis. However, the synthetic utility of DHF's nucleophilic reactivity, contained in the ene-diol moiety, has been underexplored. Inspired by recently observed pH-dependent chemodivergent nucleophilic aldol reactions of dihydroxyfumarate (DHF2-) with glyoxylate and formaldehyde, we report herein the control and synthetic application of base-controlled chemodivergent reactions between dihydroxyfumarate and aromatic and heteroaromatic aldehydes. With hydroxide as the base in a predominantly aqueous medium, aldol addition followed by deoxalation occurs to provide various 3-aryl-2,3-dihydroxypropanoic acids. With triethylamine as the base in THF, 1-aryl-2,3-dihydroxypropanones are the products of the reaction. In order to understand the difference in reactivity between DHF, its dicarboxylate, and its dimethyl ester, we undertook computational and experimental studies that provide a rationale as to why the dihydroxyfumarate (DHF2-) is a nucleophile while the corresponding diester reacts as an electrophile.
RESUMO
Support for populism has grown substantially during the past 2 decades, a development that has coincided with a marked increase in the experience of negative affect around the world. We use a multimodal, multimethod empirical approach, with data from a diverse set of geographical and political contexts, to investigate the extent to which the rising electoral demand for populism can be explained by negative affect. We demonstrate that negative affect-measured via (a) self-reported emotions in surveys as well as (b) automated text analyses of Twitter data-predicts individual-level populist attitudes in two global surveys (Studies 1a and 1b), longitudinal changes in populist party vote shares at general elections in Europe (Study 2), district-level Brexit voting in the 2016 U.K. referendum (Study 3), and county-level vote shares for Donald Trump in the 2016 and 2020 U.S. presidential elections (Studies 4a and 4b). We find that negative emotions-such as fear and anger as well as more often overlooked low-arousal negative emotions like depression and sadness-are predictive of populist beliefs as well as voting and election results at scale. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
RESUMO
Programmed cell death mechanisms are important for the regulation of tumor development and progression. Evasion of and resistance to apoptosis are significant factors in tumorigenesis and drug resistance. Bypassing apoptotic pathways and eliciting another form of regulated cell death, namely necroptosis, an immunogenic cell death (ICD), may override apoptotic resistance. Here, we present the mechanistic rationale for combining tolinapant, an antagonist of the inhibitor of apoptosis proteins (IAP), with decitabine, a hypomethylating agent (HMA), in T-cell lymphoma (TCL). Tolinapant treatment alone of TCL cells in vitro and in syngeneic in vivo models demonstrated that ICD markers can be upregulated, and we have shown that epigenetic priming with decitabine further enhances this effect. The clinical relevance of ICD markers was confirmed by the direct measurement of plasma proteins from patients with peripheral TCL treated with tolinapant. We showed increased levels of necroptosis in TCL lines, along with the expression of cancer-specific antigens (such as cancer testis antigens) and increases in genes involved in IFN signaling induced by HMA treatment, together deliver a strong adaptive immune response to the tumor. These results highlight the potential of a decitabine and tolinapant combination for TCL and could lead to clinical evaluation. SIGNIFICANCE: The IAP antagonist tolinapant can induce necroptosis, a key immune-activating event, in TCL. Combination with DNA hypomethylation enhances tolinapant sensitivity and primes resistant cells by re-expressing necrosome proteins. In addition, this combination leads to increases in genes involved in IFN signaling and neoantigen expression, providing further molecular rationale for this novel therapeutic option.
Assuntos
Metilação de DNA , Decitabina , Epigênese Genética , Linfoma de Células T , Humanos , Epigênese Genética/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Animais , Decitabina/farmacologia , Decitabina/uso terapêutico , Camundongos , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/imunologia , Linfoma de Células T/genética , Linfoma de Células T/patologia , Linhagem Celular Tumoral , Necroptose/efeitos dos fármacos , Apoptose/efeitos dos fármacosRESUMO
Extracellular vesicles (EVs) are lipid bilayer structures released by all cells that mediate cell-to-cell communication via the transfer of bioactive cargo. Because of the natural origin of EVs, their efficient uptake by recipient cells, capacity to stabilize and transport biomolecules and their potential for cell/tissue targeting and preferential uptake by cancer cells, they have enormous potential for bioengineering into improved and targeted drug delivery systems. In this work, we investigated the use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a tool to measure the loading of platinum-based chemotherapeutic agents. The EV loading of oxaliplatin via co-incubation was demonstrated, and LA-ICP-MS imaging showed greater efficiency of delivery to colorectal cancer cells compared to free oxaliplatin, leading to enhanced cytotoxic effect. Further, the impact of EV co-loading with a porphyrin (C5SHU, known as 'C5') photosensitizer on oxaliplatin delivery was assessed. Fluorescence analysis using nano-flow cytometry showed dose-dependent EV loading as well as a trend towards the loading of larger particles. Exposure of OXA-C5-EV-treated colorectal cancer cells to light indicated that delivery was enhanced by both light exposure and porphyrins, with a synergistic effect on cell viability observed between oxaliplatin, EVs and light exposure after the delivery of the co-loaded EVs. In summary, this work demonstrates the utility of LA-ICP-MS and mass spectrometry imaging in assessing the loading efficiency and cellular delivery of platinum-based therapeutics, which would also be suitable for agents containing other elements, confirms that EVs are more efficient at delivery compared to free drugs, and describes the use of light exposure in optimizing delivery and therapeutic effects of EV-mediated drug delivery both in combination and independently of porphyrin-based photosensitizers.
Assuntos
Neoplasias Colorretais , Vesículas Extracelulares , Terapia a Laser , Porfirinas , Humanos , Oxaliplatina/farmacologia , Espectrometria de Massas , Neoplasias Colorretais/tratamento farmacológicoRESUMO
A rapidly growing literature has attempted to explain Donald Trump's success in the 2016 U.S. presidential election as a result of a wide variety of differences in individual characteristics, attitudes, and social processes. We propose that the economic and psychological processes previously established have in common that they generated or electorally capitalized on unhappiness in the electorate, which emerges as a powerful high-level predictor of the 2016 electoral outcome. Drawing on a large dataset covering over 2 million individual surveys, which we aggregated to the county level, we find that low levels of evaluative, experienced, and eudaemonic subjective well-being (SWB) are strongly predictive of Trump's victory, accounting for an extensive list of demographic, ideological, and socioeconomic covariates and robustness checks. County-level future life evaluation alone correlates with the Trump vote share over Republican baselines at r = -.78 in the raw data, a magnitude rarely seen in the social sciences. We show similar findings when examining the association between individual-level life satisfaction and Trump voting. Low levels of SWB also predict anti-incumbent voting at the 2012 election, both at the county and individual level. The findings suggest that SWB is a powerful high-level marker of (dis)content and that SWB should be routinely considered alongside economic explanations of electoral choice. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Assuntos
Felicidade , Política , Atitude , Humanos , Saúde Mental , Inquéritos e Questionários , Estados UnidosRESUMO
Tolinapant (ASTX660) is a potent, nonpeptidomimetic antagonist of cellular inhibitor of apoptosis proteins 1 and 2 (cIAP1/2) and X-linked IAP, which is currently being evaluated in a phase 2 study in T-cell lymphoma (TCL) patients. Tolinapant has demonstrated evidence of single-agent clinical activity in relapsed/refractory peripheral TCL and cutaneous TCL. To investigate the mechanism of action underlying the single-agent activity observed in the clinic, we have used a comprehensive translational approach integrating in vitro and in vivo models of TCL confirmed by data from human tumor biopsies. Here, we show that tolinapant acts as an efficacious immunomodulatory molecule capable of inducing complete tumor regression in a syngeneic model of TCL exclusively in the presence of an intact immune system. These findings were confirmed in samples from our ongoing clinical study showing that tolinapant treatment can induce changes in gene expression and cytokine profile consistent with immune modulation. Mechanistically, we show that tolinapant can activate both the adaptive and the innate arms of the immune system through the induction of immunogenic forms of cell death. In summary, we describe a novel role for IAP antagonists as immunomodulatory molecules capable of promoting a robust antitumor immune response in TCL.
Assuntos
Linfoma de Células T , Neoplasias Cutâneas , Apoptose , Humanos , Imunidade , Morfolinas , Recidiva Local de Neoplasia , Piperazinas , PirróisRESUMO
Necroptosis is a lytic, inflammatory form of cell death that not only contributes to pathogen clearance but can also lead to disease pathogenesis. Necroptosis is triggered by RIPK3-mediated phosphorylation of MLKL, which is thought to initiate MLKL oligomerisation, membrane translocation and membrane rupture, although the precise mechanism is incompletely understood. Here, we show that K63-linked ubiquitin chains are attached to MLKL during necroptosis and that ubiquitylation of MLKL at K219 significantly contributes to the cytotoxic potential of phosphorylated MLKL. The K219R MLKL mutation protects animals from necroptosis-induced skin damage and renders cells resistant to pathogen-induced necroptosis. Mechanistically, we show that ubiquitylation of MLKL at K219 is required for higher-order assembly of MLKL at membranes, facilitating its rupture and necroptosis. We demonstrate that K219 ubiquitylation licenses MLKL activity to induce lytic cell death, suggesting that necroptotic clearance of pathogens as well as MLKL-dependent pathologies are influenced by the ubiquitin-signalling system.
Assuntos
Infecções por Herpesviridae/metabolismo , Lisina/metabolismo , Proteínas Quinases/metabolismo , Pele/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Células HEK293 , Células HT29 , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/virologia , Humanos , Lisina/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Muromegalovirus/fisiologia , Células NIH 3T3 , Necroptose/genética , Necrose , Proteínas Quinases/genética , Pele/patologia , UbiquitinaçãoRESUMO
Therapeutic efficacy of first-generation hypomethylating agents (HMAs) is limited in elderly acute myeloid leukemia (AML) patients. Therefore, combination strategies with targeted therapies are urgently needed. Here, we discover that priming with SGI-110 (guadecitabine), a next-generation HMA, sensitizes AML cells to ASTX660, a novel antagonist of cellular inhibitor of apoptosis protein 1 and 2 (cIAP1/2) and X-linked IAP (XIAP). Importantly, SGI-110 and ASTX660 synergistically induced cell death in a panel of AML cell lines as well as in primary AML samples while largely sparing normal CD34+ human progenitor cells, underlining the translational relevance of this combination. Unbiased transcriptome analysis revealed that SGI-110 alone or in combination with ASTX660 upregulated the expression of key regulators of both extrinsic and intrinsic apoptosis signaling pathways such as TNFRSF10B (DR5), FAS, and BAX. Individual knockdown of the death receptors TNFR1, DR5, and FAS significantly reduced SGI-110/ASTX660-mediated cell death, whereas blocking antibodies for tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) or FAS ligand (FASLG) failed to provide protection. Also, TNFα-blocking antibody Enbrel had little protective effect on SGI-110/ASTX660-induced cell death. Further, SGI-110 and ASTX660 acted in concert to promote cleavage of caspase-8 and BID, thereby providing a link between extrinsic and intrinsic apoptotic pathways. Consistently, sequential treatment with SGI-110 and ASTX660-triggered loss of mitochondrial membrane potential (MMP) and BAX activation which contributes to cell death, as BAX silencing significantly protected from SGI-110/ASTX660-mediated apoptosis. Together, these events culminated in the activation of caspases-3/-7, nuclear fragmentation, and cell death. In conclusion, SGI-110 and ASTX660 cooperatively induced apoptosis in AML cells by engaging extrinsic and intrinsic apoptosis pathways, highlighting the therapeutic potential of this combination for AML.
Assuntos
Apoptose/efeitos dos fármacos , Azacitidina/análogos & derivados , Leucemia Mieloide Aguda/tratamento farmacológico , Morfolinas/farmacologia , Piperazinas/farmacologia , Pirróis/farmacologia , Idoso , Azacitidina/farmacologia , Proteína 3 com Repetições IAP de Baculovírus/antagonistas & inibidores , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Ubiquitina-Proteína Ligases/antagonistas & inibidoresRESUMO
Are individuals more sensitive to losses than gains in terms of economic growth? We find that measures of subjective well-being are more than twice as sensitive to negative as compared to positive economic growth. We use Gallup World Poll data from over 150 countries, BRFSS data on 2.3 million US respondents, and Eurobarometer data that cover multiple business cycles over four decades. This research provides a new perspective on the welfare cost of business cycles, with implications for growth policy and the nature of the long-run relationship between GDP and subjective well-being.
RESUMO
Because of their roles in the evasion of apoptosis, inhibitor of apoptosis proteins (IAP) are considered attractive targets for anticancer therapy. Antagonists of these proteins have the potential to switch prosurvival signaling pathways in cancer cells toward cell death. Various SMAC-peptidomimetics with inherent cIAP selectivity have been tested clinically and demonstrated minimal single-agent efficacy. ASTX660 is a potent, non-peptidomimetic antagonist of cIAP1/2 and XIAP, discovered using fragment-based drug design. The antagonism of XIAP and cIAP1 by ASTX660 was demonstrated on purified proteins, cells, and in vivo in xenograft models. The compound binds to the isolated BIR3 domains of both XIAP and cIAP1 with nanomolar potencies. In cells and xenograft tissue, direct antagonism of XIAP was demonstrated by measuring its displacement from caspase-9 or SMAC. Compound-induced proteasomal degradation of cIAP1 and 2, resulting in downstream effects of NIK stabilization and activation of noncanonical NF-κB signaling, demonstrated cIAP1/2 antagonism. Treatment with ASTX660 led to TNFα-dependent induction of apoptosis in various cancer cell lines in vitro, whereas dosing in mice bearing breast and melanoma tumor xenografts inhibited tumor growth. ASTX660 is currently being tested in a phase I-II clinical trial (NCT02503423), and we propose that its antagonism of cIAP1/2 and XIAP may offer improved efficacy over first-generation antagonists that are more cIAP1/2 selective. Mol Cancer Ther; 17(7); 1381-91. ©2018 AACR.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Proteínas Inibidoras de Apoptose/química , Proteínas Inibidoras de Apoptose/metabolismo , Camundongos , Mimetismo Molecular , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Relação Estrutura-Atividade , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/química , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Inhibitor of apoptosis proteins (IAPs) are promising anticancer targets, given their roles in the evasion of apoptosis. Several peptidomimetic IAP antagonists, with inherent selectivity for cellular IAP (cIAP) over X-linked IAP (XIAP), have been tested in the clinic. A fragment screening approach followed by structure-based optimization has previously been reported that resulted in a low-nanomolar cIAP1 and XIAP antagonist lead molecule with a more balanced cIAP-XIAP profile. We now report the further structure-guided optimization of the lead, with a view to improving the metabolic stability and cardiac safety profile, to give the nonpeptidomimetic antagonist clinical candidate 27 (ASTX660), currently being tested in a phase 1/2 clinical trial (NCT02503423).
Assuntos
Antineoplásicos/farmacologia , Compostos Heterocíclicos com 2 Anéis/farmacologia , Piperazinas/farmacologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , Administração Oral , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Cristalografia por Raios X , Canal de Potássio ERG1/antagonistas & inibidores , Compostos Heterocíclicos com 2 Anéis/química , Compostos Heterocíclicos com 2 Anéis/farmacocinética , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Macaca fascicularis , Masculino , Camundongos Endogâmicos BALB C , Piperazinas/química , Piperazinas/farmacocinética , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/química , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Notch signaling plays a fundamental role in determining the outcome of differentiation processes in many tissues. Notch signaling has been implicated in T versus B cell lineage commitment, thymic differentiation, and bone marrow hematopoietic precursor renewal and differentiation. Notch receptors and their ligands are also expressed on the surface of mature lymphocytes and APCs, but the effects of Notch signaling in the peripheral immune system remain poorly defined. The aim of the studies reported here was to investigate the effects of signaling through the Notch receptor using a ligand of the Delta-like family. We show that Notch ligation in the mature immune system markedly decreases responses to transplantation antigens. Constitutive expression of Delta-like 1 on alloantigen-bearing cells renders them nonimmunogenic and able to induce specific unresponsiveness to a challenge with the same alloantigen, even in the form of a cardiac allograft. These effects could be reversed by depletion of CD8+ cells at the time of transplantation. Ligation of Notch on splenic CD8+ cells results in a dramatic decrease in IFN-gamma with a concomitant enhancement of IL-10 production, suggesting that Notch signaling can alter the differentiation potential of CD8+ cells. These data implicate Notch signaling in regulation of peripheral immunity and suggest a novel approach for manipulating deleterious immune responses.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade/imunologia , Proteínas de Membrana/fisiologia , Receptores de Superfície Celular/fisiologia , Transdução de Sinais/fisiologia , Animais , Células Apresentadoras de Antígenos/fisiologia , Apoptose , Células CHO , Proteínas de Ligação ao Cálcio , Cricetinae , Rejeição de Enxerto/prevenção & controle , Peptídeos e Proteínas de Sinalização Intercelular , Interferon gama/biossíntese , Interleucina-10/biossíntese , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Endogâmicos , Proteínas/fisiologia , Receptor Notch2 , Proteínas Serrate-Jagged , TransfecçãoRESUMO
XIAP and cIAP1 are members of the inhibitor of apoptosis protein (IAP) family and are key regulators of anti-apoptotic and pro-survival signaling pathways. Overexpression of IAPs occurs in various cancers and has been associated with tumor progression and resistance to treatment. Structure-based drug design (SBDD) guided by structural information from X-ray crystallography, computational studies, and NMR solution conformational analysis was successfully applied to a fragment-derived lead resulting in AT-IAP, a potent, orally bioavailable, dual antagonist of XIAP and cIAP1 and a structurally novel chemical probe for IAP biology.
Assuntos
Compostos Heterocíclicos com 2 Anéis/química , Compostos Heterocíclicos com 2 Anéis/farmacologia , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Piperazinas/química , Piperazinas/farmacologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Cristalografia por Raios X , Descoberta de Drogas , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Peptidomiméticos , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
Fibroblast growth factor (FGF) signaling plays critical roles in key biological processes ranging from embryogenesis to wound healing and has strong links to several hallmarks of cancer. Genetic alterations in FGF receptor (FGFR) family members are associated with increased tumor growth, metastasis, angiogenesis, and decreased survival. JNJ-42756493, erdafitinib, is an orally active small molecule with potent tyrosine kinase inhibitory activity against all four FGFR family members and selectivity versus other highly related kinases. JNJ-42756493 shows rapid uptake into the lysosomal compartment of cells in culture, which is associated with prolonged inhibition of FGFR signaling, possibly due to sustained release of the inhibitor. In xenografts from human tumor cell lines or patient-derived tumor tissue with activating FGFR alterations, JNJ-42756493 administration results in potent and dose-dependent antitumor activity accompanied by pharmacodynamic modulation of phospho-FGFR and phospho-ERK in tumors. The results of the current study provide a strong rationale for the clinical investigation of JNJ-42756493 in patients with tumors harboring FGFR pathway alterations. Mol Cancer Ther; 16(6); 1010-20. ©2017 AACR.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Quinoxalinas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Lisossomos/metabolismo , Masculino , Camundongos , Terapia de Alvo Molecular , Fosforilação , Ligação Proteica , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Pirazóis/administração & dosagem , Pirazóis/farmacocinética , Quinoxalinas/administração & dosagem , Quinoxalinas/farmacocinética , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Notch plays a wide-ranging role in controlling cell fate, differentiation and development. The PI3K-Akt pathway is a similarly conserved signalling pathway which regulates processes such as differentiation, proliferation and survival. Mice with disrupted Notch and PI3K signalling show phenotypic similarities during haematopoietic cell development, suggesting functional interaction between these pathways. RESULTS: We show that cellular responsiveness to Notch signals depends on the activity of the PI3K-Akt pathway in cells as diverse as CHO cells, primary T-cells and hippocampal neurons. Induction of the endogenous PI3K-Akt pathway in CHO cells (by the insulin pathway), in T-cells (via TCR activation) or in neurons (via TrKB activation) potentiates Notch-dependent responses. We propose that the PI3K-Akt pathway exerts its influence on Notch primarily via inhibition of GSK3-beta, a kinase known to phosphorylate and regulate Notch signals. CONCLUSION: The PI3K-Akt pathway acts as a "gain control" for Notch signal responses. Since physiological levels of intracellular Notch are often low, coincidence with PI3K-activation may be crucial for induction of Notch-dependent responses.
Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Antígenos CD4/metabolismo , Células CHO , Células Cultivadas , Cricetinae , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Células Jurkat , Cloreto de Lítio/farmacologia , Modelos Biológicos , Neurônios/metabolismo , Ratos , Linfócitos T/efeitos dos fármacosRESUMO
PTEN loss is prognostic for patient relapse post-radiotherapy in prostate cancer (CaP). Infiltration of tumor-associated macrophages (TAMs) is associated with reduced disease-free survival following radical prostatectomy. However, the association between PTEN loss, TAM infiltration and radiotherapy response of CaP cells remains to be evaluated. Immunohistochemical and molecular analysis of surgically-resected Gleason 7 tumors confirmed that PTEN loss correlated with increased CXCL8 expression and macrophage infiltration. However PTEN status had no discernable correlation with expression of other inflammatory markers by CaP cells, including TNF-α. In vitro, exposure to conditioned media harvested from irradiated PTEN null CaP cells induced chemotaxis of macrophage-like THP-1 cells, a response partially attenuated by CXCL8 inhibition. Co-culture with THP-1 cells resulted in a modest reduction in the radio-sensitivity of DU145 cells. Cytokine profiling revealed constitutive secretion of TNF-α from CaP cells irrespective of PTEN status and IR-induced TNF-α secretion from THP-1 cells. THP-1-derived TNF-α increased NFκB pro-survival activity and elevated expression of anti-apoptotic proteins including cellular inhibitor of apoptosis protein-1 (cIAP-1) in CaP cells, which could be attenuated by pre-treatment with a TNF-α neutralizing antibody. Treatment with a novel IAP antagonist, AT-IAP, decreased basal and TNF-α-induced cIAP-1 expression in CaP cells, switched TNF-α signaling from pro-survival to pro-apoptotic and increased radiation sensitivity of CaP cells in co-culture with THP-1 cells. We conclude that targeting cIAP-1 can overcome apoptosis resistance of CaP cells and is an ideal approach to exploit high TNF-α signals within the TAM-rich microenvironment of PTEN-deficient CaP cells to enhance response to radiotherapy.
Assuntos
Quimiorradioterapia , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Macrófagos/patologia , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias da Próstata/radioterapia , Radiossensibilizantes/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Western Blotting , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células Cultivadas , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/efeitos da radiação , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/efeitos da radiação , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Proteínas Inibidoras de Apoptose/efeitos dos fármacos , Proteínas Inibidoras de Apoptose/metabolismo , Interleucina-8/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/efeitos da radiação , Masculino , Gradação de Tumores , Prognóstico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/metabolismo , Raios XRESUMO
Inhibitor of apoptosis proteins (IAPs) are important regulators of apoptosis and pro-survival signaling pathways whose deregulation is often associated with tumor genesis and tumor growth. IAPs have been proposed as targets for anticancer therapy, and a number of peptidomimetic IAP antagonists have entered clinical trials. Using our fragment-based screening approach, we identified nonpeptidic fragments binding with millimolar affinities to both cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP). Structure-based hit optimization together with an analysis of protein-ligand electrostatic potential complementarity allowed us to significantly increase binding affinity of the starting hits. Subsequent optimization gave a potent nonalanine IAP antagonist structurally distinct from all IAP antagonists previously reported. The lead compound had activity in cell-based assays and in a mouse xenograft efficacy model and represents a highly promising start point for further optimization.
Assuntos
Antineoplásicos/farmacologia , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Proteínas Inibidoras de Apoptose/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Proliferação de Células/efeitos dos fármacos , Biologia Computacional , Desenho de Fármacos , Descoberta de Drogas , Ensaios de Triagem em Larga Escala , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/farmacocinética , Piperazinas/síntese química , Piperazinas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We have shown that two of the matrix metalloproteinases (MMPs), matrilysin and stromelysin-1, are capable of cleaving all of the human IgG subclasses. The cleavage occurs at a conserved site in the CH(2) domain of the heavy chain of IgG, releasing a single chain Fc-like fragment. We have not been able to demonstrate cleavage of IgA, IgD, IgM or IgE classes, which lack the cleavage site, nor could we show cleavage of IgG by collagenase, gelatinase, macrophage metalloelastase or membrane-type (MT)-MMP. This cleavage of IgG, by separating the antigen-binding (Fabprime prime or minute)(2) from the Fc portion, will remove much of the immunoglobulins' functionality, e.g. complement fixation, Fc receptor binding. In the context of a tumour producing matrilysin or stromelysin, this may represent a way in which the tumour protects itself from ADCC. In inflamed or damaged tissues where plasma protein leakage occurs, degradation by MMPs may be a mechanism for clearance of IgG.
Assuntos
Imunoglobulina G/metabolismo , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 7 da Matriz/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Clonagem Molecular , Cricetinae , Humanos , Dados de Sequência Molecular , Papaína/metabolismo , Pepsina A/metabolismo , Proteínas Recombinantes/metabolismo , Especificidade por SubstratoRESUMO
We describe here the identification and characterization of 2 novel inhibitors of the fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases. The compounds exhibit selective inhibition of FGFR over the closely related VEGFR2 receptor in cell lines and in vivo. The pharmacologic profile of these inhibitors was defined using a panel of human tumor cell lines characterized for specific mutations, amplifications, or translocations known to activate one of the four FGFR receptor isoforms. This pharmacology defines a profile for inhibitors that are likely to be of use in clinical settings in disease types where FGFR is shown to play an important role.