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1.
J Biol Chem ; 299(6): 104815, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37178918

RESUMO

Ceramides have been shown to play a major role in the onset of skeletal muscle insulin resistance and therefore in the prevalence of type 2 diabetes. However, many of the studies involved in the discovery of deleterious ceramide actions used a nonphysiological, cell-permeable, short-chain ceramide analog, the C2-ceramide (C2-cer). In the present study, we determined how C2-cer promotes insulin resistance in muscle cells. We demonstrate that C2-cer enters the salvage/recycling pathway and becomes deacylated, yielding sphingosine, re-acylation of which depends on the availability of long chain fatty acids provided by the lipogenesis pathway in muscle cells. Importantly, we show these salvaged ceramides are actually responsible for the inhibition of insulin signaling induced by C2-cer. Interestingly, we also show that the exogenous and endogenous monounsaturated fatty acid oleate prevents C2-cer to be recycled into endogenous ceramide species in a diacylglycerol O-acyltransferase 1-dependent mechanism, which forces free fatty acid metabolism towards triacylglyceride production. Altogether, the study highlights for the first time that C2-cer induces a loss in insulin sensitivity through the salvage/recycling pathway in muscle cells. This study also validates C2-cer as a convenient tool to decipher mechanisms by which long-chain ceramides mediate insulin resistance in muscle cells and suggests that in addition to the de novo ceramide synthesis, recycling of ceramide could contribute to muscle insulin resistance observed in obesity and type 2 diabetes.


Assuntos
Ceramidas , Resistência à Insulina , Humanos , Ceramidas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo , Resistência à Insulina/fisiologia , Células Musculares/metabolismo , Músculo Esquelético/metabolismo
2.
Exp Dermatol ; 33(1): e14949, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37864429

RESUMO

Intraoperative margin analysis is crucial for the successful removal of cutaneous squamous cell carcinomas (cSCC). Artificial intelligence technologies (AI) have previously demonstrated potential for facilitating rapid and complete tumour removal using intraoperative margin assessment for basal cell carcinoma. However, the varied morphologies of cSCC present challenges for AI margin assessment. The aim of this study was to develop and evaluate the accuracy of an AI algorithm for real-time histologic margin analysis of cSCC. To do this, a retrospective cohort study was conducted using frozen cSCC section slides. These slides were scanned and annotated, delineating benign tissue structures, inflammation and tumour to develop an AI algorithm for real-time margin analysis. A convolutional neural network workflow was used to extract histomorphological features predictive of cSCC. This algorithm demonstrated proof of concept for identifying cSCC with high accuracy, highlighting the potential for integration of AI into the surgical workflow. Incorporation of AI algorithms may improve efficiency and completeness of real-time margin assessment for cSCC removal, particularly in cases of moderately and poorly differentiated tumours/neoplasms. Further algorithmic improvement incorporating surrounding tissue context is necessary to remain sensitive to the unique epidermal landscape of well-differentiated tumours, and to map tumours to their original anatomical position/orientation.


Assuntos
Carcinoma Basocelular , Carcinoma de Células Escamosas , Aprendizado Profundo , Neoplasias Cutâneas , Humanos , Carcinoma de Células Escamosas/patologia , Cirurgia de Mohs , Neoplasias Cutâneas/patologia , Estudos Retrospectivos , Secções Congeladas , Inteligência Artificial , Carcinoma Basocelular/patologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-39073184

RESUMO

BACKGROUND: Perceptual and speech production abilities of children with cochlear implants (CIs) are usually tested by word and sentence repetition or naming tests. However, these tests are quite far apart from daily life linguistic contexts. AIM: Here, we describe a way of investigating the link between language comprehension and anticipatory verbal behaviour promoting the use of more complex listening situations. METHODS AND PROCEDURE: The setup consists in watching the audio-visual dialogue of two actors. Children's gaze switches from one speaker to the other serve as a proxy of their prediction abilities. Moreover, to better understand the basis and the impact of anticipatory behaviour, we also measured children's ability to understand the dialogue content, their speech perception and memory skills as well as their rhythmic skills, that also require temporal predictions. Importantly, we compared children with CI performances with those of an age-matched group of children with normal hearing (NH). OUTCOMES AND RESULTS: While children with CI revealed poorer speech perception and verbal working memory abilities than NH children, there was no difference in gaze anticipatory behaviour. Interestingly, in children with CI only, we found a significant correlation between dialogue comprehension, perceptual skills and gaze anticipatory behaviour. CONCLUSION: Our results extend to a dialogue context of previous findings showing an absence of predictive deficits in children with CI. The current design seems an interesting avenue to provide an accurate and objective estimate of anticipatory language behaviour in a more ecological linguistic context also with young children. WHAT THIS PAPER ADDS: What is already known on the subject Children with cochlear implants seem to have difficulties extracting structure from and learning sequential input patterns, possibly due to signal degradation and auditory deprivation in the first years of life. They also seem to have a reduced use of contextual information and slow language processing among children with hearing loss. What this paper adds to existing knowledge Here we show that when adopting a rather complex linguistic context such as watching a dialogue of two individuals, children with cochlear implants are able to use the speech and language structure to anticipate gaze switches to the upcoming speaker. What are the clinical implications of this work? The present design seems an interesting avenue to provide an accurate and objective estimate of anticipatory behaviour in a more ecological and dynamic linguistic context. Importantly, this measure is implicit and it has been previously used with very young (normal-hearing) children, showing that they spontaneously make anticipatory gaze switches by age two. Thus, this approach may be of interest to refine the speech comprehension assessment at a rather early age after cochlear implantation where explicit behavioural tests are not always reliable and sensitive.

4.
Int J Mol Sci ; 24(16)2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37628901

RESUMO

Sphingolipids are a family of lipid molecules produced through different pathways in mammals. Sphingolipids are structural components of membranes, but in response to obesity, they are implicated in the regulation of various cellular processes, including inflammation, apoptosis, cell proliferation, autophagy, and insulin resistance which favors dysregulation of glucose metabolism. Of all sphingolipids, two species, ceramides and sphingosine-1-phosphate (S1P), are also found abundantly secreted into the bloodstream and associated with lipoproteins or extracellular vesicles. Plasma concentrations of these sphingolipids can be altered upon metabolic disorders and could serve as predictive biomarkers of these diseases. Recent important advances suggest that circulating sphingolipids not only serve as biomarkers but could also serve as mediators in the dysregulation of glucose homeostasis. In this review, advances of molecular mechanisms involved in the regulation of ceramides and S1P association to lipoproteins or extracellular vesicles and how they could alter glucose metabolism are discussed.


Assuntos
Ceramidas , Esfingolipídeos , Animais , Homeostase , Glucose , Mamíferos
5.
J Biopharm Stat ; 29(2): 229-243, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30359557

RESUMO

In randomized controlled trials with delayed treatment effect, there is a delay period before the experimental therapy starts to exhibit a beneficial effect. The phenomenon of delayed treatment effect is often observed in the emerging and important field of immuno-oncology. It is important to estimate the duration of delay as this information helps in characterizing the pattern of comparative treatment effect, understanding the mechanism of action of the experimental therapy, and forming optimal treatment strategies. For a fixed delay time, we propose a maximum likelihood estimator and evaluate its asymptotic properties via simulation. We further evaluate two functions that link the pre- and postdelay hazard ratios to the average hazard ratio given a fixed delay time. For the case of random delay time, where the delay time may vary from patient to patient, we propose a semiparametric joint survival model for delay time and event time to estimate the mean delay time and the postdelay hazard ratio, assuming a Beta distribution for the delay time. We describe an extension of the model to estimate subgroup-specific mean delay times. Simulation study and application to data from a clinical trial in colon cancer patients demonstrate the robustness of the proposed model.


Assuntos
Neoplasias do Colo/terapia , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Análise de Sobrevida , Tempo para o Tratamento/estatística & dados numéricos , Neoplasias do Colo/mortalidade , Simulação por Computador , Humanos , Funções Verossimilhança , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Tempo para o Tratamento/tendências
6.
Int J Mol Sci ; 20(3)2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30678043

RESUMO

Insulin-resistance is a characteristic feature of type 2 diabetes (T2D) and plays a major role in the pathogenesis of this disease. Skeletal muscles are quantitatively the biggest glucose users in response to insulin and are considered as main targets in development of insulin-resistance. It is now clear that circulating fatty acids (FA), which are highly increased in T2D, play a major role in the development of muscle insulin-resistance. In healthy individuals, excess FA are stored as lipid droplets in adipocytes. In situations like obesity and T2D, FA from lipolysis and food are in excess and eventually accumulate in peripheral tissues. High plasma concentrations of FA are generally associated with increased risk of developing diabetes. Indeed, ectopic fat accumulation is associated with insulin-resistance; this is called lipotoxicity. However, FA themselves are not involved in insulin-resistance, but rather some of their metabolic derivatives, such as ceramides. Ceramides, which are synthetized de novo from saturated FA like palmitate, have been demonstrated to play a critical role in the deterioration of insulin sensitivity in muscle cells. This review describes the latest progress involving ceramides as major players in the development of muscle insulin-resistance through the targeting of selective actors of the insulin signaling pathway.


Assuntos
Ceramidas/metabolismo , Suscetibilidade a Doenças , Metabolismo dos Lipídeos , Células Musculares/metabolismo , Esfingolipídeos/metabolismo , Animais , Ceramidas/efeitos adversos , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Metabolismo Energético , Humanos , Insulina/metabolismo , Resistência à Insulina , Células Musculares/efeitos dos fármacos , Transdução de Sinais , Esfingolipídeos/sangue
7.
Semin Cancer Biol ; 35 Suppl: S199-S223, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25865775

RESUMO

Cancer arises in the context of an in vivo tumor microenvironment. This microenvironment is both a cause and consequence of tumorigenesis. Tumor and host cells co-evolve dynamically through indirect and direct cellular interactions, eliciting multiscale effects on many biological programs, including cellular proliferation, growth, and metabolism, as well as angiogenesis and hypoxia and innate and adaptive immunity. Here we highlight specific biological processes that could be exploited as targets for the prevention and therapy of cancer. Specifically, we describe how inhibition of targets such as cholesterol synthesis and metabolites, reactive oxygen species and hypoxia, macrophage activation and conversion, indoleamine 2,3-dioxygenase regulation of dendritic cells, vascular endothelial growth factor regulation of angiogenesis, fibrosis inhibition, endoglin, and Janus kinase signaling emerge as examples of important potential nexuses in the regulation of tumorigenesis and the tumor microenvironment that can be targeted. We have also identified therapeutic agents as approaches, in particular natural products such as berberine, resveratrol, onionin A, epigallocatechin gallate, genistein, curcumin, naringenin, desoxyrhapontigenin, piperine, and zerumbone, that may warrant further investigation to target the tumor microenvironment for the treatment and/or prevention of cancer.


Assuntos
Carcinogênese/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Microambiente Tumoral/genética , Antineoplásicos/uso terapêutico , Carcinogênese/genética , Proliferação de Células/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Neoplasias/genética , Neoplasias/prevenção & controle , Neovascularização Patológica/genética , Neovascularização Patológica/prevenção & controle , Transdução de Sinais , Microambiente Tumoral/efeitos dos fármacos
8.
Semin Cancer Biol ; 35 Suppl: S104-S128, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25869441

RESUMO

One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression. When activated in the absence of normal terminal differentiation cues, these mechanisms can result in a state of persistent cytostasis. This state, termed "senescence," can be triggered by intrinsic cellular processes such as telomere dysfunction and oncogene expression, and by exogenous factors such as DNA damaging agents or oxidative environments. Despite differences in upstream signaling, senescence often involves convergent interdependent activation of tumor suppressors p53 and p16/pRB, but can be induced, albeit with reduced sensitivity, when these suppressors are compromised. Doses of conventional genotoxic drugs required to achieve cancer cell senescence are often much lower than doses required to achieve outright cell death. Additional therapies, such as those targeting cyclin dependent kinases or components of the PI3K signaling pathway, may induce senescence specifically in cancer cells by circumventing defects in tumor suppressor pathways or exploiting cancer cells' heightened requirements for telomerase. Such treatments sufficient to induce cancer cell senescence could provide increased patient survival with fewer and less severe side effects than conventional cytotoxic regimens. This positive aspect is countered by important caveats regarding senescence reversibility, genomic instability, and paracrine effects that may increase heterogeneity and adaptive resistance of surviving cancer cells. Nevertheless, agents that effectively disrupt replicative immortality will likely be valuable components of new combinatorial approaches to cancer therapy.


Assuntos
Proliferação de Células/genética , Senescência Celular/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Antineoplásicos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Instabilidade Genômica/efeitos dos fármacos , Humanos , Neoplasias/patologia , Fosfatidilinositol 3-Quinases/genética , Transdução de Sinais/genética , Telomerase/efeitos dos fármacos , Telomerase/genética , Proteína Supressora de Tumor p53/genética
9.
Semin Cancer Biol ; 35 Suppl: S224-S243, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25600295

RESUMO

Deregulation of angiogenesis--the growth of new blood vessels from an existing vasculature--is a main driving force in many severe human diseases including cancer. As such, tumor angiogenesis is important for delivering oxygen and nutrients to growing tumors, and therefore considered an essential pathologic feature of cancer, while also playing a key role in enabling other aspects of tumor pathology such as metabolic deregulation and tumor dissemination/metastasis. Recently, inhibition of tumor angiogenesis has become a clinical anti-cancer strategy in line with chemotherapy, radiotherapy and surgery, which underscore the critical importance of the angiogenic switch during early tumor development. Unfortunately the clinically approved anti-angiogenic drugs in use today are only effective in a subset of the patients, and many who initially respond develop resistance over time. Also, some of the anti-angiogenic drugs are toxic and it would be of great importance to identify alternative compounds, which could overcome these drawbacks and limitations of the currently available therapy. Finding "the most important target" may, however, prove a very challenging approach as the tumor environment is highly diverse, consisting of many different cell types, all of which may contribute to tumor angiogenesis. Furthermore, the tumor cells themselves are genetically unstable, leading to a progressive increase in the number of different angiogenic factors produced as the cancer progresses to advanced stages. As an alternative approach to targeted therapy, options to broadly interfere with angiogenic signals by a mixture of non-toxic natural compound with pleiotropic actions were viewed by this team as an opportunity to develop a complementary anti-angiogenesis treatment option. As a part of the "Halifax Project" within the "Getting to know cancer" framework, we have here, based on a thorough review of the literature, identified 10 important aspects of tumor angiogenesis and the pathological tumor vasculature which would be well suited as targets for anti-angiogenic therapy: (1) endothelial cell migration/tip cell formation, (2) structural abnormalities of tumor vessels, (3) hypoxia, (4) lymphangiogenesis, (5) elevated interstitial fluid pressure, (6) poor perfusion, (7) disrupted circadian rhythms, (8) tumor promoting inflammation, (9) tumor promoting fibroblasts and (10) tumor cell metabolism/acidosis. Following this analysis, we scrutinized the available literature on broadly acting anti-angiogenic natural products, with a focus on finding qualitative information on phytochemicals which could inhibit these targets and came up with 10 prototypical phytochemical compounds: (1) oleanolic acid, (2) tripterine, (3) silibinin, (4) curcumin, (5) epigallocatechin-gallate, (6) kaempferol, (7) melatonin, (8) enterolactone, (9) withaferin A and (10) resveratrol. We suggest that these plant-derived compounds could be combined to constitute a broader acting and more effective inhibitory cocktail at doses that would not be likely to cause excessive toxicity. All the targets and phytochemical approaches were further cross-validated against their effects on other essential tumorigenic pathways (based on the "hallmarks" of cancer) in order to discover possible synergies or potentially harmful interactions, and were found to generally also have positive involvement in/effects on these other aspects of tumor biology. The aim is that this discussion could lead to the selection of combinations of such anti-angiogenic compounds which could be used in potent anti-tumor cocktails, for enhanced therapeutic efficacy, reduced toxicity and circumvention of single-agent anti-angiogenic resistance, as well as for possible use in primary or secondary cancer prevention strategies.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias/terapia , Neovascularização Patológica/terapia , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/crescimento & desenvolvimento , Vasos Sanguíneos/patologia , Proliferação de Células/efeitos dos fármacos , Humanos , Imunoterapia , Neoplasias/prevenção & controle , Neovascularização Patológica/prevenção & controle
10.
Semin Cancer Biol ; 35 Suppl: S25-S54, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25892662

RESUMO

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression.


Assuntos
Proteínas de Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Neoplasias/patologia , Neoplasias/terapia , Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/biossíntese , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Neoplasias/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Transdução de Sinais/efeitos dos fármacos
11.
Semin Cancer Biol ; 35 Suppl: S185-S198, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25818339

RESUMO

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system. Immune editing is one of the key aspects why tumors evade surveillance causing the tumors to lie dormant in patients for years through "equilibrium" and "senescence" before re-emerging. In addition, tumors exploit several immunological processes such as targeting the regulatory T cell function or their secretions, antigen presentation, modifying the production of immune suppressive mediators, tolerance and immune deviation. Besides these, tumor heterogeneity and metastasis also play a critical role in tumor growth. A number of potential targets like promoting Th1, NK cell, γδ T cell responses, inhibiting Treg functionality, induction of IL-12, use of drugs including phytochemicals have been designed to counter tumor progression with much success. Some natural agents and phytochemicals merit further study. For example, use of certain key polysaccharide components from mushrooms and plants have shown to possess therapeutic impact on tumor-imposed genetic instability, anti-growth signaling, replicative immortality, dysregulated metabolism etc. In this review, we will discuss the advances made toward understanding the basis of cancer immune evasion and summarize the efficacy of various therapeutic measures and targets that have been developed or are being investigated to enhance tumor rejection.


Assuntos
Carcinogênese/imunologia , Evasão da Resposta Imune , Neoplasias/imunologia , Neoplasias/terapia , Apresentação de Antígeno/imunologia , Carcinogênese/efeitos dos fármacos , Humanos , Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/imunologia , Neoplasias/patologia , Compostos Fitoquímicos/uso terapêutico , Linfócitos T Reguladores/imunologia , Evasão Tumoral/efeitos dos fármacos , Evasão Tumoral/imunologia
12.
Semin Cancer Biol ; 35 Suppl: S5-S24, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25869442

RESUMO

Genomic instability can initiate cancer, augment progression, and influence the overall prognosis of the affected patient. Genomic instability arises from many different pathways, such as telomere damage, centrosome amplification, epigenetic modifications, and DNA damage from endogenous and exogenous sources, and can be perpetuating, or limiting, through the induction of mutations or aneuploidy, both enabling and catastrophic. Many cancer treatments induce DNA damage to impair cell division on a global scale but it is accepted that personalized treatments, those that are tailored to the particular patient and type of cancer, must also be developed. In this review, we detail the mechanisms from which genomic instability arises and can lead to cancer, as well as treatments and measures that prevent genomic instability or take advantage of the cellular defects caused by genomic instability. In particular, we identify and discuss five priority targets against genomic instability: (1) prevention of DNA damage; (2) enhancement of DNA repair; (3) targeting deficient DNA repair; (4) impairing centrosome clustering; and, (5) inhibition of telomerase activity. Moreover, we highlight vitamin D and B, selenium, carotenoids, PARP inhibitors, resveratrol, and isothiocyanates as priority approaches against genomic instability. The prioritized target sites and approaches were cross validated to identify potential synergistic effects on a number of important areas of cancer biology.


Assuntos
Instabilidade Genômica/efeitos dos fármacos , Neoplasias/dietoterapia , Neoplasias/genética , Centrossomo/metabolismo , Dano ao DNA/genética , Reparo do DNA/genética , Dieta , Instabilidade Genômica/genética , Humanos , Neoplasias/patologia , Prognóstico , Telomerase/antagonistas & inibidores , Telomerase/genética
13.
Semin Cancer Biol ; 35 Suppl: S78-S103, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25936818

RESUMO

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer.


Assuntos
Apoptose/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Autofagia/genética , Proliferação de Células/genética , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias/patologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
14.
Semin Cancer Biol ; 35 Suppl: S55-S77, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25749195

RESUMO

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting.


Assuntos
Carcinogênese/genética , Proliferação de Células/genética , Neoplasias/genética , Neoplasias/terapia , Transdução de Sinais , Proteínas de Ligação a DNA , Fator 15 de Diferenciação de Crescimento/genética , Via de Sinalização Hippo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Terapia de Alvo Molecular , Proteínas Nucleares/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Serina-Treonina Quinases/genética , Proteína do Retinoblastoma/genética , Somatomedinas/genética , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética
15.
Semin Cancer Biol ; 35 Suppl: S276-S304, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26590477

RESUMO

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.


Assuntos
Heterogeneidade Genética , Terapia de Alvo Molecular , Neoplasias/terapia , Medicina de Precisão , Antineoplásicos Fitogênicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias/genética , Neoplasias/patologia , Neoplasias/prevenção & controle , Transdução de Sinais , Microambiente Tumoral/genética
16.
Behav Sleep Med ; 13(5): 412-23, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25221914

RESUMO

This study examined sleep hygiene practices and bedtime resistance and tested whether associations differed by child temperament. Parents of Head Start preschoolers (n = 374, 56% non-Hispanic white) completed the Going to Bed subscale of the Children's Sleep-Wake Scale (GTB; higher score reflects less bedtime resistance), Children's Sleep Hygiene Scale (CSHS; higher score reflects better sleep hygiene), and Child Behavior Questionnaire (Anger, Activity, Impulsivity subscales indicated difficult temperament). Monte Carlo simulation adjusted for demographic covariates tested associations of CSHS with GTB in children with more- vs. less-difficult temperaments. Children with more- vs. less-difficult temperaments experienced worse sleep hygiene (p < .0001) and had more bedtime resistance (p < .0001). Among children with more difficult temperaments, better sleep hygiene was linearly associated with less bedtime resistance (ß = 1.28, 95% CI 0.77, 1.78). Among children with less difficult temperaments, the association followed a piecewise linear trend: sleep hygiene was not associated with bedtime resistance when CSHS scores were < 4.1 (ß = 0.15, 95% CI -4.87, 3.13), but for CSHS scores ≥ 4.1, an increase in CSHS was associated with lower bedtime resistance (ß = 1.33, 95% CI 1.00, 1.79). Consistent sleep hygiene is associated with less bedtime resistance and may be helpful in reducing bedtime resistance among children with more difficult temperaments.


Assuntos
Comportamento Infantil , Pobreza , Sono , Temperamento , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Método de Monte Carlo , Pais , Grupos Raciais/estatística & dados numéricos , Medicina do Sono , Inquéritos e Questionários , Fatores de Tempo
17.
Eur J Neurosci ; 39(1): 132-40, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24164635

RESUMO

The corticospinal (CS) system plays an important role in fine motor control, especially in precision grip tasks. Although the primary motor cortex (M1) is the main source of the CS projections, other projections have been found, especially from the supplementary motor area proper (SMAp). To study the characteristics of these CS projections from SMAp, we compared muscle responses of an intrinsic hand muscle (FDI) evoked by stimulation of human M1 and SMAp during an isometric static low-force control task. Subjects were instructed to maintain a small cursor on a target force curve by applying a pressure with their right precision grip on a force sensor. Neuronavigated transcranial magnetic stimulation was used to stimulate either left M1 or left SMAp with equal induced electric field values at the defined cortical targets. The results show that the SMAp stimulation evokes reproducible muscle responses with similar latencies and amplitudes as M1 stimulation, and with a clear and significant shorter silent period. These results suggest that (i) CS projections from human SMAp are as rapid and efficient as those from M1, (ii) CS projections from SMAp are directly involved in control of the excitability of spinal motoneurons and (iii) SMAp has a different intracortical inhibitory circuitry. We conclude that human SMAp and M1 both have direct influence on force production during fine manual motor tasks.


Assuntos
Força da Mão , Córtex Motor/fisiologia , Tratos Piramidais/fisiologia , Adulto , Potencial Evocado Motor , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Destreza Motora , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Tempo de Reação , Estimulação Magnética Transcraniana
18.
Cognition ; 248: 105793, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38636164

RESUMO

Speech comprehension is enhanced when preceded (or accompanied) by a congruent rhythmic prime reflecting the metrical sentence structure. Although these phenomena have been described for auditory and motor primes separately, their respective and synergistic contribution has not been addressed. In this experiment, participants performed a speech comprehension task on degraded speech signals that were preceded by a rhythmic prime that could be auditory, motor or audiomotor. Both auditory and audiomotor rhythmic primes facilitated speech comprehension speed. While the presence of a purely motor prime (unpaced tapping) did not globally benefit speech comprehension, comprehension accuracy scaled with the regularity of motor tapping. In order to investigate inter-individual variability, participants also performed a Spontaneous Speech Synchronization test. The strength of the estimated perception-production coupling correlated positively with overall speech comprehension scores. These findings are discussed in the framework of the dynamic attending and active sensing theories.


Assuntos
Compreensão , Percepção da Fala , Humanos , Percepção da Fala/fisiologia , Masculino , Feminino , Adulto Jovem , Compreensão/fisiologia , Adulto , Estimulação Acústica , Desempenho Psicomotor/fisiologia , Percepção Auditiva/fisiologia , Fala/fisiologia
19.
Neuropsychologia ; 198: 108885, 2024 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-38604495

RESUMO

When a sequence of written words is briefly presented and participants are asked to identify just one word at a post-cued location, then word identification accuracy is higher when the word is presented in a grammatically correct sequence compared with an ungrammatical sequence. This sentence superiority effect has been reported in several behavioral studies and two EEG investigations. Taken together, the results of these studies support the hypothesis that the sentence superiority effect is primarily driven by rapid access to a sentence-level representation via partial word identification processes that operate in parallel over several words. Here we used MEG to examine the neural structures involved in this early stage of written sentence processing, and to further specify the timing of the different processes involved. Source activities over time showed grammatical vs. ungrammatical differences first in the left inferior frontal gyrus (IFG: 321-406 ms), then the left anterior temporal lobe (ATL: 466-531 ms), and finally in both left IFG (549-602 ms) and left posterior superior temporal gyrus (pSTG: 553-622 ms). We interpret the early IFG activity as reflecting the rapid bottom-up activation of sentence-level representations, including syntax, enabled by partly parallel word processing. Subsequent activity in ATL and pSTG is thought to reflect the constraints imposed by such sentence-level representations on on-going word-based semantic activation (ATL), and the subsequent development of a more detailed sentence-level representation (pSTG). These results provide further support for a cascaded interactive-activation account of sentence reading.


Assuntos
Mapeamento Encefálico , Encéfalo , Magnetoencefalografia , Leitura , Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Encéfalo/fisiologia , Tempo de Reação/fisiologia , Estimulação Luminosa , Semântica
20.
Artigo em Inglês | MEDLINE | ID: mdl-39008225

RESUMO

INTRODUCTION: It remains unclear how patients with atopic dermatitis (AD) and clinicians perceive the level of patient-clinician communication and if there could be potential lapses. This cross-sectional study aims to compare perspectives between patients with AD and dermatologists regarding communication and treatment expectations in Asia. METHODS: Moderate-to-severe patients with AD and practicing dermatologists were recruited from eight Asia-Pacific territories, including Mainland China, Hong Kong, India, Japan, Singapore, South Korea, Taiwan, and Thailand. Patients and dermatologists completed separate surveys designed to elicit their expectations regarding AD management, and their perceived level of patient-clinician communication. Patients were also asked about their treatment satisfaction and whether they prefer additional treatment beyond what was prescribed. Demographic information and responses were analyzed using descriptive statistics. The study was reviewed by the institutional review board in each territory, and all participants provided informed consent. RESULTS: A total of 1103 patients and 271 dermatologists completed the surveys. Both patients and dermatologists were largely aligned in their top treatment goals in AD management. However, greater proportions of patients prioritized the prevention of exacerbation (78.0% versus 47.2%), minimization of treatment adverse effects (46.4% versus 9.1%), and improvement in mental health (16.0% versus 4.9%), compared with dermatologists. Although patient-clinician communication was observed to be generally good, 10.9% of patients reported dissatisfaction with communication in AD management. The majority of patients were either "very satisfied" or "satisfied" with their latest acute AD treatment, but 65.5% of patients still desired additional treatment. CONCLUSIONS: This multinational study has provided insights on the perspectives of Asian patients and dermatologists in treatment goals, AD management, and communication. In general, both patients and dermatologists were aligned in treatment goals and there was satisfactory patient-clinician communication in most aspects. However, potential areas of improvement have been identified to further enhance patient-centered care.

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