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Post-acute sequelae of COVID-19 (PASC, "Long COVID") pose a significant global health challenge. The pathophysiology is unknown, and no effective treatments have been found to date. Several hypotheses have been formulated to explain the etiology of PASC, including viral persistence, chronic inflammation, hypercoagulability, and autonomic dysfunction. Here, we propose a mechanism that links all four hypotheses in a single pathway and provides actionable insights for therapeutic interventions. We find that PASC are associated with serotonin reduction. Viral infection and type I interferon-driven inflammation reduce serotonin through three mechanisms: diminished intestinal absorption of the serotonin precursor tryptophan; platelet hyperactivation and thrombocytopenia, which impacts serotonin storage; and enhanced MAO-mediated serotonin turnover. Peripheral serotonin reduction, in turn, impedes the activity of the vagus nerve and thereby impairs hippocampal responses and memory. These findings provide a possible explanation for neurocognitive symptoms associated with viral persistence in Long COVID, which may extend to other post-viral syndromes.
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Síndrome de COVID-19 Pós-Aguda , Serotonina , Humanos , COVID-19/complicações , Progressão da Doença , Inflamação , Síndrome de COVID-19 Pós-Aguda/sangue , Síndrome de COVID-19 Pós-Aguda/patologia , Serotonina/sangue , VirosesRESUMO
The microbiota impedes pathogen invasion of the intestinal ecosystem, a phenomenon termed colonization resistance. In an upcoming issue of Cell, Stacy et al. describe host-initiated metabolite pathways that functionally alter the microbiota after primary infection, thereby augmenting colonization resistance to subsequent infection.
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Intestinos , MicrobiotaRESUMO
Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed1. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body ß-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2 and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.
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Neoplasias Colorretais , Transdução de Sinais , Ácido 3-Hidroxibutírico/metabolismo , Ácido 3-Hidroxibutírico/farmacologia , Animais , Proliferação de Células , Transformação Celular Neoplásica , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/prevenção & controle , HumanosRESUMO
Exercise exerts a wide range of beneficial effects for healthy physiology1. However, the mechanisms regulating an individual's motivation to engage in physical activity remain incompletely understood. An important factor stimulating the engagement in both competitive and recreational exercise is the motivating pleasure derived from prolonged physical activity, which is triggered by exercise-induced neurochemical changes in the brain. Here, we report on the discovery of a gut-brain connection in mice that enhances exercise performance by augmenting dopamine signalling during physical activity. We find that microbiome-dependent production of endocannabinoid metabolites in the gut stimulates the activity of TRPV1-expressing sensory neurons and thereby elevates dopamine levels in the ventral striatum during exercise. Stimulation of this pathway improves running performance, whereas microbiome depletion, peripheral endocannabinoid receptor inhibition, ablation of spinal afferent neurons or dopamine blockade abrogate exercise capacity. These findings indicate that the rewarding properties of exercise are influenced by gut-derived interoceptive circuits and provide a microbiome-dependent explanation for interindividual variability in exercise performance. Our study also suggests that interoceptomimetic molecules that stimulate the transmission of gut-derived signals to the brain may enhance the motivation for exercise.
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Eixo Encéfalo-Intestino , Dopamina , Exercício Físico , Microbioma Gastrointestinal , Motivação , Corrida , Animais , Camundongos , Encéfalo/citologia , Encéfalo/metabolismo , Dopamina/metabolismo , Endocanabinoides/antagonistas & inibidores , Endocanabinoides/metabolismo , Células Receptoras Sensoriais/metabolismo , Eixo Encéfalo-Intestino/fisiologia , Microbioma Gastrointestinal/fisiologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/psicologia , Modelos Animais , Humanos , Estriado Ventral/citologia , Estriado Ventral/metabolismo , Corrida/fisiologia , Corrida/psicologia , Recompensa , IndividualidadeRESUMO
OBJECTIVE: Two-staged gamma knife surgery (GKS) is a method that may extend the upper tumor volume limit for using GKS in the management of brain metastases. However, the safety of treating very large posterior fossa lesions with this technique has not been well demonstrated. Therefore, we analyzed our experience in treating cerebellar metastases larger than 12 cm3 with two-staged GKS. METHODS: Four consecutive patients harboring 12 to 30 cm3 cerebellar metastases scheduled two-staged GKS were included in the study, and all but one patient completed the treatment. The treatment doses were 10-13 Gy. All patients were followed with regular MR imaging and clinical assessments, and the tumor volumes were measured on all treatment and follow-up images. RESULTS: Tumor progression was not demonstrated in any of the patients. Tumor volumes decreased by, on average, more than half between the two stages. The median survival was 22 months, and no patient died due to intracranial tumor progression. Peritumoral edema at the first GKS resolved in all patients, replaced by asymptomatic mild T2 changes in two of them not requiring any treatment. No radiation-induced complication has developed thus far. CONCLUSION: Staged GKS seems to be a feasible management option for very large cerebellar metastases.
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Neoplasias Encefálicas , Radiocirurgia , Humanos , Estudos Retrospectivos , Radiocirurgia/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Resultado do Tratamento , SeguimentosRESUMO
BACKGROUND: Patient selection is key in Phase I studies, and prognosis can be difficult to estimate in heavily pre-treated patients. Previous prognostic models like the Royal Marsden Hospital (RMH) score or using the neutrophil-lymphocyte ratio (NLR) have not been validated in current novel therapies nor in the Asian Phase I population. METHODS: We conducted a retrospective review of 414 patients with solid tumours participating in Phase I studies at our centre between October 2013 and December 2020. RESULTS: The RMH model showed poorer prognosis with increasing scores [RMH score 1, HR 1.28 (95% CI: 0.96-1.70); RMH score 2, HR 2.27 (95% CI: 1.62-3.17); RMH score 3, HR 4.14 (95% CI: 2.62-6.53)]. NLR did not improve the AUC of the model. Poorer ECOG status (ECOG 1 vs. 0: HR = 1.59 (95% CI = 1.24-2.04), P < 0.001) and primary tumour site (GI vs. breast cancer: HR = 3.06, 95% CI = 2.16-4.35, P < 0.001) were prognostic. CONCLUSIONS: We developed a NCIS prognostic score with excellent prognostic ability for both short-term and longer-term survival (iAUC: 0.71 [95% CI 0.65-0.76]), and validated the RMH model in the largest Asian study to date.
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Neoplasias da Mama , Humanos , Feminino , Prognóstico , Resultado do Tratamento , Neoplasias da Mama/terapia , Linfócitos , Seleção de Pacientes , Estudos Retrospectivos , NeutrófilosRESUMO
Background: Stress amidst the COVID-19 pandemic is becoming more prevalent. This paper aimed to describe the validation process of the Malay Perceived Stress Scale modified for COVID-19 (PSS-10-C) amongst Malaysian youths. Methods: The cross-sectional validation study design was employed in this study. In Phase I, the scale was translated into Malay by using the forward-backward method. In Phase 2, principal axis factoring and confirmatory factor analysis were conducted in Study 1 (n = 267) and Study 2 (n = 324), respectively. Results: A two-factor solution, comprising 'distress' and 'coping' domains was derived (cumulative variance = 65.2%) in Phase 2. Concurrent validity evaluated via the Beck Hopelessness Scale revealed a moderate positive correlation (0.528). In Study 2 (n = 324), the confirmatory factor analysis showed that the two-factor model achieved acceptable model fit indices, including χ2/df ratio = 2.57; root mean square error of approximation (RMSEA) = 0.07; 95% CI = 0.05, 0.09; Tucker-Lewis Index (TLI) = 0.95 and Normed Fit Index (NFI) = 0.94. The Cronbach's alpha scale score was 0.855 for the study samples. Conclusion: The Malay PSS-10-C is a valid and reliable scale to be used amongst Malaysian youths.
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Cancer has risen up to be a major cause of mortality worldwide over the past decades. Despite advancements in cancer screening and diagnostics, a significant number of cancers are still diagnosed at a late stage with poor prognosis. Hence, the discovery of reliable and accurate methods to diagnose cancer early would be of great help in reducing cancer mortality. Extracellular vesicles (EVs) are phospholipid vesicles found in many biofluids and are released by almost all types of cells. In recent years, using EVs as cancer biomarkers has garnered attention as a novel technique of cancer diagnosis. Compared with traditional tissue biopsy, there are many advantages that this novel diagnostic tool presents - it is less invasive, detects early-stage asymptomatic cancers, and allows for monitoring of tumour progression. As such, EV biomarkers have great potential in improving the diagnostic accuracy of cancers and guiding subsequent therapeutic decisions. Efficient isolation and accurate characterization of EVs are essential for reliable outcomes of clinical application. However, these are complicated by the size and biomolecular diversity of EVs. In this review, we present an analysis and evaluation of the current techniques of EV isolation and characterization, as well as discuss the potential EV biomarkers for specific types of cancer. Taken together, EV biomarkers have a lot of potential as a novel method in cancer diagnostics and diagnosis. However, more work is still needed to streamline the purification, characterization and biomarker identification process to ensure optimal outcomes for patients.
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Biomarcadores Tumorais/análise , Vesículas Extracelulares , Neoplasias/diagnóstico , Animais , Humanos , Biópsia Líquida/métodosRESUMO
PURPOSE: Tumor angiogenesis controlled predominantly by vascular endothelial growth factor and its receptor (VEGF-VEGFR) interaction plays a key role in the growth and propagation of cancer cells. However, the newly formed network of blood vessels is disorganized and leaky. Pre-treatment with anti-angiogenic agents can "normalize" the tumor vasculature allowing effective intra-tumoral delivery of standard chemotherapy. Immunohistochemistry (IHC) analysis was applied to investigate and compare the vascular normalization and anti-angiogenic effects of two commonly used anti-angiogenic agents, Sunitinib and Bevacizumab, administered prior to chemotherapy in HER2-negative breast cancer patients. METHODS: This prospective clinical trial enrolled 38 patients into a sunitinib cohort and 24 into a bevacizumab cohort. All received 4 cycles of doxorubicin/cyclophosphamide chemotherapy and pre-treatment with either sunitinib or bevacizumab. Tumor biopsies were obtained at baseline, after cycle 1 (C1) and cycle 4 (C4) of chemotherapy. IHC was performed to assess the tumor vascular normalization index (VNI), lymphatic vessel density (LVD), Ki67 proliferation index and expression of tumor VEGFR2. RESULTS: In comparison to Bevacizumab, Sunitinib led to a significant increase in VNI post-C1 and C4 (p < 0.001 and 0.001) along with decrease in LVD post-C1 (p = 0.017). Both drugs when combined with chemotherapy resulted in significant decline in tumor proliferation after C1 and C4 (baseline vs post-C4 Ki67 index p = 0.006 for Sunitinib vs p = 0.021 for Bevacizumab). Bevacizumab resulted in a significant decrease in VEGFR2 expression post-C1 (p = 0.004). CONCLUSION: Sunitinib, in comparison to Bevacizumab showed a greater effect on tumor vessel modulation and lymphangiogenesis suggesting that its administration prior to chemotherapy might result in improved drug delivery. TRIAL REGISTRY: ClinicalTrials.gov: NCT02790580 (first posted June 6, 2016).
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Neoplasias da Mama , Inibidores da Angiogênese/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Imuno-Histoquímica , Sunitinibe/uso terapêutico , Fator A de Crescimento do Endotélio VascularRESUMO
In the United States, women, while having a longer life expectancy than men, experience a differential risk for chronic diseases and have unique nutritional needs based on physiological and hormonal changes across the life span. However, much of what is known about health is based on research conducted in men. Additional complexity in assessing nutritional needs within gender include the variations in genetics, body compositions, hormonal milieus, underlying chronic diseases, and medication usage, with this list expanding as we consider these variables across the life course. It is clear women experience nutrient shortfalls during key periods of their lives, which may differentially impact their health. Consequently, as we move into the era of precision nutrition, understanding these sex- and gender-based differences may help optimize recommendations and interventions chosen to support health and weight management. Recently, a scientific conference was convened with content experts to explore these topics from a life-course perspective at biological, physiological, and behavioral levels. This publication summarizes the presentations and discussions from the workshop and provides an overview of important nutrition and related lifestyle considerations across the life course. The landscape of addressing female-specific nutritional needs continues to grow; now more than ever, it is essential to increase our understanding of the physiological differences between men and women, and determine how these physiological considerations may aid in optimizing nutritional strategies to support certain personal goals related to health, quality of life, sleep, and exercise performance among women.
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Qualidade de Vida , Caracteres Sexuais , Feminino , Humanos , Estilo de Vida , Masculino , Estado Nutricional , Fatores Sexuais , Estados UnidosRESUMO
During the COVID-19 pandemic, the botanical product market saw a consumer interest increase in immune health supplements. While data are currently insufficient to support public health guidance for using foods and dietary supplements to prevent or treat COVID-19 and other immune disorders, consumer surveys indicate that immune support is the second-most cited reason for supplement use in the United States. Meanwhile, consumers showed increased attention to dietary supplement ingredient labels, especially concerning authenticity and ingredient claims. Top-selling botanical ingredients such as elderberry, turmeric, and functional mushrooms have been increasingly marketed toward consumers to promote immune health, but these popular products succumb to adulteration with inaccurate labeling due to the intentional or unintentional addition of lower grade ingredients, non-target plants, and synthetic compounds, partially due to pandemic-related supply chain issues. This review highlights the regulatory requirements and recommendations for analytical approaches, including chromatography, spectroscopy, and DNA approaches for ingredient claim verification. Demonstrating elderberry, turmeric, and functional mushrooms as examples, this review aims to provide industrial professionals and scientists an overview of current United States regulations, testing approaches, and trends for label compliance verification to ensure the safety of botanical products marketed for "immune health."
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PURPOSE: To identify a structure to explain the relationship between socio-clinico factors, necessity-concerns beliefs, and perceived barriers to adherence with adjuvant endocrine therapy (AET) amongst women with breast cancer. METHODS: Participants were 244 patients with early-stage breast cancer recruited from two tertiary hospitals from May 2015 to December 2018 who completed questionnaires on medication adherence (Simplified Medication Adherence Questionnaire), necessity-concerns beliefs (Beliefs about Medicine Questionnaire), and barriers to adherence (Adherence Starts with Knowledge Questionnaire). Socio-clinico variables were collected via interview and medical records review. Structural equation modelling was applied to examine the relationships between these variables and possible mediating effects of necessity-concerns beliefs on adherence to AET. RESULTS: The median age of the study participants was 61 (range 32-80) years and the median duration on AET was 1.6 (IQR 1.2-2.6) years. Adherence was positively associated with age (ß = 0.145, 95% CI: 0.011 to 0.279, p = 0.034) and negatively associated with barriers (ß = - 0.381, 95% CI: - 0.511 to - 0.251, p < 0.001). There was no effect of Necessity (ß = 0.006, 95% CI: - 0.145 to 0.158, p = 0.933) or Concerns (ß = 0.041, 95% CI: - 0.117 to 0.199, p = 0.614) on adherence. Necessity-concerns beliefs were also not significant mediators in the relationship between socio-clinico factors and medication adherence. CONCLUSIONS: Older age and lower barriers to adherence were associated with higher adherence scores. Necessity-concerns beliefs did not have a significant effect on adherence as majority of the patients identified forgetfulness as a reason for non-adherence.
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Antineoplásicos Hormonais , Neoplasias da Mama , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/epidemiologia , Terapia Combinada , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Análise de Classes Latentes , Adesão à Medicação , Pessoa de Meia-Idade , Inquéritos e QuestionáriosRESUMO
BACKGROUND & AIMS: The outbreak of COVID-19 has vastly increased the operational burden on healthcare systems worldwide. For patients with end-stage liver failure, liver transplantation is the only option. However, the strain on intensive care facilities caused by the pandemic is a major concern. There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources. METHODS: We performed an international multicenter study of transplant centers to understand the evolution of policies for transplant prioritization in response to the pandemic in March 2020. To describe the ethical tension arising in this setting, we propose a novel ethical framework, the quadripartite equipoise (QE) score, that is applicable to liver transplantation in the context of limited national resources. RESULTS: Seventeen large- and medium-sized liver transplant centers from 12 countries across 4 continents participated. Ten centers opted to limit transplant activity in response to the pandemic, favoring a "sickest-first" approach. Conversely, some larger centers opted to continue routine transplant activity in order to balance waiting list mortality. To model these and other ethical tensions, we computed a QE score using 4 factors - recipient outcome, donor/graft safety, waiting list mortality and healthcare resources - for 7 countries. The fluctuation of the QE score over time accurately reflects the dynamic changes in the ethical tensions surrounding transplant activity in a pandemic. CONCLUSIONS: This four-dimensional model of quadripartite equipoise addresses the ethical tensions in the current pandemic. It serves as a universally applicable framework to guide regulation of transplant activity in response to the increasing burden on healthcare systems. LAY SUMMARY: There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources during the COVID-19 pandemic. We describe a four-dimensional model of quadripartite equipoise that models these ethical tensions and can guide the regulation of transplant activity in response to the increasing burden on healthcare systems.
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Infecções por Coronavirus/epidemiologia , Doença Hepática Terminal , Recursos em Saúde/tendências , Transplante de Fígado , Pandemias , Pneumonia Viral/epidemiologia , Obtenção de Tecidos e Órgãos , Betacoronavirus , COVID-19 , Doença Hepática Terminal/mortalidade , Doença Hepática Terminal/cirurgia , Humanos , Cooperação Internacional , Transplante de Fígado/ética , Transplante de Fígado/métodos , Inovação Organizacional , Pandemias/ética , Pandemias/prevenção & controle , Seleção de Pacientes/ética , SARS-CoV-2 , Inquéritos e Questionários , Obtenção de Tecidos e Órgãos/ética , Obtenção de Tecidos e Órgãos/organização & administração , Obtenção de Tecidos e Órgãos/tendências , Listas de Espera/mortalidadeRESUMO
The mammalian intestine is host to a vast number of microbial organisms. The immune system must balance tolerance with innate and adaptive defense mechanisms to maintain homeostasis with the microbial community. Interestingly, microbial metabolites have been shown to play a role in shaping the host immune response, thus assisting with adaptations that have significant implications for human health and disease. New investigations have uncovered roles for metabolites in modulating almost every aspect of the immune system. In this minireview, we survey these recent findings, which taken together reveal nuanced interactions that we are just beginning to understand.
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Bactérias/metabolismo , Microbioma Gastrointestinal , Imunidade Inata , Imunidade nas Mucosas , Mucosa Intestinal/microbiologia , Animais , Anticorpos/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Bactérias/imunologia , Interações Hospedeiro-Patógeno , Humanos , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Linfócitos/imunologia , Linfócitos/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Neuroimunomodulação , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Autoimmune hemolytic anemia (AIHA) leads to accelerated destruction of autologous red blood cells (RBCs) by autoantibodies. AIHA is a severe and sometimes fatal disease. While there are several therapeutic strategies available, there are currently no licensed treatments for AIHA and few therapeutics result in treatment-free durable remission. The etiology of primary AIHA is unknown; however, secondary AIHA occurs concurrently with lymphoproliferative disorders and infections. Additionally, AIHA is the second most common manifestation of primary immunodeficiency disorders and has been described as a side effect of checkpoint inhibitor therapy. Given the severity of AIHA and the lack of treatment options, understanding the initiation of autoimmunity is imperative. Herein, we utilized a well-described model of RBC biology to dissect how RBC-specific autoreactive T cells become educated against RBC autoantigens. We show that, unlike most autoantigens, T cells do not encounter RBC autoantigens in the thymus. Instead, when they leave the thymus as recent thymic emigrants (RTEs), they retain the ability to positively respond to RBC autoantigens; only after several weeks in circulation do RTEs become nonresponsive. Together, these data suggest that any disruption in this process would lead to breakdown of tolerance and initiation of autoimmunity. Thus, RTEs and this developmental process are potential targets to prevent and treat AIHA.
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Autoimunidade , Movimento Celular/imunologia , Eritrócitos/imunologia , Tolerância Imunológica , Linfócitos T/imunologia , Timo/imunologia , Anemia Hemolítica Autoimune/sangue , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/imunologia , Anemia Hemolítica Autoimune/terapia , Autoantígenos/imunologia , Humanos , Linfócitos T/metabolismoRESUMO
Cell cycle dysregulation, characterised by aberrant activation of cyclin dependent kinases (CDKs), is a hallmark of cancer. After years of research on the first and second generations of less selective CDK inhibitors with unfavourable clinical activity and toxicity profiles, CDK4/6 inhibitors become the first and only class of highly specific CDK inhibitors being approved for cancer treatment to date. CDK4/6 inhibitors have transformed the treatment paradigm of estrogen receptor-positive (ER+) breast cancer, dramatically improving the survival outcomes of these patients when incorporated with conventional endocrine therapies in both the first and later-line settings. Currently, the efficacies of CDK4/6 inhibitors in other breast cancer subtypes and cancers are being actively explored. All three CDK4/6 inhibitors have demonstrated very similar clinical efficacies. However, being the least similar structurally, abemaciclib is the only CDK4/6 inhibitor with single agent activity in refractory metastatic ER + breast cancer, the ability to cross the blood brain barrier efficiently, and a distinct toxicity profile of lower myelosuppression such that it can be dosed continuously. Here, we further discuss the distinguishing features of abemaciclib as compared to the other two CDK4/6 inhibitors, palbociclib and ribociclib. Besides being the most potent inhibitor of CDK4/6, abemaciclib exhibits a wider selectivity towards other CDKs and kinases, and functions through additional mechanisms of action besides inducing G1 cell cycle arrest, in a dose dependent manner. Hence, abemaciclib has the potential to act independently of the CDK4/6-cyclin D-RB pathway, resulting in crucial implications on the possibly expanded clinical indications and predictive biomarkers of abemaciclib, in contrast to the other CDK4/6 inhibitors. The current status of preclinical evidence and clinical studies of abemaciclib as a single agent and in combination treatment in breast and other cancers, together with its potential predictive biomarkers, is also summarised in this review.
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Aminopiridinas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzimidazóis/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Aminopiridinas/efeitos adversos , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzimidazóis/efeitos adversos , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Neoplasias/enzimologia , Neoplasias/patologia , Inibidores de Proteínas Quinases/efeitos adversos , Transdução de Sinais , Resultado do TratamentoRESUMO
Resolution of leishmaniasis depends upon parasite control and limiting inflammation. CD4+ Th1 cells are required to control parasites, whereas CD8+ T cells play a dual role: they promote Th1 cell differentiation but can also increase inflammation at the site of infection as a consequence of cytolysis. Although CD8+ T cells taken from leishmanial lesions are cytolytic, in this study, we showed that only a few CD8+ T cells produced IFN-γ. Correspondingly, only low levels of IL-12 and/or IL-12 mRNA were present in lesions from infected mice, as well as patients. Addition of IL-12 increased IFN-γ production by CD8+ T cells isolated from leishmanial lesions, suggesting that a lack of IL-12 at the site of infection limits IFN-γ production by CD8+ T cells. To determine whether CD8+ T cells could promote resistance in vivo if IL-12 was present, we administered IL-12 to Leishmania-infected RAG mice reconstituted with CD8+ T cells. IL-12 treatment increased the ability of CD8+ T cells to make IFN-γ, but CD8+ T cells still failed to control the parasites. Furthermore, despite the ability of CD8+ T cells to promote immunity to secondary infections, we also found that CD8+ T cells from immune mice were unable to control Leishmania in RAG mice. Taken together, these results indicate that lesional CD8+ T cells fail to make IFN-γ because of a deficit in IL-12 but that, even with IL-12, CD8+ T cells are unable to control Leishmania in the absence of CD4+ T cells.
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Linfócitos T CD8-Positivos/imunologia , Interferon gama/imunologia , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Pele/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Inflamação/imunologia , Interleucina-12/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células Th1/imunologiaRESUMO
Targeting altered tumour metabolism is an emerging therapeutic strategy for cancer treatment. The metabolic reprogramming that accompanies the development of malignancy creates targetable differences between cancer cells and normal cells, which may be exploited for therapy. There is also emerging evidence regarding the role of stromal components, creating an intricate metabolic network consisting of cancer cells, cancer-associated fibroblasts, endothelial cells, immune cells, and cancer stem cells. This metabolic rewiring and crosstalk with the tumour microenvironment play a key role in cell proliferation, metastasis, and the development of treatment resistance. In this review, we will discuss therapeutic opportunities, which arise from dysregulated metabolism and metabolic crosstalk, highlighting strategies that may aid in the precision targeting of altered tumour metabolism with a focus on combinatorial therapeutic strategies.
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Metabolismo Energético/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Fibroblastos Associados a Câncer/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Neoplasias/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacosRESUMO
Vaccination remains one of the greatest medical breakthroughs in human history and has resulted in the near eradication of many formerly lethal diseases in many countries, including the complete eradication of smallpox. However, there remain a number of diseases for which there are no or only partially effective vaccines. There are numerous hurdles in vaccine development, of which knowing the appropriate immune response to target is one of them. Recently, tissue-resident T cells have been shown to mediate high levels of protection for several infections, although the best way to induce these cells is still unclear. Here we compare the ability to generate skin-resident T cells in sites distant from the immunization site following intramuscular and intradermal injection using optimized synthetic DNA vaccines. We found that mice immunized intradermally with a synthetic consensus DNA HIV envelope vaccine by electroporation (EP) are better able to maintain durable antigen-specific cellular responses in the skin than mice immunized by the intramuscular route. We extended these studies by delivering a synthetic DNA vaccine encoding Leishmania glycosomal phosphoenolpyruvate carboxykinase (PEPCK) by EP and again found that the intradermal route was superior to the intramuscular route for generating skin-resident PEPCK-specific T cells. We observed that when challenged with Leishmania major parasites, mice immunized intradermally exhibited significant protection, while mice immunized intramuscularly did not. The protection seen in intradermally vaccinated mice supports the viability of this platform not only to generate skin-resident T cells but also to promote durable protective immune responses at relevant tissue sites.
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Leishmania major/imunologia , Leishmaniose Cutânea/prevenção & controle , Vacinas Protozoárias/imunologia , Pele/imunologia , Linfócitos T/imunologia , Vacinação , Vacinas de DNA/imunologia , Animais , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Deguelin is a rotenoid compound that exists in abundant quantities in the bark, roots, and leaves of the Leguminosae family of plants. An analysis of evidence from both in vitro and in vivo studies suggests that deguelin displays potent anticancer activity against multiple cancer types and exhibits chemopreventive potential in Akt-inducible transgenic mouse models. Deguelin appears to impede carcinogenesis by enhancing cell apoptosis and hindering malignant transformation and tumor cell propagation. Crucial oncogenic pathways likely targeted by deguelin include the epithelial-to-mesenchymal transition; angiogenesis-related pathways; and the phosphoinositide 3-kinase/Akt, Wnt, epidermal growth factor receptor, c-Met, and hedgehog signal transduction cascades. This review article provides a comprehensive summary of current preclinical research featuring deguelin as a leading chemotherapeutic and chemopreventive compound, and it highlights the importance of identifying companion molecular biomarkers and performing systemic pharmacokinetic studies for accelerating the process of developing deguelin as a clinical anticancer agent.