RESUMO
The earliest events during human tumour initiation, although poorly characterized, may hold clues to malignancy detection and prevention1. Here we model occult preneoplasia by biallelic inactivation of TP53, a common early event in gastric cancer, in human gastric organoids. Causal relationships between this initiating genetic lesion and resulting phenotypes were established using experimental evolution in multiple clonally derived cultures over 2 years. TP53 loss elicited progressive aneuploidy, including copy number alterations and structural variants prevalent in gastric cancers, with evident preferred orders. Longitudinal single-cell sequencing of TP53-deficient gastric organoids similarly indicates progression towards malignant transcriptional programmes. Moreover, high-throughput lineage tracing with expressed cellular barcodes demonstrates reproducible dynamics whereby initially rare subclones with shared transcriptional programmes repeatedly attain clonal dominance. This powerful platform for experimental evolution exposes stringent selection, clonal interference and a marked degree of phenotypic convergence in premalignant epithelial organoids. These data imply predictability in the earliest stages of tumorigenesis and show evolutionary constraints and barriers to malignant transformation, with implications for earlier detection and interception of aggressive, genome-instable tumours.
Assuntos
Transformação Celular Neoplásica , Evolução Clonal , Lesões Pré-Cancerosas , Seleção Genética , Neoplasias Gástricas , Humanos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Evolução Clonal/genética , Instabilidade Genômica , Mutação , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Organoides/metabolismo , Organoides/patologia , Aneuploidia , Variações do Número de Cópias de DNA , Análise de Célula Única , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Progressão da Doença , Linhagem da CélulaRESUMO
The termination of a meal is controlled by dedicated neural circuits in the caudal brainstem. A key challenge is to understand how these circuits transform the sensory signals generated during feeding into dynamic control of behaviour. The caudal nucleus of the solitary tract (cNTS) is the first site in the brain where many meal-related signals are sensed and integrated1-4, but how the cNTS processes ingestive feedback during behaviour is unknown. Here we describe how prolactin-releasing hormone (PRLH) and GCG neurons, two principal cNTS cell types that promote non-aversive satiety, are regulated during ingestion. PRLH neurons showed sustained activation by visceral feedback when nutrients were infused into the stomach, but these sustained responses were substantially reduced during oral consumption. Instead, PRLH neurons shifted to a phasic activity pattern that was time-locked to ingestion and linked to the taste of food. Optogenetic manipulations revealed that PRLH neurons control the duration of seconds-timescale feeding bursts, revealing a mechanism by which orosensory signals feed back to restrain the pace of ingestion. By contrast, GCG neurons were activated by mechanical feedback from the gut, tracked the amount of food consumed and promoted satiety that lasted for tens of minutes. These findings reveal that sequential negative feedback signals from the mouth and gut engage distinct circuits in the caudal brainstem, which in turn control elements of feeding behaviour operating on short and long timescales.
Assuntos
Regulação do Apetite , Tronco Encefálico , Ingestão de Alimentos , Retroalimentação Fisiológica , Alimentos , Saciação , Estômago , Regulação do Apetite/fisiologia , Tronco Encefálico/citologia , Tronco Encefálico/fisiologia , Ingestão de Alimentos/fisiologia , Vias Neurais/citologia , Vias Neurais/fisiologia , Neurônios/metabolismo , Hormônio Liberador de Prolactina/metabolismo , Saciação/fisiologia , Núcleo Solitário/citologia , Núcleo Solitário/fisiologia , Estômago/fisiologia , Paladar/fisiologia , Fatores de Tempo , Animais , CamundongosRESUMO
Genetic and epigenetic variation, together with transcriptional plasticity, contribute to intratumour heterogeneity1. The interplay of these biological processes and their respective contributions to tumour evolution remain unknown. Here we show that intratumour genetic ancestry only infrequently affects gene expression traits and subclonal evolution in colorectal cancer (CRC). Using spatially resolved paired whole-genome and transcriptome sequencing, we find that the majority of intratumour variation in gene expression is not strongly heritable but rather 'plastic'. Somatic expression quantitative trait loci analysis identified a number of putative genetic controls of expression by cis-acting coding and non-coding mutations, the majority of which were clonal within a tumour, alongside frequent structural alterations. Consistently, computational inference on the spatial patterning of tumour phylogenies finds that a considerable proportion of CRCs did not show evidence of subclonal selection, with only a subset of putative genetic drivers associated with subclone expansions. Spatial intermixing of clones is common, with some tumours growing exponentially and others only at the periphery. Together, our data suggest that most genetic intratumour variation in CRC has no major phenotypic consequence and that transcriptional plasticity is, instead, widespread within a tumour.
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Adaptação Fisiológica , Neoplasias Colorretais , Regulação Neoplásica da Expressão Gênica , Fenótipo , Humanos , Adaptação Fisiológica/genética , Células Clonais/metabolismo , Células Clonais/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Mutação , Sequenciamento do Exoma , Transcrição GênicaRESUMO
Ovarian high-grade serous carcinoma (HGSC) originates in the fallopian tube, with secretory cells carrying a TP53 mutation, known as p53 signatures, identified as potential precursors. p53 signatures evolve into serous tubal intraepithelial carcinoma (STIC) lesions, which in turn progress into invasive HGSC, which readily spreads to the ovary and disseminates around the peritoneal cavity. We recently investigated the genomic landscape of early- and late-stage HGSC and found higher ploidy in late-stage (median 3.1) than early-stage (median 2.0) samples. Here, to explore whether the high ploidy and possible whole-genome duplication (WGD) observed in late-stage disease were determined early in the evolution of HGSC, we analysed archival formalin-fixed paraffin-embedded (FFPE) samples from five HGSC patients. p53 signatures and STIC lesions were laser-capture microdissected and sequenced using shallow whole-genome sequencing (sWGS), while invasive ovarian/fallopian tube and metastatic carcinoma samples underwent macrodissection and were profiled using both sWGS and targeted next-generation sequencing. Results showed highly similar patterns of global copy number change between STIC lesions and invasive carcinoma samples within each patient. Ploidy changes were evident in STIC lesions, but not p53 signatures, and there was a strong correlation between ploidy in STIC lesions and invasive ovarian/fallopian tube and metastatic samples in each patient. The reconstruction of sample phylogeny for each patient from relative copy number indicated that high ploidy, when present, occurred early in the evolution of HGSC, which was further validated by copy number signatures in ovarian and metastatic tumours. These findings suggest that aberrant ploidy, suggestive of WGD, arises early in HGSC and is detected in STIC lesions, implying that the trajectory of HGSC may be determined at the earliest stages of tumour development. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Assuntos
Cistadenocarcinoma Seroso , Neoplasias das Tubas Uterinas , Neoplasias Ovarianas , Proteína Supressora de Tumor p53 , Humanos , Feminino , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patologia , Neoplasias das Tubas Uterinas/genética , Neoplasias das Tubas Uterinas/patologia , Proteína Supressora de Tumor p53/genética , Carcinoma in Situ/genética , Carcinoma in Situ/patologia , Gradação de Tumores , Variações do Número de Cópias de DNA , Mutação , Genômica/métodos , Sequenciamento Completo do Genoma , Ploidias , Pessoa de Meia-Idade , Biomarcadores Tumorais/genética , Progressão da DoençaRESUMO
Rationale: Idiopathic pulmonary fibrosis (IPF) is a rare and progressive disease that causes progressive cough, exertional dyspnea, impaired quality of life, and death. Objectives: Bexotegrast (PLN-74809) is an oral, once-daily, investigational drug in development for the treatment of IPF. Methods: This Phase-2a multicenter, clinical trial randomized participants with IPF to receive, orally and once daily, bexotegrast at 40 mg, 80 mg, 160 mg, or 320 mg, or placebo, with or without background IPF therapy (pirfenidone or nintedanib), in an approximately 3:1 ratio in each bexotegrast dose cohort, for at least 12 weeks. The primary endpoint was incidence of treatment-emergent adverse events (TEAEs). Exploratory efficacy endpoints included change from baseline in FVC, quantitative lung fibrosis (QLF) extent (%), and changes from baseline in fibrosis-related biomarkers. Measurements and Main Results: Bexotegrast was well tolerated, with similar rates of TEAEs in the pooled bexotegrast and placebo groups (62/89 [69.7%] and 21/31 [67.7%], respectively). Diarrhea was the most common TEAE; most participants with diarrhea also received nintedanib. Participants who were treated with bexotegrast experienced a reduction in FVC decline over 12 weeks compared with those who received placebo, with or without background therapy. A dose-dependent antifibrotic effect of bexotegrast was observed with QLF imaging, and a decrease in fibrosis-associated biomarkers was observed with bexotegrast versus placebo. Conclusions: Bexotegrast demonstrated a favorable safety and tolerability profile, up to 12 weeks for the doses studied. Exploratory analyses suggest an antifibrotic effect according to FVC, QLF imaging, and circulating levels of fibrosis biomarkers. Clinical trial registered with www.clinicaltrials.gov (NCT04396756).
Assuntos
Fibrose Pulmonar Idiopática , Indóis , Piridonas , Humanos , Fibrose Pulmonar Idiopática/tratamento farmacológico , Fibrose Pulmonar Idiopática/fisiopatologia , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Indóis/uso terapêutico , Piridonas/uso terapêutico , Piridonas/efeitos adversos , Resultado do Tratamento , Método Duplo-Cego , Relação Dose-Resposta a DrogaRESUMO
The field of optimal experimental design uses mathematical techniques to determine experiments that are maximally informative from a given experimental setup. Here we apply a technique from artificial intelligence-reinforcement learning-to the optimal experimental design task of maximizing confidence in estimates of model parameter values. We show that a reinforcement learning approach performs favourably in comparison with a one-step ahead optimisation algorithm and a model predictive controller for the inference of bacterial growth parameters in a simulated chemostat. Further, we demonstrate the ability of reinforcement learning to train over a distribution of parameters, indicating that this approach is robust to parametric uncertainty.
Assuntos
Inteligência Artificial , Projetos de Pesquisa , Reforço Psicológico , Algoritmos , BiologiaRESUMO
Predictability is a fundamental requirement in biological engineering. As we move to building coordinated multicellular systems, the potential for such systems to display chaotic behaviour becomes a concern. Therefore understanding which systems show chaos is an important design consideration. We developed a methodology to explore the potential for chaotic dynamics in small microbial communities governed by resource competition, intercellular communication and competitive bacteriocin interactions. Our model selection pipeline uses Approximate Bayesian Computation to first identify oscillatory behaviours as a route to finding chaotic behaviour. We have shown that we can expect to find chaotic states in relatively small synthetic microbial systems, understand the governing dynamics and provide insights into how to control such systems. This work is the first to query the existence of chaotic behaviour in synthetic microbial communities and has important ramifications for the fields of biotechnology, bioprocessing and synthetic biology.
Assuntos
Bacteriocinas , Microbiota , Teorema de Bayes , Biologia Sintética/métodos , Consórcios MicrobianosRESUMO
Climate change effects over the last century have seen grape wine growers being faced with earlier budburst and shorter seasons. One effect is higher sugar levels in the grape berries, resulting in wines with higher than typical alcohol concentrations. Winemakers, both in Australia and globally, need to reassess their wine making approaches to address the challenges associated with warmer drier conditions. This review focuses on two pre-fermentation approaches that address ethanol production during fermentation, so that wine makers can produce a wine with lower final alcohol levels at the same time as addressing any negative impacts on wine quality. First, microbiological yeast approaches are reviewed. This approach can reduce final alcohol levels in a treated wine between 0.2% v/v-3.7% v/v; however, diverse wine quality impacts can result, dependant on the microbiological yeast approach taken. Second, the pre-fermentation approach of water addition/substitution into a high sugar grape must is reviewed. To date, recent studies indicate that this 'water treatment' of musts approach is effective with respect to reducing final alcohol levels from between 0.6% v/v-5.9% v/v in the resultant wines, with less variation effects on final wine quality. It is noted that further studies for the 'water treatment' of high sugar musts approach are required to provide additional foundational data sets with respect to impacts on chemical, phenolic and sensory attributes of the final wine products, both within and across vintages. This is especially important as winemakers adapt their winemaking approaches in a changing climate. © 2022 Society of Chemical Industry.
Assuntos
Vitis , Água , Vinho , Leveduras , Etanol/análise , Fermentação , Açúcares , Vitis/microbiologia , Vinho/análise , Leveduras/metabolismoRESUMO
Whole-cell biosensors hold potential in a variety of industrial, medical, and environmental applications. These biosensors can be constructed through the repurposing of bacterial sensing mechanisms, including the common two-component system (TCS). Here we report on the construction of a range of novel biosensors that are sensitive to acetoacetate, a molecule that plays a number of roles in human health and biology. These biosensors are based on the AtoSC TCS. An ordinary differential equation model to describe the action of the AtoSC TCS was developed and sensitivity analysis of this model used to help inform biosensor design. The final collection of biosensors constructed displayed a range of switching behaviours at physiologically relevant acetoacetate concentrations and can operate in several Escherichia coli host strains. It is envisaged that these biosensor strains will offer an alternative to currently available commercial strip tests and, in future, may be adopted for more complex in vivo or industrial monitoring applications.
Assuntos
Acetoacetatos/metabolismo , Técnicas Biossensoriais , Proteínas de Escherichia coli , Escherichia coli , Regulação Bacteriana da Expressão Gênica , Acetoacetatos/análise , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Humanos , ÓperonRESUMO
Multi-species microbial communities are widespread in natural ecosystems. When employed for biomanufacturing, engineered synthetic communities have shown increased productivity in comparison with monocultures and allow for the reduction of metabolic load by compartmentalising bioprocesses between multiple sub-populations. Despite these benefits, co-cultures are rarely used in practice because control over the constituent species of an assembled community has proven challenging. Here we demonstrate, in silico, the efficacy of an approach from artificial intelligence-reinforcement learning-for the control of co-cultures within continuous bioreactors. We confirm that feedback via a trained reinforcement learning agent can be used to maintain populations at target levels, and that model-free performance with bang-bang control can outperform a traditional proportional integral controller with continuous control, when faced with infrequent sampling. Further, we demonstrate that a satisfactory control policy can be learned in one twenty-four hour experiment by running five bioreactors in parallel. Finally, we show that reinforcement learning can directly optimise the output of a co-culture bioprocess. Overall, reinforcement learning is a promising technique for the control of microbial communities.
Assuntos
Técnicas de Cocultura/métodos , Inteligência Artificial , Reatores Biológicos/microbiologia , Simulação por Computador , Ecossistema , Retroalimentação , Aprendizagem/fisiologia , Microbiota/fisiologia , Reforço PsicológicoRESUMO
BACKGROUND: Despite evidence that communication and teamwork are critical to patient safety, few care processes have been intentionally designed for this purpose in labor and delivery. The purpose of this project was to design an intrapartum care process that aims to improve communication and teamwork between clinicians and patients. METHODS: We followed the "Double-Diamond" design method with four sequential steps: Discover, Define, Develop, and Deliver. In Discover, we searched professional guidelines and peer-reviewed literature to delineate the challenges to quality of intrapartum care and to uncover options for solutions. In Define, we convened an interdisciplinary group of experts to focus the problem scope and prioritize solution features. In Develop, we created initial prototype solutions. In Deliver, we engaged clinicians and patients in rapid cycle testing to iteratively produce a care process called "TeamBirth" that aims to improve team communication. RESULTS: We designed TeamBirth, an intrapartum care process composed of brief team meetings ("huddles") between clinicians and patients. Huddles are navigated by a shared planning board placed in the labor and delivery room in view of the patient and their care team. The board promotes transparent and reliable communication and contains four areas to be acknowledged or discussed: (a) the names of the team members, starting with the patient; (b) the patient's preferences; (c) the care plan for the patient, baby, and labor progress; and (d) when the next team huddle is anticipated. DISCUSSION: We identified an opportunity to improve the safety and dignity of childbirth care through an intrapartum care process that promotes reliable and structured communication and teamwork. Future work should evaluate the acceptability and feasibility of implementation and potential impact on safety and experience of care.
Assuntos
Comunicação , Trabalho de Parto , Feminino , Humanos , Equipe de Assistência ao Paciente , Segurança do Paciente , GravidezRESUMO
Revefenacin inhalation solution is an anticholinergic indicated for the maintenance treatment of patients with chronic obstructive pulmonary disease. Mass balance, pharmacokinetics, and metabolism of revefenacin were evaluated after intravenous and oral administration of [14C]-revefenacin in healthy subjects. Pharmacological activity of the major revefenacin metabolite was also assessed. Adult males (n = 9) received 20 µg intravenously of approximately 1 µCi [14C]-revefenacin and/or a single 200-µg oral solution of approximately 10 µCi [14C]-revefenacin. Mean recovery of radioactive material was 81.4% after intravenous administration (54.4% in feces; 27.1% in urine) and 92.7% after oral dosing (88.0% in feces, 4.7% in urine). Mean absolute bioavailability of oral revefenacin was low (2.8%). Intact revefenacin accounted for approximately 52.1% and 13.1% of the total radioactivity in plasma after intravenous and oral administration, respectively. Two main circulating metabolites were observed in plasma. After an intravenous dose, a hydrolysis product, THRX-195518 (M2) was observed that circulated in plasma at 14.3% of total radioactivity. After an oral dose, both THRX-195518 and THRX-697795 (M10, N-dealkylation and reduction of the parent compound) were observed at 12.5% of total circulating radioactivity. THRX-195518 was the major metabolite excreted in feces and comprised 18.8% and 9.4% of the administered intravenous and oral dose, respectively. The major metabolic pathway for revefenacin was hydrolysis to THRX-195518. In vitro pharmacological evaluation of THRX-195518 indicated that it had a 10-fold lower binding affinity for the M3 receptor relative to revefenacin. Receptor occupancy analysis suggested that THRX-195518 has minimal contribution to systemic pharmacology relative to revefenacin after inhaled administration. SIGNIFICANCE STATEMENT: The major metabolic pathway for revefenacin was hydrolysis to the metabolite THRX-195518 (M2), and both revefenacin and THRX-195518 underwent hepatic-biliary and fecal elimination after oral or intravenous administration with negligible renal excretion. Pharmacological evaluation of THRX-195518 indicated that it had a 10-fold lower binding affinity for the M3 muscarinic receptor relative to revefenacin and that THRX-195518 has minimal contribution to systemic pharmacology after inhaled administration.
Assuntos
Benzamidas/farmacocinética , Broncodilatadores/farmacocinética , Carbamatos/farmacocinética , Antagonistas Muscarínicos/farmacocinética , Administração por Inalação , Administração Oral , Adulto , Benzamidas/administração & dosagem , Benzamidas/análise , Disponibilidade Biológica , Broncodilatadores/administração & dosagem , Carbamatos/administração & dosagem , Carbamatos/análise , Fezes/química , Voluntários Saudáveis , Eliminação Hepatobiliar , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Antagonistas Muscarínicos/administração & dosagem , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Soluções , Adulto JovemRESUMO
BACKGROUND: Fatty acids derived de novo or taken up from the extracellular space are an essential source of nutrient for cell growth and proliferation. Radiopharmaceuticals including 11C-acetate, and 18F-FAC (2-18F-fluoroacetate), have previously been used to study short-chain fatty acid (SCFA) metabolism. We developed 18F-fluoropivalate (18F-FPIA; 3-18F-fluoro-2,2-dimethylpropionic acid) bearing a gem-dimethyl substituent to assert metabolic stability for studying SCFA metabolism. We report the safety, biodistribution, and internal radiation dosimetry profile of 18F-FPIA in 24 healthy volunteers and the effect of dietary conditions. MATERIALS AND METHODS: Healthy volunteer male and female subjects were enrolled (n = 24), and grouped into 12 fed and 12 fasted. Non-esterified fatty acids (NEFA) and carnitine blood measurements were assessed. Subjects received 159.48 MBq (range, 47.31-164.66 MBq) of 18F-FPIA. Radiochemical purity was > 99%. Safety data were obtained during and 24 h after radiotracer administration. Subjects underwent detailed multiple whole-body PET/CT scanning with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose was calculated using OLINDA 1.1. RESULTS: All subjects tolerated 18F-FPIA with no adverse events. Over 90% of radiotracer was present in plasma at 60 min post-injection. The organs receiving highest absorbed dose (in mGy/MBq) were the liver (0.070 ± 0.023), kidneys (0.043 ± 0.013), gallbladder wall (0.026 ± 0.003), and urinary bladder (0.021 ± 0.004); otherwise there was low tissue uptake. The calculated effective dose using mean organ residence times over all 24 subjects was 0.0154 mSv/MBq (SD ± 0.0010). No differences in biodistribution or dosimetry were seen in fed and fasted subjects, though systemic NEFA and carnitine levels reflected fasted and fed states. CONCLUSION: The favourable safety, imaging, and dosimetric profile makes 18F-FPIA a promising candidate radiotracer for tracing SCFA metabolism.
Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Ácidos Graxos Voláteis , Feminino , Voluntários Saudáveis , Humanos , Masculino , Radiometria , Compostos Radiofarmacêuticos , Distribuição TecidualRESUMO
INTRODUCTION: The efficacy and safety of recombinant factor VIII Fc fusion protein (rFVIIIFc) as an extended half-life treatment for severe haemophilia A were demonstrated in the Phase 3 A-LONG and Kids A-LONG studies. Eligible subjects who completed A-LONG and Kids A-LONG could enrol in ASPIRE (NCT01454739), an open-label extension study. AIM: To report the long-term safety and efficacy of rFVIIIFc in subjects with severe haemophilia A who enrolled in ASPIRE. METHODS: Previously treated subjects received one or more of the following regimens: individualized prophylaxis (IP), weekly prophylaxis, modified prophylaxis or episodic treatment. Subjects could switch treatment regimen at any time. The primary endpoint was inhibitor development. RESULTS: A total of 150 subjects from A-LONG and 61 subjects from Kids A-LONG enrolled in ASPIRE. Most subjects received the IP regimen (A-LONG: n = 110; Kids A-LONG: n = 59). Median (range) treatment duration in ASPIRE for subjects from A-LONG and Kids A-LONG was 3.9 (0.1-5.3) years and 3.2 (0.3-3.9) years, respectively. No inhibitors were observed (0 per 1000 subject-years; 95% confidence interval, 0-5.2) and the overall rFVIIIFc safety profile was consistent with prior studies. For subjects on the IP regimen, annualized bleed rates (ABR) remained low (median overall ABR for adults and adolescents was <1.0) and extended-dosing intervals were maintained (median of 3.5 days) for the majority of subjects in ASPIRE. CONCLUSION: ASPIRE results, which include up to 5 years of follow-up data, confirm earlier reports on the consistent and well-characterized safety and efficacy of rFVIIIFc treatment for severe haemophilia A.
Assuntos
Fator VIII/uso terapêutico , Hemofilia A/tratamento farmacológico , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Fator VIII/farmacologia , Feminino , Humanos , Fragmentos Fc das Imunoglobulinas/farmacologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes de Fusão/farmacologia , Resultado do Tratamento , Adulto JovemRESUMO
The cancer genome is shaped by three components of the evolutionary process: mutation, selection and drift. While many studies have focused on the first two components, the role of drift in cancer evolution has received little attention. Drift occurs when all individuals in the population have the same likelihood of producing surviving offspring, and so by definition a drifting population is one that is evolving neutrally. Here we focus on how neutral evolution is manifested in the cancer genome. We discuss how neutral passenger mutations provide a magnifying glass that reveals the evolutionary dynamics underpinning cancer development, and outline how statistical inference can be used to quantify these dynamics from sequencing data. We argue that only after we understand the impact of neutral drift on the genome can we begin to make full sense of clonal selection. This article is part of a Special Issue entitled: Evolutionary principles - heterogeneity in cancer? Edited by Dr. Robert A. Gatenby.
Assuntos
Biomarcadores Tumorais/genética , Transformação Celular Neoplásica/genética , Evolução Molecular , Deriva Genética , Aptidão Genética , Heterogeneidade Genética , Neoplasias/genética , Adaptação Fisiológica , Animais , Biomarcadores Tumorais/metabolismo , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Genômica/métodos , Hereditariedade , Humanos , Modelos Genéticos , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Linhagem , Fenótipo , Transdução de Sinais/genética , Fatores de TempoRESUMO
BACKGROUND: Revefenacin, a once-daily, long-acting muscarinic antagonist delivered via standard jet nebulizer, increased trough forced expiratory volume in 1 s (FEV1) in patients with moderate to very severe chronic obstructive pulmonary disease (COPD) in prior phase 3 trials. We evaluated the efficacy of revefenacin in patients with markers of more severe COPD. METHODS: A post hoc subgroup analysis of two replicate, randomized, phase 3 trials was conducted over 12 weeks. Endpoints included least squares change from baseline in trough FEV1, St. George's Respiratory Questionnaire (SGRQ) responders, and transition dyspnea index (TDI) responders at Day 85. This analysis included patient subgroups at high risk for COPD exacerbations and compared patients who received revefenacin 175 µg and placebo: severe and very severe airflow limitation (percent predicted FEV1 30%-< 50% and < 30%), 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) D, reversibility (≥ 12% and ≥ 200 mL increase in FEV1) to short-acting bronchodilators, concurrent use of long-acting ß agonists and/or inhaled corticosteroids, older age (> 65 and > 75 years), and comorbidity risk factors. RESULTS: Revefenacin demonstrated significant improvements in FEV1 versus placebo at Day 85 among the intention-to-treat (ITT) population and all subgroups. Additionally, there was a greater number of SGRQ and TDI responders in the ITT population and the majority of subgroups analyzed among patients who received revefenacin versus placebo. For the SGRQ responders, the odds of response (odds ratio > 2.0) were significantly greater in the revefenacin arm versus the placebo arm among the severe airflow obstruction, very severe airflow obstruction and 2011 GOLD D subgroups. For the TDI responders, the odds of response (odds ratio > 2.0) were significantly greater among the severe airflow obstruction subgroup and patients aged > 75 years. CONCLUSIONS: Revefenacin showed significantly greater improvements in FEV1 versus placebo in the ITT population and all subgroups. Furthermore, there were a greater number of SGRQ and TDI responders in the ITT population, and in the majority of patient subgroups among patients who received revefenacin versus placebo. Based on the data presented, revefenacin could be a therapeutic option among patients with markers of more severe COPD. TRIAL REGISTRATION: Clinical trials registered with www.clinicaltrials.gov (Studies 0126 [NCT02459080; prospectively registered 22 May 2015] and 0127 [NCT02512510; prospectively registered 28 July 2015]).
Assuntos
Benzamidas/administração & dosagem , Broncodilatadores/administração & dosagem , Carbamatos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Administração por Inalação , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Índice de Gravidade de Doença , Fatores de TempoRESUMO
OBJECTIVE: The crypt population in the human intestine is dynamic: crypts can divide to produce two new daughter crypts through a process termed crypt fission, but whether this is balanced by a second process to remove crypts, as recently shown in mouse models, is uncertain. We examined whether crypt fusion (the process of two neighbouring crypts fusing into a single daughter crypt) occurs in the human colon. DESIGN: We used somatic alterations in the gene cytochrome c oxidase (CCO) as lineage tracing markers to assess the clonality of bifurcating colon crypts (n=309 bifurcating crypts from 13 patients). Mathematical modelling was used to determine whether the existence of crypt fusion can explain the experimental data, and how the process of fusion influences the rate of crypt fission. RESULTS: In 55% (21/38) of bifurcating crypts in which clonality could be assessed, we observed perfect segregation of clonal lineages to the respective crypt arms. Mathematical modelling showed that this frequency of perfect segregation could not be explained by fission alone (p<10-20). With the rates of fission and fusion taken to be approximately equal, we then used the distribution of CCO-deficient patch size to estimate the rate of crypt fission, finding a value of around 0.011 divisions/crypt/year. CONCLUSIONS: We have provided the evidence that human colonic crypts undergo fusion, a potential homeostatic process to regulate total crypt number. The existence of crypt fusion in the human colon adds a new facet to our understanding of the highly dynamic and plastic phenotype of the colonic epithelium.
Assuntos
Focos de Criptas Aberrantes/patologia , Colo/patologia , Homeostase/fisiologia , Mucosa Intestinal/patologia , Adulto , Idoso , Técnicas de Cultura de Células , Fusão Celular , Complexo IV da Cadeia de Transporte de Elétrons , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos TeóricosRESUMO
BACKGROUND: Revefenacin is a long-acting muscarinic antagonist that was recently approved for the nebulized treatment of chronic obstructive pulmonary disease (COPD). Although shorter duration studies have documented the efficacy of revefenacin in COPD, longer-term efficacy has not been described. In a recent 52-week safety trial, revefenacin was well tolerated and had a favorable benefit-risk profile. Here we report exploratory efficacy and health outcomes in patients receiving revefenacin 175 µg or 88 µg daily during the 52-week trial. METHODS: In this randomized, parallel-group, 52-week trial (NCT02518139), 1055 participants with moderate to very severe COPD received revefenacin 175 µg or 88 µg in a double-blind manner, or open-label active control tiotropium. RESULTS: Over the 52-week treatment period, both doses of revefenacin, as well as tiotropium, elicited significant (all p < 0.0003) improvements from baseline in trough forced expiratory volume in 1 s (FEV1). The trough FEV1 profile (least squares mean change from baseline) for revefenacin 175 µg ranged from 52.3-124.3 mL and the trough FEV1 profile for tiotropium ranged from 79.7-112.8 mL. In subgroup comparisons, the effect of revefenacin on trough FEV1 was comparable in patients taking concomitant long-acting ß-agonists, with or without inhaled corticosteroids, with patients who were not taking these medications. There were statistically significant (p < 0.05) improvements in all measured health status outcomes (evaluated using St. George's Respiratory Questionnaire, COPD Assessment Test, Clinical COPD Questionnaire and Baseline and Transition Dyspnea Index) from 3 months onward, in all treatment arms. CONCLUSIONS: Significant sustained improvements from baseline in trough FEV1 and respiratory health outcomes were demonstrated for 175-µg revefenacin over 52 weeks, further supporting its use as a once-daily bronchodilator for the nebulized treatment of patients with COPD. TRIAL REGISTRATION: NCT02518139 ; Registered 5 August 2015.
Assuntos
Benzamidas/administração & dosagem , Broncodilatadores/administração & dosagem , Carbamatos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Índice de Gravidade de Doença , Idoso , Método Duplo-Cego , Esquema de Medicação , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Resultado do TratamentoRESUMO
In humans, C-X-C chemokine receptor type 4 (CXCR4) is a protein that is encoded by the CXCR4 gene and binds the ligand CXCL12 (also known as SDF-1). The CXCR4-CXCL12 interaction in cancer elicits biological activities that result in tumor progression and has accordingly been the subject of significant investigation for detection and treatment of the disease. Peptidic antagonists have been labeled with a variety of radioisotopes for the detection of CXCR4, but the methodology utilizing small molecules has predominantly used radiometals. We report here the development of a 18F-radiolabeled cyclam-based small molecule radioprobe, [18F]MCFB, for imaging CXCR4 expression. The IC50 value of [19F]MCFB for CXCR4 was similar to that of AMD3465 (111.3 and 89.8 nM, respectively). In vitro binding assays show that the tracer depicted a differential CXCR4 expression, which was blocked in the presence of AMD3465, demonstrating the specificity of [18F]MCFB. Positron emission tomography (PET) imaging studies showed a distinct uptake of the radioprobe in lymphoma and breast cancer xenografts. High liver and kidney uptakes were seen with [18F]MCFB, leading us to further examine the basis of its pharmacokinetics in relation to the tracer's cationic nature and thus the role of organic cation transporters (OCTs). Substrate competition following the intravenous injection of metformin led to a marked decrease in the urinary excretion of [18F]MCFB, with moderate changes observed in other organs, including the liver. Our results suggest involvement of OCTs in the renal elimination of the tracer. In conclusion, the 18F-radiolabeled monocyclam, [18F]MCFB, has potential to detect tumor CXCR4 in nonhepatic tissues.
Assuntos
Fluordesoxiglucose F18/química , Compostos Heterocíclicos/química , Neoplasias/metabolismo , Compostos Radiofarmacêuticos/química , Receptores CXCR4/metabolismo , Animais , Linhagem Celular Tumoral , Quimiocina CXCL12/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Concentração Inibidora 50 , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Neoplasias/diagnóstico por imagem , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Piridinas , Receptores CXCR4/genética , Eliminação Renal , Distribuição TecidualRESUMO
The cardiovascular safety of revefenacin, an anticholinergic indicated for the maintenance treatment of patients with chronic obstructive lung disease (COPD), was evaluated in phase 3 trials in patients with moderate to very severe COPD. No clinically meaningful changes in 12-lead electrocardiogram recordings were observed with up to 52 weeks of once-daily revefenacin 88 or 175⯵g. In a pooled analysis of Studies 0126 and 0127, the incidence of prolonged QT interval corrected for heart rate using the Fridericia correction formula (QTcF; >450 msec) for revefenacin 88⯵g (nâ¯=â¯23, 5.6%) and revefenacin 175⯵g (nâ¯=â¯23, 5.9%) was similar to that for placebo (nâ¯=â¯22, 5.3%). In Study 0128, the incidence of prolonged QTcF was similar in the revefenacin 175⯵g (nâ¯=â¯25, 7.7%) and tiotropium (nâ¯=â¯26, 7.3%) groups and lower in the revefenacin 88⯵g (nâ¯=â¯15, 4.2%) group. There were four major adverse cardiac events (MACEs) in Study 0126 (one, two, and one in the placebo, revefenacin 88⯵g, and revefenacin 175⯵g groups, respectively), no MACEs in Study 0127 and 26 MACEs in Study 0128 (9, 10 and 7 in the revefenacin 88⯵g, revefenacin 175⯵g and tiotropium groups, respectively). In Study 0128, only one MACE was considered possibly/probably related to revefenacin (atrial fibrillation in the revefenacin 175⯵g group). Thus, revefenacin may provide beneficial nebulized therapy for patients with COPD without further elevating their risk of cardiovascular events.