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1.
Nature ; 631(8022): 819-825, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38843826

RESUMO

Horses revolutionized human history with fast mobility1. However, the timeline between their domestication and their widespread integration as a means of transport remains contentious2-4. Here we assemble a collection of 475 ancient horse genomes to assess the period when these animals were first reshaped by human agency in Eurasia. We find that reproductive control of the modern domestic lineage emerged around 2200 BCE, through close-kin mating and shortened generation times. Reproductive control emerged following a severe domestication bottleneck starting no earlier than approximately 2700 BCE, and coincided with a sudden expansion across Eurasia that ultimately resulted in the replacement of nearly every local horse lineage. This expansion marked the rise of widespread horse-based mobility in human history, which refutes the commonly held narrative of large horse herds accompanying the massive migration of steppe peoples across Europe around 3000 BCE and earlier3,5. Finally, we detect significantly shortened generation times at Botai around 3500 BCE, a settlement from central Asia associated with corrals and a subsistence economy centred on horses6,7. This supports local horse husbandry before the rise of modern domestic bloodlines.


Assuntos
Domesticação , Cavalos , Animais , Europa (Continente) , História Antiga , Humanos , Ásia , Migração Humana/história , Feminino , Masculino , Migração Animal , Genoma/genética , Reprodução , Criação de Animais Domésticos/história
2.
Blood ; 141(25): 3065-3077, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-36888932

RESUMO

Mitochondrial damage-associated molecular patterns (mtDAMPs) include proteins, lipids, metabolites, and DNA and have various context-specific immunoregulatory functions. Cell-free mitochondrial DNA (mtDNA) is recognized via pattern recognition receptors and is a potent activator of the innate immune system. Cell-free mtDNA is elevated in the circulation of trauma patients and patients with cancer; however, the functional consequences of elevated mtDNA are largely undefined. Multiple myeloma (MM) relies upon cellular interactions within the bone marrow (BM) microenvironment for survival and progression. Here, using in vivo models, we describe the role of MM cell-derived mtDAMPs in the protumoral BM microenvironment and the mechanism and functional consequence of mtDAMPs in myeloma disease progression. Initially, we identified elevated levels of mtDNA in the peripheral blood serum of patients with MM compared with those of healthy controls. Using the MM1S cells engrafted into nonobese diabetic severe combined immunodeficient gamma mice, we established that elevated mtDNA was derived from MM cells. We further show that BM macrophages sense and respond to mtDAMPs through the stimulator of interferon genes (STING) pathway, and inhibition of this pathway reduces MM tumor burden in the KaLwRij-5TGM1 mouse model. Moreover, we found that MM-derived mtDAMPs induced upregulation of chemokine signatures in BM macrophages, and inhibition of this signature resulted in egress of MM cells from the BM. Here, we demonstrate that malignant plasma cells release mtDNA, a form of mtDAMPs, into the myeloma BM microenvironment, which in turn activates macrophages via STING signaling. We establish the functional role of these mtDAMP-activated macrophages in promoting disease progression and retaining MM cells in the protumoral BM microenvironment.


Assuntos
Mieloma Múltiplo , Animais , Camundongos , Mieloma Múltiplo/metabolismo , Plasmócitos/patologia , Macrófagos/metabolismo , DNA Mitocondrial/genética , Progressão da Doença , Microambiente Tumoral
3.
J Anim Ecol ; 93(6): 743-754, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38415301

RESUMO

Animal space use and spatial overlap can have important consequences for population-level processes such as social interactions and pathogen transmission. Identifying how environmental variability and inter-individual variation affect spatial patterns and in turn influence interactions in animal populations is a priority for the study of animal behaviour and disease ecology. Environmental food availability and macroparasite infection are common drivers of variation, but there are few experimental studies investigating how they affect spatial patterns of wildlife. Bank voles (Clethrionomys glareolus) are a tractable study system to investigate spatial patterns of wildlife and are amenable to experimental manipulations. We conducted a replicated, factorial field experiment in which we provided supplementary food and removed helminths in vole populations in natural forest habitat and monitored vole space use and spatial overlap using capture-mark-recapture methods. Using network analysis, we quantified vole space use and spatial overlap. We compared the effects of food supplementation and helminth removal and investigated the impacts of season, sex and reproductive status on space use and spatial overlap. We found that food supplementation decreased vole space use while helminth removal increased space use. Space use also varied by sex, reproductive status and season. Spatial overlap was similar between treatments despite up to threefold differences in population size. By quantifying the spatial effects of food availability and macroparasite infection on wildlife populations, we demonstrate the potential for space use and population density to trade-off and maintain consistent spatial overlap in wildlife populations. This has important implications for spatial processes in wildlife including pathogen transmission.


Assuntos
Arvicolinae , Animais , Arvicolinae/fisiologia , Feminino , Masculino , Estações do Ano , Helmintíase Animal/parasitologia , Helmintíase Animal/epidemiologia , Doenças dos Roedores/parasitologia , Helmintos/fisiologia
4.
Nature ; 559(7714): 400-404, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29988082

RESUMO

The incidence of acute myeloid leukaemia (AML) increases with age and mortality exceeds 90% when diagnosed after age 65. Most cases arise without any detectable early symptoms and patients usually present with the acute complications of bone marrow failure1. The onset of such de novo AML cases is typically preceded by the accumulation of somatic mutations in preleukaemic haematopoietic stem and progenitor cells (HSPCs) that undergo clonal expansion2,3. However, recurrent AML mutations also accumulate in HSPCs during ageing of healthy individuals who do not develop AML, a phenomenon referred to as age-related clonal haematopoiesis (ARCH)4-8. Here we use deep sequencing to analyse genes that are recurrently mutated in AML to distinguish between individuals who have a high risk of developing AML and those with benign ARCH. We analysed peripheral blood cells from 95 individuals that were obtained on average 6.3 years before AML diagnosis (pre-AML group), together with 414 unselected age- and gender-matched individuals (control group). Pre-AML cases were distinct from controls and had more mutations per sample, higher variant allele frequencies, indicating greater clonal expansion, and showed enrichment of mutations in specific genes. Genetic parameters were used to derive a model that accurately predicted AML-free survival; this model was validated in an independent cohort of 29 pre-AML cases and 262 controls. Because AML is rare, we also developed an AML predictive model using a large electronic health record database that identified individuals at greater risk. Collectively our findings provide proof-of-concept that it is possible to discriminate ARCH from pre-AML many years before malignant transformation. This could in future enable earlier detection and monitoring, and may help to inform intervention.


Assuntos
Predisposição Genética para Doença , Saúde , Leucemia Mieloide Aguda/genética , Mutação , Adulto , Fatores Etários , Idoso , Progressão da Doença , Registros Eletrônicos de Saúde , Feminino , Humanos , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Mutagênese , Prevalência , Medição de Risco
5.
Cell Mol Life Sci ; 80(2): 40, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36629955

RESUMO

Since the turn of the century, advances in targeted therapy and immunotherapy have revolutionized the treatment of cancer. Although these approaches have far outperformed traditional therapies in various clinical settings, both remain plagued by mechanisms of innate and acquired resistance that limit therapeutic efficacy in many patients. With a focus on tumor-intrinsic resistance to immunotherapy, this review highlights our current understanding of the immunologic and oncogenic pathways whose genetic dysregulation in cancer cells enables immune escape. Emphasis is placed on genomic, epigenomic, transcriptomic, and proteomic aberrations that influence the activity of these pathways in the context of immune resistance. Specifically, the role of pathways that govern interferon signaling, antigen processing and presentation, and immunologic cell death as determinants of tumor immune susceptibility are discussed. Likewise, mechanisms of tumor immune resistance mediated by dysregulated RAS-MAPK, WNT, PI3K-AKT-mTOR, and cell cycle pathways are described. Finally, this review highlights the ways in which recent insight into genetic dysregulation of these immunologic and oncogenic signaling pathways is informing the design of combination targeted therapy-immunotherapy regimens that aim to restore immune susceptibility of cancer cells by overcoming resistance mechanisms that often limit the success of monotherapies.


Assuntos
Neoplasias , Fosfatidilinositol 3-Quinases , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Proteômica , Neoplasias/genética , Neoplasias/terapia , Neoplasias/metabolismo , Imunoterapia , Transdução de Sinais , Microambiente Tumoral
6.
Emerg Infect Dis ; 29(12): 2576-2578, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37987606

RESUMO

We report a novel orthohantavirus, putatively named Ozark orthohantavirus, in hispid cotton rats captured within the Ozark Plateau in Arkansas, USA. This virus phylogenetically clusters with other orthohantaviruses that cause severe human disease. Continued orthohantavirus surveillance and virus sequencing are needed to address the potential public health threat of this virus.


Assuntos
Infecções por Hantavirus , Orthohantavírus , Vírus de RNA , Animais , Humanos , Arkansas/epidemiologia , Anticorpos Antivirais , Sigmodontinae
7.
Emerg Infect Dis ; 29(5): 1029-1032, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37081584

RESUMO

We found similar mild perivascular inflammation in lungs of Bombali virus-positive and -negative Mops condylurus bats in Kenya, indicating the virus is well-tolerated. Our findings indicate M. condylurus bats may be a reservoir host for Bombali virus. Increased surveillance of these bats will be important to reduce potential virus spread.


Assuntos
Quirópteros , Reservatórios de Doenças , Ebolavirus , Pulmão , Animais , Quirópteros/virologia , Reservatórios de Doenças/virologia , Ebolavirus/isolamento & purificação , Quênia , Zoonoses/epidemiologia , Zoonoses/patologia , Zoonoses/virologia , Pulmão/irrigação sanguínea , Pulmão/patologia , Inflamação/patologia
8.
Cancer Metastasis Rev ; 41(4): 833-852, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35701636

RESUMO

Epigenetic regulation of gene expression is a fundamental determinant of molecular and cellular function, and epigenetic reprogramming in the context of cancer has emerged as one of the key enabling characteristics associated with acquisition of the core hallmarks of this disease. As such, there has been renewed interest in studying the role of transcription factors as epigenetic regulators of gene expression in cancer. In this review, we discuss the current state of knowledge surrounding the oncogenic functions of FOXC2, a transcription factor that frequently becomes dysregulated in a variety of cancer types. In addition to highlighting the clinical impact of aberrant FOXC2 activity in cancer, we discuss mechanisms by which this transcription factor becomes dysregulated in both tumor and tumor-associated cells, placing particular emphasis on the ways in which FOXC2 promotes key hallmarks of cancer progression. Finally, we bring attention to important issues related to the oncogenic dysregulation of FOXC2 that must be addressed going forward in order to improve our understanding of FOXC2-mediated cancer progression and to guide prognostic and therapeutic applications of this knowledge in clinical settings.


Assuntos
Transição Epitelial-Mesenquimal , Neoplasias , Humanos , Transição Epitelial-Mesenquimal/genética , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Epigênese Genética , Neoplasias/genética
9.
J Sports Sci ; 41(4): 342-349, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37149899

RESUMO

The relationships between movement style and golf performance have been well researched, but the premise of segregated movement styles has not been fully examined. The purpose of this investigation was to examine the postulation that centre of pressure data are not best described by segregated styles but instead by a continuum and to determine relationships between centre of pressure, handicap and clubhead speed using a continuous approach. Centre of pressure paths of driver and 5-iron shots from 104 amateur golfers were analysed using discrete and continuous methods. Discrete methods used different cluster evaluation criteria which result in two-cluster and twenty-cluster solutions being considered "optimum". The two-cluster solution showed the characteristics of "front-foot" and "reverse" centre of pressure styles. However, a continuous principal component analysis method revealed that the clusters were not well separated and provided support for a multidimensional continuum. The principal components had a high correlation with handicap and clubhead speed. Lower handicap and higher swing speed golfers tended to display a centre of pressure with a "front-foot" style and a fast transition towards the front foot at the start of the downswing. A continuous characterisation of centre of pressure styles has more utility than the segregated styles previously described.


Assuntos
Golfe , Humanos , Análise e Desempenho de Tarefas , , Movimento , Atletas , Fenômenos Biomecânicos
10.
J Cancer Educ ; 38(3): 991-999, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36094725

RESUMO

Recent advances in tumor immunology and cancer immunotherapy have generated significant interest in the field of immuno-oncology. With the promise of these advances comes an increasing need to train the next generation of scientists who will support ongoing basic and clinical research efforts in this field. At this time, however, there remains a documented underrepresentation of tumor immunology as a core content area in many undergraduate science curricula. This study introduces a novel pedagogical strategy that aimed to promote undergraduate student interest in tumor immunology in ways that support recent education guidelines published by the American Association of Immunologists, and it highlights the efficacy of this approach in enhancing student understanding of concepts relevant to the Cancer-Immunity Cycle. Using RNA-sequencing data obtained from clinical specimens catalogued in The Cancer Genome Atlas, students performed Kaplan-Meier survival analyses to identify Cancer-Immunity Cycle genes with prognostic significance. After correlating expression of such genes with tumor-infiltrating immune cell populations using a bioinformatic tool to deconvolute whole tumor-transcriptome data, students undertook an exercise that requires integration of course content and findings from the primary literature to generate hypotheses about the influence of genetic factors and immune cell types on the Cancer-Immunity Cycle and overall patient outcome. A pre-/post-project assessment instrument demonstrated the efficacy of this approach as a means of improving undergraduate student understanding of core cancer immunology concepts. This report describes these data and discusses potential ways in which the project can be adapted to extend its utility to broad and diverse student populations.


Assuntos
Neoplasias , Estudantes , Humanos , Currículo , Biologia Computacional , Avaliação Educacional , Neoplasias/genética , Neoplasias/terapia
11.
Br J Cancer ; 127(1): 69-78, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35347324

RESUMO

INTRODUCTION: Progress in the knowledge of metabolic interactions between cancer and its microenvironment is ongoing and may lead to novel therapeutic approaches. Until recently, melanoma was considered a glycolytic tumour due to mutations in mitochondrial-DNA, however, these malignant cells can regain OXPHOS capacity via the transfer of mitochondrial-DNA, a process that supports their proliferation in-vitro and in-vivo. Here we study how melanoma cells acquire mitochondria and how this process is facilitated from the tumour microenvironment. METHODS: Primary melanoma cells, and MSCs derived from patients were obtained. Genes' expression and DNA quantification was analysed using Real-time PCR. MSC migration, melanoma proliferation and tumour volume, in a xenograft subcutaneous mouse model, were monitored through bioluminescent live animal imaging. RESULTS: Human melanoma cells attract bone marrow-derived stromal cells (MSCs) to the primary tumour site where they stimulate mitochondrial biogenesis in the MSCs through upregulation of PGC1a. Mitochondria are transferred to the melanoma cells via direct contact with the MSCs. Moreover, inhibition of MSC-derived PGC1a was able to prevent mitochondrial transfer and improve NSG melanoma mouse tumour burden. CONCLUSION: MSC mitochondrial biogenesis stimulated by melanoma cells is prerequisite for mitochondrial transfer and subsequent tumour growth, where targeting this pathway may provide an effective novel therapeutic approach in melanoma.


Assuntos
Melanoma , Células-Tronco Mesenquimais , Animais , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Humanos , Melanoma/patologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Mitocôndrias/metabolismo , Biogênese de Organelas , Microambiente Tumoral
12.
Chembiochem ; 23(1): e202100253, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34252249

RESUMO

The identification of growth inhibitory compounds with the ability to selectively target the cellular oxygenation state may be of therapeutic interest. Here, a phenotypic screen of a covalent fragment library revealed diverse compounds containing propiolamide warheads with selective toxicity for liver cancer cells in normoxic conditions. Target identification and validation through CETSA and direct pulldown experiments demonstrated that several compounds target glutathione peroxidase 4 (GPX4) and induce ferroptotic cell death. Although being an oxidative cell death mechanism, ferroptosis can be induced also under hypoxic conditions. Prompted by the selective toxicity discovered in the screen, we mapped the oxygen-dependence of several ferroptosis-inducing compounds across three different cell lines. These studies revealed combinations with notable reductions in sensitivity under hypoxic conditions. These observations are mechanistically interesting and may be relevant for the use of ferroptosis-inducers as anti-cancer agents.


Assuntos
Antineoplásicos/farmacologia , Citotoxinas/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Peroxidase/antagonistas & inibidores , Oxigênio/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citotoxinas/química , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Glutationa Peroxidase/metabolismo , Células Hep G2 , Humanos , Estrutura Molecular , Oxigênio/química
13.
J Anim Ecol ; 91(6): 1290-1302, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35362148

RESUMO

Identifying reservoir host species is crucial for understanding the ecology of multi-host pathogens and predicting risks of pathogen spillover from wildlife to people. Predictive models are increasingly used for identifying ecological traits and prioritizing surveillance of likely zoonotic reservoirs, but these often employ different types of evidence for establishing host associations. Comparisons between models with different infection evidence are necessary to guide inferences about the trait profiles of likely hosts and identify which hosts and geographical regions are likely sources of spillover. Here, we use New World rodent-orthohantavirus associations to explore differences in the performance and predictions of models trained on two types of evidence for infection and onward transmission: RT-PCR and live virus isolation data, representing active infections versus host competence, respectively. Orthohantaviruses are primarily carried by muroid rodents and cause the diseases haemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS) in humans. We show that although boosted regression tree (BRT) models trained on RT-PCR and live virus isolation data both performed well and capture generally similar trait profiles, rodent phylogeny influenced previously collected RT-PCR data, and BRTs using virus isolation data displayed a narrower list of predicted reservoirs than those using RT-PCR data. BRT models trained on RT-PCR data identified 138 undiscovered hosts and virus isolation models identified 92 undiscovered hosts, with 27 undiscovered hosts identified by both models. Distributions of predicted hosts were concentrated in several different regions for each model, with large discrepancies between evidence types. As a form of validation, virus isolation models independently predicted several orthohantavirus-rodent host associations that had been previously identified through empirical research using RT-PCR. Our model predictions provide a priority list of species and locations for future orthohantavirus sampling. More broadly, these results demonstrate the value of multiple data types for predicting zoonotic pathogen hosts. These methods can be applied across a range of systems to improve our understanding of pathogen maintenance and increase efficiency of pathogen surveillance.


Assuntos
Infecções por Hantavirus , Orthohantavírus , Doenças dos Roedores , Animais , Reservatórios de Doenças/veterinária , Infecções por Hantavirus/epidemiologia , Humanos , Filogenia , Doenças dos Roedores/epidemiologia , Roedores
14.
Proc Natl Acad Sci U S A ; 116(49): 24610-24619, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31727843

RESUMO

Hematopoietic stem cells (HSCs) undergo rapid expansion in response to stress stimuli. Here we investigate the bioenergetic processes which facilitate the HSC expansion in response to infection. We find that infection by Gram-negative bacteria drives an increase in mitochondrial mass in mammalian HSCs, which results in a metabolic transition from glycolysis toward oxidative phosphorylation. The initial increase in mitochondrial mass occurs as a result of mitochondrial transfer from the bone marrow stromal cells (BMSCs) to HSCs through a reactive oxygen species (ROS)-dependent mechanism. Mechanistically, ROS-induced oxidative stress regulates the opening of connexin channels in a system mediated by phosphoinositide 3-kinase (PI3K) activation, which allows the mitochondria to transfer from BMSCs into HSCs. Moreover, mitochondria transfer from BMSCs into HSCs, in the response to bacterial infection, occurs before the HSCs activate their own transcriptional program for mitochondrial biogenesis. Our discovery demonstrates that mitochondrial transfer from the bone marrow microenvironment to HSCs is an early physiologic event in the mammalian response to acute bacterial infection and results in bioenergetic changes which underpin emergency granulopoiesis.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Mitocôndrias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Infecções por Salmonella/patologia , Células Estromais/metabolismo , Animais , Células da Medula Óssea , Ativação Enzimática , Sangue Fetal , Glicólise , Humanos , Subunidade gama Comum de Receptores de Interleucina/genética , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos NOD , Camundongos Knockout , Infecções por Salmonella/metabolismo , Salmonella typhimurium , Células Estromais/citologia
15.
Int J Mol Sci ; 23(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35269611

RESUMO

Epidermal growth factor receptor (EGFR) is a validated tumor marker overexpressed in various cancers such as squamous cell carcinoma (SSC) of the head and neck and gliomas. We constructed protein-drug conjugates based on the anti-EGFR Designed Ankyrin Repeat Protein (DARPin) E01, and compared the bivalent DARPin dimer (DD1) and a DARPin-Fc (DFc) to the monomeric DARPin (DM) and the antibody derived scFv425-Fc (scFvFc) in cell culture and a mouse model. The modular conjugation system, which was successfully applied for the preparation of protein-drug and -dye conjugates, uses bio-orthogonal protein-aldehyde generation by the formylglycine-generating enzyme (FGE). The generated carbonyl moiety is addressed by a bifunctional linker with a pyrazolone for a tandem Knoevenagel reaction and an azide for strain-promoted azide-alkyne cycloaddition (SPAAC). The latter reaction with a PEGylated linker containing a dibenzocyclooctyne (DBCO) for SPAAC and monomethyl auristatin E (MMAE) as the toxin provided the stable conjugates DD1-MMAE (drug-antibody ratio, DAR = 2.0) and DFc-MMAE (DAR = 4.0) with sub-nanomolar cytotoxicity against the human squamous carcinoma derived A431 cells. In vivo imaging of Alexa Fluor 647-dye conjugates in A431-xenografted mice bearing subcutaneous tumors as the SCC model revealed unspecific binding of bivalent DARPins to the ubiquitously expressed EGFR. Tumor-targeting was verified 6 h post-injection solely for DD1 and scFvFc. The total of four administrations of 6.5 mg/kg DD1-MMAE or DFc-MMAE twice weekly did not cause any sequela in mice. MMAE conjugates showed no significant anti-tumor efficacy in vivo, but a trend towards increased necrotic areas (p = 0.2213) was observed for the DD1-MMAE (n = 5).


Assuntos
Imunoconjugados , Animais , Anticorpos , Azidas , Linhagem Celular Tumoral , Proteínas de Repetição de Anquirina Projetadas , Receptores ErbB/metabolismo , Camundongos , Oligopeptídeos , Ensaios Antitumorais Modelo de Xenoenxerto
16.
J Cancer Educ ; 37(5): 1357-1363, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-33454838

RESUMO

Undergraduate students harbor a number of misconceptions about the complexity of cancer. Though educational interventions have been shown to promote student learning of various aspects of this ubiquitous disease, to date no studies have evaluated undergraduate student understanding of the Hallmarks of Cancer, a set of core properties that have emerged as the defining characteristics that drive cancer development and progression. This study documents poor baseline knowledge of many fundamental aspects of cancer biology and genetics by 2nd- and 3rd-year undergraduate students, and it evaluates the efficacy of a student-centered project as a pedagogical strategy for improving student understanding of both the hallmarks of cancer and the genetic influences that drive their acquisition by cancer cells. Using genomic and transcriptomic datasets from The Cancer Genome Atlas, students investigated the most common genetic aberrations associated with specific cancer types of interest and then researched the functions of these altered genes in order to link their aberrations with specific hallmark properties of cancer. A pre-/post-project assessment of student understanding of topics related to the hallmarks of cancer demonstrated the efficacy of this approach as a means of educating undergraduate students about core cancer concepts.


Assuntos
Neoplasias , Estudantes , Currículo , Humanos , Neoplasias/genética
17.
Beilstein J Org Chem ; 18: 1-12, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35047078

RESUMO

The development of peptide stapling techniques to stabilise α-helical secondary structure motifs of peptides led to the design of modulators of protein-protein interactions, which had been considered undruggable for a long time. We disclose a novel approach towards peptide stapling utilising macrocyclisation by late-stage Suzuki-Miyaura cross-coupling of bromotryptophan-containing peptides of the catenin-binding domain of axin. Optimisation of the linker length in order to find a compromise between both sufficient linker rigidity and flexibility resulted in a peptide with an increased α-helicity and enhanced binding affinity to its native binding partner ß-catenin. An increased proteolytic stability against proteinase K has been demonstrated.

18.
Br J Cancer ; 124(1): 115-123, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33204029

RESUMO

The Warburg effect in tumour cells is associated with the upregulation of glycolysis to generate ATP, even under normoxic conditions and the presence of fully functioning mitochondria. However, scientific advances made over the past 15 years have reformed this perspective, demonstrating the importance of oxidative phosphorylation (OXPHOS) as well as glycolysis in malignant cells. The metabolic phenotypes in melanoma display heterogeneic dynamism (metabolic plasticity) between glycolysis and OXPHOS, conferring a survival advantage to adapt to harsh conditions and pathways of chemoresistance. Furthermore, the simultaneous upregulation of both OXPHOS and glycolysis (metabolic symbiosis) has been shown to be vital for melanoma progression. The tumour microenvironment (TME) has an essential supporting role in promoting progression, invasion and metastasis of melanoma. Mesenchymal stromal cells (MSCs) in the TME show a symbiotic relationship with melanoma, protecting tumour cells from apoptosis and conferring chemoresistance. With the significant role of OXPHOS in metabolic plasticity and symbiosis, our review outlines how mitochondrial transfer from MSCs to melanoma tumour cells plays a key role in melanoma progression and is the mechanism by which melanoma cells regain OXPHOS capacity even in the presence of mitochondrial mutations. The studies outlined in this review indicate that targeting mitochondrial trafficking is a potential novel therapeutic approach for this highly refractory disease.


Assuntos
Melanoma/metabolismo , Melanoma/patologia , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Microambiente Tumoral/fisiologia , Animais , Humanos , Melanoma Maligno Cutâneo
19.
New Phytol ; 229(4): 1970-1982, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33006137

RESUMO

Methane emission from trees may partially or completely offset the methane sink in upland soils, the only process that has been regularly included in methane budgets for forest ecosystems. Our objective was to analyze multiple biogeochemical processes that influence the production, oxidation and transport of methane in a riparian cottonwood ecosystem and its adjacent river. We combined chamber flux measurements on tree stems, forest soil and the river surface with eddy covariance measurements of methane net ecosystem exchange. In addition, we tested whether methanogens were present in cottonwood stems, shallow soil layers and alluvial groundwater. Average midday peak in net methane emission measured by eddy covariance was c. 12 nmol m-2  s-1 . The average uptake of methane by soils (0.87 nmol m-2  s-1 ) was largely offset by tree stem methane emission (0.75 nmol m-2  s-1 ). There was evidence of methanogens in tree stems but not in shallow soil. Growing season (May-September) cumulative net methane emission (17.4 mmol CH4  m-2 ) included methane produced in cottonwood stems and methane input to the nocturnal boundary layer from the forest and the adjacent river. The multiple processes contributing to methane emission illustrated the linked nature of these adjacent terrestrial and aquatic ecosystems.


Assuntos
Ecossistema , Populus , Florestas , Metano , Solo , Árvores
20.
Bioconjug Chem ; 32(6): 1167-1174, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34060308

RESUMO

Multiple, site-specific protein conjugation is increasingly attractive for the generation of antibody-drug conjugates (ADCs). As it is important to control the number and position of cargoes in an ADC, position-selective generation of reactive sites in the protein of interest is required. Formylglycine (FGly) residues are generated by enzymatic conversion of cysteine residues embedded in a certain amino acid sequence motif with a formylglycine-generating enzyme (FGE). The addition of copper ions increases FGE activity leading to the conversion of cysteines within less readily accepted sequences. With this tuned enzyme activity, it is possible to address two different recognition sequences using two aerobic formylglycine-generating enzymes. We demonstrate an improved and facile strategy for the functionalization of a DARPin (designed ankyrin repeat protein) and the single-chain antibody scFv425-Fc, both directed against the epidermal growth factor receptor (EGFR). The single-chain antibody was conjugated with monomethyl auristatin E (MMAE) and carboxyfluorescein (CF) and successfully tested for receptor binding, internalization, and cytotoxicity in cell culture, respectively.


Assuntos
Enzimas/metabolismo , Glicina/análogos & derivados , Imunoconjugados/química , Imunoconjugados/metabolismo , Aerobiose , Repetição de Anquirina , Cobre/química , Fluoresceínas/química , Glicina/metabolismo , Oligopeptídeos/química
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