Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO Rep ; 24(2): e54977, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36416237

RESUMO

High-risk neuroblastoma patients have poor survival rates and require better therapeutic options. High expression of a multifunctional DNA and RNA-binding protein, NONO, in neuroblastoma is associated with poor patient outcome; however, there is little understanding of the mechanism of NONO-dependent oncogenic gene regulatory activity in neuroblastoma. Here, we used cell imaging, biochemical and genome-wide molecular analysis to reveal complex NONO-dependent regulation of gene expression. NONO forms RNA- and DNA-tethered condensates throughout the nucleus and undergoes phase separation in vitro, modulated by nucleic acid binding. CLIP analyses show that NONO mainly binds to the 5' end of pre-mRNAs and modulates pre-mRNA processing, dependent on its RNA-binding activity. NONO regulates super-enhancer-associated genes, including HAND2 and GATA2. Abrogating NONO RNA binding, or phase separation activity, results in decreased expression of HAND2 and GATA2. Thus, future development of agents that target RNA-binding activity of NONO may have therapeutic potential in this cancer context.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Proteínas de Ligação a DNA , Neuroblastoma , Humanos , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA2/metabolismo , Neuroblastoma/genética , Neuroblastoma/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
2.
Semin Cell Dev Biol ; 120: 66-74, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34275746

RESUMO

The ability to migrate is a fundamental property of animal cells which is essential for development, homeostasis and disease progression. Migrating cells sense and respond to biochemical and mechanical cues by rapidly modifying their intrinsic repertoire of signalling molecules and by altering their force generating and transducing machinery. We have a wealth of information about the chemical cues and signalling responses that cells use during migration. Our understanding of the role of forces in cell migration is rapidly evolving but is still best understood in the context of cells migrating in 2D and 3D environments in vitro. Advances in live imaging of developing embryos combined with the use of experimental and theoretical tools to quantify and analyse forces in vivo, has begun to shed light on the role of mechanics in driving embryonic cell migration. In this review, we focus on the recent studies uncovering the physical basis of embryonic cell migration in vivo. We look at the physical basis of the classical steps of cell migration such as protrusion formation and cell body translocation and review the recent research on how these processes work in the complex 3D microenvironment of a developing organism.


Assuntos
Movimento Celular/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Humanos
3.
J Fish Biol ; 103(4): 798-814, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36651356

RESUMO

Modern sharks have an evolutionary history of at least 250 million years and are known to play key roles in marine systems, from controlling prey populations to connecting habitats across oceans. These ecological roles can be quantified based on their functional traits, which are typically morphological (e.g., body size) or behavioural (e.g., feeding and diet). Nonetheless, the understanding of such roles of extinct sharks is limited due to the inherent incompleteness of their fossil record, which consists mainly of isolated teeth. As such, establishing links between tooth morphology and ecological traits in living sharks could provide a useful framework to infer sharks' ecology from the fossil record. Here, based on extant sharks from which morphological and behavioural characteristics are known, the authors assess the extent to which isolated teeth can serve as proxies for functional traits. To do so, they first review the scientific literature on extant species to evaluate the use of shark dental characters as proxies for ecology to then perform validation analyses based on an independent data set collected from museum collections. Their results reveal that 12 dental characters have been used in shark literature as proxies for three functional traits: body size, prey preference and feeding mechanism. From all dental characters identified, tooth size and cutting edge are the most widely used. Validation analyses suggest that seven dental characters - crown height, crown width, cutting edge, lateral cusplets, curvature, longitudinal outline and cross-section outline - are the best proxies for the three functional traits. In particular, tooth size (crown height and width) was found to be a reliable proxy of all three traits; the presence of serrations on the cutting edge was one of the best proxies for prey preference; and tooth shape (longitudinal outline) and the presence of lateral cusplets were among the best indicators of feeding mechanism. Overall, the authors' results suggest that in the absence of directly measurable traits in the fossil record, these seven dental characters (and different combinations of them) can be used to quantify the ecological roles of extinct sharks. This information has the potential to provide key insights into how shark functional diversity has changed through time, including their ecological responses to extinction events.


Assuntos
Tubarões , Dente , Animais , Fósseis , Dente/anatomia & histologia , Evolução Biológica , Tubarões/fisiologia , Tamanho Corporal
4.
Cell Mol Life Sci ; 78(5): 2213-2230, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32914209

RESUMO

Many long non-coding RNAs (lncRNA) are highly dysregulated in cancer and are emerging as therapeutic targets. One example is NEAT1, which consists of two overlapping lncRNA isoforms, NEAT1_1 (3.7 kb) and NEAT1_2 (23 kb), that are functionally distinct. The longer NEAT1_2 is responsible for scaffolding gene-regulatory nuclear bodies termed paraspeckles, whereas NEAT1_1 is involved in paraspeckle-independent function. The NEAT1 isoform ratio is dependent on the efficient cleavage and polyadenylation of NEAT1_1 at the expense of NEAT1_2. Here, we developed a targeted antisense oligonucleotide (ASO) approach to sterically block NEAT1_1 polyadenylation processing, achieving upregulation of NEAT1_2 and abundant paraspeckles. We have applied these ASOs to cells of the heterogeneous infant cancer, neuroblastoma, as we found higher NEAT1_1:NEAT1_2 ratio and lack of paraspeckles in high-risk neuroblastoma cells. These ASOs decrease NEAT1_1 levels, increase NEAT1_2/paraspeckles and concomitantly reduce cell viability in high-risk neuroblastoma specifically. In contrast, overexpression of NEAT1_1 has the opposite effect, increasing cell proliferation. Transcriptomic analyses of high-risk neuroblastoma cells with altered NEAT1 ratios and increased paraspeckle abundance after ASO treatment showed an upregulation of differentiation pathways, as opposed to the usual aggressive neuroblastic phenotype. Thus, we have developed potential anti-cancer ASO drugs that can transiently increase growth-inhibiting NEAT1_2 RNA at the expense of growth-promoting NEAT1_1 RNA. These ASOs, unlike others that degrade lncRNAs, provide insights into the importance of altering lncRNA polyadenylation events to suppress tumorigenesis as a strategy to combat cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neuroblastoma/genética , Oligonucleotídeos Antissenso/genética , Poli A/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Estudos de Coortes , Perfilação da Expressão Gênica/métodos , Humanos , Estimativa de Kaplan-Meier , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Poli A/metabolismo , Isoformas de RNA/genética , Isoformas de RNA/metabolismo
5.
Lancet Oncol ; 22(6): 765-778, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33930323

RESUMO

BACKGROUND: The efficacy and safety profiles of vaccines against SARS-CoV-2 in patients with cancer is unknown. We aimed to assess the safety and immunogenicity of the BNT162b2 (Pfizer-BioNTech) vaccine in patients with cancer. METHODS: For this prospective observational study, we recruited patients with cancer and healthy controls (mostly health-care workers) from three London hospitals between Dec 8, 2020, and Feb 18, 2021. Participants who were vaccinated between Dec 8 and Dec 29, 2020, received two 30 µg doses of BNT162b2 administered intramuscularly 21 days apart; patients vaccinated after this date received only one 30 µg dose with a planned follow-up boost at 12 weeks. Blood samples were taken before vaccination and at 3 weeks and 5 weeks after the first vaccination. Where possible, serial nasopharyngeal real-time RT-PCR (rRT-PCR) swab tests were done every 10 days or in cases of symptomatic COVID-19. The coprimary endpoints were seroconversion to SARS-CoV-2 spike (S) protein in patients with cancer following the first vaccination with the BNT162b2 vaccine and the effect of vaccine boosting after 21 days on seroconversion. All participants with available data were included in the safety and immunogenicity analyses. Ongoing follow-up is underway for further blood sampling after the delayed (12-week) vaccine boost. This study is registered with the NHS Health Research Authority and Health and Care Research Wales (REC ID 20/HRA/2031). FINDINGS: 151 patients with cancer (95 patients with solid cancer and 56 patients with haematological cancer) and 54 healthy controls were enrolled. For this interim data analysis of the safety and immunogenicity of vaccinated patients with cancer, samples and data obtained up to March 19, 2021, were analysed. After exclusion of 17 patients who had been exposed to SARS-CoV-2 (detected by either antibody seroconversion or a positive rRT-PCR COVID-19 swab test) from the immunogenicity analysis, the proportion of positive anti-S IgG titres at approximately 21 days following a single vaccine inoculum across the three cohorts were 32 (94%; 95% CI 81-98) of 34 healthy controls; 21 (38%; 26-51) of 56 patients with solid cancer, and eight (18%; 10-32) of 44 patients with haematological cancer. 16 healthy controls, 25 patients with solid cancer, and six patients with haematological cancer received a second dose on day 21. Of the patients with available blood samples 2 weeks following a 21-day vaccine boost, and excluding 17 participants with evidence of previous natural SARS-CoV-2 exposure, 18 (95%; 95% CI 75-99) of 19 patients with solid cancer, 12 (100%; 76-100) of 12 healthy controls, and three (60%; 23-88) of five patients with haematological cancers were seropositive, compared with ten (30%; 17-47) of 33, 18 (86%; 65-95) of 21, and four (11%; 4-25) of 36, respectively, who did not receive a boost. The vaccine was well tolerated; no toxicities were reported in 75 (54%) of 140 patients with cancer following the first dose of BNT162b2, and in 22 (71%) of 31 patients with cancer following the second dose. Similarly, no toxicities were reported in 15 (38%) of 40 healthy controls after the first dose and in five (31%) of 16 after the second dose. Injection-site pain within 7 days following the first dose was the most commonly reported local reaction (23 [35%] of 65 patients with cancer; 12 [48%] of 25 healthy controls). No vaccine-related deaths were reported. INTERPRETATION: In patients with cancer, one dose of the BNT162b2 vaccine yields poor efficacy. Immunogenicity increased significantly in patients with solid cancer within 2 weeks of a vaccine boost at day 21 after the first dose. These data support prioritisation of patients with cancer for an early (day 21) second dose of the BNT162b2 vaccine. FUNDING: King's College London, Cancer Research UK, Wellcome Trust, Rosetrees Trust, and Francis Crick Institute.


Assuntos
Vacinas contra COVID-19/uso terapêutico , COVID-19/imunologia , Neoplasias/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Vacina BNT162 , COVID-19/sangue , COVID-19/complicações , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Relação Dose-Resposta Imunológica , Feminino , Humanos , Imunogenicidade da Vacina/imunologia , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/complicações , Neoplasias/virologia , Estudos Prospectivos , SARS-CoV-2 , País de Gales
6.
Front Digit Health ; 5: 1125276, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37122814

RESUMO

mHealth researchers can now collect a wealth of data using "life tracking apps" (LTAs), which are smartphone applications that use mobile sensing to capture and summarise a multitude of data channels (e.g., location, movement, keyword use, sleep, exercise, and so on). The combined wealth of information can create digital signatures of individuals, which hold immense promise for mental health research and interventions by allowing new insights into moment-to-moment changes in behaviour and mental states. However, little is known about what a common research demographic (university students) thinks about these apps and what might factor into their decisions to participate in research using a LTA. This qualitative study ran five focus group sessions (21 students in total) to explore students' experiences, beliefs, and opinions about LTAs to generate insights into what would make them more or less likely to participate in research involving LTAs. Transcripts were coded and examined for categories using qualitative content analysis. Important categories that emerged were privacy (although this varied based on the individual and data being collected), data security, inconvenience, intrusiveness, financial compensation, and the perceived nature of the research team responsible. On the basis of these categories, we derived seven key insights to increase student participation in research using LTAs: strengthen and communicate privacy and data security, design the app to be as convenient as possible to users, maximise passive data collection, think cautiously before tracking data perceived as "creepy" such as messages, offer suitable financial compensation, be transparent about goals and justification for data being collection to build trust, and attract participants by highlighting how the app can help them achieve their goals. With these insights, mHealth researchers can maximise their participant pool and improve this nascent and promising field.

7.
Psychoneuroendocrinology ; 154: 106296, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37216738

RESUMO

On the basis of substantial preclinical evidence, the endogenous cannabinoid system has been proposed to be closely involved in stress reactivity and extinction of fear. Existing human research supports this proposal to some extent, but existing studies have used only a narrow range of tools and biomatrices to measure endocannabinoids during stress and fear experiments. In the present study we collected hair and saliva samples from 99 healthy participants who completed a fear conditioning and intrusive memory task. Subjective, physiological and biological stress reactivity to a trauma film, which later served as unconditional stimulus during fear conditioning, was also measured. We found that salivary endocannabinoid concentrations predicted subjective responses to stress, but not cortisol stress reactivity, and replicated previous findings demonstrating a sex dimorphism in hair and salivary endocannabinoid levels. Hair 2-arachidonoyl glycerol levels were significantly associated with better retention of safety learning during extinction and renewal phases of fear conditioning, while hair concentrations of oleoylethanolamide and palmitoylethanolamide were associated with overall physiological arousal, but not conditional learning, during fear conditioning. This study is the first to test the relationship between hair and salivary endocannabinoids and these important psychological processes. Our results suggest that these measures may serve as biomarkers of dysregulation in human fear memory and stress.


Assuntos
Endocanabinoides , Extinção Psicológica , Humanos , Extinção Psicológica/fisiologia , Condicionamento Clássico/fisiologia , Medo/fisiologia , Cabelo
8.
Sci Adv ; 8(33): eabm9424, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35977007

RESUMO

Although shark teeth are abundant in the fossil record, their bodies are rarely preserved. Thus, our understanding of the anatomy of the extinct Otodus megalodon remains rudimentary. We used an exceptionally well-preserved fossil to create the first three-dimensional model of the body of this giant shark and used it to infer its movement and feeding ecology. We estimate that an adult O. megalodon could cruise at faster absolute speeds than any shark species today and fully consume prey the size of modern apex predators. A dietary preference for large prey potentially enabled O. megalodon to minimize competition and provided a constant source of energy to fuel prolonged migrations without further feeding. Together, our results suggest that O. megalodon played an important ecological role as a transoceanic superpredator. Hence, its extinction likely had large impacts on global nutrient transfer and trophic food webs.

9.
Front Genet ; 13: 791416, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464859

RESUMO

Oligonucleotides and nucleic acid analogues that alter gene expression are now showing therapeutic promise in human disease. Whilst the modification of synthetic nucleic acids to protect against nuclease degradation and to influence drug function is common practice, such modifications may also confer unexpected physicochemical and biological properties. Gapmer mixed-modified and DNA oligonucleotides on a phosphorothioate backbone can bind non-specifically to intracellular proteins to form a variety of toxic inclusions, driven by the phosphorothioate linkages, but also influenced by the oligonucleotide sequence. Recently, the non-antisense or other off-target effects of 2' O- fully modified phosphorothioate linkage oligonucleotides are becoming better understood. Here, we report chemistry-specific effects of oligonucleotides composed of modified or unmodified bases, with phosphorothioate linkages, on subnuclear organelles and show altered distribution of nuclear proteins, the appearance of highly stable and strikingly structured nuclear inclusions, and disturbed RNA processing in primary human fibroblasts and other cultured cells. Phosphodiester, phosphorodiamidate morpholino oligomers, and annealed complimentary phosphorothioate oligomer duplexes elicited no such consequences. Disruption of subnuclear structures and proteins elicit severe phenotypic disturbances, revealed by transcriptomic analysis of transfected fibroblasts exhibiting such disruption. Our data add to the growing body of evidence of off-target effects of some phosphorothioate nucleic acid drugs in primary cells and suggest alternative approaches to mitigate these effects.

10.
Sci Rep ; 10(1): 14596, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883981

RESUMO

Inferring the size of extinct animals is fraught with danger, especially when they were much larger than their modern relatives. Such extrapolations are particularly risky when allometry is present. The extinct giant shark †Otodus megalodon is known almost exclusively from fossilised teeth. Estimates of †O. megalodon body size have been made from its teeth, using the great white shark (Carcharodon carcharias) as the only modern analogue. This can be problematic as the two species likely belong to different families, and the position of the †Otodus lineage within Lamniformes is unclear. Here, we infer †O. megalodon body dimensions based on anatomical measurements of five ecologically and physiologically similar extant lamniforms: Carcharodon carcharias, Isurus oxyrinchus, Isurus paucus, Lamna ditropis and Lamna nasus. We first assessed for allometry in all analogues using linear regressions and geometric morphometric analyses. Finding no evidence of allometry, we made morphological extrapolations to infer body dimensions of †O. megalodon at different sizes. Our results suggest that a 16 m †O. megalodon likely had a head ~ 4.65 m long, a dorsal fin ~ 1.62 m tall and a tail ~ 3.85 m high. Morphometric analyses further suggest that its dorsal and caudal fins were adapted for swift predatory locomotion and long-swimming periods.


Assuntos
Tamanho Corporal , Processamento de Imagem Assistida por Computador/métodos , Tubarões/anatomia & histologia , Tubarões/fisiologia , Animais , Natação
12.
Cancer Cell ; 39(11): 1445-1447, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34678151
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA