Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
Am J Chin Med ; 51(6): 1577-1594, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37465963

RESUMO

Colorectal cancer (CRC) is a leading cause of cancer-related death in the United States, and chronic gut inflammation is a risk factor for CRC initiation and development. Curcuma longa L., or turmeric, has become one of the most studied herbal medicines in recent years due to its anticancer potentials. It is generally accepted that the major component in turmeric is curcuminoids, and the active constituent in curcuminoids is curcumin. However, unprocessed curcumin is characterized by poor water solubility, which means low bioavailability in humans. To increase the bioavailability of curcumin, in this study, we utilized a novel surfactant-formulated curcumin (CuminUP60[Formula: see text]) and evaluated its CRC chemopreventive activities. Compared with the chemo-sensitive CRC cell line HCT-116, the management of the CRC SW-480 cell line is a challenge, since the latter is chemo-resistant. In other words, these cancer cells resist the effects of the chemotherapy. Using the newly formulated CuminUP60[Formula: see text] water solution, this study demonstrated its strong antiproliferative effects on the SW-480 cells in a dose- and time-dependent manner. This new formulation induced early apoptosis and arrested the cell cycle in the G2/M phase via the upregulation of cyclin B1. We also observed that this new formulation possessed inhibitory effects on Th17 cell differentiation, which regulates the body's immune response against gut malignancies. In summary, our results exhibited a potential clinical utility of the surfactant-formulated curcumin in chemo-resistant colorectal cancer management.


Assuntos
Neoplasias Colorretais , Curcumina , Humanos , Curcumina/farmacologia , Diarileptanoides , Tensoativos , Curcuma , Neoplasias Colorretais/tratamento farmacológico , Água
2.
Environ Microbiol ; 24(11): 5534-5545, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36100999

RESUMO

Cold surface sediments host a seedbank of functionally diverse thermophilic bacteria. These thermophiles are present as endospores, which are widely dispersed in aquatic environments. Here, we investigated the functional potential of endospore populations in cold surface sediments heated to 80°C. Microbial production of acetate was observed at 80°C and could be enhanced by supplying additional organic carbon substrates. Comparison of 16S rRNA gene amplicon libraries from 80°C enrichments to sediments heated to lower temperatures (50-70°C) showed that temperature selects for distinct populations of endospore-forming bacteria. Whereas sulfate-reducing thermophiles were enriched in 50-70°C incubations, 80°C exceeds their thermal tolerance and selects for hyperthermophilic organotrophic bacteria that are similarly detected in amplicon libraries from sediments heated to 90°C. Genome-resolved metagenomics revealed novel carbon cycling members of Symbiobacteriales, Thermosediminibacteraceae, Thermanaeromonas and Calditerricola with the genomic potential for the degradation of carbohydrates, sugars, amino acids and nucleotides. Endospores of thermophilic bacteria are deposited on seabed sediments worldwide where they remain dormant as they are buried in the accumulating sediments. Our results suggest that endospore populations could be activated by temperature increases encountered during burial and show the potential for organotrophic metabolic activity contributing to acetate generation in deep hot sediments.


Assuntos
Carbono , Sedimentos Geológicos , RNA Ribossômico 16S/genética , Sedimentos Geológicos/microbiologia , Archaea/genética , Esporos Bacterianos/genética , Bactérias Anaeróbias/genética , Firmicutes/genética
3.
Nat Cancer ; 3(4): 471-485, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35484422

RESUMO

Aberrant expression of MYC transcription factor family members predicts poor clinical outcome in many human cancers. Oncogenic MYC profoundly alters metabolism and mediates an antioxidant response to maintain redox balance. Here we show that MYCN induces massive lipid peroxidation on depletion of cysteine, the rate-limiting amino acid for glutathione (GSH) biosynthesis, and sensitizes cells to ferroptosis, an oxidative, non-apoptotic and iron-dependent type of cell death. The high cysteine demand of MYCN-amplified childhood neuroblastoma is met by uptake and transsulfuration. When uptake is limited, cysteine usage for protein synthesis is maintained at the expense of GSH triggering ferroptosis and potentially contributing to spontaneous tumor regression in low-risk neuroblastomas. Pharmacological inhibition of both cystine uptake and transsulfuration combined with GPX4 inactivation resulted in tumor remission in an orthotopic MYCN-amplified neuroblastoma model. These findings provide a proof of concept of combining multiple ferroptosis targets as a promising therapeutic strategy for aggressive MYCN-amplified tumors.


Assuntos
Ferroptose , Neuroblastoma , Morte Celular , Criança , Cisteína/uso terapêutico , Ferroptose/genética , Glutationa/uso terapêutico , Humanos , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética
4.
ISME J ; 16(6): 1583-1593, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35173296

RESUMO

Microbial life is widespread in the terrestrial subsurface and present down to several kilometers depth, but the energy sources that fuel metabolism in deep oligotrophic and anoxic environments remain unclear. In the deep crystalline bedrock of the Fennoscandian Shield at Olkiluoto, Finland, opposing gradients of abiotic methane and ancient seawater-derived sulfate create a terrestrial sulfate-methane transition zone (SMTZ). We used chemical and isotopic data coupled to genome-resolved metaproteogenomics to demonstrate active life and, for the first time, provide direct evidence of active anaerobic oxidation of methane (AOM) in a deep terrestrial bedrock. Proteins from Methanoperedens (formerly ANME-2d) are readily identifiable despite the low abundance (≤1%) of this genus and confirm the occurrence of AOM. This finding is supported by 13C-depleted dissolved inorganic carbon. Proteins from Desulfocapsaceae and Desulfurivibrionaceae, in addition to 34S-enriched sulfate, suggest that these organisms use inorganic sulfur compounds as both electron donor and acceptor. Zerovalent sulfur in the groundwater may derive from abiotic rock interactions, or from a non-obligate syntrophy with Methanoperedens, potentially linking methane and sulfur cycles in Olkiluoto groundwater. Finally, putative episymbionts from the candidate phyla radiation (CPR) and DPANN archaea represented a significant diversity in the groundwater (26/84 genomes) with roles in sulfur and carbon cycling. Our results highlight AOM and sulfur disproportionation as active metabolisms and show that methane and sulfur fuel microbial activity in the deep terrestrial subsurface.


Assuntos
Archaea , Metano , Anaerobiose , Archaea/metabolismo , Carbono/metabolismo , Sedimentos Geológicos , Metano/metabolismo , Methanosarcinales/metabolismo , Oxirredução , Filogenia , Sulfatos/metabolismo , Enxofre/metabolismo
5.
J Bus Ethics ; 178(3): 597-608, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33840869

RESUMO

Posthuman affirmative ethics relies upon a fluid, nomadic conception of the ethical subject who develops affective, material and immaterial connections to multiple others. Our purpose in this paper is to consider what posthuman affirmative business ethics would look like, and to reflect on the shift in thinking and practice this would involve. The need for a revised understanding of human-animal relations in business ethics is amplified by crises such as climate change and pandemics that are related to ecologically destructive business practices such as factory farming. In this analysis, we use feminist speculative fiction as a resource for reimagination and posthuman ethical thinking. By focusing on three ethical movements experienced by a central character named Toby in Margaret Atwood's MaddAddam trilogy, we show how she is continually becoming through affective, embodied encounters with human and nonhuman others. In the discussion, we consider the vulnerability that arises from openness to affect which engenders heightened response-ability to and with, rather than for, multiple others. This expanded concept of subjectivity enables a more relational understanding of equality that is urgently needed in order to respond affirmatively to posthuman futures.

6.
Nat Commun ; 12(1): 4253, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253732

RESUMO

While oligotrophic deep groundwaters host active microbes attuned to the low-end of the bioenergetics spectrum, the ecological constraints on microbial niches in these ecosystems and their consequences for microbiome convergence are unknown. Here, we provide a genome-resolved, integrated omics analysis comparing archaeal and bacterial communities in disconnected fracture fluids of the Fennoscandian Shield in Europe. Leveraging a dataset that combines metagenomes, single cell genomes, and metatranscriptomes, we show that groundwaters flowing in similar lithologies offer fixed niches that are occupied by a common core microbiome. Functional expression analysis highlights that these deep groundwater ecosystems foster diverse, yet cooperative communities adapted to this setting. We suggest that these communities stimulate cooperation by expression of functions related to ecological traits, such as aggregate or biofilm formation, while alleviating the burden on microorganisms producing compounds or functions that provide a collective benefit by facilitating reciprocal promiscuous metabolic partnerships with other members of the community. We hypothesize that an episodic lifestyle enabled by reversible bacteriostatic functions ensures the subsistence of the oligotrophic deep groundwater microbiome.


Assuntos
Metabolismo Energético , Água Subterrânea/microbiologia , Microbiota , Biodiversidade , Bases de Dados Genéticas , Regulação da Expressão Gênica , Ponto Isoelétrico , Metagenoma , Microbiota/genética , Filogenia , Transcrição Gênica , Transcriptoma/genética
7.
Mol Cell ; 81(7): 1469-1483.e8, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33609448

RESUMO

We demonstrate that DNA hypomethylating agent (HMA) treatment can directly modulate the anti-tumor response and effector function of CD8+ T cells. In vivo HMA treatment promotes CD8+ T cell tumor infiltration and suppresses tumor growth via CD8+ T cell-dependent activity. Ex vivo, HMAs enhance primary human CD8+ T cell activation markers, effector cytokine production, and anti-tumor cytolytic activity. Epigenomic and transcriptomic profiling shows that HMAs vastly regulate T cell activation-related transcriptional networks, culminating with over-activation of NFATc1 short isoforms. Mechanistically, demethylation of an intragenic CpG island immediately downstream to the 3' UTR of the short isoform was associated with antisense transcription and alternative polyadenylation of NFATc1 short isoforms. High-dimensional single-cell mass cytometry analyses reveal a selective effect of HMAs on a subset of human CD8+ T cell subpopulations, increasing both the number and abundance of a granzyme Bhigh, perforinhigh effector subpopulation. Overall, our findings support the use of HMAs as a therapeutic strategy to boost anti-tumor immune response.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Ilhas de CpG/imunologia , Metilação de DNA/efeitos dos fármacos , Decitabina/farmacologia , Granzimas/imunologia , Ativação Linfocitária/efeitos dos fármacos , Metilação de DNA/imunologia , Humanos , Fatores de Transcrição NFATC/imunologia , Perforina/imunologia
8.
Front Microbiol ; 12: 764058, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35069469

RESUMO

Many pathways for hydrocarbon degradation have been discovered, yet there are no dedicated tools to identify and predict the hydrocarbon degradation potential of microbial genomes and metagenomes. Here we present the Calgary approach to ANnoTating HYDrocarbon degradation genes (CANT-HYD), a database of 37 HMMs of marker genes involved in anaerobic and aerobic degradation pathways of aliphatic and aromatic hydrocarbons. Using this database, we identify understudied or overlooked hydrocarbon degradation potential in many phyla. We also demonstrate its application in analyzing high-throughput sequence data by predicting hydrocarbon utilization in large metagenomic datasets from diverse environments. CANT-HYD is available at https://github.com/dgittins/CANT-HYD-HydrocarbonBiodegradation.

9.
Nat Commun ; 11(1): 1112, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111830

RESUMO

Clusters of enhancers, referred as to super-enhancers (SEs), control the expression of cell identity genes. The organisation of these clusters, and how they are remodelled upon developmental transitions remain poorly understood. Here, we report the existence of two types of enhancer units within SEs typified by distinctive CpG methylation dynamics in embryonic stem cells (ESCs). We find that these units are either prone for decommissioning or remain constitutively active in epiblast stem cells (EpiSCs), as further established in the peri-implantation epiblast in vivo. Mechanistically, we show a pivotal role for ESRRB in regulating the activity of ESC-specific enhancer units and propose that the developmentally regulated silencing of ESRRB triggers the selective inactivation of these units within SEs. Our study provides insights into the molecular events that follow the loss of ESRRB binding, and offers a mechanism by which the naive pluripotency transcriptional programme can be partially reset upon embryo implantation.


Assuntos
Ilhas de CpG , Metilação de DNA , Elementos Facilitadores Genéticos/genética , Células-Tronco Pluripotentes/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/citologia , Complexo Mediador/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Ligação Proteica , RNA Polimerase II/metabolismo , Transcrição Gênica
10.
ISME J ; 14(5): 1260-1272, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32047278

RESUMO

The deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is therefore critical to evaluate the potential impact microbial metabolism, including sulfide generation, could have upon the safety of the repository. We investigated a deep groundwater where sulfate is present, but groundwater geochemistry suggests limited microbial sulfate-reducing activity. Examination of the microbial community at the genome-level revealed microorganisms with the metabolic capacity for both oxidative and reductive sulfur transformations. Deltaproteobacteria are shown to have the genetic capacity for sulfate reduction and possibly sulfur disproportionation, while Rhizobiaceae, Rhodocyclaceae, Sideroxydans, and Sulfurimonas oxidize reduced sulfur compounds. Further examination of the proteome confirmed an active sulfur cycle, serving for microbial energy generation and growth. Our results reveal that this sulfide-poor groundwater harbors an active microbial community of sulfate-reducing and sulfide-oxidizing bacteria, together mediating a sulfur cycle that remained undetected by geochemical monitoring alone. The ability of sulfide-oxidizing bacteria to limit the accumulation of sulfide was further demonstrated in groundwater incubations and highlights a potential sink for sulfide that could be beneficial for geological repository safety.


Assuntos
Água Subterrânea/microbiologia , Enxofre/metabolismo , Bactérias/metabolismo , Finlândia , Microbiota , Oxirredução , Sulfatos/metabolismo , Sulfetos/metabolismo
11.
Environ Microbiol ; 22(1): 456-465, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31742859

RESUMO

Thermophilic endospores are widespread in cold marine sediments where the temperature is too low to support growth and activity of thermophiles in situ. These endospores are likely expelled from warm subsurface environments and subsequently dispersed by ocean currents. The endospore upper temperature limit for survival is 140°C, which can be tolerated in repeated short exposures, potentially enabling transit through hot crustal fluids. Longer-term thermal tolerance of endospores, and how long they could persist in an environment hotter than their maximum growth temperature, is less understood. To test whether thermophilic endospores can survive prolonged exposure to high temperatures, sediments were incubated at 80-90°C for 6, 12 or 463 days. Sediments were then cooled by 10-40°C, mimicking the cooling in subsurface oil reservoirs subjected to seawater injection. Cooling the sediments induced sulfate reduction, coinciding with an enrichment of endospore-forming Clostridia. Different Desulfofundulus, Desulfohalotomaculum, Desulfallas, Desulfotomaculum and Desulfofarcimen demonstrated different thermal tolerances, with some Desulfofundulus strains surviving for >1 year at 80°C. In an oil reservoir context, heat-resistant endospore-forming sulfate-reducing bacteria have a survival advantage if they are introduced to, or are resident in, an oil reservoir normally too hot for germination and growth, explaining observations of reservoir souring following cold seawater injection.


Assuntos
Clostridiaceae/metabolismo , Sedimentos Geológicos/microbiologia , Peptococcaceae/metabolismo , Água do Mar/microbiologia , Sulfatos/metabolismo , Archaea , Clostridiaceae/classificação , Clostridiaceae/genética , Temperatura Baixa , Temperatura Alta , Oxirredução , Peptococcaceae/classificação , Peptococcaceae/genética , Filogenia , Esporos Bacterianos/genética , Esporos Bacterianos/crescimento & desenvolvimento
12.
BMJ Open ; 9(6): e027307, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167867

RESUMO

INTRODUCTION: Smoke-free policies have been introduced in prisons internationally. However, high rates of relapse to smoking after release from prison indicate that these policies typically result in short-term smoking cessation only. These high rates of relapse, combined with a lack of investment in relapse prevention, highlight a missed opportunity to improve the health of a population who smoke tobacco at two to six times the rate of the general population. This paper describes the rationale and design of a randomised controlled trial, testing the effectiveness of a caseworker-delivered intervention promoting smoking cessation among former smokers released from smoke-free prisons in Victoria, Australia. METHODS AND ANALYSIS: The multicomponent, brief intervention consists of behavioural counselling, provision of nicotine spray and referral to Quitline and primary care to promote use of government-subsidised smoking cessation pharmacotherapy. The intervention is embedded in routine service delivery and is administered at three time points: one prerelease and two postrelease from prison. Control group participants will receive usual care. Smoking abstinence will be assessed at 1 and 3 months postrelease, and confirmed with carbon monoxide breath testing. Linkage of participant records to survey and routinely collected administrative data will provide further information on postrelease use of health services and prescribed medication. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Corrections Victoria Research Committee, the Victorian Department of Justice Human Research Ethics Committee, the Department of Human Services External Request Evaluation Committee and the University of Melbourne Human Research Ethics Committee. Results will be submitted to major international health-focused journals. In case of success, findings will assist policymakers to implement urgently needed interventions promoting the maintenance of prison-initiated smoking abstinence after release, to reduce the health disparities experienced by this marginalised population. TRIAL REGISTRATION NUMBER: ACTRN12618000072213; Pre-results.


Assuntos
Prevenção Secundária/métodos , Abandono do Hábito de Fumar/métodos , Ex-Fumantes/psicologia , Ex-Fumantes/estatística & dados numéricos , Humanos , Prisioneiros , Ensaios Clínicos Controlados Aleatórios como Assunto , Política Antifumo , Tabagismo/tratamento farmacológico , Tabagismo/psicologia , Vitória
13.
Stem Cell Res Ther ; 10(1): 122, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999923

RESUMO

BACKGROUND: Sox2 is a well-established pluripotent transcription factor that plays an essential role in establishing and maintaining pluripotent stem cells (PSCs). It is also thought to be a linage specifier that governs PSC neural lineage specification upon their exiting the pluripotent state. However, the exact role of SOX2 in human PSCs was still not fully understood. In this study, we studied the role of SOX2 in human embryonic stem cells (hESCs) by gain- and loss-of-function approaches and explored the possible underlying mechanisms. RESULTS: We demonstrate that knockdown of SOX2 induced hESC differentiation to endoderm-like cells, whereas overexpression of SOX2 in hESCs enhanced their pluripotency under self-renewing culture conditions but promoted their neural differentiation upon replacing the culture to non-self-renewal conditions. We show that this culture-dependent dual function of SOX2 was probably attributed to its interaction with different transcription factors predisposed by the culture environments. Whilst SOX2 interacts with OCT4 under self-renewal conditions, we found that, upon neural differentiation, PAX6, a key neural transcription factor, is upregulated and shows interaction with SOX2. The SOX2-PAX6 complex has different gene regulation pattern from that of SOX2-OCT4 complex. CONCLUSIONS: Our work provides direct evidence that SOX2 is necessarily required for hESC pluripotency; however, it can also function as a neural factor, depending on the environmental input. OCT4 and PAX6 might function as key SOX2-interacting partners that determine the function of SOX2 in hESCs.


Assuntos
Diferenciação Celular , Células-Tronco Embrionárias Humanas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Fator de Transcrição PAX6/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Linhagem Celular , Células-Tronco Embrionárias Humanas/citologia , Humanos , Células-Tronco Neurais/citologia
14.
Front Microbiol ; 9: 2129, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30245678

RESUMO

Olkiluoto, an island on the south-west coast of Finland, will host a deep geological repository for the storage of spent nuclear fuel. Microbially induced corrosion from the generation of sulphide is therefore a concern as it could potentially compromise the longevity of the copper waste canisters. Groundwater at Olkiluoto is geochemically stratified with depth and elevated concentrations of sulphide are observed when sulphate-rich and methane-rich groundwaters mix. Particularly high sulphide is observed in methane-rich groundwater from a fracture at 530.6 mbsl, where mixing with sulphate-rich groundwater occurred as the result of an open drill hole connecting two different fractures at different depths. To determine the electron donors fuelling sulphidogenesis, we combined geochemical, isotopic, metagenomic and metaproteomic analyses. This revealed a low diversity microbial community fuelled by hydrogen and organic carbon. Sulphur and carbon isotopes of sulphate and dissolved inorganic carbon, respectively, confirmed that sulphate reduction was ongoing and that CO2 came from the degradation of organic matter. The results demonstrate the impact of introducing sulphate to a methane-rich groundwater with limited electron acceptors and provide insight into extant metabolisms in the terrestrial subsurface.

15.
J Virus Erad ; 4(3): 189-192, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30050684

RESUMO

There is increasing recognition that violence against women is a barrier to sexual and reproductive health and rights, and a cause and consequence of HIV. In this viewpoint, we describe the recently published Action Linking Initiatives on Violence Against Women and HIV Everywhere (ALIV[H]E) framework [1]. The potential of this framework is explored in terms of it contributing to paradigm change to achieve the sexual and reproductive health rights of women experiencing, or living in contexts of, violence and/or HIV. We go on to suggest that a holistic approach to research and evaluation is vital to strengthen learning and expand the evidence base on violence against women and HIV.

16.
Environ Microbiol ; 20(3): 1134-1147, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29393553

RESUMO

Endospores of thermophilic bacteria are found in cold and temperate sediments where they persist in a dormant state. As inactive endospores that cannot grow at the low ambient temperatures, they are akin to tracer particles in cold sediments, unaffected by factors normally governing microbial biogeography (e.g., selection, drift, mutation). This makes thermophilic endospores ideal model organisms for studying microbial biogeography since their spatial distribution can be directly related to their dispersal history. To assess dispersal histories of estuarine bacteria, thermophilic endospores were enriched from sediments along a freshwater-to-marine transect of the River Tyne in high temperature incubations (50°C). Dispersal histories for 75 different taxa indicated that the majority of estuarine endospores were of terrestrial origin; most closely related to bacteria from warm habitats associated with industrial activity. A subset of the taxa detected were marine derived, with close relatives from hot deep marine biosphere habitats. These patterns are consistent with the sources of sediment in the River Tyne being predominantly terrestrial in origin. The results point to microbial communities in estuarine and marine sediments being structured by bi-directional currents, terrestrial run-off and industrial effluent as vectors of passive dispersal and immigration.


Assuntos
Bactérias/isolamento & purificação , Sedimentos Geológicos/microbiologia , Rios/microbiologia , Esporos Bacterianos/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Temperatura Baixa , Estuários , Temperatura Alta , Microbiota
17.
Cell Syst ; 5(3): 237-250.e8, 2017 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-28843484

RESUMO

While many tumors initially respond to chemotherapy, regrowth of surviving cells compromises treatment efficacy in the long term. The cell-biological basis of this regrowth is not understood. Here, we characterize the response of individual, patient-derived neuroblastoma cells driven by the prominent oncogene MYC to the first-line chemotherapy, doxorubicin. Combining live-cell imaging, cell-cycle-resolved transcriptomics, and mathematical modeling, we demonstrate that a cell's treatment response is dictated by its expression level of MYC and its cell-cycle position prior to treatment. All low-MYC cells enter therapy-induced senescence. High-MYC cells, by contrast, disable their cell-cycle checkpoints, forcing renewed proliferation despite treatment-induced DNA damage. After treatment, the viability of high-MYC cells depends on their cell-cycle position during treatment: newborn cells promptly halt in G1 phase, repair DNA damage, and form re-growing clones; all other cells show protracted DNA repair and ultimately die. These findings demonstrate that fast-proliferating tumor cells may resist cytotoxic treatment non-genetically, by arresting within a favorable window of the cell cycle.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas Proto-Oncogênicas c-myc/genética , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Doxorrubicina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença/genética , Humanos , Modelos Teóricos , Neuroblastoma/genética , Cultura Primária de Células , Transcriptoma/genética
18.
Methods Mol Biol ; 1580: 265-279, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28439839

RESUMO

Reverse-transcriptase quantitative PCR (RT-qPCR) is a widely used method for quantifying microRNAs (miRNAs) in cells and tissues. However, the quantification of miRNAs in the circulation presents specific challenges. Here, we describe an optimized protocol using a small amount of input material to assess serum sample quality and quantify levels of a panel of up to 20 miRNAs. This is achieved by multiplexing Taqman miRNA stem-loop primers in the reverse transcription step. An additional multiplexed pre-amplification step is used to increase the sensitivity of the final quantification step, which is carried out using standard Taqman qPCR methodology.


Assuntos
MicroRNA Circulante/sangue , Neoplasias/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/isolamento & purificação , MicroRNA Circulante/genética , MicroRNA Circulante/isolamento & purificação , Perfilação da Expressão Gênica/métodos , Humanos , Neoplasias/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Transcrição Reversa , Tamanho da Amostra
19.
Development ; 144(4): 567-579, 2017 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-28087629

RESUMO

Jmjd2 H3K9 demethylases cooperate in promoting mouse embryonic stem cell (ESC) identity. However, little is known about their importance at the exit of ESC pluripotency. Here, we reveal that Jmjd2c facilitates this process by stabilising the assembly of mediator-cohesin complexes at lineage-specific enhancers. Functionally, we show that Jmjd2c is required in ESCs to initiate appropriate gene expression programs upon somatic multi-lineage differentiation. In the absence of Jmjd2c, differentiation is stalled at an early post-implantation epiblast-like stage, while Jmjd2c-knockout ESCs remain capable of forming extra-embryonic endoderm derivatives. Dissection of the underlying molecular basis revealed that Jmjd2c is re-distributed to lineage-specific enhancers during ESC priming for differentiation. Interestingly, Jmjd2c-bound enhancers are co-occupied by the H3K9-methyltransferase G9a (also known as Ehmt2), independently of its H3K9-modifying activity. Loss of Jmjd2c abrogates G9a recruitment and further destabilises loading of the mediator and cohesin components Med1 and Smc1a at newly activated and poised enhancers in ESC-derived epiblast-like cells. These findings unveil Jmjd2c and G9a as novel enhancer-associated factors, and implicate Jmjd2c as a molecular scaffold for the assembly of essential enhancer-protein complexes with an impact on timely gene activation.


Assuntos
Células-Tronco Embrionárias/citologia , Elementos Facilitadores Genéticos , Histona-Lisina N-Metiltransferase/fisiologia , Histona Desmetilases com o Domínio Jumonji/fisiologia , Animais , Proteínas de Ciclo Celular/fisiologia , Diferenciação Celular , Linhagem da Célula , Proteínas Cromossômicas não Histona/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/citologia , Histonas/metabolismo , Camundongos , Camundongos Knockout , Células-Tronco Pluripotentes/citologia , Ligação Proteica , Análise de Sequência de RNA , Coesinas
20.
Health Hum Rights ; 19(2): 155-168, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29302173

RESUMO

There is rightly a huge global effort to enable women living with HIV to have long productive lives, through treatment access. However, many women living with HIV experience violence against women (VAW), in both domestic and health care settings. The ways in which VAW might prevent treatment access and adherence for women has not to date been reviewed coherently at the global level, from women's own perspectives. Meanwhile, funding for global health care, including HIV treatment, is shrinking. To optimize women's health and know how best to optimize facilitators and minimize barriers to access and adherence, especially in this shrinking funding context, we need to understand more about these issues from women's own perspectives. In response, we conducted a three-phase review: (1) a literature review (phase one); (2) focus group discussions and interviews with nearly 200 women living with HIV from 17 countries (phase two); and (3) three country case studies (phase three). The results presented here are based predominantly on women's own experiences and are coherent across all three phases. Recommendations are proposed regarding laws, policies, and programs which are rights-based, gendered, and embrace diversity, to maximize women's voluntary, informed, confidential, and safe access to and adherence to medication, and optimize their long-term sexual and reproductive health.


Assuntos
Infecções por HIV/terapia , Saúde Reprodutiva , Saúde da Mulher/economia , Direitos da Mulher/legislação & jurisprudência , Feminino , Saúde Global , Infecções por HIV/economia , Infecções por HIV/prevenção & controle , Humanos , Fatores Socioeconômicos , Violência/prevenção & controle
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...