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1.
Cell ; 177(3): 572-586.e22, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30955884

RESUMO

Drug resistance and relapse remain key challenges in pancreatic cancer. Here, we have used RNA sequencing (RNA-seq), chromatin immunoprecipitation (ChIP)-seq, and genome-wide CRISPR analysis to map the molecular dependencies of pancreatic cancer stem cells, highly therapy-resistant cells that preferentially drive tumorigenesis and progression. This integrated genomic approach revealed an unexpected utilization of immuno-regulatory signals by pancreatic cancer epithelial cells. In particular, the nuclear hormone receptor retinoic-acid-receptor-related orphan receptor gamma (RORγ), known to drive inflammation and T cell differentiation, was upregulated during pancreatic cancer progression, and its genetic or pharmacologic inhibition led to a striking defect in pancreatic cancer growth and a marked improvement in survival. Further, a large-scale retrospective analysis in patients revealed that RORγ expression may predict pancreatic cancer aggressiveness, as it positively correlated with advanced disease and metastasis. Collectively, these data identify an orthogonal co-option of immuno-regulatory signals by pancreatic cancer stem cells, suggesting that autoimmune drugs should be evaluated as novel treatment strategies for pancreatic cancer patients.


Assuntos
Adenocarcinoma/patologia , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/patologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular , Epigênese Genética , Biblioteca Gênica , Humanos , Camundongos , Camundongos Knockout , Camundongos SCID , Células-Tronco Neoplásicas/citologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/antagonistas & inibidores , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Interleucina-10/antagonistas & inibidores , Receptores de Interleucina-10/genética , Receptores de Interleucina-10/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transcriptoma , Células Tumorais Cultivadas
2.
Genes Dev ; 37(19-20): 865-882, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37852796

RESUMO

The MYC oncogenic transcription factor is acetylated by the p300 and GCN5 histone acetyltransferases. The significance of MYC acetylation and the functions of specific acetylated lysine (AcK) residues have remained unclear. Here, we show that the major p300-acetylated K148(149) and K157(158) sites in human (or mouse) MYC and the main GCN5-acetylated K323 residue are reversibly acetylated in various malignant and nonmalignant cells. Oncogenic overexpression of MYC enhances its acetylation and alters the regulation of site-specific acetylation by proteasome and deacetylase inhibitors. Acetylation of MYC at different K residues differentially affects its stability in a cell type-dependent manner. Lysine-to-arginine substitutions indicate that although none of the AcK residues is required for MYC stimulation of adherent cell proliferation, individual AcK sites have gene-specific functions controlling select MYC-regulated processes in cell adhesion, contact inhibition, apoptosis, and/or metabolism and are required for the malignant cell transformation activity of MYC. Each AcK site is required for anchorage-independent growth of MYC-overexpressing cells in vitro, and both the AcK148(149) and AcK157(158) residues are also important for the tumorigenic activity of MYC transformed cells in vivo. The MYC AcK site-specific signaling pathways identified may offer new avenues for selective therapeutic targeting of MYC oncogenic activities.


Assuntos
Histona Acetiltransferases , Lisina , Animais , Humanos , Camundongos , Acetilação , Adesão Celular/genética , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Histona Acetiltransferases/metabolismo , Lisina/metabolismo
3.
Vet Surg ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38952025

RESUMO

OBJECTIVE: To report the technique and the outcome for the repair of pelvic fractures in cats using external skeletal fixation (ESF). STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned cats (n = 125). METHODS: Medical records of cats with pelvic fractures, treated with an ESF between June 2001 and June 2009, were reviewed. Preoperative, immediate postoperative, and more than 4 weeks' postoperative radiographs were compared. Clinical examination was performed 4 to 9 weeks following surgery. Longer term follow up (4 to 80 months) was conducted by client questionnaire. RESULTS: No intraoperative complications occurred. There was no change in the pelvic canal width observed on follow-up radiographs (p = .16). Implant loosening was noted on follow-up radiographs in 16/125 (13%) of cases, and 67/803 (8%) pins were palpably loose at the time of frame removal. The mean time to frame removal was 37 ± 9 days. No long-term complications were reported. Long-term mean mobility score was 95 ± 5 and median lameness was 0 (range: 0-2). CONCLUSION: An ESF may be successfully applied for the stabilization of various pelvic fractures in cats. CLINICAL SIGNIFICANCE: The application of an ESF for the management of pelvic fractures in cats provides good outcomes.

4.
BMC Public Health ; 23(1): 774, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37101181

RESUMO

BACKGROUND: In response to the rise in opioid-related deaths, communities across Ontario have developed opioid or overdose response plans to address issues at the local level. Public Health Ontario (PHO) leads the Community Opioid / Overdose Capacity Building (COM-CAP) project, which aims to reduce overdose-related harms at the community level by working with communities to identify, develop, and evaluate capacity building supports for local needs around overdose planning. The 'From Design to Action' co-design workshop used a participatory design approach to engage communities in identifying the requirements for capacity building support. METHODS: A participatory approach (co-design) provided opportunity for collaborative discussion around capacity building needs at the community level. The co-design workshop included three structured collaborative activities to 1) prioritize scenarios that illustrated various challenges associated with community overdose response planning, 2) prioritize the challenges within each scenario and 3) prioritize the supports to address each of these challenges. It was conducted with fifty-two participants involved in opioid/overdose-related response plans in Ontario. Participatory materials were informed by the results of a situational assessment (SA) data gathering process, including survey, interview, and focus group data. A voting system, including dot stickers and discussion notes, was applied to identify priority supports and delivery mechanisms. RESULTS: At the workshop, key challenges and top-priority supports were identified, for development and implementation. The prioritized challenges were organized into five categories of capacity building supports addressing: 1) stigma & equity; 2) trust-based relationships, consensus building & on-going communication; 3) knowledge development & on-going access to information and data; 4) tailored strategies and plan adaptation to changing structures and local context; and 5) structural enablers and responsive governance. CONCLUSION: Using a participatory approach, the workshop provided an opportunity for sharing, generating, and mobilizing knowledge to address research-practice gaps at the community level for opioid response planning. The application of health design methods such as the 'From Design to Action' co-design workshop supports teams to gain a deeper understanding of needs for capacity building as well as illustrating the application of participatory approaches in identifying capacity building needs for complex public health issues such as the overdose crisis.


Assuntos
Fortalecimento Institucional , Overdose de Drogas , Humanos , Analgésicos Opioides , Overdose de Drogas/prevenção & controle , Ontário , Grupos Focais
5.
Int J Equity Health ; 21(1): 2, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012602

RESUMO

BACKGROUND: An Aboriginal-developed empowerment and social and emotional wellbeing program, known as Family Wellbeing (FWB), has been found to strengthen the protective factors that help Indigenous Australians to deal with the legacy of colonisation and intergenerational trauma. This article reviews the research that has accompanied the implementation of the program, over a 23 year period. The aim is to assess the long-term impact of FWB research and identify the key enablers of research impact and the limitations of the impact assessment exercise. This will inform more comprehensive monitoring of research impact into the future. METHODS: To assess impact, the study took an implementation science approach, incorporating theory of change and service utilisation frameworks, to create a logic model underpinned by Indigenous research principles. A research impact narrative was developed based on mixed methods analysis of publicly available data on: 1) FWB program participation; 2) research program funding; 3) program outcome evaluation (nine studies); and 4) accounts of research utilisation (seven studies). RESULTS: Starting from a need for research on empowerment identified by research users, an investment of $2.3 million in research activities over 23 years produced a range of research outputs that evidenced social and emotional wellbeing benefits arising from participation in the FWB program. Accounts of research utilisation confirmed the role of research outputs in educating participants about the program, and thus, facilitating more demand (and funding acquisition) for FWB. Overall research contributed to 5,405 recorded participants accessing the intervention. The key enablers of research impact were; 1) the research was user- and community-driven; 2) a long-term mutually beneficial partnership between research users and researchers; 3) the creation of a body of knowledge that demonstrated the impact of the FWB intervention via different research methods; 4) the universality of the FWB approach which led to widespread application. CONCLUSIONS: The FWB research impact exercise reinforced the view that assessing research impact is best approached as a "wicked problem" for which there are no easy fixes. It requires flexible, open-ended, collaborative learning-by-doing approaches to build the evidence base over time. Steps and approaches that research groups might take to build the research impact knowledge base within their disciplines are discussed.


Assuntos
Pesquisa Participativa Baseada na Comunidade , Serviços de Saúde do Indígena , Austrália , Família , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico
6.
BMC Public Health ; 22(1): 1390, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35854231

RESUMO

BACKGROUND: Many communities across North America are coming together to develop comprehensive plans to address and respond to the escalating overdose crisis, largely driven by an increasingly toxic unregulated drug supply. As there is a need to build capacity for successful implementation, the objective of our mixed methods study was to identify the current planning and implementation practices, needs, and priority areas of support for community overdose response plans in Ontario, Canada. METHODS: We used a situational assessment methodology to collect data on current planning and implementation practices, needs, and challenges related to community overdose response plans in Ontario, consisting of three components. Between November 2019 to February 2020, we conducted ten semi-structured key informant interviews, three focus groups with 25 participants, and administered an online survey (N = 66). Purposeful sampling was used to identify professionals involved in coordinating, supporting, or partnering on community overdose response plans in jurisdictions with relevant information for Ontario including other Canadian provinces and American states. Key informants included evaluators, representatives involved in centralised supports, as well as coordinators and partners on community overdose response plans. Focus group participants were coordinators or leads of community overdose response plans in Ontario. RESULTS: Sixty-six professionals participated in the study. The current planning and implementation practices of community overdose response plans varied in Ontario. Our analysis generated four overarching areas for needs and support for the planning and implementation of community overdose response plans: 1) data and information; 2) evidence and practice; 3) implementation/operational factors; and 4) partnership, engagement, and collaboration. Addressing stigma and equity within planning and implementation of community overdose response plans was a cross-cutting theme that included meaningful engagement of people with living and lived expertise and meeting the service needs of different populations and communities. CONCLUSIONS: Through exploring the needs and related supports for community overdose response plans in Ontario, we have identified key priority areas for building local capacity building to address overdose-related harms. Ongoing development and refinement, community partnership, and evaluation of our project will highlight the influence of our supports to advance the capacity, motivation, and opportunities of community overdose response plans.


Assuntos
Overdose de Drogas , Overdose de Drogas/epidemiologia , Overdose de Drogas/prevenção & controle , Grupos Focais , Humanos , América do Norte , Ontário/epidemiologia , Inquéritos e Questionários
7.
BMC Genomics ; 19(1): 21, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29304739

RESUMO

BACKGROUND: Intron retention (IR) is the most prevalent form of alternative splicing in plants. IR, like other forms of alternative splicing, has an important role in increasing gene product diversity and regulating transcript functionality. Splicing is known to occur co-transcriptionally and is influenced by the speed of transcription which in turn, is affected by chromatin structure. It follows that chromatin structure may have an important role in the regulation of splicing, and there is preliminary evidence in metazoans to suggest that this is indeed the case; however, nothing is known about the role of chromatin structure in regulating IR in plants. DNase I-seq is a useful experimental tool for genome-wide interrogation of chromatin accessibility, providing information on regions of chromatin with very high likelihood of cleavage by the enzyme DNase I, known as DNase I Hypersensitive Sites (DHSs). While it is well-established that promoter regions are highly accessible and are over-represented with DHSs, not much is known about DHSs in the bodies of genes, and their relationship to splicing in general, and IR in particular. RESULTS: In this study we use publicly available DNase I-seq data in arabidopsis and rice to investigate the relationship between IR and chromatin structure. We find that IR events are highly enriched in DHSs in both species. This implies that chromatin is more open in retained introns, which is consistent with a kinetic model of the process whereby higher speeds of transcription in those regions give less time for the spliceosomal machinery to recognize and splice out those introns co-transcriptionally. The more open chromatin in IR can also be the result of regulation mediated by DNA-binding proteins. To test this, we performed an exhaustive search for footprints left by DNA-binding proteins that are associated with IR. We identified several hundred short sequence elements that exhibit footprints in their DNase I-seq coverage, the telltale sign for binding events of a regulatory protein, protecting its binding site from cleavage by DNase I. A highly significant fraction of those sequence elements are conserved between arabidopsis and rice, a strong indication of their functional importance. CONCLUSIONS: In this study we have established an association between IR and chromatin accessibility, and presented a mechanistic hypothesis that explains the observed association from the perspective of the co-transcriptional nature of splicing. Furthermore, we identified conserved sequence elements for DNA-binding proteins that affect splicing.


Assuntos
Arabidopsis/genética , Cromatina/química , Íntrons , Oryza/genética , Processamento Alternativo , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Desoxirribonuclease I , Pegadas de Proteínas
8.
Plant Cell ; 27(12): 3294-308, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26603559

RESUMO

Plant SR45 and its metazoan ortholog RNPS1 are serine/arginine-rich (SR)-like RNA binding proteins that function in splicing/postsplicing events and regulate diverse processes in eukaryotes. Interactions of SR45 with both RNAs and proteins are crucial for regulating RNA processing. However, in vivo RNA targets of SR45 are currently unclear. Using RNA immunoprecipitation followed by high-throughput sequencing, we identified over 4000 Arabidopsis thaliana RNAs that directly or indirectly associate with SR45, designated as SR45-associated RNAs (SARs). Comprehensive analyses of these SARs revealed several roles for SR45. First, SR45 associates with and regulates the expression of 30% of abscisic acid (ABA) signaling genes at the postsplicing level. Second, although most SARs are derived from intron-containing genes, surprisingly, 340 SARs are derived from intronless genes. Expression analysis of the SARs suggests that SR45 differentially regulates intronless and intron-containing SARs. Finally, we identified four overrepresented RNA motifs in SARs that likely mediate SR45's recognition of its targets. Therefore, SR45 plays an unexpected role in mRNA processing of intronless genes, and numerous ABA signaling genes are targeted for regulation at the posttranscriptional level. The diverse molecular functions of SR45 uncovered in this study are likely applicable to other species in view of its conservation across eukaryotes.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Transcriptoma , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arginina/metabolismo , Íntrons/genética , Motivos de Nucleotídeos , Splicing de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Proteínas de Ligação a RNA/genética , Análise de Sequência de RNA , Serina/metabolismo
9.
Dev Biol ; 409(2): 451-8, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26610632

RESUMO

Frontonasal dysplasia (FND) can have severe presentations that are medically and socially debilitating. Several genes are implicated in FND conditions, including Aristaless-Like Homeobox 1 (ALX1), which is associated with FND3. Breeds of cats are selected and bred for extremes in craniofacial morphologies. In particular, a lineage of Burmese cats with severe brachycephyla is extremely popular and is termed Contemporary Burmese. Genetic studies demonstrated that the brachycephyla of the Contemporary Burmese is a simple co-dominant trait, however, the homozygous cats have a severe craniofacial defect that is incompatible with life. The craniofacial defect of the Burmese was genetically analyzed over a 20 year period, using various genetic analysis techniques. Family-based linkage analysis localized the trait to cat chromosome B4. Genome-wide association studies and other genetic analyses of SNP data refined a critical region. Sequence analysis identified a 12bp in frame deletion in ALX1, c.496delCTCTCAGGACTG, which is 100% concordant with the craniofacial defect and not found in cats not related to the Contemporary Burmese.


Assuntos
Anormalidades Craniofaciais/genética , Face/anormalidades , Estudos de Associação Genética , Predisposição Genética para Doença , Proteínas de Homeodomínio/genética , Polimorfismo de Nucleotídeo Único/genética , Animais , Cruzamento , Gatos , Ligação Genética , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem
10.
J Community Health ; 41(5): 1069-77, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27038960

RESUMO

Despite the availability of HPV prophylactic vaccines, uptake has been suboptimal in the US. In the state of Hawaii, HPV vaccine coverage has decreased among females and remains low among males aged 13-17. The reasons for low uptake are unknown and may indicate the existence of critical barriers to HPV vaccination. The purpose of this investigation was to identify policy, system and environmental barriers and promoters of pediatric HPV vaccination in Hawaii. An online 86-item survey addressing knowledge, attitudes, beliefs, practices, and barriers to HPV vaccination was distributed to practicing physicians in Hawaii specializing in Pediatrics, Family Medicine, and Obstetrics-Gynecology. Survey responses were received from a total of 120 physicians. Private practice physicians reported more concerns with vaccine ordering and stocking costs (p < 0.0001), reimbursement levels (p < 0.0001), and insurance coverage (p < 0.0001) compared to physicians in large group practices. Eighty-three percent of providers cited lack of parent knowledge and understanding of HPV infection as a barrier. Over half of physicians (58 %) reported that completion of the 3-dose schedule was a barrier. Most physicians did not use tracking or reminder systems to ensure dose completion. A majority (58 %) of providers cited the lack of school-based vaccination requirements as a barrier. Uptake of HPV vaccination in Hawaii may be impeded by physician perception of parent knowledge and attitudes. Cost-related system barriers are particular barriers among those in private practice. Completion of the 3-dose schedule also remains a challenge.


Assuntos
Promoção da Saúde , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Aceitação pelo Paciente de Cuidados de Saúde , Adulto , Idoso , Estudos Transversais , Medicina de Família e Comunidade , Feminino , Havaí , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
11.
Chaos ; 26(7): 073108, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27475068

RESUMO

The use of reverse time chaos allows the realization of hardware chaotic systems that can operate at speeds equivalent to existing state of the art while requiring significantly less complex circuitry. Matched filter decoding is possible for the reverse time system since it exhibits a closed form solution formed partially by a linear basis pulse. Coefficients have been calculated and are used to realize the matched filter digitally as a finite impulse response filter. Numerical simulations confirm that this correctly implements a matched filter that can be used for detection of the chaotic signal. In addition, the direct form of the filter has been implemented in hardware description language and demonstrates performance in agreement with numerical results.

12.
Risk Anal ; 35(7): 1348-63, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25946233

RESUMO

This article presents an analysis of postattack response strategies to mitigate the risks of reoccupying contaminated areas following a release of Bacillus anthracis spores (the bacterium responsible for causing anthrax) in an urban setting. The analysis is based on a hypothetical attack scenario in which individuals are exposed to B. anthracis spores during an initial aerosol release and then placed on prophylactic antibiotics that successfully protect them against the initial aerosol exposure. The risk from reoccupying buildings contaminated with spores due to their reaerosolization and inhalation is then evaluated. The response options considered include: decontamination of the buildings, vaccination of individuals reoccupying the buildings, extended evacuation of individuals from the contaminated buildings, and combinations of these options. The study uses a decision tree to estimate the costs and benefits of alternative response strategies across a range of exposure risks. Results for best estimates of model inputs suggest that the most cost-effective response for high-risk scenarios (individual chance of infection exceeding 11%) consists of evacuation and building decontamination. For infection risks between 4% and 11%, the preferred option is to evacuate for a short period, vaccinate, and then reoccupy once the vaccine has taken effect. For risks between 0.003% and 4%, the preferred option is to vaccinate only. For risks below 0.003%, none of the mitigation actions have positive expected monetary benefits. A sensitivity analysis indicates that for high-infection-likelihood scenarios, vaccination is recommended in the case where decontamination efficacy is less than 99.99%.


Assuntos
Antraz/transmissão , Guerra Biológica , Risco , Tomada de Decisões , Humanos
13.
Ergonomics ; 58(3): 504-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25343497

RESUMO

Postural stability is critical for ensuring a safe workplace. Employees with poor stability are more prone to falls and injuries while at work. In this study, postural sway of participants in different obesity categories was evaluated while performing an assembly workstation task. The study included three workstations: those designed for the 5th, 50th and 95th percentile workers based on anthropometric data tables. Force plates were used to study the differences in postural sway in both the medial-lateral and anterior-posterior directions. The results revealed that the obese class 1 and obese class 2 groups' anterior-posterior sway was significantly larger than that of the normal weight groups while performing assembly work tasks. Also, pace type (self-paced or time-paced) and workstation (5th, 50th and 95th percentile) significantly affected the postural sway. The postural sway was not affected by gender differences. Workstations should be designed to accommodate the increased postural sway of obese workers. PRACTITIONER SUMMARY: It is known that body mass index (BMI) affects postural sway. In this study, we examine the impact of BMI on postural sway at various workstation configurations. The postural sway was significantly larger in participants with larger BMIs.


Assuntos
Índice de Massa Corporal , Indústria Manufatureira , Obesidade/fisiopatologia , Equilíbrio Postural , Análise e Desempenho de Tarefas , Adulto , Feminino , Humanos , Masculino , Obesidade/classificação , Local de Trabalho , Adulto Jovem
14.
Risk Anal ; 34(9): 1651-62, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24660760

RESUMO

Helicobacter pylori is a microaerophilic, gram-negative bacterium that is linked to adverse health effects including ulcers and gastrointestinal cancers. The goal of this analysis is to develop the necessary inputs for a quantitative microbial risk assessment (QMRA) needed to develop a potential guideline for drinking water at the point of ingestion (e.g., a maximum contaminant level, or MCL) that would be protective of human health to an acceptable level of risk while considering sources of uncertainty. Using infection and gastric cancer as two discrete endpoints, and calculating dose-response relationships from experimental data on humans and monkeys, we perform both a forward and reverse risk assessment to determine the risk from current reported surface water concentrations of H. pylori and an acceptable concentration of H. pylori at the point of ingestion. This approach represents a synthesis of available information on human exposure to H. pylori via drinking water. A lifetime risk of cancer model suggests that a MCL be set at <1 organism/L given a 5-log removal treatment because we cannot exclude the possibility that current levels of H. pylori in environmental source waters pose a potential public health risk. Research gaps include pathogen occurrence in source and finished water, treatment removal rates, and determination of H. pylori risks from other water sources such as groundwater and recreational water.


Assuntos
Água Potável/microbiologia , Guias como Assunto , Helicobacter pylori/isolamento & purificação
15.
Bioorg Med Chem Lett ; 23(1): 194-7, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23177788

RESUMO

A novel GPR119 agonist based on the 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole scaffold was designed through lead optimization starting from pyrazole-based GPR119 agonist 1. The design is centered on the conformational restriction of the core scaffold, while minimizing the change in spatial relationships of two key pharmacophoric elements (piperidine-carbamate and aryl sulfone).


Assuntos
Pirazóis/química , Receptores Acoplados a Proteínas G/agonistas , Carbamatos/química , Humanos , Piperidinas/química , Ligação Proteica , Pirazóis/síntese química , Pirazóis/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-Atividade
16.
bioRxiv ; 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38234720

RESUMO

Myeloid leukemias, diseases marked by aggressiveness and poor outcomes, are frequently triggered by oncogenic translocations. In the case of chronic myelogenous leukemia (CML) the BCR-ABL fusion initiates chronic phase disease with second hits allowing progression to blast crisis. Although Gleevec has been transformative for CML, blast crisis CML remains relatively drug resistant. Here we show that MSI2-HOXA9, a translocation with an unknown role in cancer, can serve as a second hit in driving bcCML. Compared to BCR-ABL, BCR-ABL/MSI2-HOXA9 led to a more aggressive disease in vivo with decreased latency, increased lethality and a differentiation blockade that is a hallmark of blast crisis. Domain mapping revealed that the MSI2 RNA binding domain RRM1 had a preferential impact on growth and lethality of bcCML relative to RRM2 or the HOXA9 domain. Mechanistically, MSI2-HOXA9 triggered global downstream changes with a preferential upregulation of mitochondrial components. Consistent with this, BCR-ABL/MSI2-HOXA9 cells exhibited a significant increase in mitochondrial respiration. These data suggest that MSI2-HOXA9 acts, at least in part, by increasing expression of the mitochondrial polymerase Polrmt and augmenting mitochondrial function and basal respiration in blast crisis. Collectively, our findings demonstrate for the first time that translocations involving the stem and developmental signal MSI2 can be oncogenic, and suggest that MSI, which we found to be a frequent partner for an array of translocations, could also be a driver mutation across solid cancers.

17.
ACS Appl Mater Interfaces ; 15(33): 39697-39706, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37579298

RESUMO

The interest in the wafer-scale growth of two-dimensional (2D) materials, including transition metal dichalcogenides (TMDCs), has been rising for transitioning from lab-scale devices to commercial-scale systems. Among various synthesis techniques, physical vapor deposition, such as pulsed laser deposition (PLD), has shown promise for the wafer-scale growth of 2D materials. However, due to the high volatility of chalcogen atoms (e.g., S and Se), films deposited by PLD usually suffer from a lack of stoichiometry and chalcogen deficiency. To mitigate this issue, excess chalcogen is necessary during the deposition, which results in problems like uniformity or not being repeatable. This study demonstrates a condensed-phase or amorphous phase-mediated crystallization (APMC) approach for the wafer-scale synthesis of 2D materials. This method uses a room-temperature PLD process for the deposition and formation of amorphous precursors with controlled thicknesses, followed by a post-deposition crystallization process to convert the amorphous materials to crystalline structures. This approach maintains the stoichiometry of the deposited materials throughout the deposition and crystallization process and enables the large-scale synthesis of crystalline 2D materials (e.g., MoS2 and WSe2) on Si/SiO2 substrates, which is critical for future wafer-scale electronics. We show that the thickness of the layers can be digitally controlled by the number of laser pulses during the PLD phase. Optical spectroscopy is used to monitor the crystallization dynamics of amorphous layers as a function of annealing temperature. The crystalline quality, domain sizes, and the number of layers were explored using nanoscale and atomistic characterization (e.g., AFM, STEM, and EDS) along with electrical characterization to explore process-structure-performance relationships. This growth technique is a promising method that could potentially be adopted in conventional semiconductor industries for wafer-scale manufacturing of next-generation electronic and optoelectronic devices.

18.
Eur J Med Chem ; 247: 115001, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36577213

RESUMO

Wiskostatin (1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol) (1) is a carbazole-based compound reported as a specific and relatively potent inhibitor of the N-WASP actin remodelling complex (S-isomer EC50 = 4.35 µM; R-isomer EC50 = 3.44 µM). An NMR solution structure showed that wiskostatin interacts with a cleft in the regulatory GTPase binding domain of N-WASP. However, numerous studies have reported wiskostatin's actions on membrane transport and cytokinesis that are independent of the N-WASP-Arp2/3 complex pathway, but offer limited alternative explanation. The large GTPase, dynamin has established functional roles in these pathways. This study reveals that wiskostatin and its analogues, as well as other carbazole-based compounds, are inhibitors of helical dynamin GTPase activity and endocytosis. We characterise the effects of wiskostatin on in vitro dynamin GTPase activity, in-cell endocytosis, and determine the importance of wiskostatin functional groups on these activities through design and synthesis of libraries of wiskostatin analogues. We also examine whether other carbazole-based scaffolds frequently used in research or the clinic also modulate dynamin and endocytosis. Understanding off-targets for compounds used as research tools is important to be able to confidently interpret their action on biological systems, particularly when the target and off-targets affect overlapping mechanisms (e.g. cytokinesis and endocytosis). Herein we demonstrate that wiskostatin is a dynamin inhibitor (IC50 20.7 ± 1.2 µM) and a potent inhibitor of clathrin mediated endocytosis (IC50 = 6.9 ± 0.3 µM). Synthesis of wiskostatin analogues gave rise to 1-(9H-carbazol-9-yl)-3-((4-methylbenzyl)amino)propan-2-ol (35) and 1-(9H-carbazol-9-yl)-3-((4-chlorobenzyl)amino)propan-2-ol (43) as potent dynamin inhibitors (IC50 = 1.0 ± 0.2 µM), and (S)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8a) and (R)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8b) that are amongst the most potent inhibitors of clathrin mediated endocytosis yet reported (IC50 = 2.3 ± 3.3 and 2.1 ± 1.7 µM, respectively).


Assuntos
Dinamina I , Dinaminas , Dinamina I/química , Dinamina I/metabolismo , Dinaminas/farmacologia , Carbazóis/farmacologia , GTP Fosfo-Hidrolases , Actinas , Clatrina/metabolismo , Clatrina/farmacologia , Endocitose
19.
Cancer Cell ; 41(11): 1989-2005.e9, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37802055

RESUMO

Identifying the cells from which cancers arise is critical for understanding the molecular underpinnings of tumor evolution. To determine whether stem/progenitor cells can serve as cells of origin, we created a Msi2-CreERT2 knock-in mouse. When crossed to CAG-LSL-MycT58A mice, Msi2-CreERT2 mice developed multiple pancreatic cancer subtypes: ductal, acinar, adenosquamous, and rare anaplastic tumors. Combining single-cell genomics with computational analysis of developmental states and lineage trajectories, we demonstrate that MYC preferentially triggers transformation of the most immature MSI2+ pancreas cells into multi-lineage pre-cancer cells. These pre-cancer cells subsequently diverge to establish pancreatic cancer subtypes by activating distinct transcriptional programs and large-scale genomic changes, and enforced expression of specific signals like Ras can redirect subtype specification. This study shows that multiple pancreatic cancer subtypes can arise from a common pool of MSI2+ cells and provides a powerful model to understand and control the programs that shape divergent fates in pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Camundongos , Animais , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/patologia
20.
Nat Commun ; 14(1): 292, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653361

RESUMO

Pancreatic cancer is characterized by extensive resistance to conventional therapies, making clinical management a challenge. Here we map the epigenetic dependencies of cancer stem cells, cells that preferentially evade therapy and drive progression, and identify SWI/SNF complex member SMARCD3 as a regulator of pancreatic cancer cells. Although SWI/SNF subunits often act as tumor suppressors, we show that SMARCD3 is amplified in cancer, enriched in pancreatic cancer stem cells and upregulated in the human disease. Diverse genetic mouse models of pancreatic cancer and stage-specific Smarcd3 deletion reveal that Smarcd3 loss preferentially impacts established tumors, improving survival especially in context of chemotherapy. Mechanistically, SMARCD3 acts with FOXA1 to control lipid and fatty acid metabolism, programs associated with therapy resistance and poor prognosis in cancer. These data identify SMARCD3 as an epigenetic modulator responsible for establishing the metabolic landscape in aggressive pancreatic cancer cells and a potential target for new therapies.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Camundongos , Animais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Epigênese Genética , Neoplasias Pancreáticas
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