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1.
J Pathol ; 262(4): 454-466, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38229581

RESUMO

MAP4K4 is a serine/threonine kinase of the STE20 family involved in the regulation of actin cytoskeleton dynamics and cell motility. It has been proposed as a target of angiogenesis and inhibitors show potential in cardioprotection. MAP4K4 also mediates cell invasion in vitro, is overexpressed in various types of cancer, and is associated with poor patient prognosis. Recently, MAP4K4 has been shown to be overexpressed in pancreatic cancer, but its role in tumour initiation, progression, and metastasis is unknown. Here, using the KrasG12D Trp53R172H Pdx1-Cre (KPC) mouse model of pancreatic ductal adenocarcinoma (PDAC), we show that deletion of Map4k4 drives tumour initiation and progression. Moreover, we report that the acceleration of tumour onset is also associated with an overactivation of ERK and AKT, two major downstream effectors of KRAS, in vitro and in vivo. In contrast to the accelerated tumour onset caused by loss of MAP4K4, we observed a reduction in metastatic burden with both the KPC model and in an intraperitoneal transplant assay indicating a major role of MAP4K4 in metastatic seeding. In summary, our study sheds light on the dichotomous role of MAP4K4 in the initiation of PDAC onset, progression, and metastatic dissemination. It also identifies MAP4K4 as a possible druggable target against pancreatic cancer spread, but with the caveat that targeting MAP4K4 might accelerate early tumorigenesis. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Camundongos , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Sistema de Sinalização das MAP Quinases , Linhagem Celular Tumoral , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Serina , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
2.
J Cell Sci ; 135(24)2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36546396

RESUMO

Pancreatic cancer is a deadly and highly metastatic disease, although how metastatic lesions establish is not fully understood. A key feature of pancreatic tumours is extensive fibrosis and deposition of extracellular matrix (ECM). While pancreatic cancer cells are programmed by stimuli derived from a stiff ECM, metastasis requires loss of attachment and adaptation to a softer microenvironment at distant sites. Growing evidence suggests that stiff ECM influences pancreatic cancer cell behaviour. Here, we argue that this influence is reversible and that pancreatic cancer cells can be reprogrammed upon sensing soft substrates. Using engineered polyacrylamide hydrogels with tuneable mechanical properties, we show that collagen VI is specifically upregulated in pancreatic cancer cells on soft substrates, due to a lack of integrin engagement. Furthermore, the expression of collagen VI is inversely correlated with mechanosensing and activity of YAP (also known as YAP1), which might be due to a direct or indirect effect on transcription of genes encoding collagen VI. Collagen VI supports migration in vitro and metastasis formation in vivo. Metastatic nodules formed by pancreatic cancer cells lacking Col6a1 display stromal cell-derived collagen VI deposition, suggesting that collagen VI derived from either cancer cells or the stroma is an essential component of the metastatic niche. This article has an associated First Person interview with Vasileios Papalazarou, joint first author of the paper.


Assuntos
Colágeno , Neoplasias Pancreáticas , Humanos , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Integrinas/metabolismo , Microambiente Tumoral , Neoplasias Pancreáticas
3.
Development ; 147(22)2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-33028610

RESUMO

The Arp2/3 complex is essential for the assembly of branched filamentous actin, but its role in physiology and development is surprisingly little understood. Melanoblasts deriving from the neural crest migrate along the developing embryo and traverse the dermis to reach the epidermis, colonising the skin and eventually homing within the hair follicles. We have previously established that Rac1 and Cdc42 direct melanoblast migration in vivo We hypothesised that the Arp2/3 complex might be the main downstream effector of these small GTPases. Arp3 depletion in the melanocyte lineage results in severe pigmentation defects in dorsal and ventral regions of the mouse skin. Arp3 null melanoblasts demonstrate proliferation and migration defects and fail to elongate as their wild-type counterparts. Conditional deletion of Arp3 in primary melanocytes causes improper proliferation, spreading, migration and adhesion to extracellular matrix. Collectively, our results suggest that the Arp2/3 complex is absolutely indispensable in the melanocyte lineage in mouse development, and indicate a significant role in developmental processes that require tight regulation of actin-mediated motility.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Adesão Celular , Proliferação de Células , Melanócitos/metabolismo , Pigmentação da Pele , Pele/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Animais , Linhagem Celular , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Melanócitos/citologia , Camundongos , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Pele/citologia , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
4.
Harm Reduct J ; 20(1): 135, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37715202

RESUMO

Meaningful engagement and partnerships with people who use drugs are essential to conducting research that is relevant and impactful in supporting desired outcomes of drug consumption as well as reducing drug-related harms of overdose and COVID-19. Community-based participatory research is a key strategy for engaging communities in research that directly affects their lives. While there are growing descriptions of community-based participatory research with people who use drugs and identification of key principles for conducting research, there is a gap in relation to models and frameworks to guide research partnerships with people who use drugs. The purpose of this paper is to provide a framework for research partnerships between people who use drugs and academic researchers, collaboratively developed and implemented as part of an evaluation of a provincial prescribed safer supply initiative introduced during dual public health emergencies (overdose and COVID-19) in British Columbia, Canada. The framework shifts from having researchers choose among multiple models (advisory, partnership and employment) to incorporating multiple roles within an overall community-based participatory research approach. Advocacy by and for drug users was identified as a key role and reason for engaging in research. Overall, both academic researchers and Peer Research Associates benefited within this collaborative partnerships approach. Each offered their expertise, creating opportunities for omni-directional learning and enhancing the research. The shift from fixed models to flexible roles allows for a range of involvement that accommodates varying time, energy and resources. Facilitators of involvement include development of trust and partnering with networks of people who use drugs, equitable pay, a graduate-level research assistant dedicated to ongoing orientation and communication, technical supports as well as fluidity in roles and opportunities. Key challenges included working in geographically dispersed locations, maintaining contact and connection over the course of the project and ensuring ongoing sustainable but flexible employment.


Assuntos
COVID-19 , Overdose de Drogas , Humanos , Emergências , Saúde Pública , Overdose de Drogas/prevenção & controle , Pesquisa Participativa Baseada na Comunidade , Colúmbia Britânica
5.
Harm Reduct J ; 19(1): 46, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35590375

RESUMO

BACKGROUND: British Columbia (BC) has been in a state of public health emergency since 2016, due to the unprecedented numbers of fatal and non-fatal drug toxicity (i.e. overdose) events. Methamphetamine detection in illicit drug toxicity deaths increased from 14% in 2012 to 43% in 2020 suggesting a concerning trend of concurrent methamphetamine and opioid use in BC, consistent with rising patterns identified across North America. People who use methamphetamine concurrently with opioids face an elevated risk of harm. This study aimed to identify behaviours for survival and wellness practiced by people who concurrently use methamphetamine and opioids. METHODS: One-on-one semi-structured interviews were conducted by peer research assistants in person and by telephone. Thematic analysis was carried out to identify patterns in behaviours participants described as important to their safety in the context of concurrent use of methamphetamine and opioids. RESULTS: Participants (n = 22) were distributed across the province with at least four participants from each of the five geographic health regions: 64% self-identified as men, and 50% self-identified as Indigenous. Daily methamphetamine use was reported by 72.7% of participants, and 67.3% reported using alone either often or always. Participants made several considerations and adaptations in order to balance the perceived benefits and risks of their use of methamphetamine with opioids. Two overarching themes were identified to describe how participants adapted their use for survival and wellness. The first was personal safety behaviours which included self-regulation and self-care behaviours. The second was interpersonal safety behaviours which included using alongside peers, and engaging with peer-led services (e.g. community outreach organizations) and public health-led services (e.g. overdose prevention sites) to reduce the risk of harm. Participants identified many gaps in available services to meet their diverse needs. CONCLUSIONS: This manuscript identified diversity in participants' methamphetamine and opioid use (i.e. frequency, route of administration), and a range of behaviours that were performed to improve wellness and survival while using methamphetamine and opioids. Harm reduction and treatment responses must be robust and adaptable to respond to the diversity of patterns of substance use among people who use methamphetamine and opioids concurrently, so as to not perpetuate harm and leave people behind.


Assuntos
Overdose de Drogas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Metanfetamina , Transtornos Relacionados ao Uso de Opioides , Analgésicos Opioides/uso terapêutico , Colúmbia Britânica/epidemiologia , Overdose de Drogas/tratamento farmacológico , Overdose de Drogas/prevenção & controle , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/tratamento farmacológico , Humanos , Masculino , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico
6.
J Pathol ; 245(3): 337-348, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29672847

RESUMO

N-WASP (WASL) is a widely expressed cytoskeletal signalling and scaffold protein also implicated in regulation of Wnt signalling and homeostatic maintenance of skin epithelial architecture. N-WASP mediates invasion of cancer cells in vitro and its depletion reduces invasion and metastatic dissemination of breast cancer. Given this role in cancer invasion and universal expression in the gastrointestinal tract, we explored a role for N-WASP in the initiation and progression of colorectal cancer. While deletion of N-wasp is not detectably harmful in the murine intestinal tract, numbers of Paneth cells increased, indicating potential changes in the stem cell niche, and migration up the crypt-villus axis was enhanced. Loss of N-wasp promoted adenoma formation in an adenomatous polyposis coli (Apc) deletion model of intestinal tumourigenesis. Thus, we establish a tumour suppressive role of N-WASP in early intestinal carcinogenesis despite its later pro-invasive role in other cancers. Our study highlights that while the actin cytoskeletal machinery promotes invasion of cancer cells, it also maintains normal epithelial tissue function and thus may have tumour suppressive roles in pre-neoplastic tissues. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Polipose Adenomatosa do Colo/genética , Transformação Celular Neoplásica/genética , Colo/metabolismo , Genes APC , Genes Supressores de Tumor , Proteína Neuronal da Síndrome de Wiskott-Aldrich/genética , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/patologia , Idoso , Animais , Diferenciação Celular , Movimento Celular , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Colo/patologia , Reparo de Erro de Pareamento de DNA , Modelos Animais de Doenças , Progressão da Doença , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Celulas de Paneth/metabolismo , Celulas de Paneth/patologia , Fenótipo , Nicho de Células-Tronco , Microambiente Tumoral , Proteína Neuronal da Síndrome de Wiskott-Aldrich/deficiência
7.
BJU Int ; 122(4): 705-712, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29777617

RESUMO

OBJECTIVE: To report our experience of an exercise designed to train newly appointed urology trainees in non-technical skills on ward rounds as a part of a simulation 'boot camp', through a qualitative analysis of participant feedback on the utility of this method of training. PATIENTS AND METHODS: The simulations took place in a high-fidelity simulated ward bay. Forty-eight doctors with formal urology training ranging between 2 and 60 months (mean 19.1 ± 11.6 months) took part. Thirty-one participants were on a formal urology specialty training pathway. The remaining participants were core (pre-specialty) surgical trainees. The entry requirement was that participants must be junior-level urologists, ideally at the beginning of specialty training. Participants individually led a simulated ward round, which was devised using actors to play patients and a simulated 'switchboard' for telephone conversations. Distractions were introduced deliberately for participants to manage an emergent urology-related scenario. 'Freeze-frames' were used to 'pause' the ward round, whereby observing consultants provided feedback on performance. After the simulated exercises, a whole-group structured debriefing took place. Non-Technical Skills for Surgeons (NOTSS) scores were generated for participants by seven consultant urologists. Participants completed a two-part feedback form. Part one involved nine questions scored on a Likert scale, and part two required free-text responses. RESULTS: The mean (±sd) itemized NOTSS scores for situational awareness, decision-making, communication and teamwork, and leadership were 3.01 (±0.15), 2.95 (±0.16), 3.05 (±0.19), and 2.98 (±0.15), respectively. From the thematic analysis, participants commented positively on the number of scenarios per participant, the use of actors as patients and real staff, and the use of freeze-frames for immediate feedback. Residents also provided suggestions for distractions to be considered in the future. CONCLUSIONS: This simulated ward round was generally well received by participants, and the obtained feedback provides an insight into how this can be adapted to maximize the benefits for new specialty residents. The mean NOTSS scores indicated that non-technical skills performances could be improved. This supports our rationale to train non-technical skills in a safe environment to bolster career transition into positions of greater decision-making autonomy.


Assuntos
Competência Clínica/normas , Treinamento por Simulação , Urologia/educação , Comunicação , Tomada de Decisões , Avaliação Educacional , Processos Grupais , Humanos , Internato e Residência , Liderança , Equipe de Assistência ao Paciente , Aprendizagem Baseada em Problemas , Pesquisa Qualitativa , Urologia/normas
8.
Elife ; 132024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38712822

RESUMO

Pancreatic ductal adenocarcinoma carries a dismal prognosis, with high rates of metastasis and few treatment options. Hyperactivation of KRAS in almost all tumours drives RAC1 activation, conferring enhanced migratory and proliferative capacity as well as macropinocytosis. Macropinocytosis is well understood as a nutrient scavenging mechanism, but little is known about its functions in trafficking of signalling receptors. We find that CYRI-B is highly expressed in pancreatic tumours in a mouse model of KRAS and p53-driven pancreatic cancer. Deletion of Cyrib (the gene encoding CYRI-B protein) accelerates tumourigenesis, leading to enhanced ERK and JNK-induced proliferation in precancerous lesions, indicating a potential role as a buffer of RAC1 hyperactivation in early stages. However, as disease progresses, loss of CYRI-B inhibits metastasis. CYRI-B depleted tumour cells show reduced chemotactic responses to lysophosphatidic acid, a major driver of tumour spread, due to impaired macropinocytic uptake of the lysophosphatidic acid receptor 1. Overall, we implicate CYRI-B as a mediator of growth and signalling in pancreatic cancer, providing new insights into pathways controlling metastasis.


Pancreatic cancer is an aggressive disease with limited treatment options. It is also associated with high rates of metastasis ­ meaning it spreads to other areas of the body. Environmental pressures, such as a lack of the nutrients metastatic cancer cells need to grow and divide, can change how the cells behave. Understanding the changes that allow cancer cells to respond to these pressures could reveal new treatment options for pancreatic cancer. When nutrients are scarce, metastatic cancer cells can gather molecules and nutrients by capturing large amounts of the fluid that surrounds them using a mechanism called macropinocytosis. They can also migrate to areas of the body with higher nutrient levels, through a process called chemotaxis. This involves cells moving towards areas with higher levels of certain molecules. For example, cancer cells migrate towards high levels of a lipid called lysophosphatidic acid, which promotes their growth and survival. A newly discovered protein known as CYRI-B has recently been shown to regulate how cells migrate and take up nutrients. It also interacts with proteins known to be involved in pancreatic cancer progression. Therefore, Nikolaou et al. set out to investigate whether CYRI-B also plays a role in metastatic pancreatic cancer. Experiments in a mouse model of pancreatic cancer showed that CYRI-B levels were high in pancreatic tumour cells. And when the gene for CYRI-B was removed from the tumour cells, they did not metastasise. Further analysis revealed that CYRI-B controls uptake and processing of nutrients and other signalling molecules through macropinocytosis. In particular, it ensures uptake of the receptor for lysophosphatidic acid, allowing the metastatic cancer cells to migrate. The findings of Nikolaou et al. reveal that CYRI-B is involved in metastasis of cancer cells in a mouse model of pancreatic cancer. This new insight into how metastasis is controlled could help to identify future targets for treatments that aim to prevent pancreatic cancer cells spreading to distant sites.


Assuntos
Neoplasias Pancreáticas , Pinocitose , Receptores de Ácidos Lisofosfatídicos , Animais , Humanos , Camundongos , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/genética , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Metástase Neoplásica , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores de Ácidos Lisofosfatídicos/genética
9.
J Cell Sci ; 124(Pt 22): 3753-9, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22114305

RESUMO

The actin cytoskeleton provides scaffolding and physical force to effect fundamental processes such as motility, cytokinesis and vesicle trafficking. The Arp2/3 complex nucleates actin structures and contributes to endocytic vesicle invagination and trafficking away from the plasma membrane. Internalisation and directed recycling of integrins are major driving forces for invasive cell motility and potentially for cancer metastasis. Here, we describe a direct requirement for WASH and Arp2/3-mediated actin polymerisation on the endosomal membrane system for α5ß1 integrin recycling. WASH regulates the trafficking of endosomal α5ß1 integrin to the plasma membrane and is fundamental for integrin-driven cell morphology changes and integrin-mediated cancer cell invasion. Thus, we implicate WASH and Arp2/3-driven actin nucleation in receptor recycling leading to invasive motility.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Movimento Celular , Integrina alfa5beta1/metabolismo , Neoplasias/fisiopatologia , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Actinas/metabolismo , Animais , Linhagem Celular Tumoral , Membrana Celular/genética , Membrana Celular/metabolismo , Endossomos/genética , Endossomos/metabolismo , Humanos , Integrina alfa5beta1/genética , Invasividade Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Transporte Proteico , Proteína da Síndrome de Wiskott-Aldrich/genética
10.
Biochem J ; 448(1): 35-42, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22909346

RESUMO

The Scar (suppressor of cAMP receptor)/WAVE [WASP (Wiskott-Aldrich syndrome protein) verprolin homologous] complex plays a major role in the motility of cells by activating the Arp2/3 complex, which initiates actin branching and drives protrusions. Mammals have three Scar/WAVE isoforms, which show some tissue-specific expression, but their functions have not been differentiated. In the present study we show that depletion of Scar/WAVE3 in the mammalian breast cancer cells MDA-MB-231 results in larger and less dynamic lamellipodia. Scar/WAVE3-depleted cells move more slowly but more persistently on a two-dimensional matrix and they typically only show one lamellipod. However, Scar/WAVE3 appears to have no role in driving invasiveness in a three-dimensional Matrigel™ invasion assay or a three-dimensional collagen invasion assay, suggesting that lamellipodial persistence as seen in two-dimensions is not crucial in three-dimensional environments.


Assuntos
Proteínas de Neoplasias/fisiologia , Pseudópodes/fisiologia , Família de Proteínas da Síndrome de Wiskott-Aldrich/fisiologia , Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral/citologia , Linhagem Celular Tumoral/ultraestrutura , Movimento Celular , Forma Celular , Células Clonais/citologia , Colágeno , Combinação de Medicamentos , Feminino , Géis , Humanos , Técnicas In Vitro , Laminina , Invasividade Neoplásica , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteoglicanas , Pseudópodes/química , Pseudópodes/ultraestrutura , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Imagem com Lapso de Tempo , Família de Proteínas da Síndrome de Wiskott-Aldrich/antagonistas & inibidores , Família de Proteínas da Síndrome de Wiskott-Aldrich/genética
11.
J Palliat Med ; 26(11): 1562-1577, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37366688

RESUMO

Background: The benefits of palliative care programs are well documented. However, the effectiveness of specialist palliative care services is not well established. The previous lack of consensus on criteria for defining and characterizing models of care has restrained direct comparison between these models and limited the evidence base to inform policy makers. A rapid review for studies published up to 2012 was unable to find an effective model. Aim: To identify effective models of community specialist palliative care services. Design: A mixed-method synthesis design reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Prospero: CRD42020151840. Data sources: Medline, PubMed, EMBASE, CINAHL and the Cochrane Database of Systematic Reviews were searched in September 2019 for primary research and review articles from 2012 to 2019. Supplementary search was conducted on Google in 2020 for policy documents to identify additional relevant studies. Results: The search yielded 2255 articles; 36 articles satisfied the eligibility criteria and 6 additional articles were identified from other sources. Eight systematic reviews and 34 primary studies were identified: observational studies (n = 24), randomized controlled trials (n = 5), and qualitative studies (n = 5). Community specialist palliative care was found to improve symptom burden/quality of life and to reduce secondary service utilization across cancer and noncancer diagnoses. Much of this evidence relates to face-to-face care in home-based settings with both round-the-clock and episodic care. There were few studies addressing pediatric populations or minority groups. Findings from qualitative studies revealed that care coordination, provision of practical help, after-hours support, and medical crisis management were some of the factors contributing to patients' and caregivers' positive experience. Conclusion: Strong evidence exists for community specialist palliative care to improve quality of life and reducing secondary service utilization. Future research should focus on equity outcomes and the interface between generalist and specialist care.


Assuntos
Enfermagem de Cuidados Paliativos na Terminalidade da Vida , Neoplasias , Criança , Humanos , Cuidados Paliativos/métodos , Qualidade de Vida , Cuidadores
12.
Dev Cell ; 13(4): 496-510, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17925226

RESUMO

Here, we report a direct interaction between the beta1 integrin cytoplasmic tail and Rab25, a GTPase that has been linked to tumor aggressiveness and metastasis. Rab25 promotes a mode of migration on 3D matrices that is characterized by the extension of long pseudopodia, and the association of the GTPase with alpha5beta1 promotes localization of vesicles that deliver integrin to the plasma membrane at pseudopodial tips as well as the retention of a pool of cycling alpha5beta1 at the cell front. Furthermore, Rab25-driven tumor-cell invasion into a 3D extracellular matrix environment is strongly dependent on ligation of fibronectin by alpha5beta1 integrin and the capacity of Rab25 to interact with beta1 integrin. These data indicate that Rab25 contributes to tumor progression by directing the localization of integrin-recycling vesicles and thereby enhancing the ability of tumor cells to invade the extracellular matrix.


Assuntos
Movimento Celular/fisiologia , Matriz Extracelular/metabolismo , Integrina alfa5beta1/fisiologia , Invasividade Neoplásica , Proteínas rab de Ligação ao GTP/fisiologia , Animais , Adesão Celular , Linhagem Celular Tumoral , Chlorocebus aethiops , Colágeno , Combinação de Medicamentos , Humanos , Integrina alfa5beta1/metabolismo , Laminina , Camundongos , Transporte Proteico , Proteoglicanas , Pseudópodes/metabolismo , Ratos
13.
Biochem J ; 436(1): 45-52, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21401524

RESUMO

I-BAR (inverse-Bin/amphiphysin/Rvs)-domain-containing proteins such as IRSp53 (insulin receptor substrate of 53 kDa) associate with outwardly curved membranes and connect them to proteins involved in actin dynamics. Research on I-BAR proteins has focussed on possible roles in filopod and lamellipod formation, but their full physiological function remains unclear. The social amoeba Dictyostelium encodes a single I-BAR/SH3 (where SH3 is Src homology 3) protein, called IBARa, along with homologues of proteins that interact with IRSp53 family proteins in mammalian cells, providing an excellent model to study its cellular function. Disruption of the gene encoding IBARa leads to a mild defect in development, but filopod and pseudopod dynamics are unaffected. Furthermore, ectopically expressed IBARa does not induce filopod formation and does not localize to filopods. Instead, IBARa associates with clathrin puncta immediately before they are endocytosed. This role is conserved: human BAIAP2L2 (brain-specific angiogenesis inhibitor 1-associated protein 2-like 2) also tightly co-localizes with clathrin plaques, although its homologues IRSp53 and IRTKS (insulin receptor tyrosine kinase substrate) associate with other punctate structures. The results from the present study suggest that I-BAR-containing proteins help generate the membrane curvature required for endocytosis and implies an unexpected role for IRSp53 family proteins in vesicle trafficking.


Assuntos
Dictyostelium/metabolismo , Endocitose/fisiologia , Proteínas de Protozoários/metabolismo , Membrana Celular/metabolismo , Clatrina/genética , Clatrina/metabolismo , Células HeLa , Humanos , Proteínas Substratos do Receptor de Insulina/química , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Domínios de Homologia de src
14.
Am J Physiol Cell Physiol ; 300(6): C1345-55, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21368295

RESUMO

The BTB-Kelch protein Krp1 is highly and specifically expressed in skeletal muscle, where it is proposed to have a role in myofibril formation. We observed significant upregulation of Krp1 in C2 cells early in myoblast differentiation, well before myofibrillogenesis. Krp1 has a role in cytoskeletal organization and cell motility; since myoblast migration and elongation/alignment are important events in early myogenesis, we hypothesized that Krp1 is involved with earlier regulation of differentiation. Krp1 protein levels were detectable by 24 h after induction of differentiation in C2 cells and were significantly upregulated by 48 h, i.e., following the onset myogenin expression and preceding myosin heavy chain (MHC) upregulation. Upregulation of Krp1 required a myogenic stimulus as signaling derived from increased myoblast cell density was insufficient to activate Krp1 expression. Examination of putative Krp1 proximal promoter regions revealed consensus E box elements associated with myogenic basic helix-loop-helix binding. The activity of a luciferase promoter-reporter construct encompassing this 2,000-bp region increased in differentiating C2 myoblasts and in C2 cells transfected with myogenin and/or MyoD. Knockdown of Krp1 via short hairpin RNA resulted in increased C2 cell number and proliferation rate as assessed by bromodeoxyuridine incorporation, whereas overexpression of Krp1-myc had the opposite effect; apoptosis was unchanged. No effects of changed Krp1 protein levels on cell migration were observed, either by scratch wound assay or live cell imaging. Paradoxically, both knockdown and overexpression of Krp1 inhibited myoblast differentiation assessed by expression of myogenin, MEF2C, MHC, and cell fusion.


Assuntos
Proteínas de Transporte/metabolismo , Diferenciação Celular/fisiologia , Proliferação de Células , Mioblastos/fisiologia , Animais , Sequência de Bases , Proteínas de Transporte/genética , Linhagem Celular , Proteínas do Citoesqueleto , Técnicas de Silenciamento de Genes , Humanos , Dados de Sequência Molecular , Mioblastos/citologia , Regiões Promotoras Genéticas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Alinhamento de Sequência
15.
Nurs Manag (Harrow) ; 18(3): 20-4, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21736169

RESUMO

The government has emphasised that, to deliver high quality, integrated care, staff must work across organisational boundaries using a team approach so that everyone works towards the same goals. This article describes how one NHS-managed intermediate care unit has integrated care staff employed by the independent sector.


Assuntos
Instituições para Cuidados Intermediários/organização & administração , Relações Interprofissionais , Equipe de Assistência ao Paciente/organização & administração , Parcerias Público-Privadas/organização & administração , Idoso , Inglaterra , Implementação de Plano de Saúde , Humanos
16.
Cell Rep ; 36(11): 109689, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34525350

RESUMO

Assessing drug response within live native tissue provides increased fidelity with regards to optimizing efficacy while minimizing off-target effects. Here, using longitudinal intravital imaging of a Rac1-Förster resonance energy transfer (FRET) biosensor mouse coupled with in vivo photoswitching to track intratumoral movement, we help guide treatment scheduling in a live breast cancer setting to impair metastatic progression. We uncover altered Rac1 activity at the center versus invasive border of tumors and demonstrate enhanced Rac1 activity of cells in close proximity to live tumor vasculature using optical window imaging. We further reveal that Rac1 inhibition can enhance tumor cell vulnerability to fluid-flow-induced shear stress and therefore improves overall anti-metastatic response to therapy during transit to secondary sites such as the lung. Collectively, this study demonstrates the utility of single-cell intravital imaging in vivo to demonstrate that Rac1 inhibition can reduce tumor progression and metastases in an autochthonous setting to improve overall survival.


Assuntos
Técnicas Biossensoriais/métodos , Neoplasias da Mama/patologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Aminoquinolinas/farmacologia , Animais , Neoplasias da Mama/diagnóstico por imagem , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Transferência Ressonante de Energia de Fluorescência , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Pirimidinas/farmacologia , Resistência ao Cisalhamento , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores
17.
J Biol Chem ; 284(44): 30498-507, 2009 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-19726686

RESUMO

Kelch-related protein 1 (Krp1) is up-regulated in oncogene-transformed fibroblasts. The Kelch repeats interact directly with the actin-binding protein Lasp-1 in membrane ruffles at the tips of pseudopodia, where both proteins are necessary for pseudopodial elongation. Herein, we investigate the molecular basis for this interaction. Probing an array of overlapping decapeptides of Rattus norvegicus (Rat) Krp1 with recombinant Lasp-1 revealed two binding sites; one ((317)YDPMENECYLT(327)) precedes the first of five Kelch repeats, and the other ((563)TEVNDIWKYEDD(574)) is in the last of the five Kelch repeats. Mutational analysis established that both binding sites are necessary for Krp1-Lasp-1 interaction in vitro and function in vivo. The crystal structure of the C-terminal domain of rat Krp1 (amino acids 289-606) reveals that both binding sites are brought into close proximity by the formation of a novel six-bladed beta-propeller, where the first blade is not formed by a Kelch repeat.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas Motores Moleculares/química , Proteínas do Tecido Nervoso/metabolismo , Pseudópodes/ultraestrutura , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Transporte/química , Proteínas de Transporte/fisiologia , Cristalografia por Raios X , Proteínas do Citoesqueleto , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/fisiologia , Proteínas Motores Moleculares/metabolismo , Proteínas Motores Moleculares/fisiologia , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/fisiologia , Ligação Proteica , Conformação Proteica , Ratos , Sequências Repetitivas de Ácido Nucleico
18.
Curr Opin Genet Dev ; 16(1): 65-70, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16377173

RESUMO

The invasive and metastatic behaviour of tumours impacts crucially on the clinical management of cancer. Accordingly, it is important to understand the regulation of tumour cell invasiveness. Genetic analysis of worms, Drosophila and mice has provided evidence that invasion is a genetic pathway regulated by transcription factors that are often implicated in tumour cell invasion. Recent evidence has revealed much concerning the role of one particular transcription factor, AP1, which is involved in the regulation of a multigenic invasion program in which upregulated and downregulated genes function as invasion effectors and suppressors, respectively. Differentially expressed genes cooperatively enhance pseudopod elongation during the mesenchymal mode of invasion by altering the function, localisation and activity of non-differentially expressed proteins.


Assuntos
Invasividade Neoplásica/genética , Fatores de Transcrição/genética , Animais , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes fos , Humanos , Oncogenes , Fator de Transcrição AP-1/genética
19.
J Surg Educ ; 77(4): 921-930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32192885

RESUMO

OBJECTIVE: To assess the utility of simulated ward rounds to train healthcare professionals in nontechnical skills using a qualitative analysis of participant feedback. DESIGN: We developed simulated scenarios to train members of the surgical healthcare team in nontechnical skills, derived from observations of real ward rounds. Participants performed the simulated ward rounds as a team, led by a Urology trainee. Scenarios were carried out using actors as patients, and a simulated "switchboard" for phone conversations. Throughout the scenarios, distractions were introduced and directed at different members of the participating team. Following each scenario, a whole group debrief took place to discuss and provide feedback on performances. All participants completed a 2-part feedback form comprising of questions answered on a Likert scale, as well as free-text responses. SETTING: All simulations took place in a high-fidelity simulated ward bay. Observers were in a separate room, where the scenarios were projected on a screen in real-time. PARTICIPANTS: Thirty-five healthcare professionals in the department of Urology attended this session. There was no restriction on professional background or seniority for attendees. RESULTS: The qualitative thematic analysis revealed that participants commented positively on the type of scenarios, but would have preferred if more participants could partake in scenarios. The attendees also commended the use of debriefs between scenarios. Suggestions were also given regarding types of scenarios; and involved ensuring that participants are well briefed before each scenario. CONCLUSIONS: This simulated ward round exercise was positively received by participants. The approach to derive scenarios from real ward round observations permitted a variety of the main themes of nontechnical skills to be tested, and improved the fidelity of the simulation. The reflections expressed by participants demonstrate a need for this training, and drives our initiative to raise awareness and develop nontechnical skills in a controlled environment, supported with transparent discussion and feedback.


Assuntos
Treinamento por Simulação , Visitas de Preceptoria , Urologia , Competência Clínica , Comunicação , Humanos , Equipe de Assistência ao Paciente , Urologia/educação
20.
Mol Cell Biol ; 26(4): 1480-95, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16449658

RESUMO

The transcription factor AP-1, which is composed of Fos and Jun family proteins, plays an essential role in tumor cell invasion by altering gene expression. We report here that Krp1, the AP-1 up-regulated protein that has a role in pseudopodial elongation in v-Fos-transformed rat fibroblast cells, forms a novel interaction with the nondifferentially expressed actin binding protein Lasp-1. Krp1 and Lasp-1 colocalize with actin at the tips of pseudopodia, and this localization is maintained by continued AP-1 mediated down-regulation of fibronectin that in turn suppresses integrin and Rho-ROCK signaling and allows pseudopodial protrusion and mesenchyme-like invasion. Mutation analysis of Lasp-1 demonstrates that its SH3 domain is necessary for pseudopodial extension and invasion. The results support the concept of an AP-1-regulated multigenic invasion program in which proteins encoded by differentially expressed genes direct the function, localization, and activity of proteins that are not differentially expressed to enhance the invasiveness of cells.


Assuntos
Proteínas de Transporte/metabolismo , Fibronectinas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Transcrição AP-1/metabolismo , Animais , Proteínas de Transporte/genética , Linhagem Celular , Transformação Celular Neoplásica , Proteínas do Citoesqueleto , Fibronectinas/genética , Genes fos , Peptídeos e Proteínas de Sinalização Intracelular , Mesoderma/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Modelos Biológicos , Mutagênese Sítio-Dirigida , Invasividade Neoplásica , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fenótipo , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Pseudópodes/metabolismo , RNA Interferente Pequeno/genética , Ratos , Transdução de Sinais , Fator de Transcrição AP-1/genética , Quinases Associadas a rho
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