106 research outputs found

    Mesothelioma: identical routes to malignancy from asbestos and carbon nanotubes

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    Exposure of laboratory mice to carbon nanotubes mimics exposure to asbestos, from initial and chronic inflammation, through loss of the same tumour-suppressor pathways and eventual sporadic development of malignant mesothelioma. Fibres of a similar nature may pose significant health risks to humans

    PAI-1 is a Critical Upstream Regulator of the TGF-β1/EGF-Induced Invasive Phenotype in Mutant p53 Human Cutaneous Squamous Cell Carcinoma

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    The emergence of highly aggressive subtypes of human cutaneous squamous cell carcinoma (SCC) often reflects increased autocrine/paracrine TGF-β synthesis and epidermal growth factor receptor (EGFR) amplification. Cooperative TGF-β/EGFR signaling promotes cell migration and induces expression of both proteases and protease inhibitors that regulate stromal remodeling resulting in acquisition of an invasive phenotype. TGF-β1+EGF stimulation increases the production of several matrix metalloproteinases (MMPs) in human SCC. Among the most prominent is MMP-10 which is known to be elevated in SCC in situ. Activation of stromal plasminogen appears to be critical in triggering downstream MMP activity. Paradoxically, PAI-1, the major physiological inhibitor of plasmin generation, is also up-regulated under these conditions and is an early event in progression of incipient epidermal SCC. A model is proposed in which TGF-β1+EGF-dependent MMP-10 elevation directs focalized matrix remodeling events that promote epithelial cell plasticity and tissue invasion. Increased PAI-1 expression serves to temporally and spatially modulate plasmin-initiated pericellular proteolysis, further facilitating epithelial invasive potential. Defining the complex signaling mechanisms that maintain this elegant balance is critical to developing potential therapeutics for the treatment of human cutaneous malignancies

    PAI-1 Regulates the Invasive Phenotype in Human Cutaneous Squamous Cell Carcinoma

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    The emergence of highly aggressive subtypes of human cutaneous squamous cell carcinoma (SCC) often reflects increased autocrine/paracrine TGF-β synthesis and epidermal growth factor receptor (EGFR) amplification. Cooperative TGF-β/EGFR signaling promotes cell migration and induces expression of both proteases and protease inhibitors that regulate stromal remodeling resulting in the acquisition of an invasive phenotype. In one physiologically relevant model of human cutaneous SCC progression, TGF-β1+EGF stimulation increases the production of several matrix metalloproteinases (MMPs), among the most prominent of which is MMP-10—an MMP known to be elevated in SCC in situ. Activation of stromal plasminogen appears to be critical in triggering downstream MMP activity. Paradoxically, PAI-1, the major physiological inhibitor of plasmin generation, is also upregulated under these conditions and is an early event in progression of incipient epidermal SCC. One testable hypothesis proposes that TGF-β1+EGF-dependent MMP-10 elevation directs focalized matrix remodeling events that promote epithelial cell plasticity and tissue invasion. Increased PAI-1 expression serves to temporally and spatially modulate plasmin-initiated pericellular proteolysis, further facilitating epithelial invasive potential. Defining the complex signaling and transcriptional mechanisms that maintain this delicate balance is critical to developing targeted therapeutics for the treatment of human cutaneous malignancies

    PAI-1: An Integrator of Cell Signaling and Migration

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    Cellular migration, over simple surfaces or through complex stromal barriers, requires coordination between detachment/re-adhesion cycles, involving structural components of the extracellular matrix and their surface-binding elements (integrins), and the precise regulation of the pericellular proteolytic microenvironment. It is now apparent that several proteases and protease inhibitors, most notably urokinase plasminogen activator (uPA) and plasminogen activator inhibitor type-1 (PAI-1), also interact with several cell surface receptors transducing intracellular signals that significantly affect both motile and proliferative programs. These events appear distinct from the original function of uPA/PAI-1 as modulators of the plasmin-based proteolytic cascade. The multifaceted interactions of PAI-1 with specific matrix components (i.e., vitronectin), the low-density lipoprotein receptor-related protein-1 (LRP1), and the uPA/uPA receptor complex have dramatic consequences on the migratory phenotype and may underlie the pathophysiologic sequalae of PAI-1 deficiency and overexpression. This paper focuses on the increasingly intricate role of PAI-1 as a major mechanistic determinant of the cellular migratory phenotype

    Depression as a predictor of mortality and hospitalization among hemodialysis patients in the United States and Europe

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    Depression as a predictor of mortality and hospitalization among hemodialysis patients in the United States and Europe.BackgroundDepression is not uncommon among patients with end-stage renal disease (ESRD) being treated by hemodialysis. We investigated whether risk of mortality and rate of hospitalization may be predicted from physician-diagnosed depression and patients' self-reports of depressive symptoms.MethodsData were analyzed from the Dialysis Outcomes and Practice Patterns Study (DOPPS) for randomly selected ESRD patients being treated by hemodialysis in the United States (142 facilities, 2855 patients) and five European countries (101 facilities, 2401 patients). The diagnosis of depression during the past year was abstracted from the medical records. In addition, the patients were asked to indicate how much of their time over the previous four weeks they had felt (1) “so down in the dumps that nothing could cheer you up” and (2) “downhearted and blue.” A response of “a good bit,”“most,” or “all” of the time were classified as depressed.ResultsThe prevalence of depression was nearly 20%. The relative risks of mortality and hospitalization among depressed (vs. non-depressed), adjusted for time on dialysis, age, race, socioeconomic status, comorbid indicators and country were, respectively: 1.23 and 1.11 for physician-diagnosed depression, 1.48 and 1.15 for the “so down in the dumps” question, and 1.35 and 1.11 for the “downhearted and blue” question (P < 0.05 for all six relative risks). These associations were not significantly different between US and European patients.ConclusionsSelf-reported depression by two simple questions was associated with increased risks of mortality and hospitalization for hemodialysis patients. Future research needs to assess whether early identification and treatment of depression may help to improve quality of life and survival in hemodialysis patients

    Nonadherence in hemodialysis: Associations with mortality, hospitalization, and practice patterns in the DOPPS

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    Nonadherence in hemodialysis: Associations with mortality, hospitalization, and practice patterns in the DOPPS.BackgroundNonadherence among hemodialysis patients compromises dialysis delivery, which could influence patient morbidity and mortality. The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides a unique opportunity to review this problem and its determinants on a global level.MethodsNonadherence was studied using data from the DOPPS, an international, observational, prospective hemodialysis study. Patients were considered nonadherent if they skipped one or more sessions per month, shortened one or more sessions by more than 10 minutes per month, had a serum potassium level openface>6.0mEq/L, a serum phosphate level openface>7.5mg/dL (>2.4mmol/L), or interdialytic weight gain (IDWG)>5.7% of body weight. Predictors of nonadherence were identified using logistic regression. Survival analysis used the Cox proportional hazards model adjusting for case-mix.ResultsSkipping treatment was associated with increased mortality [relative risk (RR) = 1.30, P = 0.01], as were excessive IDWG (RR = 1.12, P = 0.047) and high phosphate levels (RR = 1.17, P = 0.001). Skipping also was associated with increased hospitalization (RR = 1.13, P = 0.04), as were high phosphate levels (RR = 1.07, P = 0.05). Larger facility size (per 10 patients) was associated with higher odds ratios (OR) of skipping (OR = 1.03, P = 0.06), shortening (OR = 1.03, P = 0.05), and IDWG (OR = 1.02, P = 0.07). An increased percentage of highly trained staff hours was associated with lower OR of skipping (OR = 0.84 per 10%, P = 0.02); presence of a dietitian was associated with lower OR of excessive IDWG (OR = 0.75, P = 0.08).ConclusionNonadherence was associated with increased mortality risk (skipping treatment, excessive IDWG, and high phosphate) and with hospitalization risk (skipping, high phosphate). Certain patient/facility characteristics also were associated with nonadherence

    Colorectal tumors require NUAK1 for protection from oxidative stress

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    The authors wish to thank the staff of the CRUK Beatson Institute Biological Services Unit for animal husbandry and assistance with in vivo experiments; the staff of the CRUK BI Histology core facility and William Clark of the NGS core facility; David McGarry, Rene Jackstadt, Jiska Van der Reest, Justin Bower and Heather McKinnon for many helpful discussions, and countless colleagues at the CRUK BI and Glasgow Institute of Cancer Sciences for support; Prem Premsrirut & Mirimus Inc. for design and generation of dox-inducible Nuak1 shRNA expressing mice Nathanael Gray for initial provision of NUAK1 inhibitors. Funding was provided by the University of Glasgow and the CRUK Beaton Institute. J.P. was supported by European Commission Marie Curie actions C.I.G. 618448 “SERPLUC” to D.J.M.; N.M. was supported through Worldwide Cancer (formerly AICR) grant 15-0279 to O.J.S. & D.J.M.; B.K. was funded through EC Marie Curie actions mobility award 705190 “NuSiCC”; T.M. was funded through British Lung Foundation grant APHD13-5. The laboratories of S.R.Z. (A12935), O.J.S. (A21139) and M.D. (A17096) are funded by Cancer Research UK. O.J.S. was additionally supported by European Research Council grant 311301 “ColoCan”.Peer reviewedPostprin

    To bite or not to bite! A questionnaire-based survey assessing why some people are bitten more than others by midges

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    BACKGROUND: The Scottish biting midge, Culicoides impunctatus, responsible for more than 90% of biting attacks on human beings in Scotland, is known to demonstrate a preference for certain human hosts over others. METHODS: In this study we used a questionnaire-based survey to assess the association between people's perception of how badly they get bitten by midges and their demographic, lifestyle and health related characteristics. RESULTS: Most people (85.8%) reported being bitten sometimes, often or always with only 14.2% reporting never being bitten by midges when in Scotland. There was no association between level of bites received and age, smoking, diet, exercise, medication, eating strongly flavoured foods or alcohol consumption. However, there was a strong association between the probability of being bitten and increasing height (in men) and BMI (in women). A large proportion of participants (33.8%) reported experiencing a bad/severe reaction to midge bites while 53.1% reported a minor reaction and 13.1% no reaction at all. Also, women tend to react more than men to midge bites. Additionally, the results indicated that the susceptibility to being bitten by midges is hereditary. CONCLUSIONS: This study suggests that midges prefer to bite men that are tall and women that have a large BMI, and that the tendency for a child to be bitten or not could be inherited from their parent. The study is questionnaire-based; therefore, the interpretation of the results may be limited by the subjectivity of the answers given by the respondents. Although the results are relevant only to the Scottish biting midge, the approach used here could be useful for investigating human-insect interactions for other insects, particularly those which transmit pathogens that cause disease
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