107 research outputs found

    Comparison of Effects of p53 Null and Gain-of-Function Mutations on Salivary Tumors in MMTV-Hras Transgenic Mice

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    p53 is an important tumor suppressor gene which is mutated in ~50% of all human cancers. Some of these mutants appear to have acquired novel functions beyond merely losing wild-type functions. To investigate these gain-of-function effects in vivo, we generated mice of three different genotypes: MMTV-Hras/p53+/+, MMTV-Hras/p53-/-, and MMTV-Hras/p53R172H/R172H. Salivary tumors from these mice were characterized with regard to age of tumor onset, tumor growth rates, cell cycle distribution, apoptotic levels, tumor histopathology, as well as response to doxorubicin treatment. Microarray analysis was also performed to profile gene expression. The MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H mice displayed similar properties with regard to age of tumor onset, tumor growth rates, tumor histopathology, and response to doxorubicin, while both groups were clearly distinct from the MMTV-Hras/p53+/+ mice by these measurements. In addition, the gene expression profiles of the MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H tumors were tightly clustered, and clearly distinct from the profiles of the MMTV-Hras/p53+/+ tumors. Only a small group of genes showing differential expression between the MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H tumors, that did not appear to be regulated by wild-type p53, were identified. Taken together, these results indicate that in this MMTV-Hras-driven salivary tumor model, the major effect of the p53 R172H mutant is due to the loss of wild-type p53 function, with little or no gain-of-function effect on tumorigenesis, which may be explained by the tissue- and tumor type-specific properties of this gain-of-function mutant of p53

    Loss of the p53/p63 Regulated Desmosomal Protein Perp Promotes Tumorigenesis

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    Dysregulated cell–cell adhesion plays a critical role in epithelial cancer development. Studies of human and mouse cancers have indicated that loss of adhesion complexes known as adherens junctions contributes to tumor progression and metastasis. In contrast, little is known regarding the role of the related cell–cell adhesion junction, the desmosome, during cancer development. Studies analyzing expression of desmosome components during human cancer progression have yielded conflicting results, and therefore genetic studies using knockout mice to examine the functional consequence of desmosome inactivation for tumorigenesis are essential for elucidating the role of desmosomes in cancer development. Here, we investigate the consequences of desmosome loss for carcinogenesis by analyzing conditional knockout mice lacking Perp, a p53/p63 regulated gene that encodes an important component of desmosomes. Analysis of Perp-deficient mice in a UVB-induced squamous cell skin carcinoma model reveals that Perp ablation promotes both tumor initiation and progression. Tumor development is associated with inactivation of both of Perp's known functions, in apoptosis and cell–cell adhesion. Interestingly, Perp-deficient tumors exhibit widespread downregulation of desmosomal constituents while adherens junctions remain intact, suggesting that desmosome loss is a specific event important for tumorigenesis rather than a reflection of a general change in differentiation status. Similarly, human squamous cell carcinomas display loss of PERP expression with retention of adherens junctions components, indicating that this is a relevant stage of human cancer development. Using gene expression profiling, we show further that Perp loss induces a set of inflammation-related genes that could stimulate tumorigenesis. Together, these studies suggest that Perp-deficiency promotes cancer by enhancing cell survival, desmosome loss, and inflammation, and they highlight a fundamental role for Perp and desmosomes in tumor suppression. An understanding of the factors affecting cancer progression is important for ultimately improving the diagnosis, prognostication, and treatment of cancer

    Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

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    A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

    Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

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    As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016

    Global, regional, and national disability-adjusted life-years (DALYs) for 333 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

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    BACKGROUND: Measurement of changes in health across locations is useful to compare and contrast changing epidemiological patterns against health system performance and identify specific needs for resource allocation in research, policy development, and programme decision making. Using the Global Burden of Diseases, Injuries, and Risk Factors Study 2016, we drew from two widely used summary measures to monitor such changes in population health: disability-adjusted life-years (DALYs) and healthy life expectancy (HALE). We used these measures to track trends and benchmark progress compared with expected trends on the basis of the Socio-demographic Index (SDI). METHODS: We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2016. We calculated DALYs by summing years of life lost and years of life lived with disability for each location, age group, sex, and year. We estimated HALE using age-specific death rates and years of life lived with disability per capita. We explored how DALYs and HALE differed from expected trends when compared with the SDI: the geometric mean of income per person, educational attainment in the population older than age 15 years, and total fertility rate. FINDINGS: The highest globally observed HALE at birth for both women and men was in Singapore, at 75·2 years (95% uncertainty interval 71·9-78·6) for females and 72·0 years (68·8-75·1) for males. The lowest for females was in the Central African Republic (45·6 years [42·0-49·5]) and for males was in Lesotho (41·5 years [39·0-44·0]). From 1990 to 2016, global HALE increased by an average of 6·24 years (5·97-6·48) for both sexes combined. Global HALE increased by 6·04 years (5·74-6·27) for males and 6·49 years (6·08-6·77) for females, whereas HALE at age 65 years increased by 1·78 years (1·61-1·93) for males and 1·96 years (1·69-2·13) for females. Total global DALYs remained largely unchanged from 1990 to 2016 (-2·3% [-5·9 to 0·9]), with decreases in communicable, maternal, neonatal, and nutritional (CMNN) disease DALYs offset by increased DALYs due to non-communicable diseases (NCDs). The exemplars, calculated as the five lowest ratios of observed to expected age-standardised DALY rates in 2016, were Nicaragua, Costa Rica, the Maldives, Peru, and Israel. The leading three causes of DALYs globally were ischaemic heart disease, cerebrovascular disease, and lower respiratory infections, comprising 16·1% of all DALYs. Total DALYs and age-standardised DALY rates due to most CMNN causes decreased from 1990 to 2016. Conversely, the total DALY burden rose for most NCDs; however, age-standardised DALY rates due to NCDs declined globally. INTERPRETATION: At a global level, DALYs and HALE continue to show improvements. At the same time, we observe that many populations are facing growing functional health loss. Rising SDI was associated with increases in cumulative years of life lived with disability and decreases in CMNN DALYs offset by increased NCD DALYs. Relative compression of morbidity highlights the importance of continued health interventions, which has changed in most locations in pace with the gross domestic product per person, education, and family planning. The analysis of DALYs and HALE and their relationship to SDI represents a robust framework with which to benchmark location-specific health performance. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform health policies, health system improvement initiatives, targeted prevention efforts, and development assistance for health, including financial and research investments for all countries, regardless of their level of sociodemographic development. The presence of countries that substantially outperform others suggests the need for increased scrutiny for proven examples of best practices, which can help to extend gains, whereas the presence of underperforming countries suggests the need for devotion of extra attention to health systems that need more robust support. FUNDING: Bill & Melinda Gates Foundation

    Analysis of a p53 Gain-of-function Mutation in Transgenic Mouse Salivary Tumors

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    p53 is an important tumor suppressor gene which is mutated in ~50% of all human cancers. Some of the p53 mutants appear to have acquired novel functions beyond merely losing wild-type functions. To investigate these gain-of-function effects in vivo, we interbred MMTV-v-Ha-ras transgenic mice to either p53-/- knock-out mice or p53R172H/+ knock-in mice to generate mice of three different genotypes: MMTV-ras, MMTV-ras/p53-/-, and MMTV-ras/p53R172H/R172H. Male mice of each of these genotypes were characterized with regard to age of salivary tumor onset and the tumors were characterized with regard to mean growth rates, proliferation fraction, apoptotic levels, and tumor histopathology, as well as responses to doxorubicin treatment. Microarray analysis was also performed to profile gene expression.The MMTV-ras/p53-/- and MMTV-ras/p53R172H/R172H mice display similar properties in age of tumor onset, tumor growth rates, and tumor histopathology, as well as response to doxorubicin. However, a subset of genes show differential expression between the two groups of tumor , and do not appear to be regulated by wild-type p53. At the same time, the MMTV-ras/p53R172H/R172H and MMTV-ras/p53+/+ tumors share similar expression levels of a group of genes that are differentially expressed in the MMTV-ras/p53-/- tumors. Thus, the gain-of-function effects may be caused in part by perturbed regulation of genes not normally regulated by wild-type p53, in addition to imbalances in the regulation of normal p53 target genes

    Comprehensive analysis of metabolic changes in spontaneously hypertensive rats

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    Objectives Hypertension is a chronic disease with multiple causative factors that involve metabolic disturbances and can cause various complications. However, the metabolic characteristics of hypertension at different stages are still unclear. This study aimed to explore the metabolic changes induced by hypertension at different ages. Methods Spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats were divided into four groups according to age: 5-week-old SHR (n = 6), 5-week-old WKY rats (n = 6), 32-week-old SHR (n = 6), and 32-week-old WKY rats (n = 6). Metabolites were analyzed in primary tissues (serum, heart, lung, kidney, brain, and brown adipose) using a non-targeted metabolomics approach. Results Thirty-five metabolites and nine related metabolic pathways were identified in 5-week-old SHR, mainly related to the metabolism of amino acids. Fifty-one metabolites and seven related metabolic pathways were identified in the 32-week-old SHR, involving glycolysis, lipid, and amino acid metabolisms. Conclusion This experiment elucidates the metabolic profile of SHR at different ages and provides a basis for predicting and diagnosing hypertension. It also provides a reference for the pathogenesis of hypertension

    Clinical and radiologic outcomes after a modified bone plug technique with anatomical meniscal root reinsertion for meniscal allograft transplantation and a minimum 18-month follow-up

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    Abstract Objective To evaluate the clinical and radiologic outcomes of meniscal allograft transplantation (MAT) using a modified bone plug technique. Methods We conducted a retrospective single-center study of 73 patients who underwent MAT between January 2007 and December 2013. The International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score, visual analogue scale (VAS), and physical examinations were retrospectively reviewed to measure clinical outcomes after MAT, and questionnaires regarding activity and factors were analyzed. Magnetic resonance imaging (MRI) was used to assess the cartilage status and meniscal extrusion. Results The mean follow-up was 37 months for 61 patients (65 knees), and 12 patients were lost to follow-up. The mean meniscal extrusion was 3.39 ± 0.90 mm, the relative percentage of extrusion (RPE) was 34.82% ± 12.71%, and arthrosis progression was observed in 8 of 61 cases (13.1%). The mean results for VAS, IKDC, and Lysholm scores were significantly improved after MAT (P  0.05). Thirty-eight (62.3%) patients were able to return to their previous level of activity, and 23 (37.7%) patients reached a mean 76.7% of the previous level of activity. Of the 23 patients reporting a decrease in activity, 10 reported a fear of reinjury as the primary factor limiting activity. The patient satisfaction rate in the study was 78.7%. Conclusion Our modified bone plug method with anatomical meniscal root reinsertion was an effective surgical method, and the majority of active patients with meniscal disorders returned to preinjury levels of activity

    Overexpression of DAPK1 and Beclin1 under oxygen and glucose deprivation conditions promotes excessive autophagy and apoptosis in A549 cells

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    Abstract In this study, we aimed to determine the specific roles of death‐associated protein kinase 1 (DAPK1) and Beclin1 in non‐small cell lung cancer (NSCLC) under oxygen and glucose deprivation (OGD). We found that OGD caused most cells to shrink, aggregate, and produce many vacuoles in the cytoplasm. Transmission electron microscopy revealed the presence of autophagic vesicles in the OGD group but not in the Control group. Moreover, the cell counting kit‐8 assay showed that cell proliferation was reduced in the OGD group. Quantitative reverse transcription‐polymerase chain reaction, western blot, and cell function assays showed that DAPK1 overexpression under OGD promoted apoptosis and autophagy in A549 cells. The coimmunoprecipitation assay confirmed the interaction between DAPK1 and Beclin1 protein. Moreover, knockdown of Beclin1 inhibited autophagy, but its overexpression promoted apoptosis in A549 cells. In vivo tumorigenesis experiment revealed that overexpression of DAPK1 promoted A549 cell apoptosis. Collectively, overexpression of DAPK1 and Beclin1 under OGD promoted excessive autophagy and apoptosis in A549 cells. Our study may provide a novel therapeutic target and theoretical basis for NSCLC treatment
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