1,840 research outputs found

    ANALYSIS OF ENDOTHELIN DURING ANDROGEN DEPRIVATION: IMPLICATIONS FOR PROSTATE CANCER PROGRESSION

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    Background. Androgen deprivation has been in use for the treatment of advanced prostate cancer since 1941; however, most patients develop resistance to treatment leading to incurable, androgen-independent disease. Previous reports have correlated endothelin A receptor (ETA) expression with increasing prostate cancer grade and stage, and have shown that endothelin-1 (ET-1) treatment of ETA-expressing prostate cancer cells inhibits apoptosis. ETA blockade has emerged as a potential strategy in the treatment of advanced prostate cancer. Here, the potential role of endothelin signaling in promoting prostate cancer cell survival during androgen ablation therapy is evaluated in efforts to establish the potential value of ETA blockade in improving hormone therapy.Methodology and Principle Findings. Androgen-dependent human prostate cancer cells were androgen deprived and evaluated for expression changes in ET-1, ETA, ETB, and AR. Ligand binding, real time quantitative PCR, and immunohistochemical studies show that androgen deprivation increased ET-1, ETA, ETB, and AR expression in prostate cancer cell lines, and ETA expression in human prostate tissue. Using the specific AR inhibitor bicalutamide, acute androgen receptor blockade increased prostate cancer cell ET-1 secretion. Following androgen deprivation, LNCaP cells acquired androgen independence (LNCaP-AI), but retained sensitivity to androgens. ET-1 treatment of ETA over-expressing prostate cancer cells induced a more rapid and sustained activation of Akt, and ETA blockade significantly reduced Akt activation. In vivo ETA blockade, in combination with castration, significantly reduced LNCaP xenograft cell growth, compared to either treatment alone. Affymetrix GeneChip HG-U133 Plus 2 expression array analysis of androgen deprived prostate cancer cells discovered dramatic changes in gene expression patterns throughout the transition to androgen independence. Lastly, the role of ETB signaling in prostate cancer cell apoptosis was examined but remains to be further elucidated.Conclusions and Significance. During androgen deprivation, prostate cancer cells up-regulate ET-1 and ETA expression. Upon engagement of ET-1, ETA invokes activation of the survival factor Akt. In vivo, ETA blockade plus castration inhibits prostate cancer growth. Collectively, these results implicate endothelin survival signaling in promoting progression to androgen-independent disease, and lend support to the targeted disruption of endothelin survival signaling in treating advanced, metastatic prostate cancer

    TGF beta type II receptor signaling controls Schwann cell death and proliferation in developing nerves

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    During development, Schwann cell numbers are precisely adjusted to match the number of axons. It is essentially unknown which growth factors or receptors carry out this important control in vivo. Here, we tested whether the type II transforming growth factor (TGF)beta receptor has a role in this process. We generated a conditional knock-out mouse in which the type II TGF beta receptor is specifically ablated only in Schwann cells. Inactivation of the receptor, evident at least from embryonic day 18, resulted in suppressed Schwann cell death in normally developing and injured nerves. Notably, the mutants also showed a strong reduction in Schwann cell proliferation. Consequently, Schwann cell numbers in wild-type and mutant nerves remained similar. Lack of TGF beta signaling did not appear to affect other processes in which TGF beta had been implicated previously, including myelination and response of adult nerves to injury. This is the first in vivo evidence for a growth factor receptor involved in promoting Schwann cell division during development and the first genetic evidence for a receptor that controls normal developmental Schwann cell death

    Data report: electron microprobe investigation of primary minerals in basalts from the west philippine sea basin (ocean drilling program leg 195, site 1201)

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    The basement cored at Site 1201 (west Philippine Basin) during Ocean Drilling Program Leg 195 consists of a 91-m-thick sequence of basalts, mostly pillow lavas and perhaps one sheet lava flow, with a few intercalations of hyaloclastite and interpillow sedimentary material. Hydrothermal alteration pervasively affected the basalt sequence, giving rise to a variety of secondary minerals such as K-Fe-Mg-clay minerals, oxyhydroxides and clay minerals mixtures, natrolite group zeolites, analcite, alkali feldspar, and carbonate. The primary minerals of pillow and sheet basalts that survived the intense hydrothermal alteration were investigated by electron microprobe with the aim of characterizing their chemical composition and variability. The primary minerals are mostly plagioclase, ranging in composition from bytownite through labradorite to andesine, chromian-magnesian-diopside, and spinels, both Ti magnetite (partially maghemitized) and chromian spinel. Overall, the chemical features of the primary minerals of Site 1201 basalts correspond to the primitive character of the bulk rocks, suggesting that the parent magma of these basalts was a mafic tholeiitic magma that most likely only suffered limited fractional crystallization and crystallized at high temperatures (slightly below 1200°C) and under increasing ƒO2 conditions. The major element composition of clinopyroxene suggests a backarc affinity of the mantle source of Site 1201 basement

    Dietary Modulation of Oxidative Stress From Edible Insects: A Mini-Review

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    Edible insects are proposed as a nutritious and environmentally sustainable alternative source to animal proteins, due to their numerous advantages in terms of reduced ecological impact and high nutritional value. However, the novelty for edible insects relies on the content of bioactive ingredients potentially able to induce a functional effect in the body. The present review summarizes the main findings on the antioxidant properties of edible insects available in the literature. A total of 30 studies involving animals, cell cultures, or in vitro experimental studies evaluating the antioxidant effect of edible insects are presented in this work. When the antioxidant activity was investigated, using a wide variety of in vitro tests and in cellular models, positive results were shown. Dietary supplementation with edible insects was also able to counteract dietary oxidative stress in animal models, restoring the balance of antioxidant enzymes and reducing the formation of oxidation damage markers. On the basis of the reviewed evidences, edible insects might represent a source of novel redox ingredients at low ecological impact able to modulate oxidative stress. However, due to the fact that majority of these evidences have been obtained in vitro and in cellular and animal models, dietary intervention trials are needed to assess the efficacy of edible insect consumption to modulate redox status in humans

    High-Throughput and Cost-Effective Characterization of Induced Pluripotent Stem Cells.

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    Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) offers the possibility of studying the molecular mechanisms underlying human diseases in cell types difficult to extract from living patients, such as neurons and cardiomyocytes. To date, studies have been published that use small panels of iPSC-derived cell lines to study monogenic diseases. However, to study complex diseases, where the genetic variation underlying the disorder is unknown, a sizable number of patient-specific iPSC lines and controls need to be generated. Currently the methods for deriving and characterizing iPSCs are time consuming, expensive, and, in some cases, descriptive but not quantitative. Here we set out to develop a set of simple methods that reduce cost and increase throughput in the characterization of iPSC lines. Specifically, we outline methods for high-throughput quantification of surface markers, gene expression analysis of in vitro differentiation potential, and evaluation of karyotype with markedly reduced cost

    Attenuation of choroidal tickness in patients with Alzheimer disease: evidence from an Italian prospective study

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    INTRODUCTION: To compare the 12-month choroidal thickness (CT) change between Alzheimer disease (AD) patients and normal subjects. METHODS: In this prospective, observational study, 39 patients with a diagnosis of mild to moderate AD and 39 age-matched control subjects were included. All the subjects underwent neuropsychological (Mini Mental State Examination, Alzheimer disease Assessment Scale-Cognitive Subscale, and the Clinical Dementia Rating Scale) and ophthalmological evaluation, including spectral domain optical coherence tomography, at baseline and after 12 months. CT was measured manually using the caliper tool of the optical coherence tomography device. RESULTS: After 12 months, AD patients had a greater reduction of CT than controls (P≤0.05, adjusted for baseline CT, age, sex, axial length, and smoking). DISCUSSION: CT in patients with AD showed a rate of thinning greater than what could be expected during the natural course of aging

    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues.

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types
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