1,105 research outputs found
The bisphosphonate zoledronic acid inhibits the growth of HCT-116 colon carcinoma cells and induces tumor cell apoptosis
Besides its preventive action on bone resorption the third generation bisphosphonate zoledronic acid (ZOL) has been shown to display potent inhibitory action on the formation of bone metastases of various human cancers. Recent research also indicates an antitumoral effect on primary tumors and visceral metastases. Here we investigate for the first time the effect of ZOL on the human colon carcinoma cell line HCT-116. ZOL strongly inhibited the proliferation and soft agar colony formation of HCT-116 cells and caused a G1 cell cycle arrest in a population of ZOL treated cells. This cell cycle arrest was accompanied by an induction of apoptosis via a caspase dependent mechanism. Activation of Caspases 3, 7, 8 and 9, cleavage of PARP as well as the release of cytochrome C into the cytosol were detected in HCT-116 cells treated with low micromolar concentrations of ZOL. The induction of the mitochondrial pathway of apoptosis was accompanied by a translocation of Bax into the mitochondria, Bid activation and a decrease of overall Bcl-2 expression. We also detected a cytosolic increase of apoptosis inducing factor (AIF), a trigger of caspase-independent apoptosis. Taken together, our data indicate a potent antitumoral and apoptosis inducing effect of ZOL on HCT-116 colon carcinoma cell
A Transcriptome-Led Exploration of Molecular Mechanisms Regulating Somatostatin-Producing D-Cells in the Gastric Epithelium.
The stomach epithelium contains a myriad of enteroendocrine cells that modulate a range of physiological functions, including postprandial secretion of regulatory peptides, gastric motility, and nutrient absorption. Somatostatin (SST)-producing D-cells are present in the oxyntic and pyloric regions of the stomach, and provide a tonic inhibitory tone that regulates activity of neighboring enteroendocrine cells and gastric acid secretion. Cellular mechanisms underlying the effects of regulatory factors on gastric D-cells are poorly defined due to problems in identifying primary D-cells, and uncertainty remains about which stimuli influence D-cells directly. In this study, we introduce a transgenic mouse line, SST-Cre, which upon crossing with Cre reporter strains, facilitates the identification and purification of gastric D-cells, or cell-specific expression of genetically encoded calcium indicators. Populations of D-cells from the gastric antrum and corpus were isolated and analyzed by RNA sequencing and quantitative RT-PCR. The expression of hormones, hormone receptors, neurotransmitter receptors, and nutrient receptors was quantified. Pyy, Gipr, Chrm4, Calcrl, Taar1, and Casr were identified as genes that are highly enriched in D-cells compared with SST-negative cells. Hormone secretion assays performed in mixed gastric epithelial cultures confirmed that SST secretion is regulated by incretin hormones, cholecystokinin, acetylcholine, vasoactive intestinal polypeptide, calcitonin gene-related polypeptide, oligopetides, and trace amines. Cholecystokinin and oligopeptides elicited increases in intracellular calcium in single-cell imaging experiments performed using cultured D-cells. Our data provide the first transcriptomic analysis and functional characterization of gastric D-cells, and identify regulatory pathways that underlie the direct detection of stimuli by this cell type.This work was supported by the Wellcome Trust (WT088357/Z/09/Z and WT084210/Z/07/Z) and the MRC Metabolic Diseases Unit (MRC_MC_UU_12012/3).This is the final version of the article. It first appeared from Endocrine Society via http://dx.doi.org/10.1210/en.2015-1301
Suppression of Raf-1 kinase activity and MAP kinase signalling by RKIP
Raf-1 phosphorylates and activates MEK-1, a kinase that activates the extracellular signal regulated kinases (ERK). This kinase cascade controls the proliferation and differentiation of different cell types. Here we describe a Raf-1-interacting protein, isolated using a yeast two-hybrid screen. This protein inhibits the phosphorylation and activation of MEK by Raf-1 and is designated RKIP (Raf kinase inhibitor protein). In vitro, RKIP binds to Raf-1, MEK and ERK, but not to Ras. RKIP co-immunoprecipitates with Raf-1 and MEK from cell lysates and colocalizes with Raf-1 when examined by confocal microscopy. RKIP is not a substrate for Raf-1 or MEK, but competitively disrupts the interaction between these kinases. RKIP overexpression interferes with the activation of MEK and ERK, induction of AP-1-dependent reporter genes and transformation elicited by an oncogenically activated Raf-1 kinase. Downregulation of endogenous RKIP by expression of antisense RNA or antibody microinjection induces the activation of MEK-, ERK- and AP-1-dependent transcription. RKIP represents a new class of protein-kinase-inhibitor protein that regulates the activity of the Raf/MEK/ERK modul
First events from the CNGS neutrino beam detected in the OPERA experiment
The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS)
was designed to perform the first detection of neutrino oscillations in
appearance mode, through the study of nu_mu to nu_tau oscillations. The
apparatus consists of a lead/emulsion-film target complemented by electronic
detectors. It is placed in the high-energy, long-baseline CERN to LNGS beam
(CNGS) 730 km away from the neutrino source. In August 2006 a first run with
CNGS neutrinos was successfully conducted. A first sample of neutrino events
was collected, statistically consistent with the integrated beam intensity.
After a brief description of the beam and of the various sub-detectors, we
report on the achievement of this milestone, presenting the first data and some
analysis results.Comment: Submitted to the New Journal of Physic
Neues Zuhause für Musikalien: Umzug des Deutschen Musikarchivs der Deutschen Nationalbibliothek von Berlin nach Leipzig
Im Dezember 2010 zieht das Deutsche Musikarchiv (DMA) von Berlin an den Standort der Deutschen Nationalbibliothek Leipzig. Mit dem DMA wird sich in Leipzig die zentrale nationale Sammlung von Musikalien und Tonträgern und das musikbibliografische Informationszentrum Deutschlands ansiedeln
Politik der Profession: Das Leitbild der Berlinischen Architektur
"Die beispiellose städtebauliche Erfassung des Berliner Zentrums in den letzten fünf Jahren hat zu einem charakteristischen Bild von Stadt geführt Diese Bild nimmt bereits in einer Reihe von Großprojekten Gestalt an. Es kann gezeigt werden, daß die herkömmliche Analyse von Investoreninteressen und Bodenverwertung nicht ausreicht, die Entstehung dieser gebauten Ordnung zu erfassen. Vielmehr kann in einer kultursoziologisch gerichteten Akteursanalyse der spezifische Einfluß professioneller Deutungsmuster und Weltbilder demonstriert werden. Die Wechselwirkung von urbanistischer Theorie und medialer Inszenierung hat die kulturelle Deutungsmacht von Architekten und Planern gegenüber ökonomischen, politischen, vor allem aber auch den marginalen sozialwissenschaftlichen Interventionen deutlich gemacht. In der 'negotiated order' der Stadtpolitik hat die Profession der Architekten als Mittler zwischen divergierenden Interessen eine eigenständige Politik treiben können. Dies kann anhand des Berliner Architekturstreites exemplarisch gezeigt werden." (Autorenreferat
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