Search results for "Genou"
showing 10 items of 610 documents
Biopiracy and the right to self-determination of indigenous peoples.
2018
Abstract Background: Since over thirty years, I work on the unclear legal situation of in which indigenous peoples find themselves today in the beginning mainly in the USA and later also in Canada, Australia and New Zealand. The status of indigenous people and native nations is characterized as a mixture of national and international law. Hypothesis/Purpose: To clarify the status of indigenous people it is necessary to analyze and interpret carefully hundreds of old treaties, international declarations and covenants, national statutes and jurisprudence, especially the old leading decisions of the US-Supreme Court. Such an analysis and interpretation should prove that indigenous people have …
Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis
2012
The present study is designed to assess if exosomes released from Chronic Myelogenous Leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-ca…
Novel pathway in Bcr-Abl signal transduction involves Akt-independent, PLC-γ1-driven activation of mTOR/p70S6-kinase pathway
2009
In chronic myeloid leukemia, activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway is crucial for survival and proliferation of leukemic cells. Essential downstream molecules involve mammalian target of rapamycin (mTOR) and S6-kinase. Here, we present a comprehensive analysis of the molecular events involved in activation of these key signaling pathways. We provide evidence for a previously unrecognized phospholipase C-gamma1 (PLC-gamma1)-controlled mechanism of mTOR/p70S6-kinase activation, which operates in parallel to the classical Akt-dependent machinery. Short-term imatinib treatment of Bcr-Abl-positive cells caused dephosphorylation of p70S6-K and S6-protein without inactivat…
Exosomal shuttling of miR-126 in endothelial cells modulates adhesive and migratory abilities of chronic myelogenous leukemia cells.
2014
BACKGROUND: Recent findings indicate that exosomes released from cancer cells contain microRNAs (miRNAs) that may be delivered to cells of tumor microenvironment. RESULTS: To elucidate whether miRNAs secreted from chronic myelogenous leukemia cells (CML) are shuttled into endothelial cells thus affecting their phenotype, we first analysed miRNAs content in LAMA84 exosomes. Among the 124 miRNAs identified in LAMA84 exosomes, we focused our attention on miR-126 which was found to be over-overexpressed in exosomes compared with producing parental cells. Transfection of LAMA84 with Cy3-labelled miR-126 and co-culture of leukemia cells with endothelial cells (EC) confirmed that miR-126 is shuttl…
Tyrosine Kinase Inhibitors for the Treatment of Chronic Myeloid Leukemia
2009
Imatinib mesylate (Gleevec) is a drug unique for the treatment of certain forms of cancer. It works by targeting, and turning off, specific tyrosine kinase proteins that cause the uncontrolled cell growth and the inhibition of apoptosis in cancer cells. Imatinib was designed on the basis of the structure of the ATP binding site of the Abl protein kinase with the aim to stabilizes the inactive form of Bcr-Abl, an oncoprotein involved in malignant transformation in chronic myelogenous leukemia (CML). However, imatinib can also target other tyrosine kinase proteins different from Bcr-Abl such as Kit, that is the suspected cause of gastrointestinal stromal tumor (GIST). Despite successful clini…
The new iodoacetamidobenzofuran derivative TR120 decreases STAT5 expression and induces antitumor effects in imatinib-sensitive and imatinib-resistan…
2013
The identification of novel compounds modulating the expression/activity of molecular targets downstream to BCR-ABL could be a new approach in the treatment of chronic myeloid leukemias (CMLs) resistant to imatinib or other BCR-ABL-targeted molecules. Recently, we synthesized a new class of substituted 2-(3,4,5-trimethoxybenzoyl)-2-N,N-dimethylamino-benzo[b]furans, and among these 3-iodoacetylamino-6-methoxybenzofuran-2-yl(3,5-trimethoxyphenyl)methanone (TR120) showed marked cytotoxic activity in BCR-ABL-expressing cells. Interestingly, TR120 was more potent than imatinib in cell growth inhibition and apoptosis induction in both BCR-ABL-expressing K562 and KCL22 cells. Moreover, it showed a…
STAT5 is crucial to maintain leukemic stem cells in acute myelogenous leukemias induced by MOZ-TIF2.
2012
Abstract MOZ-TIF2 is a leukemogenic fusion oncoprotein that confers self-renewal capability to hematopoietic progenitor cells and induces acute myelogenous leukemia (AML) with long latency in bone marrow transplantation assays. Here, we report that FLT3-ITD transforms hematopoietic cells in cooperation with MOZ-TIF2 in vitro and in vivo. Coexpression of FLT3-ITD confers growth factor independent survival/proliferation, shortens disease latency, and results in an increase in the number of leukemic stem cells (LSC). We show that STAT5, a major effector of aberrant FLT3-ITD signal transduction, is both necessary and sufficient for this cooperative effect. In addition, STAT5 signaling is essent…
In BCR-ABL-positive cells, STAT-5 tyrosine-phosphorylation integrates signals induced by imatinib mesylate and Ara-C.
2003
In BCR-ABL-positive cells, the transcription factor STAT-5 is constitutively activated by tyrosine phosphorylation. STAT-5 activation results in upregulation of bcl-X(L) and increased resistance to induction of apoptosis. Here, we investigated the effects of imatinib mesylate and cytosine arabinoside (Ara-C) on STAT-5 tyrosine-phosphorylation, cellular proliferation and induction of apoptosis in cell lines and primary hematopoietic cells. Imatinib mesylate treatment strongly suppressed STAT-5 tyrosine-phosphorylation in K562 and primary CML blasts. In contrast to JAK-2 and PI-3-kinase inhibition, exposure of K562 cells to imatinib mesylate resulted in obvious suppression of proliferation. R…
Galangin increases the cytotoxic activity of imatinib mesylate in imatinib-sensitive and imatinib-resistant Bcr-Abl expressing leukemia cells
2008
Resistance to imatinib mesylate is an emergent problem in the treatment of Bcr-Abl expressing myelogenous leukemias and additional therapeutic strategies are required. We observed that galangin, a non-toxic, naturally occurring flavonoid was effective as anti-proliferative, and apoptotic agent in Bcr-Abl expressing K562 and KCL22 cells and in imatinib mesylate resistant K562-R and KCL22-R cells. Galangin induced an arrest of cells in G0–G1phase of cell cycle and a decrease in pRb, cdk4, cdk1, cycline B levels; moreover, it was able to induce a monocytic differentiation of leukemic Bcr-Abl+ cells. Of note, galangin caused a decrease in Bcl-2 levels and markedly increased the apoptotic activi…
Influence of interferon-alpha on cytokine expression by the bone marrow microenvironment--impact on treatment of myeloproliferative disorders.
1996
Myeloproliferative disorders (MPD) are characterized by several common clinical and biological features, although at the molecular level, each disease entity exhibits distinct abnormalities. IFN-alpha exerts beneficial therapeutic effects in chronic myelogenous leukemia, polycythemia vera and essential thrombocythemia, resulting in control of hematopoietic hyperplasia and, in a minority of patients, in induction of cytogenetic remission. The mechanism of action of IFN-alpha in MPD is poorly defined. Recently published in vitro findings suggest that IFN-alpha interacts with the regulation of hematopoiesis by multiple ways. Its antiproliferative activity is well known for more than a decade, …