Search results for "K562 Cell"
showing 10 items of 83 documents
Biochemical and chemical characterization of Cynara cardunculus L. extract and its potential use as co-adjuvant therapy of chronic myeloid leukemia
2017
Abstract Ethnopharmacological relevance Ancient mediterranean diet was characterized by consuming the spontaneous forms of Cynara cardunculus L. (CCL), commonly called artichoke. Cultivated and/or spontaneous forms of CC studies have demonstrated that methanol extract of CCL flower and/or cynaropicrin showed remarkable anti-proliferative activity in vitro models of leukocyte cancer cell. Aim of the study Chronic myeloid leukemia (CML) is associated with a reciprocal translocation of the long arms of chromosomes 9 and 22 generating the BCR/ABL fusion gene, translated in the p210 BCR/ABL oncoprotein kinase. This chimeric protein is the target of a kinase inhibitor, imatinib, but the developme…
Combining dasatinib with dexamethasone long-term leads to maintenance of antiviral and antileukemia specific cytotoxic T cell responses in vitro
2012
Maintaining graft versus leukemia (GvL) and antivirus responses of cytotoxic T cells (CTLs) while suppressing graft-versus-host disease (GvHD) remains a challenge after allogeneic bone marrow transplantation. Clinical observations indicate that combining glucocorticoids with multi-tyrosine-kinase inhibitors could be a successful therapeutic approach. We and others have shown that the BCR-ABL/SRC kinase inhibitor dasatinib may enhance or suppress T cells in vitro. In this report, we evaluated combination effects of dasatinib and dexamethasone on CD3 + and virus-specific CD8 + T cells directly ex vivo and on antigen-specific leukemia-reactive and alloreactive CD8 + T cell clones. Functional o…
The use of HLA-A*0201-transfected K562 as standard antigen-presenting cells for CD8+ T lymphocytes in IFN-γ ELISPOT assays
2001
ELISPOT assays are increasingly used for a direct detection and quantification of single antigen-specific T cells in freshly isolated peripheral blood mononuclear cells (PBMC). They are particularly attractive for the monitoring of specific T lymphocyte responses in clinical trials assessing antigen-specific immunizations in patients with cancer or chronic viral infections. However, one major limitation for the broad clinical implementation of ELISPOT assays is the lack of an inexhaustible source of suitable HLA-matched antigen-presenting cells (APC). Currently available allogeneic or xenogeneic APC (such as the human lymphoid hybrid T2 or HLA-transfected insect cells) can either lead to st…
Binding of Escherichia coli hemolysin and activation of the target cells is not receptor-dependent.
2005
Abstract Production of a single cysteine substitution mutant, S177C, allowed Escherichia coli hemolysin (HlyA) to be radioactively labeled with tritiated N-ethylmaleimide without affecting biological activity. It thus became possible to study the binding characteristics of HlyA as well as of toxin mutants in which one or both acylation sites were deleted. All toxins bound to erythrocytes and granulocytes in a nonsaturable manner. Only wild-type toxin and the lytic monoacylated mutant stimulated production of superoxide anions in granulocytes. An oxidative burst coincided with elevation of intracellular Ca2+, which was likely because of passive influx of Ca2+ through the toxin pores. Competi…
Design, synthesis, and biological evaluation of thiophene analogues of chalcones.
2008
Chalcones are characterized by possessing an enone moiety between two aromatic rings. A series of chalcone-like agents, in which the double bond of the enone system is embedded within a thiophene ring, were synthesized and evaluated for antiproliferative activity and inhibition of tubulin assembly and colchicine binding to tubulin. The replacement of the double bond with a thiophene maintains antiproliferative activity and therefore must not significantly alter the relative conformation of the two aryl rings. The synthesized compounds were found to inhibit the growth of several cancer cell lines at nanomolar to low micromolar concentrations. In general, all compounds having significant anti…
WT1 isoform expression pattern in acute myeloid leukemia.
2013
WT1 plays a dual role in leukemia development, probably due to an imbalance in the expression of the 4 main WT1 isoforms. We quantify their expression and evaluate them in a series of AML patients. Our data showed a predominant expression of isoform D in AML, although in a lower quantity than in normal CD34+ cells. We found a positive correlation between the total WT1 expression and A, B and C isoforms. The overexpression of WT1 in AML might be due to a relative increase in A, B and C isoforms, together with a relative decrease in isoform D expression.
Targeting Aberrant Ncam (neural cell adhesion molecule; CD56) Expression in Acute Myeloid Leukemia
2015
Abstract Background Acute myeloid leukemia (AML) is a heterogeneous disease of the hematopoietic progenitor cell driven by the subsequent acquisition of genetic alterations. Approximately 20% of AML patients show strong expression of CD56 (neural cell adhesion molecule; NCAM). Expression of NCAM is associated with poor overall survival; however, the functional role of aberrant NCAM expression has not been investigated to date. The goal of this study is to examine the biological role of NCAM in AML and to explore whether NCAM represents a potential therapeutic target. Results In order to evaluate the clinical significance of elevated NCAM expression in AML, we screened a panel of human cell …
Complete karyotype characterization of the K562 cell line by combined application of G-banding, multiplex-fluorescence in situ hybridization, fluores…
2001
This study combines conventional cytogenetics, fluorescence in situ hybridization (FISH), multiplex-FISH and comparative genomic hybridization (CGH). In applying this multimodal approach on the human leukemia cell line K562, the chromosome composition was refined in detail and compared with data from the literature. A hypotriploid karyotype with a modal chromosome number of 67, and 21 unique marker chromosomes were identified. The classification of six markers was identical to published data and the composition of five further markers from the literature could be fully clarified for the first time. The composition of another five markers, which have been interpreted in divergent ways in dif…
Cytotoxicity and chemosensitizing activity of amphiphilic poly(glycerol)-poly(alkylene oxide) block copolymers.
2014
All polymeric chemosensitizers proposed thus far have a linear poly(ethylene glycol) (PEG) hydrophilic block. To testify whether precisely this chemical structure and architecture of the hydrophilic block is a prerequisite for chemosensitization, we tested a series of novel block copolymers containing a hyperbranched polyglycerol segment as a hydrophilic block (PPO-NG copolymers) on multi-drug-resistant (MDR) tumor cells in culture. PPO-NG copolymers inhibited MDR of three cell lines, indicating that the linear PEG can be substituted for a hyperbranched polyglycerol block without loss of the polymers' chemosensitizing activity. The extent of MDR reversal increased with the polymers affinity…
Synthesis and induction of G0–G1 phase arrest with apoptosis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazep…
2007
The multistep synthesis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazepin-4(3H)-one 15 has been carried out. The compound showed antiproliferative and apoptotic effects against K562, K562-R (imatinib mesilate resistant), HL60 and multidrug resistant (MDR) HL60 cell lines. Compound 15 showed a pro-apoptotic activity against HL60 and K562 resistant cell lines markedly higher than etoposide and busulfan, respectively. Flow cytometry studies carried out on K562 cells allowed to establish that 15 induces G0-G1 phase arrest followed by apoptosis.