Search results for "leukemia"
showing 10 items of 976 documents
Synthesis and study of cytotoxic activity of 1,2,4-trioxane- and egonol-derived hybrid molecules against Plasmodium falciparum and multidrug-resistan…
2014
Abstract Malaria and cancer cause the death of millions of people every year. To combat these two diseases, it is important that new pharmaceutically active compounds have the ability to overcome multidrug resistance in cancer and Plasmodium falciparum strains. In search of effective anti-cancer and anti-malaria hybrids that possess improved properties compared to their parent compounds, a series of novel 1,2,4-trioxane-based hybrids incorporating egonol and/or ferrocene fragments were synthesized and tested in vitro against P. falciparum strains, CCRF–CEM cells and the multidrug-resistant P-glycoprotein-over-expressing CEM/ADR5000 cells. The most active compounds against P. falciparum stra…
Semisynthesis and cytotoxicity of styryl-lactone derivatives.
1999
The cytotoxicity and the cell-cycle action of altholactone (1), goniofufurone (2), and eight altholactone derivatives (5-12), were determined in vitro on L-1210 cells. Semisyntheses and structure-activity relationships of these compounds are described. The results of this study suggest that the cytotoxicity of altholactone (1), 11-nitro-altholactone (8), and 7-chloro-6,7-dihydroaltholactone (10) is due to the accumulation of the cells in the G2 + M phase of the cell cycle.
Cytotoxicity and modes of action of four naturally occuring benzophenones: 2,2′,5,6′-Tetrahydroxybenzophenone, guttiferone E, isogarcinol and isoxant…
2012
Abstract Introduction The emergence of drug-resistant cancer cells drastically reduces the efficacy of many antineoplasic agents and, consequently, increases the frequency of therapeutic failure. Benzophenones are known to display many pharmacological properties including cytotoxic activities. The present study was aimed at investigating the cytotoxicity and the modes of action of four naturally occurring benzophenones 2,2′,5,6′-tetrahydroxybenzophenone ( 1 ), isogarcinol ( 2 ), isoxanthochymol ( 3 ) and guttiferone E ( 4 ) on a panel of eleven cancer cell lines including various sensitive and drug-resistant phenotypes. Methods The cytotoxicity of the compounds was determined using a resazu…
Joziknipholones A and B: The First Dimeric Phenylanthraquinones, from the Roots ofBulbine frutescens
2007
From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-co…
REGULATORY ELEMENTS OF THE LEUKAEMIA INHIBITORY FACTOR (LIF) PROMOTER IN MURINE BONE MARROW STROMAL CELLS
1999
Leukaemia inhibitory factor (LIF) plays an important role as a haematopoietically active cytokine. As described earlier in a murine model, interleukin 1 (IL-1) induced LIF mRNA and protein expression. We utilized the murine cell line +/+-1.LDA11 to further define regulatory mechanisms of LIF expression in bone marrow stromal cells. The production of LIF mRNA is stimulated by IL-1beta, TNF-alpha, and the cAMP analogue 8-bromoadenosine 3':5'-monophosphate (8BrcAMP). LIF mRNA expression is controlled at the transcriptional level. Different fragments from -542 to -45 bp 5' upstream of the transcriptional start site of the murine LIF gene were fused to the luciferase gene. All LIF-promoter lucif…
Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells
1993
Abstract nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and…
Sympathetic neurons can produce and respond to interleukin 6
1998
Neuronal expression of cytokines is an area of active investigation in the contexts of development, disease, and normal neural function. Although cultured rat sympathetic neurons respond very weakly to exogenous interleukin 6 (IL-6), we find that addition of soluble IL-6 receptor (sIL-6R) and IL-6 enhances neuronal survival in the absence of nerve growth factor. Neutralizing monoclonal antibodies against IL-6 block these effects. Addition of IL-6 and sIL-6R also induces a subset of neuropeptide and transmitter synthetic enzyme mRNAs identical to that demonstrated for leukemia inhibitory factor, ciliary neurotrophic factor, and oncostatin M. Both of these effects are duplicated by addition o…
Chronic myeloid leukemia-derived exosomes promote tumor growth through an autocrine mechanism.
2014
Background Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder in which leukemic cells display a reciprocal t(9:22) chromosomal translocation that results in the formation of the chimeric BCR-ABL oncoprotein, with a constitutive tyrosine kinase activity. Consequently, BCR-ABL causes increased proliferation, inhibition of apoptosis, and altered adhesion of leukemic blasts to the bone marrow (BM) microenvironment. It has been well documented that cancer cells can generate their own signals in order to sustain their growth and survival, and recent studies have revealed the role of cancer-derived exosomes in activating signal transduction pathways involved in cancer cell…
Cytotoxicity and inhibition of P-glycoprotein by selected medicinal plants from Thailand.
2014
Abstract Ethnopharmacological relevance Thai medicine has a long tradition of tonifying medicinal plants. In the present investigation, we studied the flower extracts of Jasminum sambac, Mammea siamensis, Mesua ferrea, Michelia alba, Mimusops elengi, and Nelumbo nucifera and speculated that these plants might influence metabolism and substance flow in the body. Materials and methods Isolation of porcine brain capillary endothelial cells (PBCECs) as well as multidrug-resistance CEM/ADR5000 leukemia cells, MDA-M;B-231 breast cancer, U-251 brain tumor, and HCT-116 colon cancer cells were used. The calcein-acetoxymethylester (AM) assay was used to measure inhibition of P-glycoprotein transport.…
The high-performance technology CRISPR/Cas9 improves knowledge and management of acute myeloid leukemia
2021
Knowledge on acute myeloid leukemia pathogenesis and treatment has progressed recently, but not enough to provide ideal management. Improving the prognosis of acute myeloid leukemia patients depends on advances in molecular biology for the detection of new therapeutic targets and the production of effective drugs. The CRISPR/Cas9 technology allows gene insertions and deletions and it is the first step in investigating the function of their encoded proteins. Thus, new experimental models have been developed and progress has been made in understanding protein metabolism, antitumor activity, leukemic cell maintenance, differentiation, growth, apoptosis, and self-renewal, the combined pathogene…