Search results for "leukemia"

Novel insights on [1,2]oxazolo[5,4‐e]isoindoles on multidrug resistant acute myeloid leukemia cell line

2022

A series of [1,2]oxazolo[5,4‐e]isoindole derivatives was evaluated against HL‐60 cell line and its multidrug resistance (MDR) variant, HL‐60R, resistant to doxorubicin and to other P‐gp substrates by overexpressing the efflux pump. They displayed antiproliferative activities, with IC50 values ranging from 0.02 to 5.5μM. In particular, the newly synthesized compound 4k produced synergistic effects in terms of cell growth inhibition and cell death induction either in combination with a Vinca alkaloid, Vinblastine, and a Taxane, Paclitaxel in HL‐60R cells. The study of the mechanism of action indicated that all compounds showed antimitotic activity through inhibition of tubulin polymerization.…

Cytotoxicity of Endoperoxides from the Caribbean Sponge Plakortis halichondrioides towards Sensitive and Multidrug-Resistant Leukemia Cells: Acids vs…

2016

The 6-epimer of the plakortide H acid (1), along with the endoperoxides plakortide E (2), plakortin (3), and dihydroplakortin (4) have been isolated from a sample of the Caribbean sponge Plakortis halichondrioides. To perform a comparative study on the cytotoxicity towards the drug-sensitive leukemia CCRF-CEM cell line and its multi-drug resistant subline CEM/ADR5000, the acid of plakortin, namely plakortic acid (5), as well as the esters plakortide E methyl ester (6) and 6-epi-plakortide H (7) were synthesized by hydrolysis and Steglich esterification, respectively. The data obtained showed that the acids (1, 2, 5) exhibited potent cytotoxicity towards both cell lines, whereas the esters s…

Treatment with an Allogeneic Leukemia-Derived Dendritic Cell Vaccine in AML Patients Shows MRD Conversion and Improved Survival

2021

Abstract Background. Persistence of measurable residual disease (MRD) is a poor prognostic factor and predicts relapse in acute myeloid leukemia (AML). In a phase I study, the allogeneic leukemia-derived dendritic cell vaccine, DCP-001, has shown safety and humoral and cellular immune responses (A.A. van de Loosdrecht, et al. Cancer Immunol. Immunother. 2018;67:1505). In the current phase II study, (Clintrials.gov: NCT03697707) we report on progress and evaluation of MRD conversion, as primary endpoint, relapse free and overall survival. Methods. AML-patients, ineligible at screening for HSCT, who are in first complete remission (CR1) but with MRD receive 4 biweekly doses of 25e6 or 50e6 ce…

Prodrug based on halloysite delivery systems to improve the antitumor ability of methotrexate in leukemia cell lines

2021

The prodrug approach, as well as the development of specific systems able to deliver a chemotherapeutic agent in the target site, decreasing the side effects often associated with its administration, are still a challenging. In this context, both methotrexate drug molecules (MTX) and biotin ligand moieties, whose receptors are overexpressed on the surface of several cancer cells, were loaded on halloysite nanotubes (HNTs) to develop nanomaterial based on multifunctional and "smart" delivery systems. To highlight the crucial role played by biotin, carrier systems based on HNTs and MTX were also synthetized. In detail, several approaches were envisaged: i) a supramolecular interaction between…

Alpha-1-antitrypsin-induced inhibition of complement-dependent phagocytosis.

1981

Abstract In a previous investigation, inhibition of complement-dependent rosette formation by alpha1-antitrypsin (α1-AT) was observed, and it was demonstrated that α1-AT interacts through its carbohydrate portion with C3 and its fragments. In the present study, the effect of α1-AT on the complement-receptor-mediated phagocytosis by human peripheral blood monocytes was examined. Purified α1-AT inhibited in a dose-dependent manner phagocytosis of C3-carrying yeast particles. Inhibition was selective, concerned only C3-receptor-mediated phagocytosis, neither Fc-receptor-mediated phagocytosis nor uptake of untreated yeast particles was blocked by α1-AT. It was demonstrated that α1-AT exerted it…

Structure determination and preliminary cytotoxicity researches of the compounds isolated from Rumex acetosella L. on leukemia cells

2017

ChemInform Abstract: Chemoenzymatic-Chemical Synthesis of a (2-3)-Sialyl T Threonine Building Block and Its Application to the Synthesis of the N-Ter…

2010

Protection of all functional groups of the carbohydrate portion of the chemoenzymatically synthesized sialyl T threonine ester 1 (R=R1 =H, R2 =tBu, Fmoc=9-fluorenylmethoxycarbonyl) and subsequent acidolysis of the tert-butyl ester afforded the building block 2 (R=Ac, R1 =Me, R2 =H). The latter is a useful tool in the solid-phase synthesis of the N-terminal sequence 3 of the leukemia-associated leukosialin.

[Apoptosis of human leukemic cells induced by topoisomerase I and II inhibitors].

1996

International audience; Comparison between five human leukemic lines (BV173, HL60, U937, K562, KCL22) suggest that the main determinant of their sensitivity to topoisomerase I (camptothecin) and II (VP-16) inhibitors is their ability to regulate cell cycle progression in response to specific DNA damage, then to die through apoptosis: the more the cells inhibit cell cycle progression, the less sensitive they are. The final pathway of apoptosis induction involves a cytoplasmic signal, active at neutral pH, needing magnesium, sensitive to various protease inhibitors and activated directly by staurosporine. Modulators of intracellular signaling (calcium chelators, calmodulin inhibitors, PKC mod…

Leukemia Cutis: A Report of 17 Cases and a Review of the Literature

2016

Dermatologic manifestations of leukemia can be both specific and nonspecific (e.g., opportunistic infections, purpura and ecchymosis, Sweet syndrome). Leukemia cutis refers to the infiltration of the skin with neoplastic leukocytes and its early diagnosis has important prognostic implications. We report on 17 cases of leukemia cutis seen in our department between 1994 and 2014 and describe the characteristics of the patients (age, sex, medical history), the morphology of the lesions, and associations with systemic disease. Most of the patients were male and the most common associated malignancy was acute myeloid leukemia. The most frequent dermatologic manifestations were nodules or erythem…

Photolysis of N-hydroxpyridinethiones: a new source of hydroxyl radicals for the direct damage of cell-free and cellular DNA.

1996

N-Hydroxypyridine-2-thione (2-HPT), known to release hydroxyl radicals on irradiation with visible light, and two related compounds, viz. N-hydroxypyridine-4-thione (4-HPT) and N-hydroxyacridine-9-thione (HAT), were tested for their potency to induce DNA damage in L1210 mouse leukemia cells and in isolated DNA from bacteriophage PM2. DNA single-strand breaks and modifications sensitive to various repair endonucleases (Fpg protein, endonuclease III, exonuclease III, T4 endonuclease V) were quantified. Illumination of cell-free DNA in the presence of 2-HPT and 4-HPT gave rise to damage profiles characteristic for hydroxyl radicals, i.e. single-strand breaks and the various endonuclease-sensit…