Search results for "Cell Proliferation"
showing 10 items of 1056 documents
Direct determination of intracellular daunorubicin in intact confluent monolayers of AT1 prostate carcinoma cells using a multiwell–multilabel counter
2008
The cytostatic drug daunorubicin exerts its toxic action by intercalating into the DNA. The efficacy of daunorubicin depends on the intracellular amount in the tumor cell. Here we have evaluated the use of a multiwell-multilabel reader for the direct determination of the fluorescent cytostatic drug daunorubicin in a prostate carcinoma cell line (AT1 R-3327 Dunning prostate carcinoma cells) grown on 24-well plates. We present evidence that this simple fluorescent parameter is a good measure for the toxicologically relevant amount of the drug intercalated into the DNA and, therefore, is a good predictor for the drug's cytotoxicity. The amount of cationic cytostatics in a tumor cell is primari…
Lipid Bilayer Interactions of Peptidic Supramolecular Polymers and Their Impact on Membrane Permeability and Stability.
2020
The synthesis and physicochemical characterization of supramolecular polymers with tunable assembly profiles offer exciting opportunities, involving the development of new biomedical carriers. Because synthetic nanocarriers aim to transport substances across or toward cellular membranes, we evaluated the interactions of amphiphilic peptide-based supramolecular polymers with lipid bilayers. Here, we focused on nanorod-like supramolecular polymers, obtained from two C3-symmetric dendritic peptide amphiphiles with alternating Phe/His sequences, equipped with a peripheral tetraethylene glycol dendron (C3-PH) or charged ethylenediamine end groups (C3-PH+). Triggered by pH changes, these amphiphi…
Essential oils of Salvia bracteata and Salvia rubifolia from Lebanon: Chemical composition, antimicrobial activity and inhibitory effect on human mel…
2009
Aim of the study: Salvia bracteata Banks et Sol. and Salvia rubifolia Boiss. are known in folk medicine of Lebanon for the treatment of microbial infections, cancer, urinary and pulmonary problems. In the present study the chemical composition and antimicrobial activity of essential oils from aerial parts of Salvia bracteata and Salvia rubifolia collected in Lebanon were evaluated. The oils were also tested for their potential antiproliferative effects against M14 human melanoma cells. Material and methods: The oils were studied by GC and GC-MS and their antibacterial activity (MIC and MBC) was tested against ten bacteria species using the broth dilution method. The inhibitory effect on hum…
Involvement of enniatins-induced cytotoxicity in human HepG2 cells.
2012
Enniatins (ENNs) are mycotoxins found in Fusarium fungi and they appear in nature as mixtures of cyclic depsipeptides. The ability to form ionophores in the cell membrane is related to their cytotoxicity. Changes in ion distribution between inner and outer phases of the mitochondria affect to their metabolism, proton gradient, and chemiosmotic coupling, so a mitochondrial toxicity analysis of enniatins is highly recommended because they host the homeostasis required for cellular survival. Two ENNs, ENN A and ENN B on hepatocarcinoma cells (HepG2) at 1.5 and 3 μM and three exposure times (24, 48 and 72 h) were studied. Flow cytometry was used to examine their effects on cell proliferation, t…
Polyphosphate, the physiological metabolic fuel for corneal cells: a potential biomaterial for ocular surface repair
2019
The regeneration of the epithelium, covering the avascular cornea, involves the processes of differentiation, proliferation and migration of cells originating from the corneal epithelial stem cells. We ask the question if these energy-consuming processes can be fueled by the physiological, inorganic polyphosphate (polyP), the main energy storage/donor molecule in the extracellular space. The ex vivo results reveal that addition of polyP, in the form of soluble Na-polyP, to the culture medium elicits a strong stimulatory effect on cell viability/growth and migration of corneal epithelial cells. Microscopic analyses of partially denuded cornea specimens show that in the presence of polyP, but…
IgG1 B cell receptor signaling is inhibited by CD22 and promotes the development of B cells whose survival is less dependent on Ig alpha/beta.
2007
We describe a mouse strain in which B cell development relies either on the expression of membrane-bound immunoglobulin (Ig) gamma1 or mu heavy chains. Progenitor cells expressing gamma1 chains from the beginning generate a peripheral B cell compartment of normal size with all subsets, but a partial block is seen at the pro- to pre-B cell transition. Accordingly, gamma1-driven B cell development is disfavored in competition with developing B cells expressing a wild-type (WT) IgH locus. However, the mutant B cells display a long half-life and accumulate in the mature B cell compartment, and even though partial truncation of the Ig alpha cytoplasmic tail compromises their development, it does…
Polyketides from the marine-derived fungus Aspergillus falconensis: In silico and in vitro cytotoxicity studies.
2020
Abstract Fermentation of the marine-derived fungus Aspergillus falconensis, isolated from sediment collected from the Red Sea, Egypt on solid rice medium containing 3.5% NaCl yielded a new dibenzoxepin derivative (1) and a new natural isocoumarin (2) along with six known compounds (3–8). Changes in the metabolic profile of the fungus were induced by replacing NaCl with 3.5% (NH4)2SO4 that resulted in the accumulation of three further known compounds (9–11), which were not detected when the fungus was cultivated in the presence of NaCl. The structures of the new compounds were elucidated by HRESIMS and 1D/2D NMR as well as by comparison with the literature. Molecular docking was conducted fo…
Computational Evaluation and In Vitro Validation of New Epidermal Growth Factor Receptor Inhibitors
2020
Background:The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma.Methods:We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,46…
Inhibition of stearoyl-CoA desaturase 1 expression induces CHOP-dependent cell death in human cancer cells.
2010
Background Cancer cells present a sustained de novo fatty acid synthesis with an increase of saturated and monounsaturated fatty acid (MUFA) production. This change in fatty acid metabolism is associated with overexpression of stearoyl-CoA desaturase 1 (Scd1), which catalyses the transformation of saturated fatty acids into monounsaturated fatty acids (e.g., oleic acid). Several reports demonstrated that inhibition of Scd1 led to the blocking of proliferation and induction of apoptosis in cancer cells. Nevertheless, mechanisms of cell death activation remain to be better understood. Principal Findings In this study, we demonstrated that Scd1 extinction by siRNA triggered abolition of de nov…
Geldanamycin-induced osteosarcoma cell death is associated with hyperacetylation and loss of mitochondrial pool of heat shock protein 60 (hsp60)
2013
Osteosarcoma is one of the most malignant tumors of childhood and adolescence that is often resistant to standard chemo- and radio-therapy. Geldanamycin and geldanamycin analogs have been recently studied as potential anticancer agents for osteosarcoma treatment. Here, for the first time, we have presented novel anticancer mechanisms of geldanamycin biological activity. Moreover, we demonstrated an association between the effects of geldanamycin on the major heat shock proteins (HSPs) and the overall survival of highly metastatic human osteosarcoma 143B cells. We demonstrated that the treatment of 143B cells with geldanamycin caused a subsequent upregulation of cytoplasmic Hsp90 and Hsp70 w…