Search results for "Assay"

TAZ is required for metastatic activity and chemoresistance of breast cancer stem cells

2015

Metastatic growth in breast cancer (BC) has been proposed as an exclusive property of cancer stem cells (CSCs). However, formal proof of their identity as cells of origin of recurrences at distant sites and the molecular events that may contribute to tumor cell dissemination and metastasis development are yet to be elucidated. In this study, we analyzed a set of patient-derived breast cancer stem cell (BCSC) lines. We found that in vitro BCSCs exhibit a higher chemoresistance and migratory potential when compared with differentiated, nontumorigenic, breast cancer cells (dBCCs). By developing an in vivo metastatic model simulating the disease of patients with early BC, we observed that BCSCs…

In vitro effects of extracts from leaves and rhizomes of P.oceanica on HepG2 tumor cells

2023

Hsp 56 mRNA in Paracentrotus lividus embryos binds to a mitochondrial protein

2007

We previously demonstrated that Paracentrotus lividus Hsp56 mitochondrial chaperonin is constitutively expressed during development, that it has a specific territorial distribution, both in normal and heat-shocked embryos, and that its amount increases after heat shock [Roccheri MC, Patti M, Agnello M, Gianguzza F, Carra E, Rinaldi AM. Localization of mitochondrial Hsp56 chaperonin during sea urchin development. Biochem Biophys Res Commun 2001;287:1093-98] and cadmium treatment [Roccheri MC, Agnello M, Boneventura R, Matranga V. Cadmium induces the expression of specific stress proteins in sea urchin embryos. Biochem Biophys Res Commun 2004;321:80-7]. In this study, we looked at Hsp56 mRNA …

Comparison of an indirect format ELISA on modified graphite and polystyrene surfaces against triazines.

2006

An indirect format enzyme-linked immuno-sorbent assay (ELISA) on graphite rods (Ø 0.8 mm x 20 mm) and, for comparison, on microtiter plates has been developed against terbuthylazine. For this purpose, a series of 2-aminoalkyl-4-chloro-6-terbuthyl-s-triazine-2,6- diamine ELISA haptens with alkyl spacer lengths of 2, 4, 6, and 8 CH2 groups has been synthesized. The graphite rods or the microtiter plates were covered by a polymerized glutaraldehyde network, and the ELISA haptens have been coupled by imino coupling to the free aldehyde groups of that network. ε-Aminocaproic acid has been used as an agent to block unspecific binding sites. The ELISA was run in a competitive mode, where the immob…

Stabilization of anti-leukemic enzyme l-asparaginase by immobilization on polysaccharide levan

2001

Abstract Biologically active fructose polymer levan from Zymomonas mobilis of different molecular mass (75 and 2000 kDa) was covalently coupled to anti-leukemic enzyme Erwinia carotovora l -asparaginase. The method used for the immobilization of the enzyme involved periodate oxidation of the polysaccharide, followed by reductive alkylation. A gentle periodate oxidation of levan (oxidation degree ≤24%) resulted in the highest residual enzyme activity (≥55%). The K m(app.) of glycoconjugates was higher than the K m of native l -asparaginase. The conjugation of l -asparaginase widened the optimum pH range of the enzyme. The electrophoretic mobility in polyacrylamide gel of glycoconjugates obta…

Action of low doses of Aspirin in Inflammation and Oxidative Stress induced by aβ1-42 on Astrocytes in primary culture

2020

Aspirin has been used as anti-inflammatory and anti-aggregate for decades but the precise mechanism(s) of action after the presence of the toxic peptide Aβ1-42 in cultured astrocytes remains poorly resolved. Here we use low-doses of aspirin (10-7 M) in astrocytes in primary culture in presence or absence of Aβ1-42 toxic peptide. We noted an increase of cell viability and proliferation with or without Aβ1-42 peptide presence in aspirin treated cells. In addition, a decrease in apoptosis, determined by Caspase 3 activity and the expression of Cyt c and Smac/Diablo, were detected. Also, aspirin diminished necrosis process (LDH levels), pro-inflammatory mediators (IL-β and TNF-α) and NF-ᴋB prot…

Semiquantitative bioluminescent assay of glutathione

1998

A novel technique has been developed for semiquantitative detection of glutathione (GSH) in small volumes of liquid samples. GSH is detected via enzymatic linkage to the NADP/NADPH + H+ redox system through glutathione reductase. Accumulated NADPH is measured via the bioluminescent FMN oxidoreductase bacterial luciferase reaction. A linear correlation is obtained between bioluminescence intensity of the luciferase reaction and the GSH content of the liquid sample. Possible applications of this procedure are discussed. © 1998 John Wiley & Sons, Ltd.

2003

Resting cells of the yeast Rhodosporidium toruloides (UOFS Y-0471) were immobilised in calcium alginate beads for the enantioselective kinetic resolution of racemic-1,2-epoxyoctane. The initial activity exhibited by immobilised cells was almost 50% lower than that of the free counterpart but was extremely stable when compared to the free cells. The concentration of the immobilised biomass had no effect on apparent enzyme activity but did lead to a decrease in single cell activity. An increase in both the alginate and CaCl2 concentrations used for bead preparation led to a decrease in enzyme stability. An increase in the alginate concentration led to an increase in bead diameter. The stoichi…

Deglycosylated bleomycin triggers apoptosis in laryngeal carcinoma cells in a caspase and reactive oxygen species independent manner

2008

Background:  Bleomycin-A2, a member of a family of glycopeptide antibiotics, has potent antitumor activity against a range of lymphomas, head and neck cancer and germ cell tumors. However, little is known about the biologic activity of the carbohydrate moiety in Bleomycin-A2-induced cytotoxicity. Methods:  We compared the capacity of Bleomycin-A2 and its deglycosylated form (deglycoBleomycin-A2) to induce cell death. Apoptosis was analyzed by cell nuclear staining with Hoechst 33342 dye and DNA fragmentation. The signal transduction pathway was measured through Western blotting and production of reactive oxygen species (ROS). Results:  When tested on HEp-2 laryngeal carcinoma cells, Bleomyc…

ChemInform Abstract: The Synthesis and Effect of Fluorinated Chalcone Derivatives on Nitric Oxide Production.

2010

Abstract Dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, were synthesized and evaluated for their influence on nitric oxide production. Some of them, chalcones 1 , 5 , 7 , 10 , 11 and 17 , inhibited NO production with an IC 50 in the submicromolar range; 17 is especially noteworthy because of its potency (IC 50 30 nM). These effects were not the consequence of a direct inhibitory action on enzyme activity but the inhibition of enzyme expression.