In Vitro | In vitro activity: Docetaxel is a cytotoxic agent, especially for proliferating cells, which is related to its ability to promote the formation of microtubule bundles and induce sustained mitotic arrest, followed by apoptosis of mitotically arrested cells or permanent mitotic block. Docetaxel suppresses microtubule dynamic instability as well as tread-milling, resulting in the failure of chromosomes to segregate to the daughter cells, which in turn triggers premature exit from mitosis rather than a block at this phase of the cell cycle. Docetaxel inhibits the clonogenic survival of Human cancer cell Hs746T (stomach), AGS (stomach), HeLa (cervix), CaSki (cervix), BxPC3 (pancreas), Capan-1 (pancreas) with IC50 of 1 nM, 1 nM, 0.3 nM, 0.3 nM, 0.3 nM and 0.3 nM respectively. Docetaxel inhibits endothelial cell migration that does not affects microtubule gross morphology or inhibit cell proliferation, although they does produce more subtle effects on microtubule dynamics. Docetaxel inhibits HUVEC migration with an observed IC50 of 1 pM. HUVEC chemotaxis stimulated by either of two angiogenic factors, thymidine phosphorylase or VEGF, is inhibited by Docetaxel with IC 50 of 10 pM and is ablated at 1 NM.
Kinase Assay: Single-drug concentration-response curves are assessed. Seeding is done at a density of 2,000 cells/well for PC-3 and LNCaP, in 96-well plates. Cells are treated with each single drug and their combination for 72 h at different drug concentrations. Docetaxel is used at concentrations of 0.1-1,000 nM. GLU is used at concentrations of 0.1-300 µm. Cytotoxicity is assessed at the end of drug exposure using SRB assay. Following 72 h exposure the cells are fixed with 10% trichloroacetic acid (150 µL) for 1 h at 4°C. Then, cells are stained for 10 min at room temperature with 0.4% SRB dissolved in 1% acetic acid. The plates are then air dried for 24 h and the dye is made soluble with 150 µL Tris (10 mM, PH 7.4) for 5 min on a shaker at 1,600 rpm. Absorbance is then measured at 545 nM using microplate reader. Results are expressed as the relative percentage of absorbance compared to control.
Cell Assay: 2000 cells in 180 μL of medium are seeded in a 96-well plate, and 20 μL of drug solution is simultaneously added in triplicate to each well. The plate is incubated for 3 days at 37°C in a humidified atmosphere of 5% CO2. On day 3, 25 μL of MTT reagent is added to each well. After 4 h of incubation, the medium is removed by aspiration. 0.2 mL of dimethylsulphoxide (DMSO) is added to each well and thoroughly mixed by using a mechanical plate mixer to dissolve the resulting MTT-formazan crystals. Absorbance at 540 nm (OD) is measured by a reader. |
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