title: Contribution of reactive oxygen species and caspase-3 to apoptosis and attenuated ICAM-1 expression by paclitaxel-treated MDA-MB-435 breast carcinoma cells.
abstract: Paclitaxel is a microtubule-stabilizing and apoptosis-inducing drug that is commonly used to treat metastatic breast cancer, although the mechanism of paclitaxel-induced apoptosis remains incompletely understood. Furthermore, adhesion molecule expression is attenuated on mouse mastocytoma and human leukemia cells that survive short-term culture in the presence of paclitaxel. In the present study we show that MDA-MB-435 human breast carcinoma cells that survived culture for 72 h in the presence of submaximal cytotoxic concentrations of paclitaxel (0.02 and 0.01 microg/ml) showed decreased expression of the adhesion molecule ICAM-1. Paclitaxel treatment of MDA-MB-435 cells was associated with the generation of reactive oxygen species (ROS), dissipation of mitochondrial transmembrane potential, and the activation of caspase-3. The antioxidant glutathione protected MDA-MB-435 cells from paclitaxel-induced cytotoxicity and reduced ICAM-1 expression. In addition, a selective inhibitor of caspase-3 (Z-DEVD-FMK), as well as a pan-caspase inhibitor (Z-VAD-FMK), partially prevented the decrease in ICAM-1 expression observed following paclitaxel treatment, but did not protect against paclitaxel-induced cytotoxicity. We conclude that the paclitaxel-induced reduction in ICAM-1 expression by MDA-MB-435 breast carcinoma cells is both ROS- and caspase-dependent, whereas paclitaxel-induced cytotoxicity is ROS-dependent and does not involve caspases. Decreased ICAM-1 expression by breast carcinoma cells that survive paclitaxel treatment may negatively impact on cytotoxic lymphocyte-mediated destruction of paclitaxel-resistant breast cancer cells in the context of chemo-immunotherapy or chemo-adoptive immunotherapy.
authors.affiliation: Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Fawcett
authors.forename: Jamie S
authors.initials: JS
authors.lastname: Mader
authors.forename: Matthew
authors.initials: M
authors.lastname: Robichaud
authors.forename: Carman
authors.initials: C
authors.lastname: Giacomantonio
authors.forename: David W
authors.initials: DW
authors.lastname: Hoskin
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000972:Antineoplastic Agents, Phytogenic; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D005353:Fibronectins; D009842:Oligopeptides; D017382:Reactive Oxygen Species; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D018799:Intercellular Adhesion Molecule-1; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D017239:Paclitaxel