A sensitive assay for taxol and other microtubule-stabilizing agent.
The ability of taxol to protect microtubules in cultured human ovarian carcinoma cells from drug- and cold-induced depolymerization was characterized as a functional assay for microtubule stabilizing agents. Treatment of the cells with concentrations of vinblastine or colchicine of 50 nM or greater, or incubation at 4 degrees C resulted in complete depolymerization of cytoplasmic microtubules. Pretreatment with taxol for 3 h enabled the cells to maintain substantial numbers of microtubules following the application of vinblastine or colchicine. This protective effect was easily observed at 50 nM taxol, whereas taxol-induced microtubule bundling was observed only at concentrations of 500 nM or greater. Concentrations of taxol as low as 10 nM stabilized microtubules against cold-induced depolymerization. Therefore, protection of microtubules from drug- and cold-induced depolymerization provides a sensitive functional assay for taxol. These systems should be similarly effective in identifying novel compounds which stabilize microtubules.
Smith
C D
CD
Department of Pharmacology, Fox Chase Cancer Center, Philadelphia, PA 19111.
Mooberry
S L
SL
Zhang
X
X
Helt
A M
AM
D002455:Cell Division / Q000187:drug effects; D003078:Colchicine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D008870:Microtubules / Q000187:drug effects*; D010051:Ovarian Neoplasms / Q000473:pathology / Q000648:ultrastructure; D017239:Paclitaxel / Q000008:administration & dosage / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014747:Vinblastine / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D014747:Vinblastine; D017239:Paclitaxel; D003078:Colchicine