Mechanism of Action
The antitumor activity of Taxotere® (docetaxel) is derived from its ability to disrupt the normal process of microtubule assembly and disassembly.*,1,2
Microtubules are cylindrical structures that form the basis of the cellular skeleton and are essential to the reproduction, growth and spread of tumor cells.*,1 Normally, as a part of the mitotic process, microtubules are reorganized to form a spindle. Assembly of microtubules from tubulin requires the presence of guanosine triphosphate (GTP).*,1,2

Dividing cell demonstrating *,1 microtubule spindle
Taxotere® binds tubulin, promoting polymerization and preventing depolymerization of microtubules in the absence of GTP.*,2 It binds to the ß-subunit of the tubulin within the microtubule, promoting the formation of stable microtubules, which form abnormal bundles that do the following:
- Resist physiologic disassembly
- Accumulate within tumor cells
- Inhibit cell proliferation leading to cell death

Microtubule and the presence of Taxotere®
In addition, research has found Taxotere® to have:
- A high binding affinity to tubulin and is a potent promoter of microtubule formation*,3,4
- Increased cellular uptake and slow efflux*,5
* Preclinical data may not necessarily be indicative of clinical efficacy and safety.
References
- Bissery M-C, Nohynek G, Sanderink G-J, Lavelle F. Docetaxel (Taxotere®): a review of preclinical and clinical experience. Part 1: preclinical experience. Anticancer Drugs. 1995;6:339-355.
- Eisenhauer EA, Vermorken JB. The taxoids: comparative clinical pharmacology and therapeutic potential. Drugs. 1998;55:5-30.
- Ringel I, Horwitz SB. Studies with RP 56976 (Taxotere®): a semisynthetic afalogue of Taxol. J Natl Cancer Inst. 1991;83:288-291
- Díaz JF, Andreu JM. Assembly of purified GDP-tubulin into microtubules induced by Taxol and Taxotere®: reversibility, ligand stoichiometry, and competition. Biochemistry. 1993;32:2747-2755.
- Riou J-F, Petitgenet O, Combeau C, Lavelle F. Cellular uptake and efflux of docetaxel (Taxotere®) and paclitaxel (Taxol®) in P388 cell line. Proc Am Assoc Cancer Res. 1994;35:385. Abstract 2292.