Taxotere® (docetaxel) Injection Concentrate: Mechanism of Action1-4
Taxotere® works in 3 distinct pathways that contribute, directly
or indirectly, to apoptosis, or programmed cell death. The main mode of therapeutic
action of Taxotere® is the suppression of microtubule dynamics (assembly
and disassembly). Other modes include disruption of the cell cycle and phosphorylation
of Bcl-2.
Taxotere® disrupts the microtubular network in cells1,2
Taxotere® an antineoplastic agent that acts by disrupting the microtubular
network in cells that is essential for mitotic and interphase cellular functions.1
Taxotere® binds to free tubulin and promotes the assembly of tubulin
into stable microtubules while simultaneously inhibiting their disassembly. This
leads to the production of microtubule bundles without normal function and to the
stabilization of microtubules, which results in the inhibition of mitosis in cells.1
Taxotere® interrupts multiple phases of the cell cycle3
In addition to affecting microtubule structure, Taxotere® is thought
to work by interfering with 3 of the phases of the cell's life cycle. It causes
cell cycle arrest at S (synthesis) phase, G2 (growth 2) phase, and M (mitotic) phase.
At S phase, DNA doubles.3
At G2 phase, the cell grows further and gets ready to divide at M phase. By interfering
with these 3 cell cycle phases, Taxotere® causes the cell to be unable
to progress to the next phase, thus triggering apoptosis.3
Taxotere® induces Bcl-2 phosphorylation3
The third way Taxotere® initiates apoptosis is to induce the phosphorylation
of Bcl-2. In cancer cells, the overexpression of Bcl-2 prevents apoptosis. Taxotere®
phosphorylates Bcl-2, which inactivates it and allows cell death to occur. This
in vitro evaluation was conducted in human cell lines, including the breast
cancer MCF7 cell line.3