[Mechanism of taxol-induced apoptosis in human breast cancer cells].

OBJECTIVE

To investigate the mechanism by which taxol induces apoptosis in human breast cancer cells.

METHODS

Cell morphology, agarose gel electrophoresis, flow cytometry, video time-lapse monitor and Western blot were performed for taxol-induced apoptosis in human breast cancer cells (Bcap 37).

RESULTS

BCap 37 cells treated with taxol (100 nm) underwent the arrests of cell mitosis at metaphase of mitosis and induction of apoptosis. Apoptotic cells demonstrated cell shringkage, condensation and fragmentation of chromosomes. Nuclear DNA of apoptotic cells displayed ladder bands characteristic of internucleosomal DNA fragmentation. The expression of bcl-2, inhibitor of apoptosis, was decreased with modification, while that of bax, inducer of apoptosis, increased only at early stage of the apoptotic pathway and decreased later.

CONCLUSION

In human breast cancer cells the induction of apoptosis by taxol was closely associated with mitotic arrest of cell cycle, and altered expression of bcl-2 and bax gene, possibly playing an important role in regulating taxol-induced apoptosis.