Taxol-Induced Mitotic Block Triggers Rapid Onset of a p53-Independent Apoptotic Pathway

Table 1 Comparison of EC ₅₀ values for mitotic arrest and cytotoxicity induced by taxol in various human cell lines

Cell Type	Mitotic Arrest^a (nM)	Aberrant Mitosis^a (nM)	Cytotoxicity^b (nM)
Hela	8.4 ± 1.5	8.4 ± 1.5	25.6 ± 5.6
Hs578T	16.6 ± 7.6	10.0 ± 5.3	14.8 ± 4.9
Hs578Bst	18.5 ± 6.5	12.5 ± 0.5	10.0
MCF-7	6.7 ± 1.7	6.7 ± 0.5	47.0 ± 7.2

All individual curve fits gave R² values of 0.98 to 1.0. Cells were treated with taxol concentrations ranging from 1 to 0 µM and scored after ^a24 hr for mitotic effects as described in Materials and Methods.
^bCytotoxicity estimations based on # Trypan blue positive cells after 72 hr. Data was analyzed by Inplot or Prism (Graphpad, CA, U.S.A.) to obtain EC₅₀ values. Experiments were carried out in triplicate.

ISSN: 1528-3658