Figure 7. LPA causes dissociation Taxol from the polymerized tubulin compartment.

Approximately 2×10⁶ cells were seeded in 6 cm dishes. After growing cells to confluence, the medium was replaced with 3 ml RPMI 1640 containing 10% of charcoal-treated FBS containing 50 nM [³H]Taxol (0.5 µCi). Cells were preincubated for 26 h. After this, 5 µM LPA and different concentrations of inhibitors were added as indicated. Polymerized tubulin (Panel A) and soluble fractions (Panel B) were then separated and the distribution of [³H]Taxol was determined. Panels C and D show the dose response curves for LY294002 and Wortmannin, respectively. Results are means ± SD for three independent experiments. Panels A and B, * a significant difference of P<0.05.