Taxol reduces cytosolic E-cadherin and β-catenin levels in nasopharyngeal carcinoma cell line TW-039: Cross-talk between the microtubule- and actin-based cytoskeletons

Taxol affects microtubule dynamics by promoting microtubule assembly. To obtain a better insight into possible cross-talk between the microtubule- and actin-based cytoskeletons, we studied the short-term effects of Taxol treatment on the expression of actin and the E-cadherin/catenin complex in the nasopharyngeal carcinoma cell line TW-039 using immunofluorescence, immunoprecipitation, and immunoblotting methods. Morphologic changes in actin filaments, including ventral actin dumps and perijunctional actin blebs, were seen at Taxol concentrations ≥1 μM. Levels of detergent-soluble E-cadherin fell to 53% or 58% compared to controls in cells treated, respectively, with 1 or 5 μM Taxol, while levels of detergent-soluble β-catenin fell to 76% or 74%. Levels of the detergent-soluble pool of α- and γ-catenin and the detergent-insoluble pool of the E-cadherin/catenin complex were unchanged by Taxol treatment and no significant difference was seen in the levels of adenomatous polyposis coli or glycogen synthase-3β or tyrosine phosphorylation patterns. These results suggest that modulation of microtubule dynamics by Taxol may have effects on the expression of actin and the cytosolic E-cadherin and β-catenin in nasopharyngeal carcinoma cells through pathways not involving the phosphorylation of β-catenin. (C) 2000 Wiley-Liss, Inc.