Alterations in ovarian cancer cell adhesion drive taxol resistance by increasing microtubule dynamics in a FAK-dependent manner

Sci Rep. 2015 Apr 17:5:9529. doi: 10.1038/srep09529.

Abstract

Chemorefractory ovarian cancer patients show extremely poor prognosis. Microtubule-stabilizing Taxol (paclitaxel) is a first-line treatment against ovarian cancer. Despite the close interplay between microtubules and cell adhesion, it remains unknown if chemoresistance alters the way cells adhere to their extracellular environment, a process critical for cancer metastasis. To investigate this, we isolated Taxol-resistant populations of OVCAR3 and SKOV3 ovarian cancer cell lines. Though Taxol-resistant cells neither effluxed more drug nor gained resistance to other chemotherapeutics, they did display increased microtubule dynamics. These changes in microtubule dynamics coincided with faster attachment rates and decreased adhesion strength, which correlated with increased surface β1-integrin expression and decreased focal adhesion formation, respectively. Adhesion strength correlated best with Taxol-sensitivity, and was found to be independent of microtubule polymerization but dependent on focal adhesion kinase (FAK), which was up-regulated in Taxol-resistant cells. FAK inhibition also decreased microtubule dynamics to equal levels in both populations, indicating alterations in adhesive signaling are up-stream of microtubule dynamics. Taken together, this work demonstrates that Taxol-resistance dramatically alters how ovarian cancer cells adhere to their extracellular environment causing down-stream increases in microtubule dynamics, providing a therapeutic target that may improve prognosis by not only recovering drug sensitivity, but also decreasing metastasis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Cell Adhesion / drug effects
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Drug Resistance, Neoplasm / drug effects*
  • Female
  • Focal Adhesion Protein-Tyrosine Kinases / antagonists & inhibitors
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Humans
  • Integrin beta1 / metabolism
  • Microtubules / metabolism*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Paclitaxel / pharmacology*

Substances

  • Antineoplastic Agents, Phytogenic
  • Integrin beta1
  • Focal Adhesion Protein-Tyrosine Kinases
  • Paclitaxel