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Published on: August 22, 2010

Transformation by Rho exchange factor oncogenes is mediated by activation of an integrin-dependent pathway

M A Schwartz1, D Toksoz, R Khosravi-Far

  • 1Department of Vascular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.

The EMBO Journal
|December 2, 1996
PubMed

Insights

Tumor cells gain anchorage independence through constitutive activation of integrin signaling pathways. The small GTPase Rho plays a key role in mediating this crucial integrin-dependent cell growth.

Area of Science:

  • Cell Biology
  • Cancer Biology
  • Signal Transduction

Background:

  • Constitutive activation of growth factor receptor signaling drives uncontrolled tumor cell proliferation.
  • The mechanisms underlying anchorage-independent growth, a hallmark of cancer, remain incompletely understood.
  • Integrins transmit signals essential for cell growth, suggesting their downstream pathways are involved in anchorage independence.

Purpose of the Study:

  • To investigate the role of integrin signaling in mediating anchorage-independent cell growth.
  • To examine the effects of oncogenes (dbl and lbc) and serum on cell growth and signaling pathways.
  • To determine if the small GTPase Rho mediates integrin signal transduction.

Main Methods:

  • Studied the effects of serum and Rho nucleotide exchange factor oncogenes (dbl, lbc) on cell growth.
  • Analyzed signaling pathways downstream of integrins.
  • Investigated the role of the small GTPase Rho in integrin signal transduction.

Main Results:

  • Oncogenes dbl and lbc induced anchorage-independent but serum-dependent cell growth.
  • These oncogenes also stimulated key signaling pathways.
  • Data indicate that constitutive activation of integrin-dependent signaling events drives anchorage-independent growth.

Conclusions:

  • Anchorage-independent growth in tumor cells results from the constitutive activation of integrin-dependent signaling.
  • The small GTPase Rho is a functionally significant mediator of integrin signaling.
  • These findings provide insights into cancer progression and potential therapeutic targets.

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