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RhoC GTPase Activation Assay
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RhoC GTPase Activation Assay

Published on: August 22, 2010

Activated G(alpha)13 impairs cell invasiveness through p190RhoGAP-mediated inhibition of RhoA activity

Rubén A Bartolomé1, Natalia Wright, Isabel Molina-Ortiz

  • 1Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.

Cancer Research
|October 17, 2008
PubMed

Insights

Guanine nucleotide-binding protein G(13) (Gα13) signaling inhibits melanoma cell invasion and metastasis by activating p190RhoGAP, which suppresses RhoA. This pathway may be a therapeutic target for melanoma.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Heterotrimeric G(13) proteins regulate cell migration and invasion through downstream targets like RhoA.
  • RhoA activation is crucial for melanoma cell motility and metastasis.

Purpose of the Study:

  • To investigate the role of Gα13 signaling in melanoma cell invasion and metastasis.
  • To identify downstream mediators of Gα13-induced inhibition of RhoA activation and cell invasion.

Main Methods:

  • Expression of constitutively active Gα13 (Gα13QL) in human melanoma cells.
  • Lysophosphatidylcholine (LPC) stimulation of Gα13-coupled receptors.
  • Assessment of RhoA activation, p190RhoGAP activity, and cell invasion.
  • Gene knockdown of p190RhoGAP.
  • Analysis of stress fiber assembly, migration speed, and lung metastasis in SCID mice.

Main Results:

  • Gα13QL expression or LPC stimulation blocked chemokine-induced RhoA activation and melanoma cell invasion.
  • These inhibitory effects were rescued by active RhoA.
  • Gα13 signaling increased p190RhoGAP activation, and p190RhoGAP knockdown restored RhoA activation and invasion.
  • Gα13QL expression impaired stress fiber formation, reduced migration speed, inhibited lung metastasis, and prolonged survival in mice.

Conclusions:

  • Gα13 signaling inhibits melanoma cell invasion and metastasis via p190RhoGAP-mediated suppression of RhoA.
  • Cell type-specific GAP activity is critical for Gα13-dependent regulation of RhoA.
  • The Gα13-p190RhoGAP pathway represents a potential therapeutic target for melanoma metastasis.

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