Related Experiment Video

Updated: Jun 3, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
10:27

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells

Published on: March 9, 2012

Rap1-GTP-interacting adaptor molecule (RIAM) protein controls invasion and growth of melanoma cells

Pablo Hernández-Varas1, Georgina P Coló, Ruben A Bartolomé

  • 1Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, 28040 Madrid, Spain.

The Journal of Biological Chemistry
|April 2, 2011
PubMed

Insights

Rap1-GTP-interacting adaptor molecule (RIAM) is crucial for melanoma cell invasion and metastasis. Inhibiting RIAM in melanoma cells reduces tumor growth, migration, and increases apoptosis, suggesting RIAM as a therapeutic target.

Area of Science:

  • Oncology
  • Cell Biology
  • Molecular Biology

Background:

  • RIAM (Rap1-GTP-interacting adaptor molecule) is part of the Mig-10/RIAM/lamellipodin family.
  • RIAM interacts with active Rap1, a GTPase implicated in melanoma and prostate cancer.
  • RIAM is expressed in metastatic melanoma cells.

Purpose of the Study:

  • To investigate the role of RIAM in melanoma cell invasion, metastasis, and tumor growth.
  • To elucidate the molecular mechanisms underlying RIAM's function in melanoma.

Main Methods:

  • RIAM silencing in melanoma cells.
  • Severe combined immunodeficiency (SCID) xenograft models.
  • Analysis of cell migration, invasion, adhesion, proliferation, and apoptosis.
  • Western blotting to assess protein activation (Vav2, RhoA, Erk1/2, PI3K).

Main Results:

  • RIAM and Rap1 are essential for melanoma cell invasion.
  • RIAM silencing inhibited tumor growth and delayed metastasis in vivo.
  • RIAM depletion impaired cell migration directionality via the Vav2-RhoA-ROCK pathway.
  • RIAM silencing reduced β1 integrin-dependent adhesion, Erk1/2 MAPK, and PI3K activation.
  • RIAM-silenced cells showed reduced proliferation and increased apoptosis.

Conclusions:

  • RIAM plays a critical role in melanoma cell invasion, migration, and polarization.
  • RIAM influences melanoma cell adhesion, growth, and survival through integrin and kinase signaling pathways.
  • Targeting RIAM may offer a therapeutic strategy to inhibit melanoma progression and dissemination.

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