Related Experiment Video

Updated: Nov 9, 2025

RhoC GTPase Activation Assay
09:58

RhoC GTPase Activation Assay

Published on: August 22, 2010

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Nanobody-Based Quantification of GTP-Bound RHO Conformation Reveals RHOA and RHOC Activation Independent from Their

Laura Keller1,2, Claudine Tardy1, Laetitia Ligat3

  • 1Centre de Recherche en Cancérologie de Toulouse (CRCT), INSERM, Université de Toulouse, CNRS, UPS, Toulouse 31037, France.

Analytical Chemistry
|April 7, 2021
PubMed

Insights

Researchers developed a new assay to measure active RHO GTPase proteins in human tumors. This study found increased RHOA and RHOC activity in breast tumors, independent of their expression levels.

Area of Science:

  • Molecular biology
  • Cell biology
  • Biochemistry

Background:

  • RHO GTPases regulate the actin cytoskeleton and are implicated in cancer progression.
  • Previous studies primarily used cell lines, with limited investigation of RHO protein activity in human tumors.
  • Quantifying active RHO GTPases directly in tumor samples is crucial for understanding their role in tumorigenesis.

Purpose of the Study:

  • To develop a robust assay for quantifying active RHO GTPase states in human tumor samples.
  • To investigate the activity levels of RHOA and RHOC GTPases in human breast tumor samples.
  • To determine the relationship between RHO GTPase activity and expression in different breast cancer subtypes.

Main Methods:

  • Development of a nanobody-based ELISA assay for selective quantification of GTP-bound RHO proteins.
  • Application of the assay to analyze RHOA-GTP and RHOC-GTP levels in human breast tumor and normal tissue samples.
  • Comparison of RHO GTPase activity and expression levels across various breast cancer subtypes.

Main Results:

  • The developed nanobody-based ELISA assay accurately quantifies active RHO proteins in the nanomolar range.
  • GTP-bound RHOA and RHOC protein activities were significantly increased in human breast tumors compared to normal tissues.
  • RHO GTPase active state and RHO expression were found to be independent parameters in different breast cancer subtypes.

Conclusions:

  • The nanobody-based ELISA assay is a valuable tool for studying RHO GTPase activity in human tumors.
  • Elevated RHOA and RHOC activity are associated with breast tumorigenesis.
  • Direct measurement of RHO GTPase activity provides insights into their role in cancer, independent of expression levels.

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