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Affinity Labeling Detection of Endogenous Receptors from Zebrafish Embryos
08:39

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Published on: August 31, 2016

Intracellular association of a mutant insulin-like growth factor receptor with endogenous receptors

K Reiss1, X Tu, G Romano

  • 1Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|July 13, 2001
PubMed

Insights

A mutant insulin-like growth factor receptor (IGF-IR), 486/STOP, induces apoptosis in tumor cells. This study reveals its mechanism involves intracellular interaction with endogenous IGF-IRs after cellular uptake.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Type 1 insulin-like growth factor receptor (IGF-IR) acts as a survival factor.
  • A mutant IGF-IR (486/STOP) inhibits human tumor cell growth and induces apoptosis.
  • Understanding the mechanism of 486/STOP is crucial for cancer therapy development.

Purpose of the Study:

  • To investigate the mechanism of action of the mutant IGF-IR 486/STOP.
  • To elucidate how 486/STOP induces apoptosis and inhibits tumor cell growth.

Main Methods:

  • Development of a novel retroviral vector combining a self-inactivating 5'-long terminal repeat with an inducible heat-shock promoter (heat shock protein 70) from Drosophila.
  • Analysis of 486/STOP polypeptide localization (intracellular retention and secretion).
  • Coimmunoprecipitation to demonstrate intracellular interaction with endogenous IGF-IRs.

Main Results:

  • The 486/STOP polypeptide is both retained intracellularly and secreted.
  • Secreted 486/STOP is subsequently taken up by cells.
  • Specific intracellular interaction between 486/STOP and endogenous IGF-IRs was confirmed.

Conclusions:

  • The mutant IGF-IR 486/STOP exerts its pro-apoptotic effects through intracellular interaction with endogenous IGF-IRs.
  • Cellular uptake of secreted 486/STOP contributes to its mechanism of action.
  • This research provides insights into targeting IGF-IR signaling for cancer treatment.

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