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The expression and function of the OGF-OGFr axis - a tonically active negative regulator of growth - in COS cells

Ian S Zagon1, Michael F Verderame, Patricia J McLaughlin

  • 1Department of Neuroscience and Anatomy, The Milton S. Hershey Medical Centre, College of Medicine, The Pennsylvania State University, 500 University Drive, Room C3729, Hershey, PA 17033, USA. iszl@psu.edu

Neuropeptides
|November 11, 2003
PubMed

Insights

The opioid growth factor (OGF) and its receptor (OGFr) are present and functional in COS-7 cells, regulating cell growth independently of classical opioid receptors. This OGF-OGFr axis influences cell proliferation in these cells.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Endocrinology

Background:

  • The opioid growth factor (OGF), [Met(5)]-enkephalin, and its receptor (OGFr) play roles in cell growth regulation.
  • Classical opioid receptors (mu, delta, kappa) are well-characterized, but the OGF-OGFr system's presence in cells lacking these is less understood.

Purpose of the Study:

  • To investigate the presence and function of the OGF-OGFr axis in COS-7 cells, which lack classical opioid receptors.
  • To determine if OGF influences COS-7 cell proliferation and if this effect is mediated by OGFr.

Main Methods:

  • Detection of OGF and OGFr mRNA using Northern blot and RT-PCR.
  • Characterization of OGFr binding in the nuclear fraction.
  • Immunocytochemistry to visualize OGF and OGFr.
  • Cell proliferation assays with OGF, naltrexone, and antisense OGFr oligonucleotides.

Main Results:

  • OGF and OGFr mRNA and proteins were detected in COS-7 cells.
  • Specific, saturable binding of OGFr was observed in the nuclear fraction.
  • OGF inhibited COS-7 cell growth, an effect blocked by naltrexone, indicating receptor mediation.
  • Antisense OGFr oligonucleotides significantly increased cell proliferation.

Conclusions:

  • The OGF-OGFr signaling axis is present and functionally active in COS-7 cells.
  • This axis regulates cell growth independently of classical opioid receptors.
  • The OGF-OGFr system represents a novel target for modulating cell proliferation.

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