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Suppression of Ras-mediated NIH3T3 transformation by p19ARF does not involve alterations of cell growth properties

V Calabrò1, T Parisi, A Di Cristofano

  • 1Department of Genetics, General and Molecular Biology, University of Naples Federico II, Italy.

Oncogene
|May 13, 1999
PubMed

Insights

The p19ARF protein inhibits cell proliferation and oncogene-mediated transformation. This tumor suppressor function is mediated by its amino-terminal domain and is effective even without affecting cell growth.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Biology

Background:

  • The INK4a gene produces two tumor suppressors: p16INK4a and p19ARF.
  • p16INK4a acts in the Rb pathway, while p19ARF relates to p53.
  • INK4a gene disruptions are common in human cancers, and p19ARF deficiency leads to early tumor development.

Purpose of the Study:

  • To investigate the role of p19ARF in inhibiting cell proliferation and oncogene-induced transformation.
  • To determine if p19ARF's amino-terminal domain is sufficient for its tumor-suppressive activity.
  • To assess p19ARF's impact on cell growth and transformation mediated by Ras.

Main Methods:

  • Transfection of human and mouse cell lines with p19ARF.
  • Analysis of colony formation in G418-resistant cells.
  • Cotransfection of NIH3T3 cells with p19ARF and activated Ras.
  • Isolation of stable NIH3T3 transfectants expressing p19ARF.

Main Results:

  • p19ARF inhibited colony formation in cells with wild-type p53, irrespective of p16 status.
  • The amino-terminal domain of p19ARF was sufficient for this inhibitory effect.
  • p19ARF potently inhibited Ras-mediated transformation in NIH3T3 cells in a dose-dependent manner.
  • Stable p19ARF expression did not significantly affect NIH3T3 cell growth.

Conclusions:

  • p19ARF functions as a tumor suppressor by inhibiting cell proliferation.
  • p19ARF interferes with oncogene-induced cellular transformation.
  • The amino-terminal domain of p19ARF is critical for its anti-transformation activity.

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