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Analysis of Cell Cycle Position in Mammalian Cells
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Published on: January 21, 2012

Are p27 and p21 cytoplasmic oncoproteins?

Mikhail V Blagosklonny1

  • 1Brander Cancer Research Institute, 19 Bradhurst Ave, Suite 2400, Hawthorne, New York 10532, USA. M_Blagosklonny@NYMC.EDU

Cell Cycle (Georgetown, Tex.)
|January 28, 2003
PubMed

Insights

The Akt oncogenic kinase inactivates tumor suppressor proteins p27 and p21 by moving them to the cytoplasm. Evidence suggests these proteins may gain new antiapoptotic functions in the cytoplasm, acting as oncoproteins.

Area of Science:

  • Molecular Biology
  • Oncology
  • Cell Biology

Background:

  • The Akt oncogenic kinase plays a role in cell proliferation and survival.
  • Nuclear tumor suppressor proteins p27 and p21 regulate the cell cycle and apoptosis.
  • Mislocalization of tumor suppressors can contribute to cancer development.

Purpose of the Study:

  • To investigate the functional consequences of cytoplasmic mislocalization of p27 and p21.
  • To determine if cytoplasmic p27 and p21 acquire new functions.
  • To explore the potential antiapoptotic roles of cytoplasmic p27 and p21.

Main Methods:

  • The study likely involved cell-based assays to track protein localization.
  • Techniques such as Western blotting and immunofluorescence may have been used.
  • Functional assays assessing apoptosis and cell cycle progression were probably employed.

Main Results:

  • Akt oncogenic kinase induces cytoplasmic mislocalization of p27 and p21.
  • Cytoplasmic localization of p27 and p21 is associated with altered cellular functions.
  • Preliminary data suggest these cytoplasmic proteins exhibit antiapoptotic activities.

Conclusions:

  • Cytoplasmic mislocalization of p27 and p21 by Akt is not merely functional inactivation.
  • p27 and p21 may acquire oncogenic, antiapoptotic functions in the cytoplasm.
  • These findings highlight a novel mechanism in Akt-mediated oncogenesis.

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