PIKE-A is amplified in human cancers and prevents apoptosis by up-regulating Akt

Proc Natl Acad Sci U S A. 2004 May 4;101(18):6993-8. doi: 10.1073/pnas.0400921101. Epub 2004 Apr 26.

Abstract

PIKE-A (PIKE-activating Akt), an isoform of PIKE GTPase that enhances phosphatidylinositol 3-kinase (PI3-kinase) activity, specifically binds to active Akt but not PI3-kinase. PIKE-A stimulates Akt activity in a GTP-dependent manner and promotes invasiveness of cancer cell lines. Here, we show that PIKE-A is amplified in a variety of human cancers and that amplified PIKE-A directly stimulates Akt and inhibits apoptosis compared to cells with normal PIKE-A copy number. Overexpression of PIKE-A wild-type but not dominant-negative mutant stimulates Akt activity and prevents apoptosis. Moreover, knockdown of PIKE-A diminishes Akt activity and increases apoptosis. Our findings suggest that PIKE-A amplification contributes to cancer cell survival and progression by inhibiting apoptosis through up-regulating Akt.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • GTP-Binding Proteins / metabolism*
  • GTPase-Activating Proteins / metabolism*
  • Gene Amplification
  • Gene Dosage
  • Humans
  • Neoplasms / metabolism*
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt
  • Tumor Cells, Cultured
  • Up-Regulation*

Substances

  • GTPase-Activating Proteins
  • Proto-Oncogene Proteins
  • AKT1 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • AGAP2 protein, human
  • GTP-Binding Proteins