PTEN/MMAC1/TEP1 suppresses the tumorigenicity and induces G1 cell cycle arrest in human glioblastoma cells

Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15406-11. doi: 10.1073/pnas.95.26.15406.

Abstract

PTEN/MMAC1/TEP1 is a tumor suppressor that possesses intrinsic phosphatase activity. Deletions or mutations of its encoding gene are associated with a variety of human cancers. However, very little is known about the molecular mechanisms by which this important tumor suppressor regulates cell growth. Here, we show that PTEN expression potently suppressed the growth and tumorigenicity of human glioblastoma U87MG cells. The growth suppression activity of PTEN was mediated by its ability to block cell cycle progression in the G1 phase. Such an arrest correlated with a significant increase of the cell cycle kinase inhibitor p27(KIP1) and a concomitant decrease in the activities of the G1 cyclin-dependent kinases. PTEN expression also led to the inhibition of Akt/protein kinase B, a serine-threonine kinase activated by the phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway. In addition, the effect of PTEN on p27(KIP1) and the cell cycle can be mimicked by treatment of U87MG cells with LY294002, a selective inhibitor of PI 3-kinase. Taken together, our studies suggest that the PTEN tumor suppressor modulates G1 cell cycle progression through negatively regulating the PI 3-kinase/Akt signaling pathway, and one critical target of this signaling process is the cyclin-dependent kinase inhibitor p27(KIP1).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies
  • Cell Cycle / drug effects
  • Cell Cycle / genetics*
  • Cell Cycle Proteins*
  • Cell Division
  • Chromones / pharmacology
  • Cyclin-Dependent Kinase Inhibitor p27
  • Cyclin-Dependent Kinases / antagonists & inhibitors
  • Enzyme Inhibitors / pharmacology
  • G1 Phase
  • Genes, Tumor Suppressor*
  • Humans
  • Kinetics
  • Mice
  • Mice, Nude
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Molecular Sequence Data
  • Morpholines / pharmacology
  • Neuroblastoma / genetics*
  • Neuroblastoma / pathology*
  • PTEN Phosphohydrolase
  • Peptide Fragments / chemistry
  • Peptide Fragments / immunology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoric Monoester Hydrolases / chemistry
  • Phosphoric Monoester Hydrolases / genetics*
  • Phosphoric Monoester Hydrolases / metabolism*
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt
  • Signal Transduction
  • Transplantation, Heterologous
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins*

Substances

  • Antibodies
  • Cdkn1b protein, mouse
  • Cell Cycle Proteins
  • Chromones
  • Enzyme Inhibitors
  • Microtubule-Associated Proteins
  • Morpholines
  • Peptide Fragments
  • Proto-Oncogene Proteins
  • Tumor Suppressor Proteins
  • Cyclin-Dependent Kinase Inhibitor p27
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • AKT1 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Cyclin-Dependent Kinases
  • Phosphoric Monoester Hydrolases
  • PTEN Phosphohydrolase
  • PTEN protein, human