Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2002 Dec 6;277(49):47928-37. Epub 2002 Sep 25.

FOXO proteins regulate tumor necrosis factor-related apoptosis inducing ligand expression. Implications for PTEN mutation in prostate cancer.

Author information

  • 1Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

Abstract

Mutations in PTEN occur in 60-80% of prostate cancers and lead to a constitutive activation of the phosphatidylinositol 3-kinase pathway and a resultant loss of activity of the FOXO family of forkhead transcription factors FKHRL1 and FKHR. To provide insight into the role of PTEN mutations in prostate cancer, we used microarrays to identify genes regulated by FKHRL1 and FKHR in LAPC4 prostate carcinoma cells. These studies revealed that adenoviral overexpression of FKHRL1 and FKHR in the LAPC4 prostate cancer cell line resulted in apoptosis and induced the expression of many genes that affect cellular proliferation or survival. The expression of one of these FOXO-regulated genes, TRAIL, a pro-apoptotic member of the tumor necrosis factor family, was decreased in human metastatic prostate tumors. The altered expression of TRAIL in these tumors correlated directly with decreased PTEN expression and the resultant loss of FKHRL1 and FKHR activity. Analysis of the effects of FOXO proteins on the TRAIL promoter localized the FKHRL1 responsive element of the TRAIL promoter to nucleotides -138 to -121 and demonstrated that TRAIL is a direct target of FKHRL1. These findings suggest that the decreased activity of FKHRL1 and FKHR in prostate cancers resulting from loss of PTEN leads to a decrease in TRAIL expression that may contribute to increased survival of the tumor cells.

PMID:
12351634
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire
    Loading ...
    Write to the Help Desk