Ezrin mediates c-Myc actions in prostate cancer cell invasion

Oncogene. 2010 Mar 11;29(10):1531-42. doi: 10.1038/onc.2009.442. Epub 2009 Dec 14.

Abstract

The forced overexpression of c-Myc in mouse prostate and in normal human prostate epithelial cells results in tumor transformation with an invasive phenotype. How c-Myc regulates cell invasion is poorly understood. In this study, we have investigated the interplay of c-Myc and androgens in the regulation of prostate cancer cell invasion. We found that c-Myc induces cell invasion and anchorage-independent growth by regulating ezrin protein expression in the presence of androgens. The activity of the ezrin promoter is controlled by androgens through c-Myc, which binds to a phylogenetically conserved E-Box located in the proximal promoter region. Besides, we also show that ezrin is an important regulator of c-Myc protein levels. These effects are achieved through androgen-induced changes in ezrin phosphorylation, which results in the regulation of downstream signals. These downstream signals involve the modulation of Akt and GSK-3beta activity resulting in increased c-Myc protein synthesis and inhibition of its degradation. In summary, we have shown a key role for ezrin as a mediator of c-Myc-induced tumorigenesis in prostate cancer cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites / genetics
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Movement*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Humans
  • Male
  • Metribolone / pharmacology
  • Neoplasm Invasiveness
  • Phosphorylation
  • Promoter Regions, Genetic / genetics
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Protein Binding
  • Proto-Oncogene Proteins c-akt / metabolism
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Cytoskeletal Proteins
  • Proto-Oncogene Proteins c-myc
  • ezrin
  • Metribolone
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3