EBP50 exerts tumor suppressor activity by promoting cell apoptosis and retarding extracellular signal-regulated kinase activity

Amino Acids. 2010 Apr;38(4):1261-8. doi: 10.1007/s00726-009-0437-2. Epub 2009 Dec 11.


The expression of Ezrin-radixin-moesin-binding phosphoprotein-50 (EBP50) and the intragenic mutation of the ebp50 gene have been reported to correlate with human breast cancer development, but the exact impacts on breast cancer development and its molecular mechanism are not fully understood. In this study, we investigate the potential function of EBP50 through over-expression in the breast cancer cell line, MDA-MB-231, which has low EBP50 protein expression levels. The effects of EBP50 over-expression on cellular proliferation, anchorage-independent growth and apoptosis were examined. In addition, the activity of extracellular signal-regulated kinase (ERK) was also determined. Our results show that a decrease of cellular proliferation and attenuation of colony-forming ability were evident in MDA-MB-231 cells stably transfected with an EBP50 expressing plasmid (EBP-231) when compared with control cells. There was also a statistically significant increase in spontaneous apoptosis in EBP-231 cells accompanied by an attenuation in ERK activity. Altogether, our results suggest that restoring EBP50 expression could suppress breast cancer cell proliferation by promoting cell apoptosis and inhibiting ERK activity, and that EBP50 may be a target for development of diagnostics and therapeutics in breast cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Cell Adhesion
  • Cell Cycle / genetics
  • Cell Line, Tumor
  • Cell Proliferation
  • Down-Regulation
  • Enzyme Activation
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Female
  • Gene Expression
  • Humans
  • Mutation
  • Phosphoproteins / biosynthesis
  • Phosphoproteins / genetics*
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Sodium-Hydrogen Exchangers / biosynthesis
  • Sodium-Hydrogen Exchangers / genetics*
  • Time Factors
  • Transfection
  • Tumor Stem Cell Assay
  • Tumor Suppressor Proteins / biosynthesis
  • Tumor Suppressor Proteins / genetics*


  • Phosphoproteins
  • Sodium-Hydrogen Exchangers
  • Tumor Suppressor Proteins
  • sodium-hydrogen exchanger regulatory factor
  • Extracellular Signal-Regulated MAP Kinases