The detection of EBP50 expression using quantum dot immunohistochemistry in pancreatic cancer tissue and down-regulated EBP50 effect on PC-2 cells

J Mol Histol. 2012 Oct;43(5):517-26. doi: 10.1007/s10735-012-9424-0. Epub 2012 May 24.

Abstract

Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) is a putative tumor suppressor that is correlated with many human cancers. However, the function of EBP50 in pancreatic cancer (PC) has not been described. In this paper, the EBP50 expression level in PC tissues was characterized. In vitro, the effects of EBP50 down-regulation by siRNA in PC-2 and MiaPaCa-2 cells were evaluated. In addition, possible mechanisms that mediate the influence of EBP50 were examined. Our results show that the EBP50 expression pattern changes during transformation as there is a loss of the normal apical membrane distribution and an ectopic cytoplasmic over-expression of EBP50; furthermore, the EBP50 expression level is subsequently decreased during malignant progression. Down-regulation of EBP50 promoted cancer cell proliferation, increased the colony-forming ability of cells and accelerated the G1-to-S progression. Additionally, the loss of EBP50 accentuated β-catenin activity, increased cyclin E and phosphorylated Rb expression, and attenuated p27 expression compared to control cells. Our results suggest that EBP50 may function as a potential tumor suppressor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation*
  • Cell Transformation, Neoplastic / metabolism*
  • Cyclin E / metabolism
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Pancreatic Neoplasms* / metabolism
  • Pancreatic Neoplasms* / pathology
  • Phosphoproteins* / genetics
  • Phosphoproteins* / metabolism
  • Proliferating Cell Nuclear Antigen / metabolism
  • Quantum Dots
  • RNA, Small Interfering
  • Sodium-Hydrogen Exchangers* / genetics
  • Sodium-Hydrogen Exchangers* / metabolism
  • beta Catenin / metabolism

Substances

  • Cyclin E
  • Phosphoproteins
  • Proliferating Cell Nuclear Antigen
  • RNA, Small Interfering
  • Sodium-Hydrogen Exchangers
  • beta Catenin
  • p27 antigen
  • sodium-hydrogen exchanger regulatory factor