N,N'-dinitrosopiperazine-mediated ezrin protein phosphorylation via activation of Rho kinase and protein kinase C is involved in metastasis of nasopharyngeal carcinoma 6-10B cells

J Biol Chem. 2011 Oct 21;286(42):36956-67. doi: 10.1074/jbc.M111.259234. Epub 2011 Aug 30.

Abstract

N,N'-Dinitrosopiperazine (DNP) is a carcinogen for nasopharyngeal carcinoma (NPC), which shows organ specificity to nasopharyngeal epithelium. Herein, we demonstrate that DNP induces fiber formation of NPC cells (6-10B) and also increases invasion and motility of 6-10B cells. DNP-mediated NPC metastasis also was confirmed in nude mice. Importantly, DNP induced the expression of phosphorylated ezrin (phos-ezrin) at threonine 567 (Thr-567) dose- and time-dependently but had no effect on the total ezrin expression at these concentrations. Furthermore, DNP-induced phos-ezrin expression was dependent on increased Rho kinase and protein kinase C (PKC) activity. DNP may activate Rho kinase through binding to its pleckstrin homology and may activate PKC through promoting its translocation to the plasma membrane in vivo. DNP-induced phos-ezrin was associated with induction of fiber growth in 6-10B cells. However, DNP could not induce motility and invasion of NPC cells containing ezrin mutated at Thr-567. Similarly, DNP could not induce motility and invasion of the cells containing siRNAs against Rho or PKC. These results indicate that DNP induces ezrin phosphorylation at Thr-567, increases motility and invasion of cells, and promotes tumor metastasis. DNP may be involved in NPC metastasis through regulation of ezrin phosphorylation at Thr-567.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogens / pharmacokinetics*
  • Carcinoma
  • Cell Line, Tumor
  • Cell Movement / drug effects*
  • Cytoskeletal Proteins / metabolism*
  • Female
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Nasopharyngeal Carcinoma
  • Nasopharyngeal Neoplasms / metabolism*
  • Nasopharyngeal Neoplasms / pathology
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Neoplasm Proteins / metabolism*
  • Neoplasm Transplantation
  • Nitrosamines / pharmacology*
  • Phosphorylation / drug effects
  • Protein Kinase C / metabolism*
  • Transplantation, Heterologous
  • rho-Associated Kinases / metabolism*

Substances

  • Carcinogens
  • Cytoskeletal Proteins
  • Neoplasm Proteins
  • Nitrosamines
  • ezrin
  • rho-Associated Kinases
  • Protein Kinase C
  • N,N'-dinitrosopiperazine