Recombinant adeno-associated virus mediated RNA interference inhibits metastasis of nasopharyngeal cancer cells in vivo and in vitro by suppression of Epstein-Barr virus encoded LMP-1

Int J Oncol. 2006 Sep;29(3):595-603.


Nasopharyngeal carcinoma (NPC) is a highly metastatic carcinoma characterized by consistent association with Epstein-Barr virus (EBV). Of the EBV-encoded product, latent membrane protein-1 (LMP-1) is considered to be an onco-protein playing an essential role in cell transformation and metastasis. In this study, we used a recombinant adeno-associated virus type 2 vector (rAAV-2) to deliver small hairpin RNA (shRNA) targeting EBV LMP-1 into the EBV-positive human NPC C666-1 cells and evaluated the effect of long-term suppression of LMP-1 on NPC growth and metastasis in vivo and in vitro. An NPC metastasis nude mouse model with NPC xenograft transplanted in liver was established. The NPC C666-1 cells infected with rAAV-shRNA-LMP-1 or rAAV-EGFP were inoculated in the livers of nude mice. Formation of liver and lung metastasis was evaluated at day 14 after tumor inoculation. Our results demonstrate that rAAV-shRNA-LMP-1 effectively infected C666-1 cells and suppressed LMP-1 expression. Such suppression, in turn, did not significantly inhibit tumor growth, but prevented NPC metastasis in the liver as well as in the lung. Consistent with in vivo data, the in vitro studies in NPC C666-1 cell cultures showed that suppression of LMP-1 by rAAV-shRNA-LMP-1 significantly reduced cell mobility and transmembrane invasion ability. These results demonstrated for the first time that long-term suppression of EBV-encoded LMP-1 in vivo is an effective means for preventing NPC metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dependovirus / genetics*
  • Down-Regulation
  • Epstein-Barr Virus Infections / genetics
  • Epstein-Barr Virus Infections / metabolism
  • Epstein-Barr Virus Infections / virology
  • Flow Cytometry
  • Gene Targeting
  • Genetic Vectors
  • Herpesvirus 4, Human / genetics
  • Herpesvirus 4, Human / isolation & purification
  • Humans
  • Immunoenzyme Techniques
  • In Vitro Techniques
  • Liver Neoplasms / prevention & control*
  • Liver Neoplasms / secondary
  • Liver Neoplasms / virology
  • Lung Neoplasms / prevention & control*
  • Lung Neoplasms / secondary
  • Lung Neoplasms / virology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Nasopharyngeal Neoplasms / pathology
  • Nasopharyngeal Neoplasms / prevention & control*
  • Nasopharyngeal Neoplasms / virology
  • Neoplasm Transplantation
  • RNA Interference*
  • RNA, Messenger / metabolism
  • Transplantation, Heterologous
  • Tumor Cells, Cultured
  • Viral Matrix Proteins / antagonists & inhibitors*
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / metabolism


  • EBV-associated membrane antigen, Epstein-Barr virus
  • RNA, Messenger
  • Viral Matrix Proteins