Researchers reveal Epstein-Barr virus protein contributes to cancer

Oct 03, 2008

Researchers at the University of Toronto have shown that the EBNA1 protein of Epstein-Barr virus (EBV) disrupts structures in the nucleus of nasopharyngeal carcinoma (NPC) cells, thereby interfering with cellular processes that normally prevent cancer development. The study, published October 3rd in the open-access journal PLoS Pathogens, describes a novel mechanism by which viral proteins contribute to carcinogenesis.

EBV is a common herpesvirus whose latent infection is strongly associated with several types of cancer including NPC, a tumor that is endemic in several parts of the world. With NPC only a few EBV proteins are expressed, including EBNA1. EBNA1 is required for the persistence of the EBV genomes, however, whether or not EBNA1 directly contributes to the development of tumors has not been clear, until now.

In this study Frappier and her team examined PML nuclear bodies and proteins in EBV-positive and EBV-negative NPC cells. Manipulation of EBNA1 levels in each cell type clearly showed that EBNA1 expression induces the loss of PML proteins and PML nuclear bodies through an association of EBNA1 with the PML bodies. PML nuclear bodies are known to have tumor-suppressive effects due to their roles in regulating DNA repair and programmed cell death, and accordingly, EBNA1 was shown to interfere with these processes.

The researchers conclude that there is "an important role for EBNA1 in the development of NPC, in which EBNA1-mediated disruption of PML nuclear bodies promotes the survival of cells with DNA damage." Since EBNA1 is expressed in all EBV-associated tumors, including B-cell lymphomas and gastric carcinoma, these findings raise the possibility that EBNA1 could play a similar role in the development of these cancers. The cellular effects of EBNA1 in other EBV-induced cancers will require further investigation.

Citation: Sivachandran N, Sarkari F, Frappier L (2008) Epstein-Barr Nuclear Antigen 1 Contributes to Nasopharyngeal Carcinoma through Disruption of PML Nuclear Bodies. PLoS Pathog 4(10): e1000170. doi:10.1371/journal.ppat.1000170 www.plospathogens.org/doi/ppat.1000170

Source: Public Library of Science

Explore further: Overweight linked to 500,000 cancer cases per year

add to favorites email to friend print save as pdf

Related Stories

Rosetta Comet Landing in 'Thud' and 3D

43 minutes ago

(Phys.org) —A 3D image shows what it would look like to fly over the surface of comet 67P/Churyumov-Gerasimenko. The image was generated from data collected by the Rosetta Lander Imaging System (ROLIS) ...

Redbox raising DVD rental rates by 25 percent

59 minutes ago

Redbox is raising its DVD rental prices by 25 percent beginning next week in an effort to wring more revenue from the shrinking audience that still watches movies on the discs instead of Internet video services such as Netflix.

US northeast braces for flooding after record snow

22 hours ago

Weather forecasters and emergency officials warned Sunday that melting snow would lead to heavy flooding in parts of the US northeast, with hundreds of thousands of people told to brace for fast-rising waters.

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.