( Earlier this year researchers at the U...)Mechanism for Epstein-Barr virus protein's role in blood cancers discovered

Earlier this year, researchers at the University of Pennsylvania School of Medicine identified a link between a critical cancer pathway and an Epstein-Barr Virus (EBV) protein known to be expressed in a number of EBV-associated cancers. Their findings demonstrated a new mechanism by which EBV can transform human B cells from the immune system into cancerous cells, which can lead to B-cell lymphomas. Now, they have found that the viral protein--called EBNA3C (for EBV nuclear antigen)--mediates the degradation of the retinoblastoma protein, an important molecular brake for cell proliferation.

Erle S. Robertson, PhD, an Associate Professor of Microbiology who leads the Tumor Virology Program at Penn's Abramson Cancer Center, and MD/PhD student Jason Knight, published their results last week in the Proceedings of the National Academy of Sciences.

The retinoblastoma protein (Rb) is a major regulator of several genes in charge of cell proliferation and cell-cycle regulation. In the nucleus, Rb normally binds to E2F, turning off genes involved with cell proliferation. Using human cell cultures infected with the Epstein-Barr virus, the investigators found that EBNA3C recruits a group of molecules called the SCF complex, which attaches ubiquitin to Rb. This inadvertently tags Rb for degradation by the proteosome machinery, the cell's recycling plant. With Rb out of the way, the cell now reproduces uncontrollably.

"It's as simple as that, but it's a major mystery solved that many researchers have been working on for at least 15 years," says Robertson.

EBV, a member of the herpesvirus family and one of the most common human viruses, plays a role in cancers such as lymphoproliferative diseases in transplant or AIDS patients, Burkitt's lymphoma, Hodgkin's lymphoma, and nasopharyngeal carcinoma, and also causes the well-known disease infectious mononucleosis. As many as 95 percent of adults 20 years and older have been infected with EBV, but show
'"/>

Source:University of Pennsylvania School of Medicine

Page: 1 2
Related biology news :

1. Mechanism for the captation of nutrients in plants- unknown to date
2. Mechanism regulating tooth shape formulation found
3. Mechanism for memory revealed in neurons of electric fish
4. Mechanism identified for promising neurological drug
5. Mechanism for neurodenegerative diseases linked to transport proteins
6. Mechanisms involved with tumor relapse identified
7. Mechanism of nicotines learning effects explored
8. Epstein-Barr virus protein crucial to its role in blood cancers
9. U of T researchers map role of Epstein-Barr virus in cancer
10. Epstein-Barr virus may be associated with multiple sclerosis
11. Epstein-Barr virus might kick-start multiple sclerosis