Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mechanism for Epstein-Barr virus protein’s role in blood cancers discovered

27.12.2005


Implications for new therapeutic targets for B cell lymphomas and other EBV-associated illnesses



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 no symptoms.

Now, the researchers are in the process of blocking the molecular signals caused by EBNA3C’s presence in B cells. This points the way to a possible drug for EBV-related cancers. "Stopping this step in the life cycle of EBV could be a major potential target for the development of therapeutics for treating EBV-related B cell lymphomas," says Robertson. "This is especially important because a large percentage of patients are non-responsive to the current frontline drug for treating B cell lymphoma, a CD20 monoclonal antibody." The researchers surmise that the first use of future therapies from these studies could be in lymphoproliferative disease in transplant and immunocompromised patients.

Karen Kreeger | EurekAlert!
Further information:
http://www.uphs.upenn.edu

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>