(Press-News.org) You might not know it, but most of us are infected with the herpesvirus known as Epstein-Barr virus (EBV). For most of us, the virus will lead at worst to a case of infectious mononucleosis, but sometimes, and especially in some parts of the world, those viruses are found in association with cancer. Now, researchers reporting in the Cell Press journal Cell Reports on October 10 have found that the difference between a relatively harmless infection and a cancer-causing one lies at least partly in the viral strain itself.
The results offer some of the first evidence for the existence of distinct EBV subtypes with very different public health risks. The researchers say that vaccination or other strategies for preventing EBV infection will need to be designed with these most pathogenic, cancer-causing strains in mind.
"EBV is an important but neglected pathogen," said Henri-Jacques Delecluse of the German Cancer Research Centre in Heidelberg, Germany. "We have made an important step in recognizing that EBV is actually a family of viruses that have different properties, some of which are very likely to cause disease. So, the consequences of being infected with EBV might be different, depending on the strain one carries."
Delecluse and his colleagues made the discovery by sequencing the DNA of a viral strain dubbed M81 isolated from a Chinese patient with nasopharyngeal carcinoma (NPC). Their analyses revealed that M81 is highly similar to other viruses isolated from NPCs and profoundly different from Western strains in terms of its ability to infect and replicate within cells.
The M81 strain can infect epithelial cells and multiply spontaneously at a very high level in all cells it infects, including B lymphocytes, the cells in which the viruses hide, the researchers report. It remains to be seen exactly how infected epithelial cells become cancerous.
"Our results have made me radically change my strategy to address the problem of EBV-associated diseases," Delecluse said. "The current view is that the virus is essentially the same all over the world and that local conditions explain the different consequences of EBV infection. We now show that the type of EBV also plays an important role. By concentrating on the potentially pathogenic EBV strains, we will soon better understand how EBV causes diseases, and this will also help [in] designing prevention strategies."
INFORMATION:
Cell Reports, Tsai et al.: "Spontaneous lytic replication and epitheliotropism define an Epstein-Barr virus strain found in carcinomas."
How a ubiquitous herpesvirus sometimes leads to cancer
2013-10-10
ELSE PRESS RELEASES FROM THIS DATE:
Previously unstudied gene is essential for normal nerve development
2013-10-10
October 10, 2013 – (BRONX, NY) – Our ability to detect heat, touch, tickling and other sensations depends on our sensory nerves. Now, for the first time, researchers at Albert Einstein College of Medicine of Yeshiva University have identified a gene that orchestrates the crucially important branching of nerve fibers that occurs during development. The findings were published online today in the journal Cell.
The research focuses on dendrites, the string-like extensions of sensory nerves that penetrate tissues of the skin, eyes and other sensory organs. "The formation ...
A genetic variation that could protect skin from sun damage fuels testicular cancer
2013-10-10
October 10, 2013, New York, NY and Oxford, UK – A Ludwig Cancer Research study published in Cell today identifies a common mutation that dramatically increases the risk for testicular cancer—and describes a likely molecular mechanism by which it exerts that effect. The researchers also suggest why, despite its potential lethality, the genetic variation has been favored by natural selection to become common in light-skinned people. It appears this mutation might aid the tanning of Caucasian skin in response to sunlight, protecting it from UV radiation, which can burn and ...
Overweight and obese children face high risk of hypertension
2013-10-10
High body weight in children and adolescents is strongly associated with the likelihood of hypertension, according to a Kaiser Permanente Southern California study published today in The Journal of Clinical Hypertension.
Researchers found that young people who are overweight are twice as likely as their normal-weight peers to have hypertension; moderately obese youths have four times higher risk; and extremely obese children and adolescents are 10 times more likely to have hypertension. The study also found 10 percent of youths who are extremely obese have hypertension ...
Nobel Prize winner reports new model for neurotransmitter release
2013-10-10
In a Neuron article published online October 10th, recent Nobel Laureate Thomas C. Südhof challenges long-standing ideas on how neurotransmitter gets released at neuronal synapses. On October 7th, Südhof won the Nobel Prize in Physiology or Medicine, alongside James Rothman and Randy Schekman, for related work on how vesicles—such as those in neurons that contain neurotransmitter—are transported within cells.
Neurotransmitter-containing vesicles are found inside neurons very close to the end of the axon. Here, they can quickly fuse with the neuronal membrane surrounding ...
Researchers identify liver cancer progenitor cells before tumors become visible
2013-10-10
For the first time, researchers at the University of California, San Diego School of Medicine have isolated and characterized the progenitor cells that eventually give rise to malignant hepatocellular carcinoma (HCC) tumors – the most common form of liver cancer. The researchers found ways to identify and isolate the HCC progenitor cells (HcPC) long before actual tumors were apparent.
Writing in the October 10, 2013 issue of the journal Cell, principal investigator Michael Karin, PhD, Distinguished Professor of Pharmacology and Pathology, and colleagues report that HcPC ...
Stomach cells naturally revert to stem cells
2013-10-10
New research has shown that the stomach naturally produces more stem cells than previously realized, likely for repair of injuries from infections, digestive fluids and the foods we eat.
Stem cells can make multiple kinds of specialized cells, and scientists have been working for years to use that ability to repair injuries throughout the body. But causing specialized adult cells to revert to stem cells and work on repairs has been challenging.
Scientists from Washington University School of Medicine in St. Louis and Utrecht Medical Center in the Netherlands report ...
Eat more, weigh less: Worm study provides clues to better fat-loss therapies for humans
2013-10-10
LA JOLLA, CA—October 10, 2013 —Scientists at The Scripps Research Institute (TSRI) have discovered key details of a brain-to-body signaling circuit that enables roundworms to lose weight independently of food intake. The weight-loss circuit is activated by combined signals from the worm versions of the neurotransmitters serotonin and adrenaline, and there are reasons to suspect that it exists in a similar form in humans and other mammals.
"Boosting serotonin signaling has been seen as a viable strategy for weight loss in people, but our results hint that boosting serotonin ...
Stem cell breakthrough could set up future transplant therapies
2013-10-10
A new method for creating stem cells for the human liver and pancreas, which could enable both cell types to be grown in sufficient quantities for clinical use, has been developed by scientists.
Using the technique, researchers have for the first time been able to grow a pure, self-renewing population of stem cells specific to the human foregut, the upper section of the human digestive system.
These so-called "Foregut stem cells" could then be developed further to produce liver or pancreatic cells. The method significantly improves on existing techniques for cultivating ...
Soft shells and strange star clusters
2013-10-10
PGC 6240 is an elliptical galaxy that resembles a pale rose in the sky, with hazy shells of stars encircling a very bright centre. Some of these shells are packed close to the centre of the galaxy, while others are flung further out into space. Several wisps of material have been thrown so far that they appear to be almost detached from the galaxy altogether.
Astronomers have studied PGC 6240 in detail due to this structure, and also because of its surrounding globular clusters — dense, tightly packed groups of gravitationally bound stars that orbit galaxies. Over 150 ...
Direct 'writing' of artificial cell membranes on graphene
2013-10-10
Writing in Nature Communications, researchers at The University of Manchester led by Dr Aravind Vijayaraghavan, and Dr Michael Hirtz at the Karlsruhe Institute of Technology (KIT), have demonstrated that membranes can be directly 'written' on to a graphene surface using a technique known as Lipid Dip-Pen Nanolithography (L-DPN).
The human body contains 100 trillion cells, each of which is enveloped in a cell membrane which is essentially a phospholipid bi-layer membrane. These cell membranes have a plethora of proteins, ion channels and other molecules embedded in them, ...