Graduate student finds a 'start/stop switch' for retroviruses

Apr 08, 2010

A University of British Columbia doctoral candidate has discovered a previously unknown mechanism for silencing retroviruses, segments of genetic material that can lead to fatal mutations in a cell's DNA.

The findings, published today in the journal Nature, could lead to new cancer treatments that kill only and leave healthy surrounding tissue unharmed.

Danny Leung, a 27-year-old graduate student in the laboratory of Asst. Prof. Matthew Lorincz in the Dept. of , UBC Faculty of Medicine, found that a protein called ESET is crucial to preventing the activity of endogenous retroviruses in mouse . Distant relatives of such retroviruses are more active in the cells of testicular, breast and skin cancers in humans.

If ESET can be blocked, retroviruses would become dramatically more active, thus either killing the hosting them or flagging them as targets for the immune system.

Leung, who was co-lead author with a graduate student at Kyoto University in Japan, has devoted his studies at UBC to the growing field of epigenetics - changes to the genome that do not involve changes to the underlying . Such changes determine whether or not a gene is expressed.

The common method for silencing certain genes is DNA methylation, in which a chemical group attaches to the . But Leung and his collaborators at UBC and Kyoto University found that the activity of ESET is far more potent than DNA methylation in silencing retroviruses in embryonic stem cells of mice. This indicates an independent parallel pathway of silencing the retroviruses.

Their research has direct bearing on cancer treatments because cancer cells are stem-like - they can differentiate into other types of cells. Also, for unknown reasons, cancer cells have significantly less DNA methylation than normal cells. So blocking ESET holds the promise of affecting only cancer cells, allowing retroviruses to flourish to the detriment of their hosts. Normal, differentiated cells, which still have to keep retroviruses in check, would be unaffected.

"Inhibiting ESET may affect just the cancer cells, allowing further expression of retroviruses, which in turn would kill the cancer cells," says Leung, who is in his third year of graduate studies at UBC. His co-lead author on the paper, Toshiyuki Matsui, is a student in the lab of Yoichi Shinkai at Kyoto University.

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El_Nose
5 / 5 (1) Apr 08, 2010
At the risk of sounding like a troll - its a great piece of research -- but reminds me of recent zombie movies like legend -- the retroviri multiply in the cell and while they kill the cell they rupture it and attack all the other cells in the body with numbers greater than anything encountered in the past killing not only the first host cell but the entire host being the human - all of mankind perishes 10 days later
gunslingor1
5 / 5 (1) Apr 08, 2010
BRAAAAAAAAAAAAIIIIIIIIINNNNNNNNNNNNNNNSS!!

BBBBBBBBBRRRRRRRAAAAAAAAAAAAAAAAAAIIIINNNNNNNNNNNNNNNNNNSSSSSSSSSSSSSS!
GregHight
not rated yet Apr 08, 2010
Now that you mention it, Legend was about a cancer cure gone wrong... "Caution: Zombies Ahead.."

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