second life as treatment for retrovirus correlated with prostate
cancer' and 'HIV Drugs Might Combat Two Other Diseases'
'HIV drugs could have second life as treatment for retrovirus
correlated with prostate cancer'- Scientific American
Apr 1, 2010 05:01 PM in Health & Medicine
By Katherine Harmon
Some medications already being used to treat HIV appear to inhibit a
retrovirus that has been linked to prostate cancer and chronic fatigue
syndrome, reports a new study published online April 1 in PLoS ONE.
Like HIV (human immunodeficiency virus), XMRV (xenotropic murine
leukemia virus-related virus) is a retrovirus that infects host cells
with its RNA through reverse transcriptase enzymes, using protease
enzymes to process proteins for viral assembly and integrase enzymes
to help infect the host cell's DNA. Many of the drugs approved to
treat HIV target one of these processes to slow or prevent host cells
from becoming infected.
After testing 28 approved drugs on XMRV cultures, researchers found
that four of the medications (raltegravir, L-000870812, Zidovudine
(AZT) and tenofovir disoproxil fumarate) were able to stop XMRV from
replicating. Two of the drugs are reverse transcriptase inhibitors,
and the others (including raltegravir, which worked the best) are
integrase enzyme inhibitors.
In addition to the similar success of the drugs' compounds, the
researchers found that the use of the antiretrovirals might do well to
follow HIV treatment protocol, in which multiple treatments are often
used together. "These drugs inhibited XMRV at lower concentrations
when two of them were used together, suggesting that highly potent
'cocktail' therapies might inhibit the virus from replicating and
spreading," Raymond Schinazi, a professor of pediatrics and chemistry
at Emory University's Center for AIDS Research, said in a prepared
statement. "This combination of therapies might also have the added
benefit of delaying or even preventing the virus from mutating into
forms that are drug-resistant."
XMRV is one of only a few retroviruses known in humans and was found
in 2006. Since then, some studies have found a correlation between it
and some forms of prostate cancer (which is the second most common
cancer among men) as well as chronic fatigue syndrome (estimated to
affect four to 10 people per thousand). Other studies have had mixed
results, so the implications of the results hinge largely on future
findings about this retrovirus's role in human disease. "It is not yet
clear if any illnesses are directly caused by XMRV," the researchers
wrote in their study. But "our data indicates that XMRV infections
might be prevented or treated with specific antiviral agents."
And if the retrovirus does prove to play a role in causing illnesses,
the findings could help in designing clinical trials to test the
treatments in vivo.
In the meantime, Ila Singh, an associate professor of pathology at the
University of Utah School of Medicine and lead author on the new
study, concluded in a prepared statement that, "These results offer
hope to infected persons."
'HIV Drugs Might Combat Two Other Diseases'
Prostate cancer, chronic fatique are new research targets
-- Robert Preidt
THURSDAY, April 1 (HealthDay News) -- Four anti-HIV drugs inhibit a
retrovirus recently linked to prostate cancer and chronic fatigue
syndrome (CFS), say U.S. researchers.
If further investigation proves that the retrovirus xenotropic murine
leukemia virus-related virus (XMRV) causes prostate cancer or CFS,
these HIV drugs may be an effective treatment for the two conditions.
In this study, researchers from the University of Utah and Emory
University/Veterans Affair Medical Center tested how effectively 45
compounds used to treat HIV and other viral infections worked against
XMRV. Raltegravir was the most effective, and three other drugs --
L-00870812, zidovudine (ZDV or AZT), and tenofovir disoproxil fumarate
(TDF) -- also prevented XMRV replication.
"Our study showed that these drugs inhibited XMRV at lower
concentrations when two of them were used together, suggesting that
possible highly potent 'cocktail' therapies might inhibit the virus
from replicating and spreading," Raymond F. Schinazi, a professor of
pediatrics and chemistry and an investigator with the Center for AIDS
Research at the Emory University School of Medicine and the Atlanta
VA, said in a news release.
"This combination of therapies might also have the added benefit of
delaying or even preventing the virus from mutating into forms that
are drug-resistant," Schinazi added.
"These results offer hope to infected persons, but we are still at the
early stages of our understanding of the potential link between XMRV
and these diseases," Dr. Ila R. Singh, an associate professor of
pathology at the University of Utah Medical School, said in the news
The study was published April 1 in the journal PLoS One.
The U.S. Centers for Disease Control and Prevention outlines the
possible causes of chronic fatigue syndrome-
SOURCE: University of Utah Health Sciences, news release, April 1, 2010
Copyright @2010 HealthDay. All Rights Reserved.