Featured Research

from universities, journals, and other organizations

Scientists Clear Hurdle In Effort To Destroy Experimental Brain Cancers With Viruses

Date:
July 30, 1999
Source:
Harvard Medical School
Summary:
Teaming tumor-attacking viruses with an approved chemotherapeutic drug may be more effective than either agent alone for treating multi-site brain cancers, reports a team of Massachusetts General Hospital and Harvard Medical School researchers. The findings may advance efforts to treat difficult brain cancers and may shed light on the blood-tumor-brain barrier mystery.

Curbing immune system's antiviral response allows anticancer agent to reach, attack brain tumors

Related Articles


BOSTON--Teaming tumor-attacking viruses with an approved chemotherapeutic drug may be more effective than either agent alone for treating multi-site brain cancers, reports a team of Massachusetts General Hospital and Harvard Medical School researchers. The findings may advance efforts to treat difficult brain cancers and may shed light on the blood-tumor-brain barrier mystery.

Antonio Chiocca, Harvard Medical School associate professor of surgery at Massachusetts General Hospital and his collaborators found that the drug cyclophosphamide suppressed the immune system's antiviral response. Inhibiting this response allowed a modified strain of herpes simplex virus to reach the brain tumors, enabling it to attack--and in some cases destroy--the tumors. The study is published in the August Nature Medicine.

"This treatment is more efficient than anything we have done before," says Chiocca, who led the study. "By suppressing the antiviral immune mechanism, we were able to deliver into the brain a virus that selectively killed malignant cells but not normal, healthy cells." The researchers hope that their findings will lead to a brain cancer treatment that involves injecting a tumor-specific virus into the patient's bloodstream in a procedure resembling angiography. The study was conducted in rats implanted with human tumors.

Brain cancer typically is aggressive--it often results in multiple tumors that neither the surgeon, radiation, nor chemotherapy can remove--and is quite deadly. Most people diagnosed with malignant glioma, for example, die within a year.

The idea of using oncolytic, or cancer-killing, viruses dates back almost a century, when researchers injected rabies virus into cervical cancer. It was sidelined by the advent of chemotherapy agents in the 1960s but re-emerged in the 1990s.

Past efforts to develop viral therapies for cancers often failed due to the immune system's antiviral response. Viruses that destroyed cultured tumor cells were ineffective when injected into animal models. Chiocca and his colleagues found that part of this antiviral response in rats was the result of an interaction between complement, a well-known group of enzymes, and IgM, or antibodies that course through the body even in the absence of any particular pathogen. Chiocca says that other factors are probably involved in this response. The researchers discovered that cyclophosphamide, which can prevent the production of antibodies, could suppress this antiviral mechanism. Chiocca's group found that one dose of cyclophosphamide inhibited IgM and complement function and allowed for increased survival of the virus in the tumors. The drug also lowered antiviral activity in human plasma samples.

Though Chiocca cannot predict whether these results could hold up in the clinic, he says the virus's performance in this severe model of brain cancer makes him hopeful. "This is the first time, to my knowledge, that someone has effectively infected three large tumors in a rat brain with this virus through the vasculature and caused all three to shrink," he says. A small percentage of animals even survived long term with the tumors gone--and this in a model in which all untreated rats die within two weeks of having the tumors implanted.

###

The research was funded in part by the National Institutes of Health.


Story Source:

The above story is based on materials provided by Harvard Medical School. Note: Materials may be edited for content and length.


Cite This Page:

Harvard Medical School. "Scientists Clear Hurdle In Effort To Destroy Experimental Brain Cancers With Viruses." ScienceDaily. ScienceDaily, 30 July 1999. <www.sciencedaily.com/releases/1999/07/990730073615.htm>.
Harvard Medical School. (1999, July 30). Scientists Clear Hurdle In Effort To Destroy Experimental Brain Cancers With Viruses. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/1999/07/990730073615.htm
Harvard Medical School. "Scientists Clear Hurdle In Effort To Destroy Experimental Brain Cancers With Viruses." ScienceDaily. www.sciencedaily.com/releases/1999/07/990730073615.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. Video provided by Newsy
Powered by NewsLook.com
WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins