Featured Research

from universities, journals, and other organizations

Antiviral enzyme contributes to several forms of cancer

Date:
July 14, 2013
Source:
University of Minnesota
Summary:
Researchers have discovered that a human antiviral enzyme causes DNA mutations that lead to several forms of cancer.

Researchers at the University of Minnesota have discovered that a human antiviral enzyme causes DNA mutations that lead to several forms of cancer.

The discovery, reported in the July 14 issue of Nature Genetics, follows the team's earlier finding that the enzyme, called APOBEC3B, is responsible for more than half of breast cancer cases. The previous study was published in Nature in February.

APOBEC3B is part of a family of antiviral proteins that Harris has studied for more than a decade. His effort to understand how these proteins work has led to these surprising discoveries that APOBEC3B is a broadly important cancer mutagen.

"We are very excited about this discovery because it indicates that a single enzyme is one of the largest known contributors to cancer mutation, possibly even eclipsing sources such as UV rays from the sun and chemicals from smoking," says Reuben Harris, a professor of biochemistry, molecular biology and biophysics based in the College of Biological Sciences. Harris, who led the study, is also a member of the Masonic Cancer Center, University of Minnesota.

For the current study, Harris, along with colleagues Michael Burns and Alpay Temiz, analyzed tumor samples from 19 different types of cancer for the presence of APOBEC3B and 10 related proteins. Results showed that APOBEC3B alone was significantly elevated in six types (bladder, cervix, two forms of lung cancer, head & neck, and breast). Levels of the enzyme, which is present in low levels in most healthy tissues, were elevated in several other types of cancer as well.

A second key finding was that the mutational signature of APOBEC3B is a close match to the actual mutation pattern in these cancers. "Much like we each have unique written signatures, these enzymes each leave a unique mark," Harris says.

Findings from both studies are counterintuitive because the enzyme, which is produced by the immune system, is supposed to protect cells from HIV and other viruses, not harm our own genomic DNA.

While it's well known that sunlight and chemical carcinogens can mutate DNA, and that mutations are essential for cancer to develop, Harris is the first to discover that this human enzyme is a major cause mutation in cancer. He believes that APOBEC3B is a biological "double-edged sword" that protects some cells from viruses such as HIV and produces mutations that give rise to cancer in others.

Harris hopes to find a way to block APOBEC3B from mutating DNA, just as sunscreen blocks mutations that lead to melanoma. Many cancer mutations have been identified, but discovering a common source of mutation such as APOBEC3B is expected to help researchers to move "upstream" and look for a way to stop carcinogenesis closer to its source, he says, "like damming a river before it wreaks havoc on downstream areas." It's also possible that a simple test for APOBEC3B could be used to detect cancer earlier.


Story Source:

The above story is based on materials provided by University of Minnesota. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael B Burns, Nuri A Temiz, Reuben S Harris. Evidence for APOBEC3B mutagenesis in multiple human cancers. Nature Genetics, 2013; DOI: 10.1038/ng.2701

Cite This Page:

University of Minnesota. "Antiviral enzyme contributes to several forms of cancer." ScienceDaily. ScienceDaily, 14 July 2013. <www.sciencedaily.com/releases/2013/07/130714160936.htm>.
University of Minnesota. (2013, July 14). Antiviral enzyme contributes to several forms of cancer. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2013/07/130714160936.htm
University of Minnesota. "Antiviral enzyme contributes to several forms of cancer." ScienceDaily. www.sciencedaily.com/releases/2013/07/130714160936.htm (accessed September 21, 2014).

Share This



More Health & Medicine News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
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:
from the past week

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