Featured Research

from universities, journals, and other organizations

Breast cancer tumor suppressor gene silenced by low oxygen

Date:
August 16, 2011
Source:
American Society for Microbiology
Summary:
Low oxygen can silence the BRCA1 tumor suppressor gene and contribute to the progression of cancer, according to a new study. Silencing this particular gene is one of the steps on the malignant pathway to breast cancer. The research may ultimately lead to ways of reactivating this and other tumor suppressor genes, in order to thwart cancer.

Low oxygen can silence the BRCA1 tumor suppressor gene and contribute to the progression of cancer, according to a paper in the August 2011 issue of the journal Molecular and Cellular Biology. Silencing this particular gene is one of the steps on the malignant pathway to breast cancer. The research may ultimately lead to ways of reactivating this and other tumor suppressor genes, in order to thwart cancer, says corresponding author Peter Glazer of Yale University, New Haven.

This study grew out of Glazer's laboratory's previous findings that low oxygen stress to cells can cause changes in expression of many human genes, sometimes boosting, and sometimes reducing expression. "We had found a few years ago that hypoxia reduces expression of BRCA1, and so I had the idea to ask whether it could drive silencing of the gene," says Glazer.

Hypoxia is common in human tumors, partly because newly emerging tumors lack blood vessels. "They become hypoxic because they don't get enough blood," says Glazer. As they enlarge, they begin to grow blood vessels, in a process known as angiogenesis. But "that process is never perfect, so tumors have a very variable and incomplete blood supply," says Glazer. "That makes them more genetically unstable, and helps drive them towards more malignant properties," he adds, citing earlier work by his laboratory.

The silencing could be a first step towards cancer, but Glazer thinks it more likely is a later step, since without the tumor, the hypoxia that drives gene silencing is less likely to occur, says Glazer.

Understanding the mechanism of reduced expression would open the way to research that could lead to strategies for interfering with the gene silencing. What we know so far: the mechanism for the silencing involves the histones, proteins that wrap around the chromosomes when they are silent, but which unwrap around genes that are being expressed. Glazer showed that the silencing of BRCA1 is accompanied by a change in the histones, called methylation, which is frequently seen when gene expression is reduced.

"We then found that one particular enzyme, called lysine demethylase [LSD1] is manipulating the methylations," says Glazer. Finding a way to block that enzyme could lead to reactivating BRCA1, he says, noting that this might be done by finding a small molecule that inhibits that enzyme's activity. Such a drug might reactivate other tumor suppressors as well, he says.

Glazer thinks that cell stress in general caused by hormones or environmental toxins may lead to silencing BRCA1, and he plans to investigate that hypothesis.


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Y. Lu, A. Chu, M. S. Turker, P. M. Glazer. Hypoxia-Induced Epigenetic Regulation and Silencing of the BRCA1 Promoter. Molecular and Cellular Biology, 2011; 31 (16): 3339 DOI: 10.1128/MCB.01121-10

Cite This Page:

American Society for Microbiology. "Breast cancer tumor suppressor gene silenced by low oxygen." ScienceDaily. ScienceDaily, 16 August 2011. <www.sciencedaily.com/releases/2011/08/110815172117.htm>.
American Society for Microbiology. (2011, August 16). Breast cancer tumor suppressor gene silenced by low oxygen. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2011/08/110815172117.htm
American Society for Microbiology. "Breast cancer tumor suppressor gene silenced by low oxygen." ScienceDaily. www.sciencedaily.com/releases/2011/08/110815172117.htm (accessed April 21, 2014).

Share This



More Health & Medicine News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. 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