Featured Research

from universities, journals, and other organizations

Why are older women more vulnerable to breast cancer? New clues

Date:
June 5, 2014
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
More insights into why older women are more susceptible to breast cancer has been gained by researchers. They found that as women age, the cells responsible for maintaining healthy breast tissue stop responding to their immediate surroundings, including mechanical cues that should prompt them to suppress nearby tumors.

The Berkeley Lab team behind the latest insights into why older women are more susceptible to breast cancer. From left to right: Tiina Jokela, Martha Stampfer, Jim Garbe, Mark LaBarge, Masaru Miyano, and ChunHan Lin (Fanny Pelissier not pictured).
Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory

Scientists from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have gained more insights into why older women are more susceptible to breast cancer. They found that as women age, the cells responsible for maintaining healthy breast tissue stop responding to their immediate surroundings, including mechanical cues that should prompt them to suppress nearby tumors.

Related Articles


Their work sheds light on how aging alters cellular and molecular functions, and how these changes contribute to the prevalence of breast cancer in older women. The disease is most frequently diagnosed among women aged 55 to 64, according to the National Cancer Institute.

The research appears online June 5 in the journal Cell Reports. It was led by Mark LaBarge of Berkeley Lab's Life Sciences Division, with help from first author Fanny Pelissier and other Berkeley Lab scientists, and researchers from UC Berkeley and Norway's University of Bergen.

The scientists studied multipotent progenitors, a type of adult stem cell that is believed to be the origin of many breast cancers. Two years ago, LaBarge's group found that as women age, multipotent progenitors accumulate in breast epithelial tissue. They didn't know why these cells increase in numbers, but they believed their cellular microenvironment -- or the matrix of tissue surrounding them -- plays a role.

To explore this idea, the scientists examined human mammary epithelial cell samples from pre and post-menopausal women. They wanted to learn how the multipotent progenitors in these tissue samples are affected by tiny changes to their microenvironments. They placed the tissue on soft polymer surfaces that mimic healthy breast tissue, as well as on progressively stiffer polymer surfaces that mimic the rigidity of a tumor.

The Berkeley Lab team behind the latest insights into why older women are more susceptible to breast cancer. From left to right: Tiina Jokela, Martha Stampfer, Jim Garbe, Mark LaBarge, Masaru Miyano, and ChunHan Lin (Fanny Pelissier not pictured).

They found that multipotent progenitors in tissue from women less than 30 years old are extremely responsive to changes to their immediate surroundings. When tissue from young women was placed on a soft polymer, multipotent progenitors differentiated into milk-producing luminal cells. When the tissue was placed on a stiff polymer, the cells reduced the production of luminal cells and ramped up the production of tumor-fighting myoepithelial cells.

"We think this is a defense mechanism. The epithelia tissue recognizes that stiffness isn't good and produces tumor suppressants," says LaBarge.

But this defense wasn't observed in tissue from women older than 55. Instead of responding to a stiff polymer by upping the production of tumor-suppressing cells, multipotent progenitors from older women produced equal amounts of luminal and tumor-suppressing cells. They also made more of themselves. That's bad for a couple of reasons. The majority of cancers diagnosed in older women are luminal, and more multipotent progenitors means more cells that can become cancerous.

"We found that as women age, multipotent progenitors, which are the cells responsible for maintaining healthy homeostasis in breast tissue, no longer respond to their microenvironment like they do in younger women," says LaBarge.

"Our work shows that one reason for this is that multipotent progenitors in older tissue do not correctly perceive differentiation cues, such as the mechanical stiffness of their surroundings," he adds.

The scientists traced this failure to a breakdown in a cellular process. The process converts external mechanical cues, in this case the stiffness of the tissue outside of the cell membrane, into an internal molecular message that tells the cell nucleus what to do. In multipotent progenitors in women older than 55, the molecules that help deliver this message are inefficiently activated, the scientists found.

They believe this breakdown stems from changes in the way women's genes are activated and silenced as they grow older.

Their functional analysis of multipotent progenitors was made possible by the work of co-author and Berkeley Lab scientist Martha Stampfer, who curated a large collection of breast tissue samples about 30 years ago. The specimens enabled the scientists to create a wide range of normal human mammary epithelial cell strains from women aged 16 to 91 years.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. The original article was written by Dan Krotz. Note: Materials may be edited for content and length.


Journal Reference:

  1. FannyA. Pelissier, JamesC. Garbe, Badriprasad Ananthanarayanan, Masaru Miyano, ChunHan Lin, Tiina Jokela, Sanjay Kumar, MarthaR. Stampfer, JamesB. Lorens, MarkA. LaBarge. Age-Related Dysfunction in Mechanotransduction Impairs Differentiation of Human Mammary Epithelial Progenitors. Cell Reports, 2014; DOI: 10.1016/j.celrep.2014.05.021

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "Why are older women more vulnerable to breast cancer? New clues." ScienceDaily. ScienceDaily, 5 June 2014. <www.sciencedaily.com/releases/2014/06/140605155726.htm>.
DOE/Lawrence Berkeley National Laboratory. (2014, June 5). Why are older women more vulnerable to breast cancer? New clues. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2014/06/140605155726.htm
DOE/Lawrence Berkeley National Laboratory. "Why are older women more vulnerable to breast cancer? New clues." ScienceDaily. www.sciencedaily.com/releases/2014/06/140605155726.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) A new study links greater authority with increased depressive symptoms among women in the workplace. 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:

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