Social isolation worsens cancer

Sep 29, 2009

Using mice as a model to study human breast cancer, researchers have demonstrated that a negative social environment (in this case, isolation) causes increased tumor growth. The work shows -- for the first time -- that social isolation is associated with altered gene expression in mouse mammary glands, and that these changes are accompanied by larger tumors.

"This interdisciplinary research illustrates that the , and a social animal's response to that environment, can indeed alter the level of in a wide variety of tissues, not only the brain," said Suzanne D. Conzen, MD, associate professor of medicine at the University of Chicago and senior author of the study, to be published on September 30, 2009, in Prevention Research. "This is a novel finding and may begin to explain how the environment affects human susceptibility to other chronic diseases such as central obesity, , hypertension, etc."

The research began six years ago when cancer specialist Conzen joined forces with biobehavioral psychologist Martha McClintock, PhD, professor of psychology and founder of the Institute for Mind and Biology at the University of Chicago, who has long been interested in the result of in aging, to study behavior and cancer in a .

The University of Chicago scientists took mice that were genetically predisposed to develop mammary gland (breast) cancer and raised them in two environments: in groups of mice and isolated. After the same amount of time, the isolated mice grew larger mammary gland tumors. They were also found to have developed a disrupted stress hormone response.

"I doubted there would be a difference in the growth of the tumors in such a strong model of genetically inherited cancer simply based on chronic stress in their environments, so I was surprised to see a clear, measurable difference both in mammary gland tumor growth and interestingly in accompanying behavior and stress hormone levels," Conzen said.

The researchers then turned their attention to how the chronic social environment affected the biology of cancer growth. In other words, they sought to discover the precise molecular consequences of the stressful environment.

To do this, they studied gene expression in the mouse mammary tissue over time. Conzen and her colleagues found altered expression levels of metabolic pathway genes (which are expected to favor increased tumor growth) in the isolated mice. This was the case even before tumor size differences were measurable.

These altered gene expression patterns suggest potential molecular biomarkers and/or targets for preventive intervention in human .

"Given the increased knowledge of the human genome, we can begin to identify and analyze the specific alterations that take place in caner-prone tissues of individuals living in at-risk environments," Conzen said. "That will help us to better understand and implement cancer prevention strategies."

These findings do suggest novel targets for chemoprevention, according to Caryn Lerman, PhD, Scientific Director of the Abramson Cancer Center at the University of Pennsylvania, Philadelphia and Deputy Editor of Cancer Prevention Research. "Future studies should evaluate whether these molecular processes can be reversed by chemopreventive agents."

The findings also support previous epidemiologic studies suggesting that social isolation increases the mortality of chronic diseases, as well as clinical studies revealing that social support improves the outcomes of cancer patients.

Source: University of Chicago Medical Center

Explore further: Pain and itch may be signs of skin cancer

add to favorites email to friend print save as pdf

Related Stories

MRI spots DCIS in mice

Oct 01, 2008

A new magnetic resonance imaging procedure can detect very early breast cancer in mice, including ductal carcinoma in situ (DCIS), a precursor to invasive cancer. Some of the tumors detected were less than ...

The abortion pill compound prevents breast tumor growth

Nov 30, 2006

The chemical compound for the abortion pill has been found to prevent the growth of mammary tumors caused by the mutant gene responsible for a majority of breast and ovarian cancers, according to UC Irvine scientists.

Researchers discover a key to aggressive breast cancer

Oct 30, 2008

In trying to find out why HER2-positive breast cancer can be more aggressive than other forms of the disease, UC Davis Cancer Center researchers have surprisingly discovered that HER2 itself is the culprit. By shutting down ...

Recommended for you

Incomplete HPV vaccination may offer some protection

1 hour ago

Minority women who received the Human Papillomavirus Vaccination (HPV) even after becoming sexually active had lower rates of abnormal Pap test results than those who were never vaccinated. These findings appear in the journal ...

New imaging agent provides better picture of the gut

1 hour ago

A multi-institutional team of researchers has developed a new nanoscale agent for imaging the gastrointestinal (GI) tract. This safe, noninvasive method for assessing the function and properties of the GI tract in real time ...

User comments : 0