Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Short-term stress enhances anti-tumor activity in mice

23.09.2009
Public speaking, anyone? Or maybe a big job interview? Dry your palms and take a deep, calming breath; there may be a silver lining.

Researchers at the Stanford University School of Medicine have shown that, at least in laboratory mice, bouts of relatively short-term stress can boost the immune system and protect against one type of cancer.

Furthermore, the beneficial effects of this occasional angst seem to last for weeks after the stressful situation has ended. The finding is surprising because chronic stress has the opposite effect -- taxing the immune system and increasing susceptibility to disease.

"This is the first evidence that this type of short-lived stress may enhance anti-tumor activity," said Firdaus Dhabhar, PhD, associate professor of psychiatry and behavioral sciences and a member of Stanford's Cancer Center, and Institute for Immunity, Transplantation and Infection. "This is a promising new way of thinking that calls for more research. We hope that it will eventually lead to applications that help us to care for those who are ill, by maximally harnessing the body's natural defenses while also using other medical treatments."

The study will be published in a future print issue of the journal Brain, Behavior, and Immunity, and a review copy of the article is now available on the journal's Web site.

The researchers studied a particular type of skin cancer called squamous cell carcinoma that is known to be vulnerable to attack by the immune system.

Understanding how the intricate two-step between stress and the immune system plays out in the dance hall of diseases like cancer is important for future therapies. Certain types of stress, such as the so-called fight-or-flight response to an immediate but temporary threat, has been shown to increase the recruitment of immune cells to the surface of the skin and the surrounding lymph nodes -- presumably in preparation for imminent injury.

"Acute stress galvanizes an organism's protective systems," said Dhabhar, whose laboratory focuses on understanding the physiological effects of both acute and chronic stress. "But although it's one of nature's fundamental survival systems, thus far it's been rather underappreciated."

The researchers investigated the effect of short-term, or acute, stress on 30 laboratory mice exposed for 10 weeks to thrice-weekly doses of cancer-causing ultraviolet light. The light was non-blistering and non-burning and the mice experienced only a slight reddening of the skin after each exposure. But because the light was composed mainly of the most dangerous wavelength -- called UV-B -- starting at week 11, many of the mice went on to develop precancerous and cancerous growths similar to those seen in humans.

To stress the mice, the researchers placed them in well-ventilated plastic tubes for 2.5 hours prior to UV exposure from weeks four to six, for a total of nine bouts of stress. The mice were not squeezed or compressed, but their ability to move was restricted. Previous research showed that mice confined in such a way mount a behavioral and hormonal stress response.

Dhabhar and his colleagues compared the prevalence and tumor burden of the skin cancers in the stressed mice with that of a non-stressed, UV-exposed control group of 30 mice. They found that fewer of the mice that had been acutely stressed developed skin cancer during weeks 11 through 21, and that those that did exhibited a lower total amount of tumors (a measurement called tumor burden) than the non-stressed mice.

The stressed mice weren't protected indefinitely. Approximately 90 percent of the mice in both groups developed cancer after week 22, though the stressed group continued to have fewer tumors until week 26.

"It's possible that the pre-tumor cells were eliminated more efficiently in the group that was stressed. There may also have been a longer-term enhancement of immunity as we have seen in our non-cancer-related studies," said Dhabhar, explaining why tumor development appeared to lag in the stressed mice. "However, acute stress did not lower tumor burden beyond week 26. We are in the process of determining why."

Other stress-induced changes lingered for weeks, however. The researchers found that, during the same time period, the skin of the stressed mice had higher levels of immune-activating genes than did the control group -- almost as if the mice were preparing for battle.

"Evolutionarily, it makes sense," said Dhabhar. "In nature, stress and immune activity are typically coupled. It's like a lion chasing and wounding a gazelle. Nature taps into this stress response to give a boost to the immune system in the face of danger." He compared the effect to how drug-makers often increase the potency of vaccines by including generic immune-activating molecules called adjuvants.

As intriguing as the results are, Dhabhar doesn't really imagine that we'll be confining human patients in straightjackets or tossing them in front of an intimidating audience as a therapeutic technique any time soon (thank goodness!). But he is convinced that acute stress may be better for us than most of us think, and that bio-behavioral interventions are worth investigating. As long as you can return to a normal, psycho-physiological resting state within a few hours of a stressful event, you'll probably be fine.

"The key is not to let the stress response linger," he said. To understand why, Dhabhar and his colleagues are now probing more deeply into the biological basis of these protective effects of the acute stress response.

"What we want to do now is to fine-tune the stress dynamics so that we can get maximal benefits," he said. "We are working to determine what molecules and cells are involved, and when. It may be possible one day to harness these protective effects by behaviorally or pharmacologically activating the pathways involved."

Dhabhar's Stanford colleagues on the work include senior research scientist Tyson Holmes, PhD, and Donna Bouley, PhD. They also collaborated with colleagues at Ohio State University.

The research was supported by the National Cancer Institute at the National Institutes of Health.

The Stanford University School of Medicine consistently ranks among the nation's top 10 medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://mednews.stanford.edu. The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children's Hospital. For information about all three, please visit http://stanfordmedicine.org/about/news.html.

Ruthann Richter | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Studies and Analyses:

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>