Navigation Links
Stem-cell sentry sounds the alarm to maintain balance between cancer and aging, U-M researchers find
Date:10/15/2008

ANN ARBOR, Mich.---Like a sentry guarding the castle walls, a molecular messenger inside adult stem cells sounds the alarm when it senses hazards that could allow the invasion of an insidious enemy: Cancer.

The alarm bell halts the process of cell division in its tracks, preventing an error that could lead to runaway cell division and eventually, tumor formation.

"Our work suggests that to be able to prevent abnormal cell proliferation, which could lead to cancer, stem cells developed this self-checking system, what we're calling a checkpoint," said Yukiko Yamashita of the University of Michigan's Life Sciences Institute.

"And if it looks like the cell is going to divide in the wrong way, the checkpoint senses there's a problem and sends the signal: 'Don't divide! Don't divide!'" said Yamashita, a research assistant professor of life sciences and an assistant professor of cell and developmental biology at the U-M Medical School.

If everything looks OK, the checkpoint allows adult stem-cell division to proceed, providing new cells to replace damaged and worn-out tissues.

Yamashita and her colleagues have not yet identified the molecules that form the checkpoint mechanism. But they've seen it at work in adult stem cells of the fruit-fly testes, so-called germ-line stem cells.

"Aging is too few divisions and cancer is too many divisions, and people have long speculated that some process controls the balance between them," Yamashita said. "We may have found the mechanism that maintains the delicate balance between over-proliferation---which can lead to cancer---and aging."

The team's findings will be published Oct. 15 in the online version of the journal Nature.

If humans possess a similar checkpoint system and if researchers could someday harness it, they could fine-tune the rate of cellular division to control tumor development as well as tissue aging. But Yamashita stressed that no mammal studies of the checkpoint have been undertaken, so talk of potential human applications is highly speculative.

In fruit flies, the checkpoint monitors germ-line stem cells as they're about to divide. It can sense problems that would derail the division process, which is called mitosis.

Under normal conditions, adult stem-cell division creates one new stem cell and one cell committed to develop into a specific tissue type such as a skin cell, a blood cell or, in this case, a sperm cell. That form of mitosis is called asymmetric division, and it's exactly what stem cells need to maintain a healthy balance between uncommitted and committed cells.

Cell division is controlled in part by the location of a pair of cellular components called centrosomes. They provide the framework that helps direct how chromosomes are distributed between daughter cells during mitosis.

Normally, centrosomes in a dividing stem cell remain perpendicular to an adjoining messenger cell called the hub. Yamashita and her colleagues found that improper orientation of the centrosomes disrupts the mitotic machinery, steering it on a course toward stem-cell over-proliferation and cancer.

The checkpoint mechanism senses when centrosomes are misaligned, then sounds the alarm that stops cell division.

By preventing faulty cell division, the checkpoint helps ward off cancer. But a balance must be struck: If the checkpoint mechanism slows cell division to a trickle, the resulting shortage of new cells will accelerate tissue aging.

"It's a double-edged sword, and both outcomes are bad," she said. "One path leads to cancer and the other leads to aging. And we haven't found a way to avoid aging without getting cancer."


'/>"/>

Contact: Jim Erickson
ericksn@umich.edu
734-647-1842
University of Michigan
Source:Eurekalert

Related medicine news :

1. New Non-Surgical Stem-Cell Procedure Relieves Degenerative Joint Disease
2. MIT: Stem-cell therapies for brain more complicated than thought
3. Reeve Foundation Recruits Distinguished Stem-Cell Neurobiologist - The Salk Institutes Samuel L. Pfaff, Ph.D. - to its International Research Consortium
4. Sentry Telecare Establishes Partnering Program to Market Telephone Check-in and Personal Emergency Response Service
5. Cardinal Health, Sentry Data Systems Introduce New Technology to Help Health Care Providers More Cost-Efficiently Care for Underserved
6. Sentry Data Systems Announces Deficit Reduction Act Compliance Tool
7. MultiVu Video Feed: Parents of Kids With Infectious Diseases Sounds Alarm About the Dangers of Pertussis With "Silence the Sounds of Pertussis" Campaign
8. Brain Area Recognizes Familiar Sounds
9. Video: Could You Be At Risk? American Diabetes Association Sounds the Alert on March 25th - ADAs 20th Annual American Diabetes Alert(R) Day
10. Amateur Singers, Teachers Seldom Hear Sounds of Trouble
11. World No Tobacco Day Sounds Urgent Call for Nations to Fight Tobacco Use, Save Lives
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/5/2016)... ... ... weekend, from Friday, May 6 - Sunday, May 8, fifteen elite athletes from Team ... Fi Mountain Bike Camp, hosted in conjunction with WTB and Cannondale ... Moeschler, who’ll share pro tips with the injured veterans as they rip down some of ...
(Date:5/5/2016)... Stockholm/San Jose (PRWEB) , ... May 05, 2016 , ... ... the art of self-love. Every day, LELO fans reach out via email, social media ... recurring question keeps upcoming up: “Is the way I masturbate ‘normal’ or ‘correct’?” , ...
(Date:5/5/2016)... ... May 05, 2016 , ... ... laws in all U.S. states and certain Canadian provinces is now available from ... Compensation Research Institute (WCRI). , The report, Workers’ Compensation Laws as ...
(Date:5/5/2016)... ... May 05, 2016 , ... Long Island’s fastest growing ... of noted Long Island eye surgeon, Kathleen Van Valkenburg, MD as part of their ... Jeffrey Martin, MD, medical director and managing partner of North Shore Eye Care. ...
(Date:5/5/2016)... ... May 05, 2016 , ... Standard Process ... professionals across the United States. The whole food nutrient solutions company can help ... giving dog, cat and horse owners’ peace of mind. With the increased support, ...
Breaking Medicine News(10 mins):
(Date:5/4/2016)... 2016 Yissum Research Development ... today that it had signed an exclusive world-wide licensing ... of novel protein degradation and immunomodulatory drugs for cancer ... drug candidates representing first-in-class therapy for hematologic and solid ... The novel technology was developed by ...
(Date:5/4/2016)... May 4, 2016 ... the  "Global Acute Myeloid Leukemia Market and ... their offering.       (Logo: ... Leukemia Market and Competitive Landscape Highlights 2016, ... pipeline products, Acute Myeloid Leukemia epidemiology, Acute ...
(Date:5/3/2016)... Research and Markets has announced the addition ... Outlook 2020" report to their offering. ... has improved significantly in past years due to which ... years. Many cancer drugs have been developed by utilization ... expected to be developed with its help. They are ...
Breaking Medicine Technology: