Navigation Links
Salk Scientists - Links Between Cancer and Aging

Scientists at the Salk Institute for Biological Studies Wielding a palette of chromosome paints, have taken a step closer to understanding the relationship between aging and// cancer by visualizing chromosomes of cells from patients with a heritable premature aging disease known as Werner Syndrome.

In a study to be published in this week's online edition of the Proceedings of the National Academy of Sciences researchers led by Jan Karlseder, Ph.D., assistant professor in Salk's Regulatory Biology Laboratory, showed that rebuilding structures called telomeres, which are found at the tips of each chromosome, significantly blocks the type of genetic damage seen in cells of patients with Werner Syndrome.

Patients with Werner Syndrome manifest signs of aging, such as skin wrinkling, baldness, or hair graying, in their teens. Most die in their 40's or 50's due to a predisposition to diseases like cancer. 'Cancer is almost always related to chromosomal instability,' explains Karlseder. 'If telomeres are lost on individual chromosomes, then chromosomes are not protected and can fuse with other nonprotected chromosomes. Then when cells divide, chromosomes randomly break, leading to genome instability.'

The current study extended work published in 2004 by Karlseder and first author Laure Crabbe, Ph.D., who was a graduate student in the Karlseder lab at the time. In that work, the team used a technique called FISH-short for fluorescent in situ hybridization-to microscopically visualize both the telomeres and chromosomal DNA from Werner Syndrome patients. They reported that some protective telomeres were actually missing on patients' chromosomes, a finding Karlseder describes as 'a fairly catastrophic event for a cell.'

For the current study, Salk researchers grew cells from Werner Syndrome patients in tissue culture dishes and, aided by colleagues at the Institute of Human Genetics in Heidelberg, Germany, evaluated DNA damage using a h ighly colorful variation of the FISH technique called chromosome painting. This technique 'paints' or labels every pair of the 46 chromosomes with a different colored fluorescent dye, enabling investigators to easily see breakage or fusion of chromosomes that are characteristic of damaged DNA under the microscope.

Then they artificially supplied the cultured cells with one of two genes-either a functional copy of the WRN gene, which is mutant or nonfunctional in Werner Syndrome, or a gene encoding the protein telomerase, which elongates short or missing telomeres. After cells divided several times, their DNA was reexamined for the type of damage associated with both aging and cancer.

Cells supplied with a functional WRN gene showed decreased DNA damage compared to untreated cells, which was predictable: the WRN gene encodes a protein called a helicase that unwinds tightly coiled DNA strands when cells divide. Loss of WRN protein in individuals with Werner Syndrome is responsible for the disease. Explains Crabbe, now a postdoctoral fellow at The Institute of Human Genetics in Montpellier, France, 'The lack of a single protein (WRN) induced loss of some telomeres, leading to a premature cellular growth arrest.'

However, the most interesting finding was what the scientists observed in cells supplied with added telomerase. 'When we put telomerase into cells, we suppressed accumulation of mutations to the same degree as when we put the WRN protein back,' reports Karlseder. 'It fixed the defect by elongating short telomeres seen in Werner Syndrome cells.'

Crabbe, who is continuing to study DNA replication as a postdoc, concludes that these findings not only provide a mechanism underlying accelerated aging seen in Werner Syndrome but establish a link to cancer predisposition, saying, 'These results indicate that the telomere dysfunction in Werner Syndrome cells is a major cause of genomic instability and could explain the high incid ence of cancer seen in this disease.'

Translating these findings into a treatment for Werner Syndrome will be extremely difficult. However, Karlseder feels optimistic about what these investigations show. 'We study this disease because it is an excellent model for aging, and we show here a direct relation between aging, telomere loss, and cancer occurrence,' he says. 'I predict that cancer in older people has precisely the same basis as that seen in Werner Syndrome patients. That is why this was such a satisfying study.'

Source-Eurekalert
SRI
'"/>




Related medicine news :

1. Scientists plan human cloning clinic in the United States
2. Scientists found ancient Human Germ Killer
3. Scientists locate key hormone involved in appetite control
4. Scientists open the book of life
5. Scientists review SARS
6. Scientists crack dengue fever puzzle
7. Scientists push to lower hidden sodium in food
8. Indian Scientists Make Wide-Ranging Analysis And Annotation Of X Chromosome
9. Scientists have found effective brain regions for deep brain stimulation for Parkinson’s
10. Scientists reveal the secrets of sarcasm
11. Scientists Unveil Mechanism Behind Resistance to Severe Malaria
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/24/2016)... ... 24, 2016 , ... Those who have experienced traumatic events may suffer from ... avenues, such as drug or alcohol abuse, as a coping mechanism. To avoid this ... coping following a traumatic event. , Trauma sufferers tend to feel a range of ...
(Date:6/24/2016)... PASADENA, CA (PRWEB) , ... June 24, 2016 , ... Marcy was in a crisis. ... he would lash out at his family verbally and physically. , “When something upset him, ... table, he would use it. He would throw rocks at my other children and say ...
(Date:6/24/2016)... ... ... Global law firm Greenberg Traurig, P.A. announced that 20 Florida attorneys are ... for this recognition are considered among the top 2 percent of lawyers practicing within ... of this year’s Legal Elite Hall of Fame: Miami Shareholders Mark D. Bloom, ...
(Date:6/24/2016)... ... June 24, 2016 , ... Comfort Keepers® of San Diego, CA is excited ... To Recovery® program to drive cancer patients to and from their cancer treatments. ... highest quality of life and ongoing independence. Getting to and from medical treatments ...
(Date:6/24/2016)... , ... June 24, 2016 , ... People across the ... Genome magazine’s Code Talker Award, an essay contest in which patients and their families ... to be presented at the 2016 National Society of Genetic Counselors (NSGC) Annual Education ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... Tenn. , June 24, 2016  Arkis ... providing less invasive and more durable cerebrospinal fluid ... in funding.  The Series-A funding is led by ... Lighthouse Fund, and other private investors.  Arkis, new ... neurosurgical instrumentation and the market release of its ...
(Date:6/23/2016)... Research and Markets has announced ... Type (Organic Chemical (Sugar, Petrochemical, Glycerin), Inorganic Chemical), Functionality ... - Global Forecast to 2021" report to their ... global pharmaceutical excipients market is projected to reach USD ... in the forecast period 2016 to 2021. ...
(Date:6/23/2016)... ANGELES , June 23, 2016 ... CAPR ), a biotechnology company focused ... therapeutics, today announced that patient enrollment in its ... in Duchenne) has exceeded 50% of its 24-patient ... enrollment in the third quarter of 2016, and ...
Breaking Medicine Technology: