Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Variant in gene associated with telomeres predicts longer survival of deadly brain tumor

19.04.2005


An exceptionally large study of patients with glioblastoma multiforme has found an association between a genetic variation and a doubling of survival rate - the strongest link ever established between genetic variation and outcome in this deadliest form of brain cancer, according to researchers at The University of Texas M. D. Anderson Cancer Center.



The study, presented at the annual meeting of the American Association of Cancer Research, found the differences in a common variant in a number of repeats (short or long) of the hTERT gene, which produces human telomerase.

This study of 301 patients, which the researchers believe is the largest to date of patients with glioblastoma multiforme, found that the 36 patients (about 11 percent) who had the "SS" variant genotype of hTERT survived an average of 25 months, compared to about 14 months for those who had either the "SL" or "LL" genotypes.


The findings are exciting, says the lead investigator, Melissa Bondy, Ph.D., a professor in the Department of Epidemiology, because they suggest new treatment directions for patients with a cancer that is both the most common glioma and the one offering the poorest hope of survival.

"It is a real advance because we have never seen any genotype that can stratify glioblastoma multiforme patients into different treatment outcome groups like this," says Bondy. "Now we need to verify the finding, study the mechanism, and see if there is a way that these results can be used either as a biomarker or to individualize treatment."

For example, if the SS variant genotype of hTERT is confirmed to have better response to chemotherapy and radiation treatment, then it is possible that these therapies will extend survival for patients with glioblastoma multiforme, she says.

Telomeres, the structures that cap the end of cellular chromosomes, have been linked to both the aging process and cancer development. Telomerase is an enzyme that helps regulate the length of telomeres, and in normal cells, it is not generally active past fetal development. Thus, telomeres shorten each time a cell divides, until they cannot protect chromosomes and the cell dies. But in cancer, it is believed that telomerase is activated and intervenes to keep telomeres from shortening, allowing for unlimited cell division.

The research group looked at genetic variation of hTERT because abnormal expression of the gene contributes to unregulated cell growth, and expression of the gene has been evaluated as one of the most common tumor markers in most primary tumors, says the study’s first author, Luo Wang, M.D., Ph.D., a research scientist in the Department of Epidemiology.

The mechanism why the SS variant genotype of hTERT showed better survival remains unknown. But some forms of hTERT may be less destructive than others because they may be expressed at a lower level, Wang says. For instance, the SS variant genotype is more likely than the SL or LL variant genotype to produce an antisense-like molecule that suppresses the expression of human telomerase, he says, and this modulation may enhance the effect of the chemotherapy and radiation treatment on the patients with the SS variant genotype.

Bondy says the association between the SS variant genotype and improved outcome held, even when differences in age, sex and the extent of surgery, chemotherapy and radiation were taken into account. "We have looked at a lot of different genes associated with cancer, such as DNA repair genes and p53, but this is the first time we have found a genotype that has such a large effect on clinical outcome."

Nancy Jensen | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>