Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain tumor growth linked to lowered expression of hundreds of immune function genes

27.04.2010
A new study links progression of a lethal type of brain tumor with reduced expression of more than 600 immune system genes, suggesting how complex the immune response is to the cancer and the resulting difficulty in targeting specific immune system proteins for treatment.

Previous research found that people with allergies were less likely to be diagnosed with this type of brain cancer, called glioblastoma multiforme. However, it was not clear whether allergies reduce brain tumor risk or whether the growing tumor “cures” allergies.

To further explore the relationship between these two conditions, scientists examined almost 1,000 genes associated with allergies, immunity and inflammation to learn how they were affected once these tumors were present in the brain.

The researchers expected to see that allergy gene function was low in brain tumor tissue, which would be consistent with the known immune system suppression that is associated with these tumors.

What they found was a surprise: Allergy genes were not the only immune function genes suppressed during tumor growth. Instead, in almost 70 percent of the 919 genes examined, the genes’ activity was decreased as the brain tumors progressed.

“This result provides evidence that there is a relationship between glioblastoma and allergies – specifically, high tumor aggressiveness is associated with low allergy-related gene function,” said Judith Schwartzbaum, lead author of the study and an associate professor of epidemiology at Ohio State University. “But it still does not tell us whether allergies inhibit tumor growth or tumors block allergies.”

The findings also show that immune function in the brain continues to change as these tumors grow.

“As the tumor progresses, the majority of the immune-function genes express themselves at lower levels,” Schwartzbaum said. “So we know that with progression there is less immune function, but we don’t know which came first, the lowered immune function or the cancer.”

The cause of this kind of cancer remains unknown, and there is no cure. The complexity of the immune response to this tumor suggests that it will be difficult to identify key immune function proteins that inhibit tumor growth. Schwartzbaum said that in addition to using information about the immune system to treat tumors, researchers must also study the immune system to find ways to prevent these aggressive tumors.

The study is published in a recent issue of the journal Neuro-Oncology.

Glioblastomas constitute up to 60 percent of adult primary brain tumors in the United States, affecting an estimated 3 in 100,000 people. Patients who undergo surgery, radiation and chemotherapy survive on average for about one year, with fewer than a quarter of patients surviving up to two years and fewer than 10 percent surviving up to five years.

The researchers used publicly available data from genetic analysis of 142 brain tumor tissue samples collected from patients with glioblastoma multiforme tumors as part of the National Cancer Institute’s The Cancer Genome Atlas project.

The scientists used levels of expression of the CD133 gene as an indicator of tumor progression. Previous studies had suggested that activation of this gene is related to tumor aggression and a poor clinical outcome.

With these data, Schwartzbaum and colleagues then plotted expression of immune function genes against levels of CD133 expression in these tumors.

Gene expression refers to the switching on or activation of genes. Schwartzbaum and her colleagues analyzed mRNA expression data in their study; mRNA synthesis is the first step in gene expression and may lead to creation of functional proteins.

The analysis showed that higher levels of CD133 expression were associated with lower levels of immune function gene expression in 69 percent of the genes examined.

There were, however, immune function genes whose expression increased with CD133 expression, including a cytokine gene called interleukin-17 that is linked to inflammation, and a gene related to suppression of immune function called NCAM-1.

The genes whose function was lowered with tumor progression included most of those associated with allergies, as well as, paradoxically, many of those that counteract allergy genes. In another surprising finding, many genes known to suppress immune function were also expressed at lower levels as the tumor progressed.

“That was a surprise because you’d think that genes that suppress the immune system would be more active in these tumors, which may be lethal, in part, because they are immunosuppressive. But we didn’t see that,” Schwartzbaum said.

Schwartzbaum is planning to focus her subsequent research on the end products of genetic activation, immune function proteins or cytokines.

She plans to analyze 1,200 samples from the Janus Serum Bank in Norway, which were collected on average 10 years before brain tumor diagnosis, to find out whether the presence of certain cytokines in those samples might offer clues that will help identify people at high risk for brain tumor development.

This work was supported by the National Cancer Institute and the Neurosciences Signature Program in the Ohio State College of Medicine.

Schwartzbaum conducted the research with Kun Huang and Jianhua Yu of Ohio State’s Comprehensive Cancer Center; Sean Lawler and E. Antonio Chiocca of Ohio State’s Department of Neurological Surgery; and Bo Ding of the Institute of Environmental Medicine at the Karolinska Institutet in Stockholm, where Schwartzbaum is a visiting researcher.

Contact: Judith Schwartzbaum, (614) 293-3878; schwartzbaum.1@osu.edu (Schwartzbaum travels frequently. E-mail is the best way to initiate contact with her.)

Written by Emily Caldwell, (614) 292-8310; caldwell.151@osu.edu

Judith Schwartzbaum | EurekAlert!
Further information:
http://www.osu.edu

More articles from Studies and Analyses:

nachricht Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland

nachricht Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>