Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCLA discovery will aid in treatment of patients with a deadly brain cancer

10.11.2005


Researchers can identify patients likely to respond to drug therapy, saving some from undergoing harsh procedures with little chance of success



Researchers at UCLA’s Jonsson Cancer have identified key characteristics in certain deadly brain tumors that make them 51 times more likely to respond to a specific class of drugs than tumors in which the molecular signature is absent.

The discovery of the telltale molecular signature – the expression of a mutant protein and the presence of a tumor suppressor protein called PTEN – will allow researchers to identify patients who are likely to respond to the drug treatment before they undergo therapies that are not likely to work, said Dr. Paul Mischel, an associate professor of pathology and laboratory medicine and a Jonsson Cancer Center researcher.


Mischel and his colleagues say in an article in the Nov. 10 issue of the New England Journal of Medicine that the discovery could change the way doctors treat glioblastomas, the most common type of malignant brain tumor and one of the those lethal forms of cancer.

"In a biologically aggressive disease like glioblastoma, it’s vital to be able to stratify patients up front so we can treat them with drugs that they are more likely to respond to," Mischel said. "This will help prevent patients from having therapies that are much more toxic and less beneficial. With the short survival times associated with glioblastoma, that is critical."

Between 8,000 and 10,000 new cases of glioblastoma will be diagnosed in Americans this year. Average survival is less than a year, according to the American Cancer Society. Although treatment may prolong life, most malignant brain tumors are not curable, making the search for better treatments even more urgent, Mischel said.

A protein called epidermal growth factor receptor (EGFR) is commonly amplified in glioblastoma, making it a prime focus for therapies. Drugs such as Tarceva and Iressa target EGFR, blocking the cell signals that drive amplification of the protein and speed cancer growth. A subset of glioblastoma patients responded to Tarceva and Iressa, but it was not clear what characteristics made them respond to these drugs. There had to be critical molecular factors that determined response, Mischel said.

He and his team set out to find the molecular determinants that indicated which patients would respond best to EGFR blockers. Previous UCLA research in brain and other cancers suggested that the key might be the interaction of the PTEN protein and a mutant protein called EGFRvIII. About half of patients with amplified EGFR also have this mutant protein.

The UCLA team and their collaborators studied a subset of 26 glioblastoma patients who either responded very well or very poorly to EGFR blocking drugs and developed a way to test their brain tumor tissue for the presence of both the mutant and PTEN proteins. Mischel’s team found that patients with both genetic variations were 51 times more likely to respond to EGFR blockers. They also lived five times longer after initiating therapy than those without the variation, surviving 253 days versus 50 days.

To confirm their promising work, Mischel and his team obtained tissue samples from 33 brain cancer patients treated at another facility without knowing who the responders were. They were able to independently replicate their results, confirming that those with both genetic variations were more likely to respond to EGFR blocking drugs.

The study shows that glioblastoma patients can respond to targeted agents, and suggests that patients likely to benefit from treatment can be identified by molecular testing. The study also raised the possibility that patients whose tumors lack the genetic variations in the molecular signature could possibly be treated with drugs to make them more sensitive to EGFR blockers.

Of the 8,000 to 10,000 glioblastoma patients diagnosed each year, about 10 to 20 percent have the combination of the mutant and PTEN proteins, Mischel said. The next step is a prospective study, determining the molecular signature of patients’ tumors and directing those with the right protein combination to EGFR blocking therapies. Mischel’s team also is working to uncover the molecular signatures in the tumors of non-responders so they can determine what therapies might be most effective for them.

"This is a much more hopeful period now in cancer research," Mischel said. "Genomic and proteomic technologies are helping us begin to understand the underlying molecular features of disease, and new drugs are making it possible to safely and specifically target pathways that are altered in cancer cells. This was impossible five years ago. Glioblastoma is still a difficult disease, but the idea that it may be possible to induce long-term disease suppression gives us reason for hope."

The study, Mischel said, also may have important implications in other cancers.

"Many cancers have a similar combination of a mutant cancer-causing protein and either the expression or loss of the PTEN protein," Mischel said. "The interactions of the two may be important in determining response to targeted agents."

Kim Irwin | EurekAlert!
Further information:
http://www.mednet.ucla.edu

More articles from Health and Medicine:

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

nachricht NTU scientists build new ultrasound device using 3-D printing technology
07.12.2016 | Nanyang Technological University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>