Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify immune dysfunction in melanoma patients

08.05.2007
Researchers at the Stanford University School of Medicine have begun to shed light on why the human immune system isn't able to stop such cancers as melanoma, suggesting answers that could pave the way for better treatment of this often-fatal illness.

In a small study, the scientists found that the immune cells in a majority of people with this deadly skin cancer fail to respond properly to a molecule called interferon, which normally activates the immune system. Without the ability to respond to interferon, the cells are less able to fend off the cancer, according to the study that will be published in the May issue of Public Library of Science-Medicine.

These results help explain a decade of research showing that people with cancer often have dysfunctional immune systems. Until now, researchers could tell that the immune system wasn't working properly but didn't know which genes or pathways were involved in that failure. Finding the disruption in the cancer cells' interferon response could help in the development of vaccines to treat cancers.

"We think this is a dominant way that immune dysfunction occurs in people with cancer," said senior author Peter Lee, MD, associate professor of medicine.

Lee was interested in melanoma rather than other forms of cancer in part because of the deadly nature of the disease, which will kill about one in six of the 47,700 people it is expected to strike this year. Unless melanoma is caught early and removed, there is no effective treatment, although research groups have been testing vaccine therapies for the disease. However, Lee worried that unless researchers better understood immune dysfunctions in those people, the vaccines would have a low probability of success. "If you don't address the underlying immune defects, then vaccines won't do any good," Lee said.

The group started by separating out the four major types of immune cells from people with melanoma and from healthy people. These cells were B cells, two types of T cells and NK, or natural killer, cells. Then, postdoctoral scholar Rebecca Critchley-Thorne, PhD, lead author of the paper, looked in the immune cells of healthy people vs. those with melanoma to see if they had the same levels of activation of roughly 20,000 genes.

She found that the B cells and both types of T cells in people with melanoma showed activity levels that differed from healthy people in only 25 of those genes. Seventeen of those 25 were normally turned on in response to interferon.

"Interferon normally acts as a critical signal in activating immune cells," said Critchley-Thorne. Without the ability to respond to interferon, those cells might detect the cancer but won't activate properly.

This type of experiment only shows that certain genes are turned on at different levels in people with melanoma. It doesn't prove that the cells behave differently than the immune cells of normal people. To verify that the interferon signaling was defective in people with melanoma, Critchley-Thorne isolated those cells and exposed them to interferon.

As predicted, immune cells from people with melanoma also failed to respond normally to the immune activation signal. However, she found that if she left the cells in the presence of a high dose of interferon for much longer than would normally be required, those cells did begin responding.

Lee said the finding explains why a common melanoma treatment, in which some doctors have treated patients with prolonged exposure to interferon, sometimes helps. "Doctors knew it worked in some people but didn't know why," Lee said. This data suggests that treatment works by overcoming the immune system's inability to react properly to interferon.

If Lee's suspicion turns out to be true, doctors may be able to screen melanoma patients for interferon response and provide prolonged interferon treatment for only those patients whose immune cells have defects in that pathway. That means patients who wouldn't benefit from the treatment could avoid suffering through interferon's flu-like side effects.

Amy Adams | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Health and Medicine:

nachricht Tracking movement of immune cells identifies key first steps in inflammatory arthritis
23.01.2017 | Massachusetts General Hospital

nachricht Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign

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: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>