Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCLA scientists transform HIV into cancer-seeking missile

14.02.2005


Firefly protein illuminates virus’ hunt of metastasized melanoma cells in live mouse



Camouflaging an impotent AIDS virus in new clothes enables it to hunt down metastasized melanoma cells in living mice, reports a UCLA AIDS Institute study in the Feb. 13 online edition of Nature Medicine. The scientists added the protein that makes fireflies glow to the virus in order to track its journey from the bloodstream to new tumors in the animals’ lungs. "For the past 20 years, gene therapy has been hampered by the lack of a good carrier for therapeutic genes that can travel through the blood and aim itself at a precise location, thereby minimizing harmful side effects," explained Irvin S.Y. Chen, Ph.D., director of the UCLA AIDS Institute. "Our approach proves that it is possible to develop an effective carrier and reprogram it to target specific cells in the body."

The UCLA team employed a two-step approach to transform HIV into a cancer-seeking machine. First, the scientists used a version of HIV from which the viral pieces that cause AIDS had been removed. This allowed the virus to infect cells and spread throughout the body without provoking disease. "The disarmed AIDS virus acts like a Trojan horse – transporting therapeutic agents to a targeted part of the body, such as the lungs, where tumors often spread," said Chen, a professor of medicine, microbiology, immunology and molecular genetics and a member of the Jonsson Comprehensive Cancer Center at the David Geffen School of Medicine at UCLA.


Second, the scientists stripped off HIV’s viral coat and redressed it in the outer suit of the Sindbis virus, which normally infects insects and birds. By altering the Sindbis coat, they reprogrammed the AIDS virus, which ordinarily infects T-cells, to hunt down and attach to P-glycoproteins -- molecules located on the surface of many cancer cells. The UCLA team is the first to prove that modified HIV will target and bind with P-glycoproteins. "P-glycoproteins cause big problems by making the cell resistant to chemotherapy," said Chen. "They act like soccer goalies and punt therapeutic drugs out of the cancer cell. This prevents the drug from taking effect and allows the tumor to continue growing unchecked."

In order to track the carrier’s journey, the scientists added luciferase – the protein that makes fireflies glow – to the AIDS virus. They injected the camouflaged HIV into a vein in the mouse’s tail and used a special optical camera to watch the carrier’s movement. "The virus traveled through the animal’s bloodstream and homed straight to the cancer cells in the lungs, where the melanoma had migrated," said Chen.

When the researchers held the mouse under the camera, the luciferase illuminated the cancer cells, which glowed through the animal’s bones, muscles and fur. The method is non-invasive and does not cause pain or harm to the animal.

Though excited at proving that HIV can be used to target cancer cells, Chen emphasizes that the carrier must be further enhanced for safety and specificity before it can be tested as a gene-therapy method in humans. "Our next step will be to test whether we can direct therapeutic genes to the precise location where cancer cells reside," Chen said. "This approach offers many potential applications for controlling cancer and other diseases." "We may be able to boost immune-system surveillance at tumor sites, identify cancer cells’ exact location and kill them before they cause damage," he added. "Beyond cancer, it may be possible to correct acquired and genetic diseases where the mutations exert their harmful effects on the body."

Melanoma is a serious form of skin cancer. According to the American Cancer Society, an estimated 59,580 Americans will be diagnosed with melanoma in 2005, and about 7,770 people will die of the disease.

Elaine Schmidt | EurekAlert!
Further information:
http://www.mednet.ucla.edu

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

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

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

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>