Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Two-lock box delivers cancer therapy

07.05.2014

Rice University researchers find new possibilities for benign, ‘tunable’ virus

Rice University scientists have designed a tunable virus that works like a safe deposit box. It takes two keys to open it and release its therapeutic cargo.


An adeno-associated virus capsid (blue) modified by peptides (red) inserted to lock the virus is the result of research at Rice University into a new way to target cancerous and other diseased cells. The peptides are keyed to proteases overexpressed at the site of diseased tissues; they unlock the capsid and allow it to deliver its therapeutic cargo. (Credit: Junghae Suh/Rice University)

The Rice lab of bioengineer Junghae Suh has developed an adeno-associated virus (AAV) that unlocks only in the presence of two selected proteases, enzymes that cut up other proteins for disposal. Because certain proteases are elevated at tumor sites, the viruses can be designed to target and destroy the cancer cells.

The work appears online this week in the American Chemical Society journal ACS Nano. AAVs are fairly benign and have become the object of intense study as delivery vehicles for gene therapies. Researchers often try to target AAVs to cellular receptors that may be slightly overexpressed on diseased cells. The Rice lab takes a different approach. “We were looking for other types of biomarkers beyond cellular receptors present at disease sites,” Suh said.

“In breast cancer, for example, it’s known the tumor cells oversecrete extracellular proteases, but perhaps more important are the infiltrating immune cells that migrate into the tumor microenvironment and start dumping out a whole bunch of proteases as well. “So that’s what we’re going after to do targeted delivery. Our basic idea is to create viruses that, in the locked configuration, can’t do anything. They’re inert,” she said.

When programmed AAVs encounter the right protease keys at sites of disease, “these viruses unlock, bind to the cells and deliver payloads that will either kill the cells for cancer therapy or deliver genes that can fix them for other disease applications.” Suh’s lab genetically inserts peptides into the self-assembling AAVs to lock the capsids, the hard shells that protect genes contained within.

The target proteases recognize the peptides “and chew off the locks,” effectively unlocking the virus and allowing it to bind to the diseased cells. “If we were just looking for one protease, it might be at the cancer site, but it could also be somewhere else in your body where you have inflammation. This could lead to undesirable side effects,” she said.

“By requiring two different proteases – let’s say protease A and protease B – to open the locked virus, we may achieve higher delivery specificity since the chance of having both proteases elevated at a site becomes smaller.” In the future, molecular-imaging approaches will be used to detect both the identity and concentration of elevated proteases.

“With that information, we would be able to pick a virus device from our panel of engineered variants that has the right properties to target that disease site. That’s where we want to go,” she said. Suh said elevated proteases are found around many diseased tissues. She suggested these protease-activatable viruses may be useful for the treatment of not only cancers but also neurological diseases, such as stroke, Parkinson’s and Alzheimer’s diseases, and heart diseases, including myocardial infarction and congestive heart failure. The ultimate vision of this technology is to design viruses that can carry out a combination of steps for targeting.

“To increase the specificity of virus unlocking, you can imagine creating viruses that require many more keys to open,” she said. “For example, you may need both proteases A and B as well as a cellular receptor to unlock the virus. The work reported here is a good first step toward this goal.”

Co-authors are Rice alumni Justin Judd and Abhinav Tiwari; graduate students Michelle Ho, Eric Gomez and Christopher Dempsey; Oleg Igoshin, an associate professor of bioengineering; and Jonathan Silberg, an associate professor of biochemistry and cell biology, all at Rice; and Kim Van Vliet, an assistant research scientist, and Mavis Agbandje-McKenna, a professor, both at the University of Florida. Suh is an assistant professor of bioengineering. The National Science Foundation, the National Institutes of Health, the American Heart Association and the Cancer Prevention and Research Institute of Texas supported the research.

David Ruth | Eurek Alert!
Further information:
http://news.rice.edu/2014/05/06/two-lock-box-delivers-cancer-therapy/

Further reports about: Heart diseases effects enzymes genes myocardial peptides proteases stroke targeting therapy viruses

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>