Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tailor-made Cancer Drugs: Wave of the Future?

28.10.2002


Washington University chemist offers radical new strategy in fight against cancer



Today, even the best cancer treatments kill about as many healthy cells as they do cancer cells but John-Stephen A. Taylor, Ph.D., professor of chemistry at Washington University in St. Louis, has a plan to improve that ratio. Over the last several years, Taylor has begun to lay the conceptual and experimental groundwork for a radical new strategy for chemotherapy -- one that turns existing drugs into medicinal "smart bombs," if you will.

All DNA is formed of three basic components: a phosphate and a sugar, which combine to form the sides of the double helix "ladder," and a base that forms the ladder’s "rungs." All variances in DNA, including cancerous mutations, are the result of unique sequencing of the four types of bases, denoted A, G, C and T.


Taylor’s approach, described as "nucleic acid-triggered catalytic drug release," is essentially a sophisticated drug releasing system, one that is able to recognize and use cancerous sequences as triggering mechanisms for the very drugs that fight them.

"The beauty of this system is that it could use already-approved FDA drugs," Taylor explained. "So all I have to worry about is getting FDA approval on the general releasing mechanism, and then I can incorporate whatever anticancer drugs are currently on the market."

Taylor discussed his work at the 40th annual New Horizons in Science Briefing, a function of the Council for the Advancement of Science Writing. He spoke Oct. 27, 2002 at Washington University in St. Louis, which hosted the event.

Guiding drugs to their ’parking spot’

In nucleic acids, Nature has already determined the rules of base pairing -- A binds with T and G pairs with C -- a system called "Watson-Crick base-pairing," named for the discoverers of the double helix. Recent advances in biotechnology have given doctors the ability to profile a patient’s genetic information, taken during a biopsy, using something called a DNA chip, which can identify unique or uniquely overexpressed messenger RNA (mRNA). Messenger RNA is a single-stranded RNA molecule that encodes information to make a protein, using the same bases as DNA except that U replaces T. Taylor’s idea is to employ this information as a genetic roadmap, guiding drug components to where they should "park" amongst the millions of base pair "spaces."

Taylor’s system is built on three components: a "prodrug," or a dormant form of a drug; a catalyst that activates the prodrug; and a nucleic acid triggering sequence, designed to match and interlock with a unique or uniquely overexpressed strand of RNA in cancerous cells. The RNA binding drug components will be fashioned out of Peptide Nucleic Acid (PNA), which is identical to DNA, but replaces the sugar backbone with a "peptide" or protein backbone. The benefit is that a single strand of RNA actually binds tighter to a strand of PNA than it does to itself.

So, the prodrug and the catalytic components each contain a PNA strand that is complementary to the cancer cell’s mRNA, allowing them to bind right next to one another in the cancer cell. This close proximity enables a chemical reaction to occur between them, resulting in the release of a cytotoxic drug which kills the cancer cell. Although the medication might encounter healthy cells in its travels, it would not harm them because the RNA triggering sequence would not be present, or else present in a much lower amount, and the drug could not be released.

This new "rational" design doesn’t stop there -- it could be the answer to all sorts of viral diseases such as AIDS, hepatitis and herpes, and could even help guard against new biologically engineered viruses that we haven’t yet imagined.

"Here’s my vision of the future," Taylor said. "You go to a doctor’s office and take a biopsy, which is then run through a DNA chip analysis machine allowing the appropriated triggering sequence to be identified. This information is then passed to an automated synthesis machine and, iIdeally, the catalytic and prodrug components can be synthesized and administered to you within hours."

In related work, Taylor said he will be using overexpressed RNA sequences to help target drugs in research with Washington University colleague Karen Wooley, Ph.D., associate professor of chemistry, and other collaborators. The group hopes to splice Taylor’s RNA-docking molecules to Wooley’s new breed of nanoparticles for on-the-mark, stay-put delivery of diagnostic and disease-fighting agents.

Questions

Contact: Tony Fitzpatrick, senior science editor, Washington University in St. Louis, (314) 935-5272; tony_fitzpatrick@aismail.wustl.edu

Carolyn Jones Otten | EurekAlert!
Further information:
http://news-info.wustl.edu
http://dbbs.wustl.edu/Rib/Taylor.html
http://news-info.wustl.edu/feature/archive/science/dna.html

More articles from Health and Medicine:

nachricht On track to heal leukaemia
18.01.2017 | Universitätsspital Bern

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

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: 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...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>