Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Magic bullet homes in

04.03.2002


The search for a magic bullet to kill only cancer cells has been on for years.
© Getty Images


New candidate cancer drug does damage only in tumours.

A new drug turns lethal only when it reaches cancer cells. In healthy cells it is harmless. Though not yet shown to work in humans, it is a step towards a magic bullet to knock out tumour cells selectively, with minimal side effects.

The drug works in mice implanted with human tumours, say chemists Lutz Tietze and colleagues at the University of Gottingen in Germany. Before being treated with the drug, the mice are given an enzyme to activate it that sticks only to the human tumour cells, ignoring healthy mouse cells. So the drug is safe until the enzyme activates it in the tumour. Then it destroys the cancerous cells1.



The researchers report that the tumours shrank without inducing any visible side effects in the mice. They think that the same principles could be used in people. The activating enzyme could be tailored to latch onto malignant tissues and bypass normal human cells.

"We are now in contact with the pharmaceutical industry, and will start clinical tests", says Tietze.

Magic bullet

Most existing chemotherapy is toxic to normal cells as well as cancerous ones. This causes severe side effects, such as a depressed immune system. Cancer researchers long for a magic bullet: a drug that works only where it is needed.

The warhead of the Gottingen antitumour molecule is a ring of three carbon atoms. This ring is highly strained and apt to burst open. Open, it is a reactive molecule that wreaks havoc among the nucleic acid molecules essential for normal cell function. The chemists copied this trick from a highly toxic antibiotic produced by a fungus.

So that their molecular bomb does not detonate everywhere in the body, the team have made a ’prodrug’. This is like the natural antibiotic but without the strained ring and with a sugar safety-catch. Once the sugar is clipped off, the molecule rearranges itself into a three-atom ring, and proceeds to do its toxic business.

Tietze’s team uses an enzyme to cut away the sugar safety-catch. An antibody on the enzyme acts as a tumour-specific hook. Such antibodies linked to toxic or radioactive molecules have long been explored for making magic-bullet drugs; none has yet found clinical use.

The advantage of this enzyme-activated approach, originally developed in the 1980s, is that the drug isn’t even activated until it reaches the target site. The selectivity of the damage still depends on antibody’s ability to hook onto the right cells, and on the absence of other enzymes in the body that also activate the prodrug.

Whether the idea will work cleanly enough in humans remains to be seen.

References

  1. Tietze, L. F. et al. Proof of principle in the selective treatment of cancer by antibody-directed enzyme prodrug therapy: the development of a highly potent prodrug. Angewandte Chemie International Edition, 41, 759 - 761, (2002).


PHILIP BALL | © Nature News Service

More articles from Health and Medicine:

nachricht Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

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: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>