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.
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.
PHILIP BALL | © Nature News Service
TSRI researchers develop new method to 'fingerprint' HIV
29.03.2017 | Scripps Research Institute
Periodic ventilation keeps more pollen out than tilted-open windows
29.03.2017 | Technische Universität München
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences