Researchers use worms to screen drug compounds
drugs by genetically modification allowing the worm to distinguish
harmful chemicals to those with therapeutic benefit.
The use of a worm represents a screening method at its most basic and provides a viable alternative to the robotics and high-speed computer technology involved in drug compound screening.
Additionally, it eliminates the need for a highly specialised and expensive lab to run an efficient screening operation.
Researchers from the UK and The Netherlands genetically modified nematode worms (C.elegans) to have human receptors in their nerves, which they use to detect and avoid harmful chemicals in their environment.
The research carried out involved breeding the worms to include somatostatin receptors. These receptors are normally activated by the somostatin hormone that plays a key role in neural signalling.
Worms were also introduced with chemokine receptor 5, which responds to a molecule called chemokine that plays an important role in the immune system.
Experiments with these modified worms involved placing somostatin or chemokine in the pathway of the modified worms, which they moved away from when confronted.
In his paper, published in the journal Biomedcentral Biology, John McCafferty, principal investigator at the Sanger Institute, said: "To survive, the worms have to taste and smell the environment around them, and they will automatically swim towards food and away from harmful chemicals."
"We basically hijacked that system to make them respond to human signalling molecules, and effectively they are tasting the human signalling molecules and swimming away from them."
The majority of drugs on today's market utilise a 'lock and key' mechanism for its basic mode of action, meaning that drugs are often designed to provide a suitable fit to receptors either blocking or activating them.
Thus detecting whether a potential medicine interacts with the receptor in a positive or negative way determines the success of the drug.
The research sets up a hive of activity in the future, in which worms could be modified to carry a range of different human receptors that scientists are targeting for new drugs.
"This makes it a very simple response that which we can measure, and therefore provides a way to look for new molecules or substances or drugs which act on the human receptor of interest," said McCafferty.
"He added that many of the current methods for screening compounds use tissue culture, but this can be expensive and needs very purified compounds."
