Redox catalysts which cause cancer cells to undergo apoptosis - or programmed cell death - have been developed by researchers in the UK.
The research groups of Dr Claus Jacob of Exeter University and Dr Nicholas Gutowski at the Royal Devon and Exeter Hospital, with support from the Peninsula Medical School, are investigating the anticancer effects of biocatalysts that mimic the activity of the human selenium enzyme, glutathione peroxidase.
The most active compound tested so far is a multifunctional catalyst that integrates a quinone with a chalcogen redox system in one chemically simple molecule.
Jacob explained that the catalysts work by initiating pathways inside the cancer cell that stimulate apoptosis. Tumour cells proliferate under conditions of oxidative stress,so a novel therapeutic approach would be to enhance the cellular effects of the reactive oxygen species (ROS) formed under these conditions by supplementation with a redox catalyst.
"This provides a means to target and specifically destroy cancer cells via oxidation of redox-sensitive proteins, such as transcription factors, while leaving cells with a normal redox balance largely unaffected," said the researchers. As a result, the approach should target cancer cells and leave healthy cells unaffected, reducing the risk of side effects.
In addition, the catalysts are not consumed during their activity but are recycled, so in theory only minute quantities of biocatalyst are needed to kill cancer cells.
Dr Jacob said: ''Cancer therapy has long been based on highly toxic substances that randomly kill healthy and sick cells alike. This new approach might allow us to single out sick cells and kill them with a catalytic efficiency far superior to conventional radiation or chemotherapy.''
The compounds have been developed and synthesised at Exter University''s School of Biological and Chemical Sciences and tested in cancer cells at the Royal Devon and Exeter Hospital. An Exeter based company has already shown an interest in the compounds and the new method, according to researchers.