Ruthenium compounds are emerging as potential drugs for treating secondary tumours, according to European scientists. A ruthenium(III) compound (NAM1-A) has successfully completed the first round of clinical trials, and another ruthenium(II) compound (RAPTA-T) has shown similar activity in vivo. 

Paul Dyson at the École Polytechnique Fédérale de Lausanne, Switzerland, has highlighted the success of proteomics in identifying proteins for drug-targeting. The strategy has been used to develop compounds that target metastases, secondary tumours that form when cancer cells spread from the original tumour to other parts of the body. 

A combination of the ruthenium drugs with cisplatin, a platinum-based compound, has given the most successful treatment yet for a secondary tumour. Dyson carried out preliminary in vivo tests on secondary lung tumours using a combination of NAM1-A and cisplatin and found that 60 per cent were cured. 

For the past 30 years cisplatin has had no rival to its title as the most successful antitumour drug in the world, said Dyson. However, cisplatin causes unpleasant side effects and is not effective on secondary cancer cells. Researchers have searched unsuccessfully for a better drug, with few novel compounds entering clinical use. 

Gerard Jaouen of the École Nationale Supérieure de Chimie de Paris, France, welcomes the proteomic approach. 'Ideally, compounds will be created which interact with certain proteins which are overexpressed in cancer cells,' said Jaouen. In this way cancer cells can be targeted while normal cells remain unharmed. 

Understanding the interactions with target proteins is important in explaining the activity of these drugs, but the way they act in the body still needs more investigation, said Dyson. Future research should be a concerted effort 'in which proteomics, theoretical physics, bioinorganic chemistry and pharmacology are integrated,' he said.

Nina Athey-Pollard