Researchers are beginning to understand how a particular anticancer drug produces its effects. A study published in Nature (Vol. 425, No. 6956, 25 Sep 03, pp. 407-410) explains how a drug -- known as 17-AAG -- that stops the protein Hsp90 from functioning can kill off cancer cells and leave healthy neighbours unharmed.
Hsp90 regulates many of the signalling pathways that are activated in cancerous cells. However, it is found in cancerous and normal cells, so drugs that target this protein should in theory kill diseased and healthy cells. Francis J. Burrows and colleagues explain why this is not the case. They find that Hsp90 in tumours is joined together in multi-protein complexes. By linking up, the Hsp90 in these complexes becomes much more active and is 100 times more likely to bind to 17-AAG than the individual Hsp90 molecules from normal cells.
The research "will undoubtedly affect the future design of Hsp90 drugs, but the study also has general implications for anticancer drug development," say Len Neckers and Yong-Sok Lee in an accompanying News and Views article. "It suggests that it is not enough to identify a potential molecular target -- the drugs directed against the target must also be assessed in an appropriate cellular context."
Francis J. Burrows
Conforma Therapeutics Corporation
San Diego, CA, USA
Tel: +1 858 795 0104
National Cancer Institute
Tel: +1 301 496 5899
(C) Nature press release.
Message posted by: Trevor M. D'Souza