In the news
6 Sep 2008
21 May 2007
New DNA test could replace animal experiments
A new test for checking if drugs damage DNA could reduce the number of animal experiments currently conducted in drug development, and also be cheaper than conventional animal test techniques.
Before any drug can enter clinical trials in humans, the manufacturers are required to provide data on its genotoxicity – its ability to cause breakages in DNA in the nucleus of a cell. Genotoxicity can lead to mutations and cancer.
Typically, genotoxicity is tested by injecting the potential drug into live mice and then, after 24 to 48 hours, looking for damaged red blood cells formed in the bone marrow of the mice. However, at the USA’s Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, scientists have developed a new cell culture method based on cells extracted from mouse bone marrow that go on to produce red blood cells. Other test-tube techniques for assessing genotoxicity already exist, but the interesting feature of this new method is that it mimics the in vivo (‘real life’) process, in which the bone marrow cells respond to the hormone that stimulates blood cell development.
Hundreds or even thousands of tests could be performed on cells extracted from a single animal, so the researchers predict that the assay could dramatically reduce the number of animals used.
However, the Dr Hadwen Trust recommends the use of human cells rather than animal cells, since this would obviate the need to kill mice and would avoid the complications of potential species differences.
Indeed, senior researcher Professor Harvey Lodish admits that the test could use human cells instead. “This research is the first stage in a new type of clinical drug toxicity test,” said Lodish “And although we haven’t done it, you may be able to extend the technique to humans. Humans are the gold standard in that one wants an assay that directly predicts toxicity in humans, not animals, and you could obtain human bone marrow that’s left over from medical procedures.”
The results of the test are published in the 14 May edition of the Proceedings of the National Academy of Sciences journal.
