Gene screen sieves out new treatments for old drugs

Scientists have developed a technique for finding new ways to treat existing diseases using old drugs.

Writing in Science Translational Medicine, Stanford University researcher Joel Dudley and his colleagues applied the logic that if we know which genes alter their activities in a certain disease, and we can find a drug that has the reverse effect on those same genes, then that drug might well reverse at least some of the symptoms.

Focusing on the inflammatory bowel disease (IBD) ulcerative colitis as a proof of principle, the team mined the database of published gene screens relevant to the condition and also the effects of a range of drugs.

The trawl identified a number of therapeutic "hits" amongst a range of agents that had never even been considered, let alone tried, as treatments for IBD. At the top of the list was an anti-epilepsy drug called topiramate, which scored even better than the current therapeutic gold standard, prednisolone, an immune-suppressing steroid.

To find out whether topiramate is actually be effective at treating the disease, a group of rats with the rodent equivalent of ulcerative colitis were given either prednisolone, topiramate or a placebo. Sure enough, just as the test predicted, topiramate turned out to be as good as prednisolone.

Consequently, say the team, there are likely to be a host of already-approved drugs that could be re-deployed in new directions against existing diseases. So rather than trying to reinvent new ones, they suggest we seek - using tools like theirs - to repurpose the pharmacological wheels we already have in circulation...