“Humanized mouse livers” look to change drug testing

One of the more interesting medical factoids is that mice share 99% of their genes with human beings which makes them ideal when it comes to testing drugs ultimately intended for us. The one problem though as close as mice genes are to our their livers don’t react the same to drugs as human livers do.

This might not seem like much except that drugs can make it all the way through trials but never show if the drugs are toxic to our livers.  As Ariel Schwartz noted in a post at Fast Company, “90% of drugs fail in clinical testing, often because of toxicities that weren’t spotted earlier”.

Thanks to a recent discovery though by graduate student Alice Chen at MIT, researchers can grow “humanized” livers inside of mice; which means they will be able to be more accurate when it comes to predicting how human livers will react to drugs.

This was not an easy task–liver cells lose functionality quickly after being removed from the human body, and until now, generating human-like livers in the animals required using only mice with compromised immune systems, limiting their use in drug testing.

The model, in which human liver cells are suspended on “scaffolds” inside mice, is proving to work. In a paper published Chen and her team show that the implanted human liver tissue can integrate into a mouse’s circulation system–and that means the drugs can reach the implanted tissue, and proteins generated by the humanized liver can go into the bloodstream.

via Fast Company