Small molecules that switch up cell development could transform medicine

Imagine you could take a potion that returns you to an embryonic state, from which you could grow up as someone else. Or another potion that could rearrange your thoughts and features to become another person. Those are just fantasies for humans – but not for our cells. In the past two decades, biologists have become adept at reprogramming mature tissue cells (known as somatic cells) to become another sort entirely, including ones that resemble stem cells with the potential to grow into anything. And whereas the initial work demanded rather drastic addition of new genes, now many of the transformations can be achieved chemically, using mixtures of small molecules. Chemistry alone is proving able to render biology much more fluid and protean than was long thought possible.

These advances could have dramatic implications in tissue engineering and regenerative medicine, perhaps ultimately for treating heart disease or neurological damage. Chemical cell alchemy is also being explored for treating some types of cancer – not by killing the cancer cells but by switching them into other states.