Researchers have discovered that one particular signaling pathway, Wnt, helps direct lung development. A signaling pathway is how developing cells get instruction on what types of cell to become, such as a liver cell, a skin cell, a brain cell, etc.

Using this finding, researchers implemented a new way to use stem cells made from any individual, including cells from patients with cystic fibrosis, and turn them into airway cells, which they then grew into three-dimensional spheres. These airway spheres now can be used to study cystic fibrosis disease activity using a specific test called a swelling assay.

"Because airway spheres from a patient with cystic fibrosis do not swell in our assay but airway spheres from a healthy person do, we can see whether adding a certain drug or combination of drugs causes them to swell more. Finding a drug that causes them to swell might imply that patient would benefit from that treatment," explained corresponding author.

The researchers believe this process can be used to study other lung diseases such as asthma and emphysema.

The findings are published in the journal Cell Stem Cell.