Growing Trees

Stem cells replenish our tissues with new cells as and when they're needed. But over-production of cells when they’re not required can lead to cancer. One example is found in the mammary glands – more commonly known in humans as breasts – where stem cells produce tree-like milk ducts. Mammary stem cells are remarkably potent, and a single cell can recreate an entire duct tree. This picture shows a milk duct tree grown from breast duct cells, which have been converted into stem cells by the addition of two specific proteins. The duct cells have been labelled with a fluorescent ‘marker’ protein, making them glow green under an ultraviolet-light microscope and revealing the delicate, branching structure. This impressive regenerative capacity also has a dark side – researchers think that the proteins responsible for maintaining mammary stem cells may also fuel the growth of some breast cancers.

Written by Kat Arney

Kat Arney

Writer

Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

Website

• Robert Weinberg
• Whitehead Institute for Biomedical Research, USA
• Copyright Elsevier 2012
• Published in Cell 148 (5), pp 1015–1028