1st quarter 2004

Stem-cell secret of "eternal youth" discovered

A chemical could pave the way for the development of therapies based on human stem cells. This chemical derives from research on the humble sea snail, which has helped scientists to identify the signals that keep stem cells young.

Human embryonic stem (ES) cells can develop into almost all of the body's cell types and could provide patients with replacement tissues, although there are many stumbling blocks to negotiate before this technology can be put into practice. One major problem is that scientists have yet to discover how to control the transformation of cells into other types. Another is that the cells cannot be grown without the use of mouse cells and could consequently be contaminated with mouse material or viruses.

Ali Brivanlou of Rockefeller University in New York treated ES cells with a chemical (called BIO) from sea snails. BIO prevents ES cells from turning into specialised adult cells. BIO works by activating a set of protein signals (called the Wnt pathway) in the ES cells. By controlling the Wnt pathway, scientists were able to determine whether the cells stay young or specialise. Using chemical substances like BIO might also eliminate the need for mouse cells, which contain the proteins that stop stem cells specialising.

"If we want to make stem cells into therapies, we are going to need cell lines that were never grown in any foreign proteins," Brivanlou says.