A complete, functioning breast has been grown from a single stem cell, by researchers in Australia. It was done in a mouse, but experts believe it won’t be long before it happens in humans.
“Until now, no one has been able to take one cell and make it do everything involved in a fully-functioning, milk-producing breast,” notes postdoctoral fellow Kaylene Simpson, who set up the experiment before moving to Harvard Medical School. “There were lots of technical obstacles to overcome and it was very difficult to attract funding at first.”

Comparing the differences in development between normal and tumorous breasts could lead to new treatments that attack the earliest stages of breast cancer. Simpson also mentions the possibility of growing new breasts to replace those lost to surgery. As such medical applications become more likely, commercial interest in using stem cells to enhance breast size could also grow larger.

The idea of trying to produce a complete functioning breast from one adult stem cell originated with Geoffrey Lindeman and Jane Visvader at the Walter and Eliza Hall Institute of Medical Research in Melbourne. They enlisted Simpson to work with them because she had the technical expertise needed to extract individual cells from breast tissue, expertise acquired during her Ph.D. research at the Victorian Institute of Animal Science, also in Melbourne. The stem cell breast project took five years to complete.

A major challenge involved finding marker proteins that recognize and bind to the surface of breast stem cells in mice. This was necessary to separate them from the many other types of cells that make up a breast.

“We would like to find the same markers in human breasts,” Simpson points out. “They could be used to identify stem cells in either live tissue or frozen samples. Clearly, that is the next step to take, and people in Melbourne are working on this now.”

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