Researchers discover early cells, unlocking clues to breast cancer

Scientists have discovered new types of early cells in mammary glands, revealing clues to the origins of various breast cancers and potential new treatments.

At least two different types of early cells, called progenitor cells, were identified by a team of researchers at Cancer Research UK's Cambridge Research Institute in a study published in Breast Cancer Research.

Progenitor cells are only able to divide a certain amount of times, unlike stem cells which can keep on dividing and develop into any type of cell.

In the past, scientists only knew of one type of progenitor cells in mammary glands. Cancer is known to start in cells that can generate many "daughter" cells, which then form the tumour mass.

Different progenitor cells may clarify why there are various types of breast cancer.

Scientists discovered that one group of progenitor cells, named oestrogen positive progenitors, had oestrogen receptors.

The oestrogen receptor receives signals from the sex hormone, oestrogen. The other group, oestrogen negative cells, did not have this receptor.

Comparable to the breast tissue of post-menopausal women, oestrogen positive progenitor cells survive better in a low oestrogen and progesterone environment.

Tumours in post-menopausal women may be produced from these cells, however additional experiments are required to confirm this.

An aggressive type of the disease called basal-like breast cancer, which is more likely to affect younger women, shares a similar genetic fingerprint with oestrogen negative progenitor cells.

This implies the disease may be developed from the oestrogen negative progenitors, said the study.

Dr John Stingl, study author at the institute explained that this was an "exciting" discovery that reveals that mammary glands are much more complex than originally thought by scientists.

"Uncovering new types of 'mother' cells may explain why there are different types of breast cancer, and why young and older women tend to get different types. It could also provide new starting points for ways to diagnose and treat the disease in the future," said the expert.

Posted by Fiona Griffiths