Long-living breast stem cells give clues to cancer cells of origin

Researchers in Australia have found that breast stem cells and their “daughters” have a longer life than previously believed. This newly discovered longer lifespan suggests that these cells could carry damage or genetic defects earlier in life that eventually lead to cancer decades later.

The researchers, from Melbourne’s Walter and Eliza Hall Institute, have published their results in the journal Nature, and they say their discovery could help with the development of treatments and diagnostics for breast cancer.

Their project involved tracking the development of normal breast stem cells. By tracking these cells, they found they actively maintain breast tissue throughout a woman’s life, from puberty through adulthood, contributing to all major stages of breast development.

“Given that these stem cells – and their ‘daughter’ progenitor cells – can live for such a long time and are capable of self-renewing, damage to their genetic code could lead to breast cancer 10 or 20 years later,” says Prof. Geoff Lindeman, study author and oncologist at The Royal Melbourne Hospital.

He adds that their finding “has important applications for our understanding of breast cancer.”

Potential for ‘new treatment and diagnostic strategies’

Prof. Jane Visvader, another study author from the Walter and Eliza Hall Institute, says understanding how breast cells develop is crucial to establishing which cells bring about breast cancer and why.

“Without knowing the precise cell types in which breast cancer originates, we will continue to struggle in our efforts to develop new diagnostics and treatments for breast cancer, or developing preventive strategies,” she says.

She says this previous work helped them better understand normal breast development, but it will also help them further their knowledge about breast cancer.

“Our team was amongst the first to isolate ‘renewable’ breast stem cells,” Prof. Visvader says. “However, the existence of a common stem cell that can create all the cells lining the breast ducts has been a contentious issue in the field.”

She adds:

“In this study, we’ve proven that ancestral breast stem cells function in puberty and adulthood and that they give rise to all the different cell types that make up the adult breast.”

Prof. Lindemann says they hope their finding “will lead to the development of new treatment and diagnostic strategies in the clinic to help women with breast cancer in the future.”

There have been several studies recently that have suggested diet could be a major factor in development of breast cancer. One study suggested folic acid is linked to breast cancer growth, while another found that limiting alcohol and following a healthy diet could minimize risks for the disease.