FED: Scientists trace the link between gene and breast cancer

AAP General News (Australia)
08-03-2009
FED: Scientists trace the link between gene and breast cancer

By Danny Rose, Medical Writer

SYDNEY, Aug 3 AAP - Australians scientists have have made a breakthrough in understanding
why women with a specific gene mutation are more likely to develop breast cancer.

Women with a gene named BRCA1 are known to have about a 65 per cent lifetime chance
of developing the cancer, and researchers at Melbourne's Walter and Eliza Hall Institute
have traced the cause to an unexpected source.

It had been thought the cancer risk was associated with stem cells specific to the
breast but instead the problem was found to be linked to the next phase - or "daughters"

- of these stem cells known as luminal progenitor cells.

"Our gene expression studies have revealed that BRCA1 breast tissue and basal breast
tumours are more similar to normal luminal progenitor cells than any other cell type in
the breast," Associate Professor Jane Visvader said.

"This places the spotlight on errant luminal progenitors, rather than breast stem cells."

The research, published in the international journal Nature Medicine, represents a
major shift in the way breast cancer is understood to develop and points to a new avenue
for targeted treatments.

The luminal progenitor cells in these women with the BRCA1 gene appear to have "forgotten"

how to behave, said Associate Professor Geoff Lindeman.

"Usually, luminal progenitor cells multiply rapidly in the presence of certain growth
factors," Dr Lindeman said.

"In BRCA1 women, these cells don't even require growth factors to proliferate - they
misbehave from the outset."

He said the BRCA1 gene was also used by the body for DNA repair and so there could
be a potential "triple-whammy effect" - faulty growth control, faulty DNA repair and expanding
luminal progenitor cell numbers - which ultimately results in breast cancer.

"Hopefully this will lead to new, tailored therapies for the next generation of women,"

Dr Lindeman said.

AAP dr/it

KEYWORD: BREAST

2009 AAP Information Services Pty Limited (AAP) or its Licensors.