'Notch' gene may be missing part of breast cancer jigsaw puzzle
Washington, Oct 9 : Scientists from the Victorian Breast Cancer Research Consortium
have discovered an important piece in the puzzle of how breast cancer develops.
According to experts, a normal developmental protein that sometimes goes awry has been
implicated in breast cancer. The discovery indicates the mechanism by which inappropriate
expression of the Notch pathway may contribute to breast cancer.
The breast cancer team at WEHI, led by Drs Jane Visvader and Geoff Lindeman, have
identified important roles for Notch genes in regulating breast development and
function.
The discovery has important implications for breast cancer, since elevated levels of
Notch have been linked to breast cancer. The advance builds on the group's 2006 discovery
of the breast stem cell in mice.
Research carried out by Drs Toula Bouras and Bhupinder Pal has uncovered dual functions
for Notch in breast tissue.
First, Notch helps restrict breast stem cell number, so that when Notch is 'switched
off', there is a resultant expansion in breast stem cells.
Second, Notch is important for ensuring that stem cells produce the sleeve of cells
that normally line breast ducts. These 'luminal' cells may be the cells that give rise to
common types of breast cancer.
Thus, Notch helps to orchestrate the formation of breast tissue: it plays an important
role in controlling stem cell number and instructs stem cells to produce luminal
cells.
Significantly, Dr Bouras and colleagues found that errant activation of Notch resulted
in uncontrolled growth of luminal precursors, leading to the formation of breast
tumours.
The work has spotlighted the potential importance of deregulated Notch in ductal
precursor cells as a forerunner to breast cancer.
The researchers say that it is too early to speculate on whether the design of
anti-Notch therapies could help patients facing breast cancer.
--ANI
