Washington: Scientists claim to have created a protein "fingerprint" of basal breast cancer, an aggressive type of the disease, identifying specific targets
for future treatments.
An international team, led by the Garvan Institute of Medical Research, has used sophisticated new technology to create the "fingerprint" to profile basal breast cancer which represent between 10 and 27 per cent of all breast cancers.
Basil breast cancer lacks oestrogen and progesterone receptors, so is resistant to hormone therapies. As a result, the dilemma for doctors is there is no effective "targeted"
therapy for basal breast cancer.
The main reason for this absence of knowledge is that cancers behave in extraordinarily complex ways, below the cellular level. Each type has a submicroscopic fingerprint
defined by its proteins. Until now, basal breast cancer`s protein fingerprint has remained elusive.
But, the scientists, led by Dr Falko Hochgr?fe and Prof Roger Daly from the Institute, focused in particular on a process known as phosphorylation, in which proteins modify
each other`s behaviour by exchanging phosphate molecules.
In addition, they have used a new technology that allows the investigator to examine the phosphorylation of all cellular proteins.
Their findings show that basal breast cancers display a characteristic "signature" or "fingerprint" of "tyrosine phosphorylation", or phosphate molecules attaching to the
tyrosine amino acids within proteins.
In addition, these cancers show heightened activity of several different kinds of cell-signalling proteins known as "kinases". Kinases are responsible for attaching the phosphate groups to proteins.
"We were able to outline the signalling network which is characteristic for basal breast cancers, and identify which kinases are present and active. Our findings suggest that it
would be a good idea to stratify patients according to which signalling proteins, or kinases, were found in their cancers.
"These kinases can then be targeted by specific therapies - and because several kinases are commonly activated in basal breast cancers, use of combination therapies that
target more than one kinase, or multi-kinase inhibitors, is likely to more effective in the clinic.
"As well as mapping out signalling networks, we also found a couple of novel markers - proteins which could potentially be used to identify this patient subset, and which
might help create a more tailored therapy in the future," said Dr Hochgr?fe.
The findings have appeared in the `Cancer Research` journal.