50% BRCA 1 genes have PTEN mutations
December 10, 2007 by Elaine
Filed under Cancers, Genetic Epidemiology
Nature Genetics has published a report by scientists in US and Sweden who have discovered how a variant of the BRCA 1 gene helps breast cancer to grow by knocking out a tumor suppressor gene called PTEN.
The link between BRCA 1 and breast cancer was established 10 years ago but questions have been asked as to why this gene causes breast cancer.
PTEN is a key tumor suppressor gene which is knocked out in breast, brain and prostate cancers. PTEN mutations are second only to p53 as being the most frequently present in all cancers, affecting about 30% of them.
Once a cell loses PTEN it has growth advantages over its neighbours and starts on the road to cancer. PTEN mutations increase the activity of various proteins via the PTEN/P13K pathway to promote tumor growth.
The scientists examined 34 biopsies from females with BRCA 1 mutations and found one third of them the PTEN gene was incomplete, almost missing or had reattached itself to other parts of the chromosome. 50% of BRCA 1 genes have the PTEN mutation.
For further information, please go to http://www.nature.com/ng/journal/vaop/ncurrent/abs/ng.2007.39.html
Elaine Warburton
