Master gene SRC-3 enables breast cancer growth, invasion

Feb 12, 2010

The master gene called SRC-3 (steroid receptor coactivator 3) not only enhances estrogen-dependent growth of cancer cells by activating and encouraging the transcription of a genetic message into a protein, it also sends a signal to the cell membrane to promote cell motility or movement - a key element of cancer spread or metastasis, said Baylor College of Medicine researchers and collaborators in a report that appears in the current issue of the journal Molecular Cell.

The finding not only uncovers a new activity for SRC-3 at the cell's periphery, it also clears up a mystery about how the message that tells a cell to invade gets from the (EGFR) to the activating enzyme called FAK (focal adhesion kinase) found on the cell's membrane, said Dr. Bert O'Malley, chair of molecular and cellular biology at BCM and the report's senior author.

"Two-thirds of breast cancers over express the gene SRC-3," said O'Malley, who is the 2008 National Medal of Science recipient. "The work represented in this paper shows that a coactivator gene (SRC-3) can produce an alternative form of its coactivator protein - a shorter form that is missing the part of the protein that keeps it in the nucleus. With that portion (called an exon) gone, it leaves the nucleus and goes into the cytoplasm (or general area of the cell) and travels to the membrane," he said.

"At the membrane, the enzyme PAK1 (p21-activted kinase 1) phosphorylates (attaches a phosphate molecule that activates the coactivator) SRC-3, allowing it to function at the membrane," said O'Malley, responsible for identifying the first receptor coactivator and advancing the field in general.

The finding explains how the epidermal growth factor receptor at the membrane gets a signal to the enzyme that tells the cell to move - and ultimately grow, allowing the cancer to invade surrounding tissue, said O'Malley.

"Now we have a final picture as to why epidermal growth factor receptor and the estrogen receptor are the most dangerous combination of molecules overproduced in breast ," said O'Malley. "When they are both over functioning, people die quickly and are resistant to therapy."

Explore further: Death rates from pancreatic cancer predicted to rise in Europe in 2014

More information: www.cell.com/molecular-cell/home

add to favorites email to friend print save as pdf

Related Stories

Deactivating a cancer growth promoter

Sep 25, 2008

Three enzymes called phosphatases that shut down a molecule called SRC-3 (steroid receptor coactivator 3) could provide a new pathway for fighting cancer, particularly tumors of the breast and prostate, said researchers at ...

Clocking in and out of gene expression

Jun 14, 2007

A chemical signal acts as time clock in the expression of genes controlled by a master gene called a coactivator, said Baylor College of Medicine researchers in a report that appears in the journal Cell today.

Protein inhibits cancer cell growth

Dec 21, 2009

(PhysOrg.com) -- Researchers at the University of Toronto and Goethe University in Germany have discovered a protein that can inhibit the growth of cancer cells, providing crucial clues for the future development of new drugs ...

Recommended for you

US Oks first-ever DNA alternative to pap smear

7 minutes ago

Federal health regulators have cleared a genetic test from Roche as the first U.S.-approved alternative to the pap smear, the decades-old mainstay of cervical cancer screening.

New breast cancer imaging method promising

5 hours ago

The new PAMmography method for imaging breast cancer developed by the University of Twente's MIRA research institute and the Medisch Spectrum Twente hospital appears to be a promising new method that could ...

Palliation is rarely a topic in studies on advanced cancer

6 hours ago

End-of-life aspects, the corresponding terminology, and the relevance of palliation in advanced cancer are often not considered in publications on randomized controlled trials (RCTs). This is the result of an analysis by ...

User comments : 0

More news stories

Autism Genome Project delivers genetic discovery

A new study from investigators with the Autism Genome Project, the world's largest research project on identifying genes associated with risk for autism, has found that the comprehensive use of copy number variant (CNV) genetic ...

Study suggests targeting B cells may help with MS

A new study suggests that targeting B cells, which are a type of white blood cell in the immune system, may be associated with reduced disease activity for people with multiple sclerosis (MS). The study is released today ...

Study links California drought to global warming

While researchers have sometimes connected weather extremes to man-made global warming, usually it is not done in real time. Now a study is asserting a link between climate change and both the intensifying California drought ...