Researchers have discovered that a protein that triggers milk production in women is associated with aggressive form of breast cancer. The study might pave way to newer therapeutics aimed at treating this subtype of cancer, reports Reuters Health.
According to the researchers, the protein ELF5 activates milk production even in breast cells that have become cancerous. This process makes the cancer cells more aggressive.
Back in 2008, researcher Chris Ormandy from Sydney's Garvan Institute of Medical Research had found that ELF5 was responsible for cells that lack the estrogen receptors during pregnancy. The new study, also led by Ormandy, shows that ELF5 can change an existing tumor into estrogen-receptor-negative cancer cells. It is this insensitivity to estrogen that helps the cancer cells become unresponsive to anti-estrogen therapies such as Tamoxifen and aromatase inhibitors.
Most breast cancers (80 percent) are estrogen-receptor positives and women with these types of cancers are given drugs that lower the hormone estrogen in the body.
However, some women may lack receptors for estrogen. These women are generally treated with chemotherapy. The latest research found that in this group of women, the breast cells have high level of ELF5.
Ormandy and his team also identified the genetic mechanism by which ELFS opposes the action of estrogen. Researchers have even shown that it is possible to change the ELF5 levels in the cancer cells and thus changing the cancer subtype.
"This raises the therapeutic option of manipulating ELF5 levels to treat breast cancer. As ELF5 is intracellular, this could possibly be done with small molecule therapies that penetrate cells and target protein-to-protein interactions, or with small inhibitory RNAs. There is also the possibility of testing ELF5 levels in tumours to predict response to treatment and therefore guide treatment decisions," Ormandy said in a news release.
The study is published in the journal PLOS Biology.
An estimated 226,870 women will develop breast cancer in the year 2012, according to National Cancer institute. Risk factors for breast cancer include, gender, age and menstrual cycle along with certain genetic mutations.