Scientists, including an Indian-American researcher, have identified a molecule that can help treat breast cancer, giving hope to patients who have become resistant to traditional therapies.
The first-in-class molecule shuts down oestrogen- sensitive breast cancer
in a new way, researchers said.
are those that work by a unique mechanism — in this case a molecule that targets a protein on the oestrogen
receptor of tumour cells. The potential drug offers hope for patients whose breast cancer
has become resistant to traditional therapies.
“This is a fundamentally different, new class of agents for oestrogen-receptor-positive breast cancer,” said Ganesh Raj, professor at the University of Texas Southwestern (UT Southwestern) Simmons Cancer
“Its unique mechanism of action overcomes the limitations of current therapies,” Raj said. All breast cancers are tested to determine if they require oestrogen
to grow and about 80 per cent are found to be oestrogen-sensitive, researchers said. These cancers can often be effectively treated with hormone therapy, such as tamoxifen, but as many as a third of these cancers eventually become resistant, they said. The new compound is a potential highly effective, next- line treatment for these patients, said Raj.
A major breakthrough
Scientists have identified a molecule that can help treat breast cancer
The molecule shuts down oestrogen- sensitive breast cancer in a new way, researchers say
The potential drug offers hope for patients whose cancer has become resistant to traditional therapies
The new drug can be highly effective when hormone therapy does not work
Traditional hormonal drugs, such as tamoxifen, work by attaching to a molecule called the oestrogen
receptor in cancer
cells, preventing oestrogen
from binding to the receptor, a necessary step for cancer
cells to multiply.
However, the oestrogen
receptor can mutate and change its shape over time so that the treatment drug no longer fits neatly with the receptor. When this happens, the cancer
cells start multiplying again. “There has been intense interest in developing drugs
that block the ability of the oestrogen
receptor — the prime target in most breast cancers - from interacting with the co-regulator proteins that cause a tumour’s growth,” said David Mangelsdorf, professor at UT Southwestern.
Blocking such “protein-protein interactions” has been a dream of cancer
researchers for decades. The drug works by blocking other molecules - proteins called co-factors — that also must attach to the oestrogen
receptor for cancer
cells to multiply.
So far, it has been tested in mice and in cancer
cells removed from patients and works well in both models, and there have been no signs of toxicity in the tests.
If successfully translated to a human therapy, another advantage of ERX-11 is that it could be taken orally by patients, rather than as an infusion.
The researchers are hoping to get a clinical trial under way in about a year. The notion of blocking protein co-factors has implications for treatment of other cancers as well.