Predicting may Lead to Preventing

Scientists have recently made progress in unraveling the mysteries of an aggressive form of breast cancer. A new enzyme has been discovered that's involved in the growth of a potentially deadly type of the disease.

Researchers have found that estradiol, a form of the hormone estrogen, plays a role in driving the growth of a potent form of breast cancer.

Enzyme discovered that drives growth of deadly breast cancer cells.

Scientists from the University of Illinois at Chicago College of Medicine found that estrogen increases production of an unknown protein found in ovarian tissue. After working with the protein in the lab, they discovered that it is actually an enzyme that turns a weak form of estrogen - estrone - into the much more potent version of the hormone, estradiol.

"Breast cancer tumors with this enzyme are likely to be a much more aggressive and potentially deadly type of cancer," Gibori said. "Identifying this enzyme and how its expression is turned on gives medical researchers potential targets for disrupting the lethal production of estradiol in breast cancers."

Tamoxifen, an estrogen-blocking drug that's currently used to inhibit breast cancer growth, also works to prevent estradiol's stimulation of the enzyme. So tamoxifen may shut down production of estradiol in breast cancer cells.

Gibori said the enzyme may be the target of new therapies that could stop the production of the dangerous estradiol. Such therapies would reduce the side effects seen with other estrogen-blocking medications.