Scientists at the Duke Cancer Institute have identified a molecular key that breast cancer cells use to invade bone marrow in mice, where they may be protected from chemotherapy or hormonal therapies that could otherwise eradicate them.
Through years of experiments in mice, the scientists have found ways to outmaneuver this stealth tactic by not only preventing breast cancer cells from entering the bone marrow, but also by flushing cancer cells out into the blood stream where they could be targeted for destruction.
The findings provide insight into one of the most devastating tendencies of some breast cancers — the ability to return after seemingly being vanquished. The researchers hope the findings, if replicated in additional animal and human tests, could eventually lead to new therapies for treating breast cancer.
“Clinical studies have found that breast cancer can be caught early and treated, and patients can have no signs of disease,” said Dorothy A. Sipkins, M.D., Ph.D., associate professor in the division of hematological malignancies and cellular therapy at Duke. “And then five, 10 or even 15 years later, a patient can relapse. Most often, the site of the metastasized cancer is in the bone.”
In an article published online May 25 in Science Translational Medicine, the researchers describe how cells from breast cancers that are hormone receptor-positive roam through the blood and tissues of mice. They’re hunting for specific blood vessels in bone marrow that contain the molecule E-selectin. With a key — molecules on their surface that bind to E-selectin — the cancer cells enter the spongy tissue inside bones, often lying dormant for years.