Potential Therapy Found for Halting Breast Cancer Spread

Washington (PNA/Xinhua) — US researchers reported Wednesday a potential breast cancer therapy that may keep away the disease’s recurrence by halting its spread to the bones.

In a study in the US journal Science Translational Medicine, researchers at the Duke University described two proteins that breast cancer cells use to invade bone marrow in mice, where these cells can lie dormant for years to escape chemotherapy or hormonal therapies.

Mouse experiments showed that using drugs that block the two proteins can not only prevent breast cancer cells from entering the bone marrow, but also flush these cells out into the blood stream where they could be targeted for destruction.

“Clinical studies have found that breast cancer can be caught early and treated, and patients can have no signs of disease,” said senior author Dorothy Sipkins, 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 the new study, Sipkins and colleagues identified two proteins called E-selectin and CXCR4 from specific blood vessels in bone marrow, with E-selectin allowing cancer cells to enter the bone marrow and CXCR4 anchoring the cells to the bone.

Treating the mice with an E-selectin inhibitor successfully blocked the entry of breast cancer cells into the bone, whereas a CXCR4 inhibitor forced them back out into the bloodstream, where they can more easily be killed with chemotherapy or hormonal therapy.

“Our findings could offer new strategies to intervene at the molecular level before dormant cells can take hold and cause relapse,” said Sipkins. “Our hope is to move forward with additional studies in mice to better understand our approach before moving on to studies in humans.” (PNA/Xinhua) JMC/EBP