Drug-chemo combo destroys challenging breast cancer stem cells

Gregg Semenza

Gregg Semenza

Researchers affiliated with Johns Hopkins Physical Sciences-Oncology Center (PS-OC) have shown that combining chemotherapy with an agent that blocks a certain cancer survival protein holds the key to fighting one of the the toughest forms of breast cancer.

Only 20 percent of patients with what are known as “triple-negative” breast cancer cells respond to chemotherapy. PS-OC associate director and Johns Hopkins professor of  medicine Gregg Semenza demonstrated in a recent study that chemotherapy actually enhances triple-negative cancer stem cell survival by switching on proteins called hypoxia-inducible factors (HIF). But when combined with currently available and FDA-approved HIF-inhibiting drugs, such as digoxin, Semenza said, chemotherapy shrank tumors.

Mice with implanted triple-negative breast cancer stem cells were treated with a combination therapy comprised of the HIF-inhibiting drug plus the chemotherapeutic drug paclitaxel. That combo treatment decreased tumor size by 30 percent more than treatment with chemotherapy. Furthermore, Semenza’s study showed that combining digoxin with the a different chemotherapeutic agent called gemcitabine “brought tumor volumes to zero within three weeks and prevented the immediate relapse at the end of treatment that was seen in mice treated with gemcitabine alone,” a press release on the study stated. Clinical trials will be needed to verify these results.

Debangshu Samanta, Ph.D., a postdoctoral fellow in the Semenza lab, was the lead author on this research published online in the Proceedings of the National Academy of Sciences. Additional authors include Daniele Gilkes, Pallavi Chaturvedi and Lisha Xiang of the Johns Hopkins University School of Medicine.

Read the PNAS article here.

Visit the PS-OC website here.

For all press inquiries regarding INBT, its faculty and programs, contact INBT’s science writer Mary Spiro, mspiro@jhu.edu or 410-516-4802.

 

Breast cancer patient advocates offer insight

Researchers are tapping into the first-hand knowledge of survivors of breast cancer through the cancer patient advocate program at Johns Hopkins Physical Sciences-Oncology Center (PS-OC).

“Breast cancer patients can provide valuable insight into the impact of therapies,” said Abigail Hielscher, a chemical and biomolecular engineering postdoctoral fellow in the Sharon Gerecht laboratory. Hielscher is helping to organize an effort to locate breast cancer survivors and patients, as well as those who work closely with them such as oncology nurses, to inform the efforts of researchers developing cancer diagnosis and treatments.

In addition to acting as a liaison between the population of breast cancer survivors and patients and the community of Johns Hopkins PS-OC scientists performing breast cancer-related research, patient advocates also are charged with telling the public and funding agencies about the latest breast cancer research being performed in PS-OC labs.

Likewise, researchers must communicate their findings via laboratory demonstrations and brief, non-technical talks to the breast cancer advocates.

“Survivors can facilitate communication between those directly affected by the disease and those working to treat or cure it,” Hielscher said. “The advocates, both patients and nurses, allow researchers to better understand and implement the needs of breast cancer patients in terms of new therapies and treatment strategies.”

Cancer patient advocates meet periodically with Johns Hopkins PS-OC researchers. Currently, PS-OC patient advocates are Mary Capano, MSN, RN, CBPN-IC and Nancy Cardwell.

If you or someone you know is a breast cancer survivor who would like to learn about the volunteer opportunity as a patient advocate contact Abigail Hielscher at ahielsc1@jhu.edu or via phone: 402-889-0283.