Scientists identify chain reaction that shields breast cancer stem cells from chemotherapy
The regrowth of cancer stem cells is responsible for the drug resistance that develops in many breast tumors and the reason that for many patients, the benefits of chemo are short-lived. Cancer recurrence after chemotherapy is frequently fatal. "Breast cancer stem cells pose a serious problem for therapy," says lead study investigator Gregg Semenza, M.D., Ph.D., the C. Michael Armstrong Professor of Medicine, director of the Vascular Biology Program at the Johns Hopkins Institute for Cell Engineering and a member of the Johns Hopkins Kimmel Cancer Center. "These are the cells that can break away from a tumor and metastasize; these are the cells you most want to kill with chemotherapy. Paradoxically, though, cancer stem cells are quite resistant to chemotherapy." Semenza says previous studies have shown that resistance to chemotherapy arises from the hardy nature of cancer stem cells, which are often found in the centers of tumors, where oxygen levels are quite...