New drugs could target cancer stem cells

Boston-area researchers have developed a new technique to identify chemicals that kill cancer stem cells — the part of a cancer that drives tumor growth. A common problem with current chemotherapy treatments is that they knock back a cancer successfully, only for the tumor to re-grow later because, it seems, the all-important stem cells have survived.

The Boston researchers demonstrated their new technique, a chemical screen that they describe in the journal Cell, and picked out a farm antibiotic called salinomycin, which they found to be especially toxic to the stem cells of breast cancer. According to the research paper, salinomycin can cut the proportion of breast cancer stem cells more than 100 times more effectively than the common breast cancer drug, paclitaxel — at least in test tubes. Mice treated with salinomycin also showed slower tumor growth.

But the drug salinomycin has never been tested as a cancer agent in humans, so don't expect that particular drug to be available from your oncologist any time soon. Clinical trials can take years to complete, and there may be safety concerns about salinomycin following occasional adverse effects in sheep and horses. The best news about this new research is that it includes a technique for finding several compounds, like this one for breast cancer, that could target the centers of tumor growth rather than than the tumors as a whole.