Researchers at Massachusetts Institute of Technology and the Broad Institute have identified a compound, salinomycin, that cuts the number of cancer stem cells 100 times more than Taxol, a common chemotherapy medicine, does:
The researchers at MIT and Broad grew cancer cells from breast tumors in a way that increased the number of stem cells. They then used rapid screening techniques to test 16,000 commercially available chemical compounds. They identified 32 candidates before settling on salinomycin as the most potent.They also tested the compound in mice in two ways. First, they exposed breast cancer stem cells in laboratory dishes to salinomycin and Taxol and tallied how many cells they would need to inject in a mouse to trigger a tumor. It took many more of the salinomycin-treated cells to spur cancer, showing that the compound was inhibiting cancer development, Gupta said.
Second, they induced tumors in mice and treated them with the two drugs. While both drugs exerted “significant anti-tumor effects,” the mice treated with Taxol had a greater proportion of cancer stem cells left in the remaining tumor. Taxol enriched the population of cancer stem cells and salinomycin reduced it, Gupta said.
“We have now a systematic way to look for compounds that selectively kill cancer stem cells,” Gupta said. “We’ve taken a lot of the serendipity out of the equation.”