Researchers have discovered that the compound sulforaphane, found in broccoli and broccoli sprouts, can kill breast cancer stem cells where chemotherapy fails. University of Michigan researchers tested the broccoli compound in mice and in live cell cultures, discovering that sulforaphane killed breast cancer stem cells that fuel tumors and prevented new ones from growing.
Scientists believe if breast cancer stem cells can be eliminated by developing sulforaphane found in broccoli, tumor spread and metastasis might be controlled.
According to author Duxin Sun, Ph.D., associate professor of pharmaceutical sciences at the U-M College of Pharmacy and a researcher with the U-M Comprehensive Cancer Center, Sulforaphane has been studied previously for its effects on cancer, but this study shows that its benefit is in inhibiting the breast cancer stem cells. This new insight suggests the potential of sulforaphane or broccoli extract to prevent or treat cancer by targeting the critical cancer stem cells.”
Mice with breast cancer used in the study were injected with different doses of sulforaphane. The scientists measured breast cancer stem cells in tumors, finding a significant decrease in numbers after treatment with the broccoli compound. They also found that cancer cells treated with sulforaphane lost the ability to generate more cancer cells. There were no adverse effects on normal cells.
Max S. Wicha, M.D., Distinguished Professor of Oncology and director of the U-M Comprehensive Cancer Center says “Developing treatments that effectively target the cancer stem cell population is essential for improving outcomes.”
The doses of sulforaphane used in the study that killed breast cancer stem cells were higher than what could be accomplished by consuming broccoli. The scientists also warn that women with breast cancer should not add dietary supplements because information about side effects is lacking.
The researchers are planning clinical trials and are working on a means to extract sulforaphane from broccoli and preserve it in hopes of finding a way to kill breast cancer stem cells as an adjunct to chemotherapy. The scientists say the broccoli compound sulforaphane could become a new treatment for breast cancer, combined with other compounds.
Clin Cancer Res May 1, 2010 16:2580-2590: