Drug used for diabetes kills cancer cells
Findings from a new study show that the common diabetes drug metformin kills cancer cells in mice. The commonly prescribed diabetes drug works by targeting cancer stem cells and could prevent cancer recurrence. Several studies have shown that metformin can improve breast cancer survival outcomes.
Researchers from Harvard Medical School found that, combined with chemotherapy, metformin reduced tumor size faster and lead to longer periods of remission than chemotherapy alone in the mouse study. The diabetes drug acts selectively on cancer stem cells, a finding that has been a goal for cancer research.
Senior study author Kevin Struhl explains, “There is a big desire to find drugs specific to cancer stem cells. The cancer stem cell hypothesis says you cannot cure cancer unless you also get rid of the cancer stem cells. From a purely practical point of view, this could be tested in humans. It's already used as a first-line diabetes drug."
In the study, pre-treatment with metformin stopped human breast cancer stem cells from forming tumors. The researchers looked at the effect of metformin and the cancer drug doxorubicin, comparing the dual therapy in the lab to non-stem cancer cells. When the two drugs were used in cancer that was allowed to grow, tumors shrunk faster, and cancer remission was prolonged. In mice treated with metformin and doxorubicin, no tumor regrowth occurred.
Jennifer Ligibel, a medical oncologist at Dana-Farber Cancer Institute and an HMS instructor in medicine says, "This is an exciting study”. Ligibel and colleagues at the National Cancer Institute of Canada Clinical Trials Group are planning studies on the effect of metformin on early breast cancer.
Studies that target stem cells to improve cancer outcomes by combining metformin with chemotherapy are needed in humans. The results of the current research showed that metformin kills cancer cells in mice, and could provide new hope for cancer treatment in humans.