Metformin-chemo combination shrinks tumors, delays recurrence in mice: study
MONDAY, Sept. 14 (HealthDay News) -- Adding the widely used diabetes drug metformin to conventional chemotherapy shows promise for treating and delaying recurrence of breast cancer, new research suggests.
In lab tests using mice with breast cancer, researchers found that the drug combination suppressed the cancer stem cells thought to drive tumor progression.
"We discovered that metformin selectively kills cancer stem cells. Very few compounds do that," said Kevin Struhl, lead researcher of a paper appearing in the Sept. 14 online early edition of Cancer Research.
Stem cells are resistant to chemotherapy, and scientists had hoped to find a compound that kills them. "The basic idea in the stem cell hypothesis is that standard chemotherapy can kill the cancer cells that make up the bulk of the tumor, but it's not getting the stem cells, so they re-grow and the tumor comes back. That's a classic pattern," said Struhl, a professor of biological chemistry and molecular pharmacology at Harvard Medical School.
That metformin is a known compound adds to the good news. "The exciting thing was that they found an old and relatively safe compound and showed that it had a property that was selectively toxic to cancer stem cells," said Dr. Jonathan Chernoff, deputy scientific director at Fox Chase Cancer Center in Philadelphia. "That's new."
Metformin, which is marketed under the brand names Glucophage, Riomet, Fortamet, Glumetza, Obimet, Dianben and Diabex, is an agent that makes the body more sensitive to insulin. Over decades, millions of people have taken it.
"It's known that diabetics who take metformin have a much lower cancer incidence than diabetics who don't, so there has been a hint that the drug might be useful," said Struhl.
One recent study found that metformin may lower a diabetic patient
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