BASEL, Switzerland, Dec. 27 (UPI) -- Researchers have found the combination of two drugs used to treat other diseases can be effective in combating certain cancer cells in lab tests.
Metformin, commonly used to treat type 2 diabetes, showed anti-cancer properties but its effectiveness was too low to treat cancer. However, researchers from the University of Basel in Switzerland discovered that combining metformin with the antihypertensive drug syrosingopine increased the efficacy of metformin to fight cancer.
The typical dose of metformin was not effective at fighting cancer but higher doses of the drug created unwanted side effects.
So researchers led by Professor Michael Hall at the Biozentrum at the University of Basel screened more than 1,000 drugs to determine whether they could enhance the cancer fighting action of metformin. The researchers found that syrosingopine increased the effectiveness of metformin and drove the cancer cells to programmed "suicide."
Metformin lowers the blood glucose levels in type 2 diabetes patients and also blocks the respiratory chain in the mitochondria, the energy factories of the cell.
Syrosingopine inhibits the degradation of sugars, so the combination of the two interrupt the vital processes that provide energy for the cell.
"For example, in samples from leukemia patients, we demonstrated that almost all tumor cells were killed by this cocktail and at doses that are actually not toxic to normal cells," Don Benjamin, first author of the study, said in a press release. "And the effect was exclusively confined to cancer cells, as the blood cells from healthy donors were insensitive to the treatment."
Researchers found that in mice with malignant liver cancer, enlargement of the liver was reduced after being treated with the drug cocktail and the amount of tumor nodules was reduced, with some of the tumors disappearing altogether.
"We have been able to show that the two known drugs lead to more profound effects on cancer cell proliferation than each drug alone," Benjamin said. "The data from this study support the development of combination approaches for the treatment of cancer patients."
The study was published in Science Advances.