In their experiments, the researchers found that the combination of the diabetes drug metformin and the antihypertensive drug syrosingopine drives cancer cells to programmed “suicide”.
“We have been able to show that the two known drugs lead to more profound effects on cancer cell proliferation than each drug alone,” said study first author Don Benjamin from the University of Basel in Switzerland.
“The data from this study support the development of combination approaches for the treatment of cancer patients,” Benjamin noted.
Metformin is a widely prescribed drug for the treatment of Type-2 diabetes.
Besides its blood sugar lowering effect, it also displays anti-cancer properties. The usual therapeutic dose, however, is too low to effectively fight cancer.
At higher doses, the antidiabetic drug inhibits the growth of cancer cells but could also induce unwanted side effects.
The new research published in the journal Science Advances showed that the antihypertensive drug syrosingopine enhances the anti-cancer efficacy of metformin.
The study showed the cocktail of these two drugs is effective in a wide range of cancers.
“For example, in samples from leukemia patients, we demonstrated that almost all tumour cells were killed by this cocktail and at doses that are actually not toxic to normal cells”, Benjamin said.
“And the effect was exclusively confined to cancer cells, as the blood cells from healthy donors were insensitive to the treatment,” Benjamin noted.
In mice with malignant liver cancer, enlargement of the liver was reduced after the therapy. Also the number of tumour nodules was less — in some animals the tumours disappeared completely.
The researchers found that the drugs interrupt the vital processes which provide energy for the cancer cell.