Using two drugs instead of just one could help cancer patients whose tumors do not respond to standard treatment, researchers said Wednesday.
When they tested the combination therapy in mice with a type of lymphoma that is resistant to standard therapy, it caused complete remission in all the animals.
If tests in humans show it is safe and effective, scientists at the Cold Spring Harbor Laboratory in New York believe it could provide a new strategy for overcoming drug resistance in many forms of cancer.
“Our results provide in vivo (living) validation for a strategy to reverse drug resistance in human cancers,” Scott Lowe, the head of the research team, said in a report in the science journal Nature.
Chemotherapy drugs work by triggering a self-destruct program in cancerous cells but some do not respond to the toxic treatments and continue to replicate and form tumors.
Delivering a 'one-two punch'
Lowe and his team decided to use two drugs to deliver a “one-two punch” as in boxing to knock out the drug-resistant cells. They discovered that when they combined the drug rapamycin with the chemotherapy treatment doxorubicin in mice there were massive deaths of lymphoma cells.
The tumors disappeared quickly and the mice tolerated the combination therapy well.
Mice treated with the therapy had lymphomas which had a protein called Akt that inactivated the cell death mechanism in cancerous cells, which made them resistant to the chemotherapy drugs.
But they found that rapamycin blocked the action of Akt and restored the death mechanism which the second drug triggered to deliver the knock-out punch.
Lymphoma includes a variety of cancer of the lymphatic system in the body. It occurs when the cells grow abnormally and out of control. The two main types of lymphoma are Hodgkin’s disease and non-Hodgkin’s lymphoma.
The disease can be treated with surgery if it is confined to one area, as well as with radiotherapy, chemotherapy, immunotherapy or a combination of them.
