Novel combination therapy stops tumor development in mice
Scientists at the Cold Spring Harbor Laboratory have successfully treated mice with a certain type of cancerous tumor using two antibiotics. Since many types of cancer are based on the programmed cell death being switched off in the degenerated cells, the researchers led by Scott Lowe first administered rapamycin to the animals, which reactivates the cell suicide mechanism. They then gave the rodents doxorubicin, which now specifically triggered the cell death of the cancer cells by damaging the genetic material.
The combination could possibly help against a whole range of tumor variants, since rapamycin acts indirectly against the protein Akt, which is overproduced in numerous cancer diseases and thus inactivates the cell death mechanism. Such tumors therefore regressed quickly and in some cases even completely, while other types of cancer did not respond. The rodents tolerated the therapy well and survived longer than conspecifics with the same tumor types that were only treated with one of the two antibiotics.
Rapamycin was isolated from the Easter Island fungus Streptomyces hygroscopius in the 1970s and is used, among other things, to suppress the immune system after organ transplants. Doxorubicin, discovered in Streptomyces peucetius in 1967, is used as a cytostatic.