HIV Protease Inhibitors Show Potential As Cancer Treatments
Several protease inhibitors that are used in combination with other drugs to treat Human Immunodeficiency Virus (HIV) infection may also be effective against certain types of cancer.
The NCI research team investigated HIV protease inhibitors because these drugs are known to inhibit the activation of Akt, a protein that has been implicated in the development of many types of cancer, including non-small cell lung cancer. Using mouse models and in vitro studies, the researchers tested six different protease inhibitors against non-small cell lung cancer as well as a panel of 60 human cancer cell types, in cultures (called cell lines) derived from nine different kinds of malignant tissue. When given in doses that were previously proven to be safe in HIV-infected patients, three of the six protease inhibitors (nelfinavir, ritonavir and saquinavir) inhibited growth of non-small cell lung cancer and every cell type in the set of 60 kinds of cancer cells.
"There are many common threads between cancer and HIV/AIDS, and this research underscores the value of NCI�s involvement in HIV/AIDS research," said NCI Director John E. Niederhuber, M.D.
In this study, nelfinavir and saquinavir were more potent than the other HIV protease inhibitors examined. They each had similar abilities to prevent tumor growth, and induce programmed cell death, or apoptosis, which is a normal process that rids the body of old or damaged cells. The molecular structures of these two drugs share a trait that is not found in the other drugs that were tested, and the researchers speculate that this trait might provide an explanation for the relatively higher potency of these two drugs. Nelfinavir was the most effective of all the protease inhibitors tested, and was able to cause two different types of cancer cell death