Scientists from the Beth Israel Deaconess Medical Center (BIDMC) have demonstrated in mice that rapamycin (sirolimus, sold as Rapamune by Wyeth), an immunosuppresor used in organ transplant patients, can inhibit Akt-induced blood vessel changes characteristic of cancer tumors.
Using a mouse model that enabled them to activate the Akt pathway in healthy blood vessel cells – without the complicating influence of tumor cells – they observed that Akt-induced blood vessels demonstrated the very same abnormalities that are seen in tumor blood vessels. Moreover, adds Benjamin, “We discovered that simply removing the activated Akt was sufficient to reverse these vasculature changes.”
The scientists then went on to treat the animals with rapamycin. As predicted, the agent blocked the Akt-induced blood vessel changes. In subsequent experiments, rapamycin reduced tumor growth and vascular leak in a mouse tumor model.
The researchers suggest that rapamycin may have potential as an anti-angiogenic drug to treat cancer.