Rapamycin bound to mTOR
Created from a bacterium discovered on Easter Island, rapamycin (also known as sirolimus) has long been touted for its immunosuppressive abilities. It has been approved by the FDA to prevent transplant rejection and vascular restenosis after stent implantation.
Rapamycin works by binding to mTOR, a protein that controls all growth and other cellular functions. Because rapamycin is known to inhibit growth, researchers have hypothesized that the drug could have significant antitumor activity.
Dr. Robert Abraham found that this protein was part of a signaling pathway considered a major cancer driver.
In collaboration with the laboratories of Drs.
Robert Oshima and
William Stallcup at Sanford-Burnham, the group investigated how rapamycin affects breast tumor development in mice. Researchers found that rapamycin dramatically inhibited both tumor-associated angiogenesis (blood vessel growth) and tumor growth.
Research - Cancer - Your Health: Retasking Rapamycin