Researchers from the University of California in San Francisco have announced that they have discovered a new drug that successfully blocks the main source of cancer growth. It has been proven as effective on mice, and now final tests are being done to start clinical trials on human patients.
The new drug is unlike any other drug that’s currently in clinical trials — it short-circuits the normal ability of cells to sense the need to grow and divide. Normally, in response to growth signals, a multi-protein unit in cells called mTOR integrates information about the cell’s nutritional and energy needs, and prompts the cell to manufacture key proteins for cell growth. But cancer exploits this signal for its own growth.
“We were trying to synthesize compounds that could help us learn more about how cancer exploits normal growth controls,” said Kevan Shokat, one of the researchers. “Once we made it, though, we found it was even better than we thought it would be at blocking mTor signaling. It does everything that rapamycin does and more.”
The new drug is successful because there are two mTOR signal pathways, and it blocks both. On the other hand, a drug that’s currently being used is Rapamycin, which only blocks one, and so allows the growth-signaling system to still function.
“I hope the new drug can be used to treat a range of cancers,” said Shokat. “We will work with clinicians to test it against a number of types of cancer – breast, lung and others. We want to first find the cancer that is most sensitive to it.”
The details are published in PLoS Biology.