Oct 15, 2010 2:11 PM by Carina Corral
A potent drug derived from an evergreen tree may soon save the lives of patients with the most deadliest form of breast cancer.
Researchers at U.C. Santa Barbara, in cooperation with scientists in the pharmaceutical industry, have discovered the mechanism by which the clinical drug, trastuzumab-DM1, kills cancer cells.
"We discovered how the drug is taken up into the tumor cells," said one of the researchers, Mary Ann Jordan. "We found out that it is metabolized by the cancer cells, inhibits the dynamics of cellular microtubules, and thus blocks the mitosis of the spindles in the cells, causing them to die."
Microtubules are the dynamic, rapidly growing and shortening protein filaments that help cells to divide and multiply.
Trials show the drug shrank the tumors of one-third of the patients with metastatic breast cancer.
The drug, not yet approved by the FDA, was previously considered too dangerous to use, because of its toxicity to non-cancer cells.
However, researchers showed that by adding an antibody it caused the drug to target only cancer cells, reducing its toxicity.
The results are reported in two studies published as the cover story of the October issue of Molecular Cancer Therapeutics.