Research in the lab had earlier discovered a protein that binds to and inhibits LRP6. This study showed that the protein, called Mesd (mesoderm development), was able to slow the growth of breast cancer cells in the laboratory and to inhibit mammary tumor growth in laboratory mice.

Importantly, mice treated with Mesd did not experience any of the known side effects, such as bone lesions, skin disorders or intestinal malfunctions, associated with inhibition of this growth pathway.

"Our work introduces Mesd as a promising antitumor agent that might be further developed for breast cancer therapy," Bu says. "It would be analogous to such successful breast cancer therapies as Herceptin (trastuzumab), which specifically targets HER2-positive breast cancer."

The researchers also found that a small segment of Mesd has the same effect as the larger molecule. This segment, or peptide, is more stable than the whole protein molecule and can be easily synthesized.

The researchers have patented the protein and the peptide through the university's Office of Technology Management. Recently, Raptor Pharmaceutical Corp. licensed Mesd from the university to develop it for clinical use.

Liu C-C, Prior J, Piwnica-Worms D, Bu G. LRP6 overexpression defines a class of breast cancer subtype and is a target for therapy. Proceedings of the National Academy of Sciences. March 1, 2010 (advance online publication).

Source: Washington University School of Medicine