“This is a very broad-reaching discovery,” says Hammer. Indeed, King says that he has already had some success using selectin coatings to reprogram cancer cells.
Cancer cells appear to highjack selectin pathways in order to spread to other parts of the body, the process known as metastasis. Tumors shed cells into the bloodstream. Some of those cells seem to exit with the help of selectins; ensconced in new tissue, they then establish new tumors. These secondary tumors cause more cancer deaths than initial tumors do.
King says he has unpublished work demonstrating that leukemia cells that roll along a coating of selectins and a cancer-specific signaling molecule will go through a process called programmed cell death. Healthy stem cells also roll across the device because they’re attracted to the selectins, but the death signal doesn’t affect them. Leukemia is a blood cancer, but King expects that the anticancer coating would work for solid tumors as well. Devices lined with these coatings might be implanted into cancer patients to prevent or slow metastasis.
King hopes to test antimetastasis implants in animals this year. He’s collaborating with Jeffrey Karp, a bioengineer at the Harvard-MIT Division of Health Sciences and Technology, and Robert Langer, an MIT Institute Professor, to develop selectin coatings that are stable over months rather than days.
CellTraffix CEO Tom Fitzgerald says that the company’s first product, a kit that will enable researchers to capture large numbers of stem and cancer cells in the lab, will likely reach the market early next year. The company hopes to begin clinical testing of the anticancer coatings by early 2010.