Let There Be Light

A new cancer treatment approach — light-based therapy — has been shown to kill cancer cells in mice, reports Technology Review's Erica Westly. The method, developed by researchers at NCI, utilizes a heat-sensitive fluorescent dye paired with cancer-specific antibodies — the dye heats up and burns small holes into the membrane of the cell it is attached to when exposed to near-infrared light, killing the cell, Westly says. The antibodies are used to target proteins that are over-expressed in cancer cells, so normal cells will be spared. The study, published in Nature Medicine, shows that the treatment reduced tumor growth in mice, and prolonged survival. There are still a few problems to work out before the treatment can be tested in humans, however. The researchers don't know what effect the treatment will have on large tumors, and it may be hard to find the right dye-biomarker combinations, Westly says. But experts are encouraged by the lack of toxicity, and the method could serve as a secondary therapy by helping surgeons label cancer cells that remain after surgery to target them for clean-up, she adds.