Light-Based Therapy Destroys Cancer Cells

For more than two decades, researchers have tried to develop a light-activated cancer therapy that could replace standard chemotherapy, which is effective but causes serious negative side effects. Despite those efforts, they've struggled to come up with a light-activated approach that would target only cancer cells.

Now scientists at the National Cancer Institute have developed a possible solution that involves pairing cancer-specific antibodies with a heat-sensitive fluorescent dye. The dye is nontoxic on its own, but when it comes into contact with near-infrared light, it heats up and essentially burns a small hole in the cell membrane it has attached to, killing the cell.

To target the tumor cells, the researchers used antibodies that bind to proteins that are overexpressed in cancer cells. "Normal cells may have a hundred copies of these antibodies, but cancer cells have millions of copies. That's a big difference," says Hisataka Kobayashi, a molecular imaging researcher at the National Cancer Institute and the lead author of the new study, published this week in Nature Medicine. The result is that only cancer cells are vulnerable to the light-activated cascade.

The researchers tested the new treatment in mice and found that it reduced tumor growth and prolonged survival.