A Light-Activated Targeted Cancer Therapy
A good example of the next generation of targeted cancer therapies is outlined at the Technology Review: "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. ... 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. There are a few kinks to work out before the system can be adapted for humans, though. For instance, the researchers couldn't test the treatment's effect on large tumors, since killing off too many cells at once caused cardiovascular problems in the mice. Finding the right cancer-cell markers to pair with the dye may also prove difficult. For example, HER-2, one of the proteins targeted in the study, is only expressed in 40 percent of breast-cancer cells in humans. Still, the lack of toxicity associated with the treatment is a huge advantage,"