Mice that light up when cancer cells are on the rampage and dim when the tumors recede. Sounds like a biotech fantasy? It's actually a tool that may help researchers test cancer drugs -- thanks to a firefly gene.
Stanford physicians Christopher Contag and Robert Negrin developed the technique by inserting the gene that makes fireflies glow into human tumor cells and then injecting those cells into mice. When tumors are thriving, scientists can see the firefly light through the mouse's skin using color-coded images from a video camera hooked to a computer.
As tumors grow, the glow spreads. But within days after the mouse is given a cancer-fighting drug, the light diminishes as tumor cells die. Contag and Negrin tested three chemotherapy drugs on human cervical tumor cells to show that the new method is reliable and reported the results last fall in the Proceedings of the National Academy of Sciences. The two believe the technique will be especially useful in testing low-toxicity drugs as a treatment for the few cancer cells found early in disease or left behind after removal of a large tumor.
Another benefit: fewer mice will be sacrificed in the name of medical research. Says Contag, "You use fewer animals to get more data more efficiently."
