Firefly light helps destroy cancer cells

In a new study, UCL researchers found that the bioluminescence effects of fireflies may kill cancer cells from within.

By inserting the firefly gene that activates bioluminescent light into modified cancer cells, the researchers hoped to set off a chain of events that has a proven track record at fighting the disease. This light source, known as Luciferin, caused the modified cancer cells to glow much like it does with the firefly. When a photosensitizing agent was added, the combination proved lethal.

"The cells produced enough light to trigger their own death," say Drs. Theodossis Theodossiou of the National Medical Laser Centre and John Hothersall of the Institute of Urology and Nephrology University College London. The results are published today in the journal Cancer Research.

This firefly technique (BioLuminescence Activated Destruction of cancer or BLADe) may add a further layer of depth to photodymic therapy, which is effective against tumours that sit near the skin's surface or on the lining of internal organs. As part of the therapy, cancer cells are treated with a photosensitizer and then exposed to lasers or another external source of light. The light triggers the production of active oxygen species that can destroy cancer cells.

External light sources, however, can only pass through a small amount of tissue to get to the tumour. In an attempt to treat deeper malignancies, the BLADe team inserted the light source into the disease itself.

Cancer cells were modified to express the firefly Luciferase gene and then incubated with luciferin in the lab. The cells essentially became miniature lamps, giving out light that could trigger their destruction. After a photosensitizer was added, the cells produced toxic substances that forced them to commit suicide.

"The light is generated within the tumour cell, so there's no need for outside penetration," say Drs. Theodossiou and Hothersall.

The researchers are pursuing efforts to one day test the firefly-inspired treatment in patients. Already, a separate team has shown that it's feasible to deliver the Lucifirin gene to prostate cancer cells. As a mobile light source, the firefly gene may have far-reaching applications.

"Luciferase could be transferred to primary tumours, and from there it could migrate to cancer cells that spread," said Drs. Theodossiou and Hothersall.