Healing Cancer in Light and Color

December 28, 2007 at 10:14 am | In Sciences |

By: Dudi Goldman

The technique developed by Professors Avigdor Shurtz and Yoram Salomon utilizes photosynthesis to destroy cancer cells.

Professor Avigdor Schurtz of the Department of Plant Sceinces at the Weizmann Institute of Science has studied photosynthesis for years. As you learned in high school, that refers to the phenomenon by which nature converts solar energy to electrical and chemical energy.

The chlorophyll molecule is a dye molecule that drives the photosynthetic process in plants. It takes in solar energy, converts it to electrical energy, and this sets in motion a chain of biochemical processes that result in the production of sugars and oxygen in plants.

Cancer in a family member led Professor Schurtz to think of using chlorophyll molecules to treat cancerous tumors. As with all success stories, chance played its part when Schurtz met a friend and colleague, Professor Yoram Salomon, a biochemist, in the halls of Weizmann. The two decided to join forces to develop a novel approach to treating cancer.

“I researched how bacterial chlorophyll gather light energy and translate it into electrical energy and I thought it might be possible to use this to destroy cancerous tissues,” says Professor Schurtz. “There were already papers regarding this technique, called photodynamic therapy, but they did not produce good results and we thought we could improve upon them.”

DG: How does this technique work?
AS: We inject the molecules we have developed into the patient’s body intravenously. Within a short while, the substance spreads throughout the circulatory system. We then illuminate the tumor for a short period (up to 20 minutes) with a laser inserted into the area and connected to optical fibers. Molecules present in the illuminated blood vessels create poisonous oxygenated radicals that react with other particles and rapidly close off the blood vessels nourishing the cancer cells. In other words, illuminating the area of the tumor activates the treatment and closing off the blood vessels starves the cancer cells, which die within a matter of hours.
The blood vessels in the healthy tissue, which are not illuminated, are not affected. The molecules we have designed exit the body rapidly so, as opposed to the currently accepted photodynamic therapy techniques based on other molecules, the risk of skin burns from exposure to light diminishes within hours of treatment. Within 24 to 48 hours of treatment, the tumor dies and is cleaned out by the immune system.

DG: How close is this method to practical implementation?
AS: A French company and an Israeli company, which are developing the substances for clinical use, are now concentrating on clinical trials of patients with prostate cancer for whom radiation therapy was not successful or who have not yet been treated. The trials continue in the United States and Europe.

DG: There is no danger that the substance will affect healthy blood vessels?
AS: No. The toxic activity is limited to cancerous blood vessels and their surroundings.

DG: For which types of cancer would this therapy be effective?
AS: In the future, there will probably be further research on treating breast cancer, pancreatic cancer, and kidney tumors. This technique is good not only for cancer but also for diseases where it is necessary to remove unwanted blood vessels.