In an effort to destroy cancer cells without harming surrounding tissue, using beams of light to activate chemicals or particles in tumors has shown much promise. Called photodynamic therapy, most of the current methods of using it involve creating a particular deadly form of oxygen or heating up particles or chemicals in tumors. Now, a researcher has found a way to use the therapy to alter the pH of tumors so that they commit suicide without harming the rest of the body.
When a tumor grows in the body, it creates an acidic environment on the outside of its cells. This causes blood vessels to attach to it to try to remove the acid. In something of a biological trick, the tumor then commandeers the blood vessels and uses them as a source of nutrients to help it grow.
Working out of the University of Texas at San Antonio (UTSA), biology professor Matthew Gdovin decided to try an acid trick of his own. He injected a chemical compound called nitrobenzaldehyde into tumors. He then hit the tumors with a beam of ultraviolet light that caused the chemical to make the tumors so acidic that they, in effect, committed suicide.
Working with mice, Gdovin used the technique to stop the tumor growth of a particularly aggressive type of cancer known as triple negative breast cancer. The treatment doubled their chances of survival. In addition to being relatively non-invasive, the technique has the advantage of working quickly. Gdovin estimates that up to 95 percent of cancer cells can be killed within two hours of the treatment, according to UTSA.
Gdovin says the treatment might hold promise for patients who have received the maximum amount of radiation therapy for their cancer, or for those with tumors in areas where surgery is problematic such as those in the brain stem, spine or aorta.
Gdovin is now working with drug-resistant cancer cells to improve his method. His work has been published in The Journal of Clinical Oncology.