Radiation Damage May Be Prevented By A New Drug
US scientists are developing a new drug that may prevent radiation damage caused by cancer treatment or nuclear emergency.
Radiation is known to be the most powerful tool for cancer treatment, but it has also adverse side effects - it kills healthy tissues just as it kills cancerous ones. This is why physicians are very limited in using radiation therapy. If they have a drug for preventing side effects, they will be able to give necessary radiation doses to cancer sufferers.
Here is how researchers explain cancer development and radiation affect on the disease:
Apoptosis is a tool of body to prevent cells with damaged genes from spreading. Cells with damaged genes are called defective cells. In other words, apoptosis is called cell suicide. When cancer cells block apoptosis, tumors occur and grow. Scientists have identified one of the ways how apoptosis is being blocked: cancer cells activate nuclear factor-KappaB (NFKB), which is a cell-signaling pathway.
When a cancerous tissue is being exposed to radiation, cancerous cells die, but healthy cells die as well. Bone marrow and GI cells are the most vulnerable ones to radiotherapy, and patients who get exposed to high doses of radiation may later develop GI syndrome which is lethal. The same thing can happen during radiation emergencies.
In the trial, researchers used NFKB pathway to artificially block cell suicide in healthy tissues before radiation exposure. It is known that flagellin - a protein taken from gut bacteria - can trigger NFKB. Researchers injected artificially created flagellin protein - named CBLB502 - into healthy tissues.
In laboratory trials researchers used mice and rhesus monkeys. They were CBLB502 injected 15 minutes before being exposed to lethal doses of radiation. Both mice and monkeys showed significant improvement in survival rates. Cancerous cells were destroyed, meanwhile healthy cells where dramatically protected from radiation site effects.
The study plans human trials this summer. If successful, physicians will be have a great chance to fully use the power of radiotherapy in cancer patients. Drug will also save lives of those exposed to high doses of radiation during nuclear emergencies.