University of Massachusetts Amherst chemical engineering professor Neil Forbes has successfully implanted the cancer-fighting protein TRAIL into mice with breast tumors and activated it. According to a release, 100 percent of the mice survived over the next 30 days after the cancer-fighting protein was implanted.
TRAIL stands for tumor necrosis factor-related apoptosis-inducing ligand, and it is a short group of connected amino acids, known as a peptide, which targets cancer cells. It forms a bond with a cancer cell and triggers apoptosis, or programmed cell death.
According to a release, scientists had known that several common bacteria, such as salmonella, are attracted to cancer cells more than they are attracted to healthy cells. When a variety of salmonella that does not cause disease was genetically engineered, Forbes designed experiments with Sabha Ganai, a surgical oncologist with the Pioneer Valley Life Sciences Institute to see if the safe salmonella could move the TRAIL protein directly to solid tumors.
The experiment was successful. Ganai and Forbes engineered a bacterium called Salmonella typhimurium to carry the TRAIL peptide and made sure that it would only be activated by a protein responsible for DNA repair normally found in E. coli called the RecA promoter.
The modified bacterium was injected into groups of genetically identical mice who had breast cancer. After two days, according to the release, the bacteria had multiplied to around 10 million in each tumor. Then each group was given either a single dose or a double dose of low level radiation. The radiation damaged the bacterial DNA slightly but enough to activate the RecA promoter protein and trigger the production of TRAIL. Most importantly, the use of TRAIL and the modified Salmnonella typhimurium bacteria poses minimal danger to the patient.
Each group did well with the treatment; however the group that received two doses of radiation showed the most improvement.
According to the release, Ganai and Forbes believe that in the future, cancer patients will be able to receive injections of the bacteria and the light irradiation therapy with much less suffering than they experience now.
The experiments were supported with funding from the National Cancer Institute and Susan G. Komen for the Cure. The findings have appeared in the “British Journal of Cancer.”
Matthew M. Robare can be reached at [email protected].
