Stem cells loaded with herpes fight brain tumors
A new study has found that applying herpes-loaded stem cells to brain tumors may be an effective method for improving survival rates.
Previous studies have tested the effects of herpes viruses on tumors, but researchers continually ran into the problem of how to keep the viruses at the tumor site long enough to work. Scientists from the Harvard Stem Cell Institute (HSCI) at Massachusetts General Hospital addressed this problem by using a type of stem cell called mesenchymal stem cells (MSCs). This has proven to be an attractive drug delivery vehicle due to the stem cells' ability to carry viruses and because they result in a minimal immune response.
The researchers first developed the treatment by loading the herpes virus into human MSCs. Next, they tested the treatment on mice with glioblastoma multiform, which is the most common but also most difficult brain tumor to treat in humans. The researchers used an imaging technique that allowed them to watch the virus as it moved from the stem cells to the brain tumor cells. Next, they tried trapping the herpes-loaded stem cells in a gel and applying them to the tumors, as a method that could be conducted in a clinical setting.
The findings, published in the Journal of the National Cancer Institute, showed that the gel method increased the stem cells’ lifespan, which resulted in the herpes virus killing more tumor cells and a higher survival rate among the mice. The researchers concluded that their findings will help inform future clinical trials but that at least two to three years of additional preclinical work is needed.