Recent animal testing has revealed that stem cells loaded with the herpes virus can be used to specifically target and kill brain tumors, a startling revelation for the field of virotherapy.

Past research in virotherapy - the use of specially designed viruses to eliminate cancer cells in a patient - has shown that oncolytic herpes simplex viruses can be especially useful in treating brain cancer, as the virus naturally attacks dividing brain cells.

Unfortunately, the therapy hasn't worked well among humans in the past because researchers had no way to keep the virus from migrating away from the tumor site before its work was done, according to a Harvard University press release.

However, new research from the Harvard Stem Cell Institute (HSCI) has revealed that adult stem cells from bone marrow tissue - called mesenchymal stem cells - can be used to keep the virus contained as it spreads deeper and deeper into tumor tissue.

The virus, contained in the stem cells, only spreads through the division of these cells, which is in turn contained around the tumor using biocompatible gels.

According to study leader Khalid Shah, MS, PhD, of the HSCI, his team of researchers applied this practice when treating the brain tumors of lab mice.

"We loaded MSCs with oncolytic herpes virus and encapsulated these cells in biocompatible gels and applied the gels directly onto the adjacent tissue after debulking," he explained in a press release.

Imaging hardware allowed the team to follow the spread of the virus, determining if it stayed to do its job in the intended area. According to the study, the virus did just that, sticking around long enough to completely kill off the cells of the entire brain tumor.

"Our approach can overcome problems associated with current clinical procedures," Shah said. "The work will have direct implications for designing clinical trials using oncolytic viruses, not only for brain tumors, but for other solid tumors."

According to the researchers behind the study, it will be another two to three years before this procedure is moved to human clinical trials.

The study was published in the Journal of the National Cancer Institute on May 16.

Other recent advances in virotherapy already underway involve the successful use of a genetically altered measles virus to cure aggressive blood cancers.