Sponsored by
By Regina Sass
Research from the Duke University's Preston Robert Tisch Brain Tumor Center indicates that a common human virus may be a useful tool in treating the most deadly of the brain tumors. They feel their discovery will be an important step that will eventually lead to the development of a vaccine that has the capacity to attack the tumors by using the body's own immune system.
The virus is called human cytomegalovirus (HCMV) and from 50 to 90% of the population gets infected by it during their life time. It is also found to be active in more than 90% of patients with glioblastoma multiforme, the most deadly form of brain cancer.
They do not know at this point whether the virus is in part responsible for the growth of the tumor, or if the opposite is true and the tumor does something to activate the virus. What they have been able to establish is the fact that the virus has the possibility to be able to affect the growth as well as the invasivemess of the cancer cells. With this fact in mind, the figure that if they target the virus, they may boost the body's own immune system to fight the tumor and destroy the cancer.
A vaccine that would target HCMV would most likely be administered after a course of conventional chemotherapy. And the reason for this is the fact that when the immune system is recovering from chemotherapy, there is a burst of new immune cells and the vaccine would be ale to use this process to make and even stronger immune response to the virus.
In a person who does not have the cancer and is relatively healthy, with no immune system problems, the initial infection from the HCMV can be completely symptom free, or at the worse there will be mild flu like symptoms. After the infection phase had past, the virus stays with the person for the rest of his or her life, but in a dormant form.
However, in a person who has a weakened immune system, for example, AIDS patients or someone who has to undergo a bone marrow transplant, the HCMV can become reactivated and thereby be the cause of more severe illnesses, pneumonia for one.
It was back in 2002 when the connection between HCMV and brain tumors was first noticed. This was done by researchers at the University of Alabama - Birmingham, but ever since then, no one has been able to duplicate their results.
The recent study has not only confirmed the fact that the virus is associated with the tumors, but was also able to determine that the patients with the cancer also had a detectable level of the virus in their blood streams, whereas those without the cancer did not.
Based on the results of the research, they have developed a vaccine that will target HCMV and are presently conducting a clinical trial that will provide information on the safety and effectiveness of the vaccine to build up the cancer patients' immunity to HCMV. They expect to complete the enrollment in the trial sometime this year. The cancer patients get the vaccine monthly in conjunction with chemotherapy for as long as the tumors stay stable.
The lead researcher is Duane Mitchell, M.D., Ph.D., a brain cancer researcher. The rest of the team is Weihua Xie, Robert Schmittling, Chris Learn, Allan Friedman, Roger McLendon and John Sampson.
Source: Duke University http://www.dukemednews.org/