New Approach To Gene Therapy May Shrink Brain Tumors, Prevent Their Spread
Posted Sep 28 2008 3:06pm
Massachusetts General Hospital (MGH) researchers are investigating a new approach to gene therapy for brain tumors – delivering a cancer-fighting gene to normal brain tissue around the tumor to keep it from spreading. An animal study published in the journal Molecular Therapy, the first to test the feasibility of such an approach, found that inducing mouse brain cells to secrete human interferon-beta suppressed and eliminated growth of human glioblastoma cells implanted nearby.
“We had hypothesized that genetically engineering normal tissue surrounding a tumor could create a zone of resistance – a microenvironment that prevents the growth or spread of the tumor,” says Miguel Sena-Esteves, PhD, of the MGH Neuroscience Center, the study’s senior author. “This proof of principle study shows that this could be a highly effective approach, although there are many additional questions that need to be investigated.”
Glioblastoma is the most common and deadly form of brain tumor. Human clinical trials of other gene therapies have not significantly reduced tumor progression. One problem has been that patients’ immune systems target the viral vectors used to deliver cancer-eliminating genes. Another issue has been inefficient gene delivery, due in part to the inherent cellular diversity found within an individual patient’s tumor as well as among tumors from different patients. In addition, if tumor cells are successfully induced to express an anticancer protein, production of that protein will drop as the tumor dies, allowing any cells that did not receive the gene to resume growing. In the current study the MGH team examined whether expression of a therapeutic gene in normal brain cells could form a stable and effective anti-tumor reservoir.