Gene Therapy for the Treatment of Brain Tumors

Malignant brain tumors are responsible for a significant amount of deaths in children and adults. Even with advances in surgery, radiation therapy, and chemotherapy, many patients diagnosed with a malignant brain tumor survive only months to weeks. In an attempt to improve the prognosis for these patients, researchers have developed a new approach to brain tumor therapy. This approach makes use of DNA technology to transfer genes sensitive to therapy into the cells of the tumor. Infections with the herpes simplex virus can cause cold sores in the area of the mouth. A drug called ganciclovir (Cytovene) can kill the virus. Ganciclovir is effective because the herpes virus contains a gene (Herpes-Thymidine Kinase TK gene) that is sensitive to the drug. Researchers have been able to separate this gene from the virus. Using DNA technology, researchers hope to transfer and implant the TK gene into tumor cells making them sensitive to ganciclovir. In theory, giving patients ganciclovir will kill all tumor cells that have the TK gene incorporated into them.