In their study, the scientists discovered that multiple extra copies of the gene, called OTX2, had been switched back on among tumor cells removed from patients with medulloblastoma brain tumors. In the United States, medulloblastoma accounts for approximately 30 percent of all pediatric brain tumors.
Further, the scientists discovered that a potent derivative of Vitamin A, known as all trans-retinoic acid or ATRA, suppressed growth and induced cell death among the OTX2-laden tumor cells. More than half of medulloblastomas grown in the laboratory responded to ATRA treatment.
"The response that ATRA imposes upon these medulloblastoma brain tumor cell lines suggests that this type of tumor may respond favorably to ATRA-based therapy," said Hai Yan, M.D., Ph.D., the principle investigator of the study at the Brain Tumor Center at the Duke University Medical Center.
"ATRA is already clinically approved for the treatment of acute promyelocytic leukemia. These studies lay the conceptual and practical framework for clinical trials using ATRA in the treatment of a commonly lethal pediatric disease."
Yan said that the OTX2 gene normally contributes to development and growth of certain areas of the brain, such as the cerebellum, but the gene is generally turned off and no longer used after birth.
Using a novel technique that involves snipping apart the entire DNA content in the chromosomes of medulloblastoma cells and then analyzing the quantity of each, Yan and his colleagues detected an abnormally amplified segment among the tumor cells on chromosome 14.