Xandra Owens Breakefield

Professor of Neurology; Geneticist, Neurology Department, Center for Molecular Imaging Research. Pioneer in the fields on neurogenetics and gene therapy. Focused on identifying disease genes, she was among the first to clone neurologically critical genes, such as those for monoamine oxidase A and Norrie disease. Identified the DYT1 gene - responsible for early onset torsion dystonia - and led the field in elucidating function and encoded protein, torsinA, which is critical in neuronal function. She developed genetic therapies for neurologic disease, generating novel viral vectors for safe delivery of genes to neurons and cell vehicles to deliver growth factors to reduce neurodegeneration. She launched strategies for gene therapy of brain tumors, including oncolytic HSV vectors and neuroprecursor cells encoding suicide genes, now in clinical trials. Explored novel genetic mechanisms in tumor cells, including identification of microRNAs involved in angiogenesis and tumor progression. She first demonstrated that microvesicles produced by tumor cells contain a broad array of RNAs and DNA, including characteristic miRNAs, mutated RNAs and amplified oncogenes. Showed that these microvesicles mediate intercellular transfer of genetics information, modifying normal cells in the tumor environs, and when shed into the bloodstream, serve as important tumor biomarkers.