Molecular Markers of Glial Tumors: Current Targeting Strategies

Diagnosis and therapy for malignant gliomas represents one of the most challenging problems in clinical oncology. Current treatment of malignant glioma is multimodal, involving surgical resection, radiotherapy and chemotherapy. Even with these combined therapies, patients usually die within 1 to 2 years after onset of symptoms. Clearly, improved strategies for selective delivery of therapeutic agents to gliomas are needed to combat these devastating and usually fatal cancers. This review summarizes current knowledge concerning targetable molecular markers on the surface of glial tumor cells and tumor vasculature. Such markers are altered or up-regulated in gliomas compared to normal tissues, or they might be glioma-restricted. These markers include growth factor receptors, cell-surface adhesion molecules, and membrane-type matrix metalloproteinases. Current approaches that utilize growth factor peptides and peptide / antibodies identified via phage display technology as carrier ligands for targeting malignant gliomas are discussed.