Identification of a glioblastoma-associated tenascin-C isoform by a high affinity recombinant antibody

Tenascin-C exists in several polymorphic isoforms due to alternative splici ng of nine fibronectin-like type III repeats. Large Tenascin-C isoforms are present in almost all normal adult tissues but are upregulated in fetal, r egenerating, and neoplastic tissues. Here, we report a human antibody fragm ent, TN11, derived from a phage library with high affinity for the spliced repeat C and demonstrate that this repeat is undetectable in normal adult t issues, barely detectable or undetectable in breast, lung and gastric carci nomas, meningioma, and low grade astrocytoma, but extremely abundant in hig h grade astrocytoma (grade III and glioblastoma), especially around vascula r structures and proliferating cells. The antibody appears to have potentia l for development of a therapeutic agent for patients with high grade astro cytoma.