PRIMARY BRAIN-TUMORS DIFFER IN THEIR EXPRESSION OF OCTAMER DEOXYRIBONUCLEIC-ACID BINDING TRANSCRIPTION FACTORS FROM LONG-TERM CULTURED GLIOMA CELL-LINES

NERVOUS SYSTEM-SPECIFIC TRANSCRIPTION factors that bind to the octamer ic deoxyribonucleic acid sequence motif ATGCAAAT (or ATTTGCAT) are kno wn as N-Oct proteins. Neurons and glia contain the ubiquitous Oct-1 pr otein and four polypeptide complexes termed N-Oct-2, N-Oct-3, N-Oct-4, and N-Oct-5. Previously, we showed that N-Oct proteins are differenti ally expressed by human neuroblastoma and glioblastoma cell lines in v itro. We have now extended this work to freshly isolated human primary and metastatic brain tumors. Contrary to brain tumor cell lines, of t he five astrocytomas and three glioblastomas analyzed, all but two tum ors displayed the complete N-Oct protein profile, irrespective of hist opathological tumor grade. Two astrocytomas were negative for N-Oct-4. Ten of 13 ependymomas exhibited N-Oct-2, N-Oct-3, and N-Oct-4 but lac ked the N-Oct-5 complex. In contrast, brain metastases of two patients with extracerebral carcinomas contained only Oct-1, and cerebral meta stases from two cases of B cell lymphoma showed Oct-1 and Oct-2 comple xes, the characteristic Oct protein pattern of B lymphocytes. Thus, me tastatic carcinoma and lymphoma expressed a non-nervous system phenoty pe of Oct proteins.