title: Consistent nuclear expression of thyroid transcription factor 1 in subependymal giant cell astrocytomas suggests lineage-restricted histogenesis.
abstract: Thyroid transcription factor 1 (TTF-1) is encoded by the NKX2-1 homeobox gene. Besides specifying thyroid and pulmonary organogenesis, it is also temporarily expressed during embryonic development of the ventral forebrain. We recently observed widespread immunoreactivity for TTF-1 in a case of subependymal giant cell astrocytoma (SEGA, WHO grade I)--a defining lesion of the tuberous sclerosis complex (TSC). This prompted us to investigate additional SEGAs in this regard. We found tumor cells in all 7 specimens analyzed to be TTF-1 positive. In contrast, we did not find TTF-1 immunoreactivity in a cortical tuber or two renal angiomyolipomas resected from TSC patients. We propose our finding of consistent TTF-1 expression in SEGAs to indicate lineage-committed derivation of these tumors from a regionally specified cell of origin. The medial ganglionic eminence, ventral septal region, and preoptic area of the developing brain may represent candidates for the origin of SEGAs. Such lineage-restricted histogenesis may also explain the stereotypic distribution of SEGAs along the caudate nucleus in the lateral ventricles.
authors: Ekkehard
authors: E
authors: Hewer
authors: Istvan
authors: I
authors: Vajtai
mesh_terms: D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000378:metabolism / Q000473:pathology*; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D014157:Transcription Factors; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; C504003:TTF1 protein, human; D014157:Transcription Factors