Id genes encoding inhibitors of transcription are expressed during in vitro astrocyte differentiation and in cell lines derived from astrocytic tumors.
Id proteins belong to a class of nuclear transcription factors known as helix-loop-helix proteins. It has been reported that Id genes function as negative regulators of differentiation, and Id gene expression is down-regulated during cell differentiation. We examined the regulation of Id genes during astrocyte differentiation in a murine nervous system precursor cell line, NSEHip2-28, which is able to differentiate along the astroglial lineage, as well as in human astroglial tumor cell lines. Upon induction of NSEHip2-28 differentiation, at a time when glial fibrillary acidic protein expression became detectable, the expression of all four Id family members initially increased dramatically, and subsequently decreased. Furthermore, varying levels of Id gene expression were found in astroglial tumor cell lines displaying variable degrees of lineage-specific differentiation. These results suggest that the expression of Id family members may play an important role in the control of astrocyte differentiation.
Andres-Barquin
P J
PJ
Preuss Laboratory for Molecular Neuro-Oncology, Brain Tumor Research Center, Department of Neurological Surgery, School of Medicine, University of California, San Francisco 94143, USA.
Hernandez
M C
MC
Hayes
T E
TE
McKay
R D
RD
Israel
M A
MA
D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism; D001254:Astrocytoma / Q000235:genetics* / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D051379:Mice; D012097:Repressor Proteins; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D005904:Glial Fibrillary Acidic Protein; C497453:ID1 protein, human; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D014157:Transcription Factors