Retinoic acid and serum modulation of thymosin beta-10 gene expression in rat neuroblastoma cells.
A cloned thymosin beta-10 cDNA was used to study modulation of thymosin beta-10 mRNA levels in the rat B104 neuroblastoma cell line in response to retinoic acid. Northern blot analysis revealed the presence of a single greater than 600-nucleotide thymosin beta-10 mRNA species that was constitutively expressed in proliferating neuroblastoma cells. Addition of retinoic acid to the culture medium induced a dose- and time-dependent increase in thymosin beta-10 mRNA abundance. Additional studies showed that although thymosin beta-4 and beta-10 are coexpressed in this cell line, the stimulatory action of retinoic acid is specific for the thymosin beta-10 gene. Serum was found to augment the stimulatory action of retinoic acid. Blockade of protein synthesis with cycloheximide abrogated the stimulatory action of retinoic acid upon thymosin beta-10 mRNA accumulation; this observation suggests that activation of the thymosin beta-10 gene in this cell line by retinoic acid is dependent upon the de novo synthesis of a labile protein. Collectively, these findings demonstrate that the developmentally regulated thymosin beta-10 gene is a target for morphogenic retinoids in cells derived from the neural crest.
Hall
A K
AK
Department of Surgery, University of Medicine and Dentistry, New Jersey Medical School, Newark 07103-2757.
D000818:Animals; D001769:Blood; D015152:Blotting, Northern; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D015342:DNA Probes; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007700:Kinetics; D009447:Neuroblastoma; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D013947:Thymosin / Q000031:analogs & derivatives* / Q000235:genetics / Q000302:isolation & purification; D014212:Tretinoin / Q000494:pharmacology*
D003470:Culture Media; D015342:DNA Probes; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014212:Tretinoin; D013947:Thymosin; C039302:thymosin beta(10); D003513:Cycloheximide