title: Modulation of c-myc, max, and mad gene expression during neural differentiation of embryonic stem cells by all-trans-retinoic acid.
abstract: c-Myc regulates cellular proliferation, differentiation, and apoptosis. Temporal expression of c-Myc during all-trans-retinoic acid (RA)-mediated neural differentiation in murine embryonic stem cell (ES) was investigated. Correlation to the modulation of dimerizing partners Max and Mad that may influence c-Myc signaling and transcription regulation was elucidated for the first time in these cells. In RA-treated cells, increase in c-myc mRNA was detected by reverse transcriptase polymerase chain reaction on days 11 and 14 of differentiation compared with the vehicle-treated controls. The results were further corroborated by ribonuclease protection assay (RPA). Western blots revealed an increase in c-Myc protein only on day 14 of differentiation in RA-treated cells. Increases in max and mad gene transcription detected by RPA at times of elevated c-Myc in RA-treated ES cells suggest that a transient increase in c-Myc protein expression may influence differential dimerization of Myc partners needed for signaling in the neural differentiation of ES cells.
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens 30602, USA.
authors.forename: Suparna A
authors.initials: SA
authors.lastname: Sarkar
authors.forename: Raghubir P
authors.initials: RP
authors.lastname: Sharma
mesh_terms: D000818:Animals; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D016259:Genes, myc / Q000187:drug effects*; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D014157:Transcription Factors; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C499479:Mad protein, mouse; C067850:Myc associated factor X; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; C068422:Max protein, mouse; D014212:Tretinoin