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Cyclin D1-dependent regulation of B-myb activity in early stages of neuroblastoma differentiation

TitleCyclin D1-dependent regulation of B-myb activity in early stages of neuroblastoma differentiation
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2002
AuthorsCesi, Vincenzo, Tanno Barbara, Vitali Roberta, Mancini C., Giuffrida M.L., Calabretta B., and Raschellà Giuseppe
JournalCell Death and Differentiation
Volume9
Pagination1232-1239
ISSN13509047
Keywordsantineoplastic agent, Antineoplastic Agents, article, biological marker, Biological Markers, cell cycle protein, Cell Cycle Proteins, Cell Line, Cell Transformation, controlled study, cyclin A, cyclin D1, DNA binding protein, DNA-Binding Proteins, down regulation, drug effect, enzyme assay, human, human cell, Humans, Immunoprecipitation, luciferase, metabolism, MYBL2 protein, Neoplastic, nerve cell differentiation, Neuroblastoma, neuroblastoma cell, pregnancy specific beta1 glycoprotein, Pregnancy-Specific beta 1-Glycoproteins, priority journal, promoter region, protein analysis, protein degradation, protein expression, protein p21, protein stability, regulatory mechanism, Retinoic acid, rho GTP-Binding Proteins, Rho guanine nucleotide binding protein, Time, Trans-Activators, transactivation, transactivator protein, transcription factor, transcription factor B myb, transcription factor Sp1, Tretinoin, unclassified drug
Abstract

Levels of the transcription factor B-myb must be down-regulated to allow terminal differentiation of neuroectodermal cells and yet its constitutive expression induces early markers of neural differentiation. Thus, we investigated potential mechanisms of enhanced B-myb activity in early stages of neural differentiation. We report here that B-myb expression does not decrease, cyclin A and Sp1 levels remain constant while p21 levels increase continuously upon retinoic acid-induced differentiation of the LAN-5 neuroblastoma cell line. In contrast, cyclin D1 expression is down-regulated at the onset of the differentiative process by protein destabilization. Luciferase assays of promoter activity indicate that B-myb-dependent transactivation is enhanced in LAN-5 cells treated with retinoic acid (RA) for 24 h. The enhancement is independent from cyclin A but is suppressed by a degradation-resistant mutant form of cyclin D1. The importance of cyclin D1 in controlling B-myb activity is further suggested by co-immunoprecipitation experiments, showing that the amount of cyclin D1 co-immunoprecipitated with B-myb decreased after RA treatment. Thus, B-myb may play an active role in the early stages of differentiation when its transactivation activity is enhanced as a consequence of cyclin D1 down-modulation.

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URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-0036848105&doi=10.1038%2fsj.cdd.4401103&partnerID=40&md5=7d58f8407ca2f2dfdaa179e304082198
DOI10.1038/sj.cdd.4401103
Citation KeyCesi20021232