title: Retinoic acid induces CDK inhibitors and growth arrest specific (Gas) genes in neural crest cells.
abstract: Retinoic acid (RA), the active metabolite of vitamin A, regulates cellular growth and differentiation during embryonic development. In excess, this vitamin is also highly teratogenic to animals and humans. The neural crest is particularly sensitive to RA, and high levels adversely affect migration, proliferation and cell death. We investigated potential gene targets of RA associated with neural crest proliferation by determining RA-mediated changes in gene expression over time, using microarrays. Statistical analysis of the top ranked RA-regulated genes identified modest changes in multiple genes previously associated with cell cycle control and proliferation including the cyclin-dependent kinase inhibitors Cdkn1a (p21), Cdkn2b (p15(INK4b)), and Gas3/PMP22. The expression of p21 and p15(INK4b) contribute to decreased proliferation by blocking cell cycle progression at G1-S. This checkpoint is pivotal to decisions regulating proliferation, apoptosis, or differentiation. We have also confirmed the overexpression of Gas3/PMP22 in RA-treated neural crests, which is associated with cytoskeletal changes and increased apoptosis. Our results suggest that increases in multiple components of diverse regulatory pathways have an overall cumulative effect on cellular decisions. This heterogeneity contributes to the pleiotropic effects of RA, specifically those affecting proliferation and cell death.
authors.affiliation: Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
authors.forename: Linping
authors.initials: L
authors.lastname: Wang
authors.forename: John P
authors.initials: JP
authors.lastname: Mear
authors.forename: Chia-Yi
authors.initials: CY
authors.lastname: Kuan
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Colbert
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D050762:Cyclin-Dependent Kinase Inhibitor p15; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D046228:Microarray Analysis; D009185:Myelin Proteins / Q000378:metabolism; D009432:Neural Crest / Q000166:cytology* / Q000187:drug effects; D014212:Tretinoin / Q000494:pharmacology*; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: C493957:Cdkn1a protein, mouse; C493968:Cdkn2b protein, mouse; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009185:Myelin Proteins; C489545:Pmp22 protein, mouse; D025521:Tumor Suppressor Proteins; D014212:Tretinoin; D018844:Cyclin-Dependent Kinases