title: p53 transcription-dependent and -independent regulation of cerebellar neural precursor cell apoptosis.
abstract: Regulation of cerebellar neural precursor cell (NPC) death is important for both normal brain development and prevention of brain tumor formation. The tumor suppressor p53 is an important regulator of NPC apoptosis, but the precise mechanism of p53-regulated cerebellar NPC death remains largely unknown. Here, by using primary cerebellar NPCs and a mouse cerebellar NPC line, we compared the molecular regulation of cerebellar NPC death produced by staurosporine (STS), a broad-spectrum kinase inhibitor, with that caused by genotoxic agents. We found that both STS- and genotoxin-induced cerebellar NPC death were markedly inhibited by p53 or Bax deficiency. Genotoxin-induced cerebellar NPC death required new protein synthesis and PUMA, a p53 transcriptionally regulated BH3-only molecule. In contrast, STS caused cerebellar NPC death without requiring new protein synthesis or PUMA expression. In addition, genotoxic agents increased nuclear p53 immunoreactivity, whereas STS produced rapid cytoplasmic p53 accumulation. Interestingly, STS-induced death of cerebellar granule neurons was p53-independent, indicating a differentiation-dependent feature of neuronal apoptotic regulation. These results suggest that STS-induced cerebellar NPC death requires a direct effect of p53 on cytoplasmic apoptotic mediators, whereas genotoxin-induced death requires p53-dependent gene transcription of PUMA. Thus, p53 has multiple death promoting mechanisms in cerebellar NPCs.
authors.affiliation: Division of Neuropathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Geng
authors.forename: Rizwan S
authors.initials: RS
authors.lastname: Akhtar
authors.forename: John J
authors.initials: JJ
authors.lastname: Shacka
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Klocke
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: Xinbin
authors.initials: X
authors.lastname: Chen
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Roth
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western / Q000379:methods; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000172:deficiency; D019311:Staurosporine / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D015533:Transcriptional Activation / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000172:deficiency; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000172:deficiency; D051028:bcl-2-Associated X Protein / Q000172:deficiency
chemical_list: D051017:Apoptosis Regulatory Proteins; C494773:Bak1 protein, mouse; C494827:Bax protein, mouse; D004791:Enzyme Inhibitors; C488588:PUMA protein, mouse; C408009:Pmaip1 protein, mouse; D011500:Protein Synthesis Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D020169:Caspases; D019311:Staurosporine