Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by inhibiting translation and/or inducing degradation of target mRNAs, and they play important roles in a wide variety of biological functions including cell differentiation, tumorigenesis, apoptosis and metabolism. However, there is a paucity of information concerning the regulatory mechanism of miRNA expression. Here we report identification of growth factor-regulated miRNAs using the PC12 cell line, an established model of neuronal growth and differentiation. We found that expression of miR-221 and miR-222 expression were induced by nerve growth factor (NGF) stimulation in PC12 cells, and that this induction was dependent on sustained activation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway. Using a target prediction program, we also identified a pro-apototic factor, the BH3-only protein Bim, as a potential target of miR-221/222. Overexpression of miR-221 or miR-222 suppressed the activity of a luciferase reporter activity fused to the 3' UTR of Bim mRNA. Furthermore, overexpression of miR-221/222 decreased endogenous Bim mRNA expression. These results reveal that the ERK signal regulates miR-221/222 expression, and that these miRNAs might contribute to NGF-dependent cell survival in PC12 cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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5' Untranslated Regions / genetics
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Animals
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Apoptosis Regulatory Proteins / genetics
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Base Sequence
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Bcl-2-Like Protein 11
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Blotting, Western
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Butadienes / pharmacology
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Cycloheximide / pharmacology
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Enzyme Inhibitors / pharmacology
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Gene Expression / drug effects
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Luciferases / genetics
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Luciferases / metabolism
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Membrane Proteins / genetics
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MicroRNAs / genetics*
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MicroRNAs / metabolism
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Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 1 / metabolism*
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Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 3 / metabolism*
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Nerve Growth Factor / pharmacology*
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Nitriles / pharmacology
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PC12 Cells
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Protein Biosynthesis / drug effects
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Protein Synthesis Inhibitors / pharmacology
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Proto-Oncogene Proteins / genetics
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Rats
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Sequence Homology, Nucleic Acid
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Signal Transduction / drug effects
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Time Factors
Substances
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5' Untranslated Regions
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Apoptosis Regulatory Proteins
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Bcl-2-Like Protein 11
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Bcl2l11 protein, rat
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Butadienes
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Enzyme Inhibitors
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Membrane Proteins
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MicroRNAs
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Nitriles
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Protein Synthesis Inhibitors
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Proto-Oncogene Proteins
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RNA, Messenger
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Recombinant Fusion Proteins
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U 0126
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Nerve Growth Factor
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Cycloheximide
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Luciferases
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3