Abstract
Little is known about the regulation of the oncomiR miR-21 in liver. Dehydroepiandrosterone (DHEA) regulates gene expression as a ligand for a G-protein-coupled receptor and as a precursor for steroids that activate nuclear receptor signaling. We report that 10 nm DHEA increases primary miR-21 (pri-miR-21) transcription and mature miR-21 expression in HepG2 cells in a biphasic manner with an initial peak at 1 h followed by a second, sustained response from 3-12 h. DHEA also increased miR-21 in primary human hepatocytes and Hep3B cells. siRNA, antibody, and inhibitor studies suggest that the rapid DHEA-mediated increase in miR-21 involves a G-protein-coupled estrogen receptor (GPER/GPR30), estrogen receptor α-36 (ERα36), epidermal growth factor receptor-dependent, pertussis toxin-sensitive pathway requiring activation of c-Src, ERK1/2, and PI3K. GPER antagonist G-15 attenuated DHEA- and BSA-conjugated DHEA-stimulated pri-miR-21 transcription. Like DHEA, GPER agonists G-1 and fulvestrant increased pri-miR-21 in a GPER- and ERα36-dependent manner. DHEA, like G-1, increased GPER and ERα36 mRNA and protein levels. DHEA increased ERK1/2 and c-Src phosphorylation in a GPER-responsive manner. DHEA increased c-Jun, but not c-Fos, protein expression after 2 h. DHEA increased androgen receptor, c-Fos, and c-Jun recruitment to the miR-21 promoter. These results suggest that physiological concentrations of DHEA activate a GPER intracellular signaling cascade that increases pri-miR-21 transcription mediated at least in part by AP-1 and androgen receptor miR-21 promoter interaction.
Keywords:
G-protein-coupled receptor (GPCR); estrogen receptor; gene transcription; hormones; microRNA (miRNA); microRNA biogenesis.
© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Adjuvants, Immunologic / pharmacology*
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CSK Tyrosine-Protein Kinase
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Carcinoma, Hepatocellular / genetics
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Carcinoma, Hepatocellular / metabolism*
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Carcinoma, Hepatocellular / pathology
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Dehydroepiandrosterone / pharmacology*
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Estrogen Receptor alpha / genetics
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Estrogen Receptor alpha / metabolism
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Female
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Gene Expression Regulation, Neoplastic / drug effects
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Gene Expression Regulation, Neoplastic / genetics
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Hep G2 Cells
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Humans
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Liver Neoplasms / genetics
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Liver Neoplasms / metabolism*
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Liver Neoplasms / pathology
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MAP Kinase Signaling System / drug effects
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MAP Kinase Signaling System / genetics
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Male
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MicroRNAs / biosynthesis*
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MicroRNAs / genetics
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Mitogen-Activated Protein Kinase 1 / genetics
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3 / genetics
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Mitogen-Activated Protein Kinase 3 / metabolism
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Phosphatidylinositol 3-Kinases / genetics
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Phosphatidylinositol 3-Kinases / metabolism
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Proto-Oncogene Proteins c-fos / genetics
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Proto-Oncogene Proteins c-fos / metabolism
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Proto-Oncogene Proteins c-jun / genetics
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Proto-Oncogene Proteins c-jun / metabolism
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RNA, Neoplasm / biosynthesis*
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RNA, Neoplasm / genetics
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Receptors, Androgen / genetics
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Receptors, Androgen / metabolism
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Receptors, Estrogen / genetics
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Receptors, Estrogen / metabolism*
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Receptors, G-Protein-Coupled / genetics
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Receptors, G-Protein-Coupled / metabolism*
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Response Elements
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Transcription Factor AP-1 / genetics
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Transcription Factor AP-1 / metabolism
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Transcription, Genetic / drug effects*
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Transcription, Genetic / genetics
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src-Family Kinases / genetics
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src-Family Kinases / metabolism
Substances
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Adjuvants, Immunologic
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ESR1 protein, human
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Estrogen Receptor alpha
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GPER1 protein, human
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MIRN21 microRNA, human
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MicroRNAs
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Proto-Oncogene Proteins c-fos
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Proto-Oncogene Proteins c-jun
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RNA, Neoplasm
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Receptors, Androgen
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Receptors, Estrogen
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Receptors, G-Protein-Coupled
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Transcription Factor AP-1
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Dehydroepiandrosterone
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CSK Tyrosine-Protein Kinase
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src-Family Kinases
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CSK protein, human
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MAPK1 protein, human
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3