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Pan P, Treat MD, van Breukelen F. A systems-level approach to understanding transcriptional regulation by p53 during mammalian hibernation. ACTA ACUST UNITED AC 2015; 217:2489-98. [PMID: 25031456 DOI: 10.1242/jeb.103614] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Presumably to conserve energy, many mammals enter into hibernation during the winter. Homeostatic processes such as transcription and translation are virtually arrested. To further elucidate transcriptional regulation during hibernation, we studied the transcription factor p53. Here, we demonstrate that changes in liver mRNA and protein concentrations of known regulators of p53 are consistent with activation. p53 mRNA and protein concentrations are unrelated. Importantly, p53 protein concentration is increased ~2-fold during the interbout arousal that punctuates bouts of torpor. As a result, both the interbout arousal and the torpid state are characterized by high levels of nuclear-localized p53. Chromatin immunoprecipitation assays indicate that p53 binds DNA during the winter. Furthermore, p53 recruits RNA polymerase II, as indicated by nuclear run-on data. However, and consistent with previous data indicating an arrest of transcriptional elongation during torpor, p53 'activity' does not result in expected changes in target gene transcripts. These data demonstrate the importance of using a systems level-approach in understanding a complex phenotype such as mammalian hibernation. Relying on interpretations of data that are based on steady-state regulation in other systems may be misleading in the context of non-steady-state conditions such as torpor.
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Affiliation(s)
- Peipei Pan
- School of Life Sciences, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154, USA
| | - Michael D Treat
- School of Life Sciences, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154, USA
| | - Frank van Breukelen
- School of Life Sciences, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154, USA
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Gα12 gep oncogene deregulation of p53-responsive microRNAs promotes epithelial-mesenchymal transition of hepatocellular carcinoma. Oncogene 2014; 34:2910-21. [PMID: 25065598 DOI: 10.1038/onc.2014.218] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 06/12/2014] [Accepted: 06/15/2014] [Indexed: 11/09/2022]
Abstract
Hepatocellular carcinoma (HCC) has a poor prognosis owing to aggressive phenotype. Gα12 gep oncogene product couples to G-protein-coupled receptors, whose ligand levels are frequently increased in tumor microenvironments. Here, we report Gα12 overexpression in human HCC and the resultant induction of zinc-finger E-box-binding homeobox 1 (ZEB1) as mediated by microRNA deregulation. Gα12 expression was higher in HCC than surrounding non-tumorous tissue. Transfection of Huh7 cell with an activated mutant of Gα12 (Gα12QL) deregulated microRNA (miRNA or miR)-200b/a/429, -194-2/192 and -194-1/215 clusters in the miRNome. cDNA microarray analyses disclosed the targets affected by Gα12 gene knockout. An integrative network of miRNAs and mRNA changes enabled us to predict ZEB1 as a key molecule governed by Gα12. Decreases of miR-200a/b, -192 and -215 by Gα12 caused ZEB1 induction. The ability of Gα12 to decrease p53 levels, as a result of activating protein-1 (AP-1)/c-Jun-mediated mouse double minute 2 homolog induction, contributed to transcriptional deregulation of the miRNAs. Gα12QL induced ZEB1 and other epithelial-mesenchymal transition markers with fibroblastoid phenotype change. Consistently, transfection with miR-200b, -192 or -215 mimic prevented the ability of Gα12QL to increase tumor cell migration/invasion. In xenograft studies, sustained knockdown of Gα12 decreased the overall growth rate and average volume of tumors derived from SK-Hep1 cell (mesenchymal-typed). In HCC patients, miR-192, -215 and/or -200a were deregulated with microvascular invasion or growth advantage. In the HCC samples with higher Gα12 level, a correlation existed in the comparison of relative changes of Gα12 and ZEB1. In conclusion, Gα12 overexpressed in HCC causes ZEB1 induction by deregulating p53-responsive miRNAs, which may facilitate epithelial-mesenchymal transition and growth of liver tumor. These findings highlight the significance of Gα12 upregulation in liver tumor progression, implicating Gα12 as an attractive therapeutic target.
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Kim YW, Lee WH, Choi SM, Seo YY, Ahn BO, Kim SH, Kim SG. DA6034 promotes gastric epithelial cell migration and wound-healing through the mTOR pathway. J Gastroenterol Hepatol 2012; 27:397-405. [PMID: 21793913 DOI: 10.1111/j.1440-1746.2011.06873.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND AIM 7-Carboxymethyloxy-3',4',5-trimethoxy flavone (DA6034), a synthetic derivative of eupatilin, has a protective effect on gastric mucosa against various ulcerogens, and is currently in the phase III clinical trial in the treatment of peptic ulcer disease. Cell migration and/or growth plays a role in the repair process of gastric ulcer, so this study investigated the effect of DA6034 on the movement and proliferation of gastric epithelial cells and its associated signaling pathway. METHODS The migration of AGS or SNU484 human gastric epithelial cells was shown by scratch-induced wound healing and transwell assays, and the proliferation of the cells was assessed by FACS and proliferation assays. RESULTS Treatment of DA6034 promoted the migration of gastric epithelial cells in a concentration-dependent manner. DA6034 treatment facilitated the phosphorylation of mTOR that led to an increase in the activity of S6K1, indicating its ability to activate mTOR and S6K1. Rapamycin aborted the wound-healing effect of DA6034, which supported the role of mTOR activation in the wound-healing process. In addition, DA6034 treatment increased PI3K-dependent Akt phosphorylation, which was necessary for the enhancement of cell migration. DA6034, however, did not stimulate the proliferation of gastric epithelial cells, being consistent with no activation of ERK1/2 by the agent. CONCLUSIONS DA6034 has the ability to heal scratch wounds, which may result from an increase in gastric epithelial cell migration as mediated by PI3K-Akt-dependent activation of mTOR and S6K1. Our finding may be of help in understanding the molecular basis of the anti-ulcer effect of DA6034.
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Affiliation(s)
- Young Woo Kim
- Innovative Drug Research Center for Metabolic and Inflammatory Diseases, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
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Kim ES, Jeong JB, Kim S, Lee KM, Ko E, Noh DY, Hwang KT, Ha JH, Lee CH, Kim SG, Moon A. The G12 family proteins upregulate matrix metalloproteinase-2 via p53 leading to human breast cell invasion. Breast Cancer Res Treat 2010; 124:49-61. [PMID: 20044778 DOI: 10.1007/s10549-009-0697-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 12/16/2009] [Indexed: 12/27/2022]
Abstract
Although mounting evidence suggests a role for G(12) proteins, G(α12) and G(α13), in tumor progression, a direct role of G(12) proteins has not been determined. This study aims to elucidate the molecular mechanism for a tumorigenic and invasive potential of G(α12) and G(α13) in MCF10A human breast epithelial cells. Here, we report, for the first time, that G(α12) and G(α13) induce upregulation of matrix metalloproteinase (MMP)-2 leading to the invasive and migratory phenotypes in MCF10A cells. We further show that p53 is an important transcription factor for induction of MMP-2 transcriptional activation by G(α12/13). G(α12/13)-induced MMP-2 upregulation, invasion, and migration are dependent on the activation of Ras, Rac1, MKK3/6, p38, and Akt. Using human breast tissue samples, we demonstrate that the expression levels of G(α12) and MMP-2 are strongly correlated with the pathogenically diagnosed cancer (P < 0.0001). Moreover, the expression of G(α12) shows a strong correlation with that of MMP-2 in human breast cancer tissues, implicating the in vivo tumorigenic potential of G(α12). Taken together, this study elucidated the role of G(12) proteins in regulating processes for MMP-2 expression and malignant phenotypic conversion of MCF10A human breast epithelial cells, providing a molecular basis for the promoting role of G(α12) and G(α13) in breast cell invasion.
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Affiliation(s)
- Eun-Sook Kim
- College of Pharmacy, Duksung Women's University, Seoul, Korea
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Kim CS, Jung SB, Naqvi A, Hoffman TA, DeRicco J, Yamamori T, Cole MP, Jeon BH, Irani K. P53 Impairs Endothelium-Dependent Vasomotor Function Through Transcriptional Upregulation of P66shc. Circ Res 2008; 103:1441-50. [DOI: 10.1161/circresaha.108.181644] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The transcription factor, p53, and the adaptor protein, p66shc, both play essential roles in promoting oxidative stress in the vascular system. However, the relationship between the two in the context of endothelium-dependent vascular tone is unknown. Here, we report a novel, evolutionarily conserved, p53-mediated transcriptional mechanism that regulates p66shc expression and identify p53 as an important determinant of endothelium-dependent vasomotor function. We provide evidence of a p53 response element in the promoter of p66shc and show that angiotensin II-induced upregulation of p66shc in endothelial cells is dependent on p53. In addition, we demonstrate that downregulation of p66shc expression, as well as inhibition of p53 function in mice, mitigates angiotensin II-induced impairment of endothelium-dependent vasorelaxation, decrease in bioavailable nitric oxide, and hypertension. These findings reveal a novel p53-dependent transcriptional mechanism for the regulation of p66shc expression that is operative in the vascular endothelium and suggest that this mechanism is important in impairing endothelium-dependent vascular relaxation.
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Affiliation(s)
- Cuk-Seong Kim
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Saet-Byel Jung
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Asma Naqvi
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Timothy A. Hoffman
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Jeremy DeRicco
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Tohru Yamamori
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Marsha P. Cole
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Byeong-Hwa Jeon
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
| | - Kaikobad Irani
- From the Cardiovascular Institute (C.-S.K., S.-B.J., A.N., T.A.H., J.D., T.Y., K.I.), University of Pittsburgh Medical Center, Pa; Infection Signaling Network Research Center (B.-H.J.), Department of Physiology, Chungnum National University, Republic of Korea; and Departments of Pharmacology and Chemical Biology (M.P.C., K.I.), University of Pittsburgh, Pa. Present address for T.Y.: Faculty of Life and Medical Sciences, Doshisha University, Kyoto Japan
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Cho MK, Kim WD, Ki SH, Hwang JI, Choi S, Lee CH, Kim SG. Role of Galpha12 and Galpha13 as novel switches for the activity of Nrf2, a key antioxidative transcription factor. Mol Cell Biol 2007; 27:6195-208. [PMID: 17591699 PMCID: PMC1952151 DOI: 10.1128/mcb.02065-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Galpha12 and Galpha13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by Galpha12 and Galpha13. A deficiency of Galpha12, but not of Galpha13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, Galpha12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by Galpha12 gene knockout. Galpha12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did Galpha13 deficiency. The absence of Galpha12, but not of Galpha13, increased protein kinase C delta (PKC delta) activation and the PKC delta-mediated serine phosphorylation of Nrf2. Galpha13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by Galpha12 deficiency, suggesting that relief from Galpha12 repression leads to the Galpha13-mediated activation of Nrf2. Constitutive activation of Galpha13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC delta activation, corroborating positive regulation by Galpha13. In summary, Galpha12 and Galpha13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas Galpha13 regulates Rho-PKC delta-mediated Nrf2 phosphorylation, which is negatively balanced by Galpha12.
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Affiliation(s)
- Min Kyung Cho
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Sillim-dong, Gwanak-gu, Seoul, South Korea
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