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Brennan MS, Brinkmann K, Romero Sola G, Healey G, Gibson L, Gangoda L, Potts MA, Lieschke E, Wilcox S, Strasser A, Herold MJ, Janic A. Combined absence of TRP53 target genes ZMAT3, PUMA and p21 cause a high incidence of cancer in mice. Cell Death Differ 2024; 31:159-169. [PMID: 38110554 PMCID: PMC10850490 DOI: 10.1038/s41418-023-01250-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 12/20/2023] Open
Abstract
Transcriptional activation of target genes is essential for TP53-mediated tumour suppression, though the roles of the diverse TP53-activated target genes in tumour suppression remains poorly understood. Knockdown of ZMAT3, an RNA-binding zinc-finger protein involved in regulating alternative splicing, in haematopoietic cells by shRNA caused leukaemia only with the concomitant absence of the PUMA and p21, the critical effectors of TRP53-mediated apoptosis and cell cycle arrest respectively. We were interested to further investigate the role of ZMAT3 in tumour suppression beyond the haematopoietic system. Therefore, we generated Zmat3 knockout and compound gene knockout mice, lacking Zmat3 and p21, Zmat3 and Puma or all three genes. Puma-/-p21-/-Zmat3-/- triple knockout mice developed tumours at a significantly higher frequency compared to wild-type, Puma-/-Zmat3-/- or p21-/-Zmat3-/-deficient mice. Interestingly, we observed that the triple knockout and Puma-/-Zmat3-/- double deficient animals succumbed to lymphoma, while p21-/-Zmat3-/- animals developed mainly solid cancers. This analysis suggests that in addition to ZMAT3 loss, additional TRP53-regulated processes must be disabled simultaneously for TRP53-mediated tumour suppression to fail. Our findings reveal that the absence of different TRP53 regulated tumour suppressive processes changes the tumour spectrum, indicating that different TRP53 tumour suppressive pathways are more critical in different tissues.
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Affiliation(s)
- Margs S Brennan
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
- Department of Medicine Huddinge, Centre for Haematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kerstin Brinkmann
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Gerard Romero Sola
- Department of Medicine and Life Sciences, Universidad Pompeu Fabra, Barcelona, Spain
| | - Geraldine Healey
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Genome Engineering and Cancer Modelling Program, Olivia Newton-John Cancer Research Institute, Melbourne, VIC, Australia
| | - Leonie Gibson
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Lahiru Gangoda
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Margaret A Potts
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Elizabeth Lieschke
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stephen Wilcox
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.
| | - Marco J Herold
- The Walter and Eliza Hall Institute of Medical Research (WEHI), 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.
- Genome Engineering and Cancer Modelling Program, Olivia Newton-John Cancer Research Institute, Melbourne, VIC, Australia.
- School of Cancer Medicine, La Trobe University, Melbourne, VIC, Australia.
| | - Ana Janic
- Department of Medicine and Life Sciences, Universidad Pompeu Fabra, Barcelona, Spain.
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Wang QH, Wu RX, Ji JN, Zhang J, Niu SF, Tang BG, Miao BB, Liang ZB. Integrated Transcriptomics and Metabolomics Reveal Changes in Cell Homeostasis and Energy Metabolism in Trachinotus ovatus in Response to Acute Hypoxic Stress. Int J Mol Sci 2024; 25:1054. [PMID: 38256129 PMCID: PMC10815975 DOI: 10.3390/ijms25021054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/04/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Trachinotus ovatus is an economically important mariculture fish, and hypoxia has become a critical threat to this hypoxia-sensitive species. However, the molecular adaptation mechanism of T. ovatus liver to hypoxia remains unclear. In this study, we investigated the effects of acute hypoxic stress (1.5 ± 0.1 mg·L-1 for 6 h) and re-oxygenation (5.8 ± 0.3 mg·L-1 for 12 h) in T. ovatus liver at both the transcriptomic and metabolic levels to elucidate hypoxia adaptation mechanism. Integrated transcriptomics and metabolomics analyses identified 36 genes and seven metabolites as key molecules that were highly related to signal transduction, cell growth and death, carbohydrate metabolism, amino acid metabolism, and lipid metabolism, and all played key roles in hypoxia adaptation. Of these, the hub genes FOS and JUN were pivotal hypoxia adaptation biomarkers for regulating cell growth and death. During hypoxia, up-regulation of GADD45B and CDKN1A genes induced cell cycle arrest. Enhancing intrinsic and extrinsic pathways in combination with glutathione metabolism triggered apoptosis; meanwhile, anti-apoptosis mechanism was activated after hypoxia. Expression of genes related to glycolysis, gluconeogenesis, amino acid metabolism, fat mobilization, and fatty acid biosynthesis were up-regulated after acute hypoxic stress, promoting energy supply. After re-oxygenation for 12 h, continuous apoptosis favored cellular function and tissue repair. Shifting from anaerobic metabolism (glycolysis) during hypoxia to aerobic metabolism (fatty acid β-oxidation and TCA cycle) after re-oxygenation was an important energy metabolism adaptation mechanism. Hypoxia 6 h was a critical period for metabolism alteration and cellular homeostasis, and re-oxygenation intervention should be implemented in a timely way. This study thoroughly examined the molecular response mechanism of T. ovatus under acute hypoxic stress, which contributes to the molecular breeding of hypoxia-tolerant cultivars.
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Affiliation(s)
- Qing-Hua Wang
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
| | - Ren-Xie Wu
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524025, China
| | - Jiao-Na Ji
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
| | - Jing Zhang
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524025, China
| | - Su-Fang Niu
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524025, China
| | - Bao-Gui Tang
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524025, China
| | - Ben-Ben Miao
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
| | - Zhen-Bang Liang
- College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; (Q.-H.W.); (R.-X.W.); (J.-N.J.); (J.Z.); (B.-G.T.); (B.-B.M.); (Z.-B.L.)
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3
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Singh AK, Peng BY, Chien ST, Chan CH, Deng YH, Pai HY, Wei HJ, Wang MF, Wang SH, Wu CY, Deng WP. Anti-aging biomaterial sturgeon chondroitin sulfate upregulating anti-oxidant and SIRT-1/c-fos gene expression to reprogram stem cell senescence and prolong longevity. Biomater Sci 2023. [PMID: 37158091 DOI: 10.1039/d2bm01997c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Aging involves tissue and cell potential dysfunction characterized by stem cell senescence and extracellular matrix microenvironment (ECM) alteration. Chondroitin sulfate (CS), found in the ECM of normal cells and tissues, aids in maintaining tissue homeostasis. Here, CS-derived biomaterial (CSDB) from sturgeon is extracted to investigate its antiaging effect in senescence-accelerated mouse prone-8 (SAMP8) mice and elucidate the underlying mechanism of its action. Although CSDB has been widely extracted from different sources and used as a scaffold, hydrogel, or drug carrier for the treatment of various pathological diseases, CSDB has not yet been used as a biomaterial for the amelioration of senescence and aging features. In this study, the extracted sturgeon CSDB showed a low molecular weight and comprised 59% 4-sulfated CS and 23% 6-sulfated CS. In an in vitro study, sturgeon CSDB promoted cell proliferation and reduced oxidative stress to inhibit stem cell senescence. In an ex vivo study, after oral CSDB treatment of SAMP8 mice, the stem cells were extracted to analyze the p16Ink4a and p19Arf gene-related pathways, which were inhibited and then SIRT-1 gene expression was upregulated to reprogram stem cells from a senescence state for retarding aging. In an in vivo study, CSDB also restored the aging-phenotype-related bone mineral density and skin morphology to prolong longevity. Thus, sturgeon CSDB may be useful for prolonging healthy longevity as an anti-aging drug.
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Affiliation(s)
- Abhinay Kumar Singh
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
| | - Bou-Yue Peng
- Department of Dentistry, Taipei Medical University Hospital, Taipei 110301, Taiwan
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
| | - Shaw-Ting Chien
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
| | - Chun-Hao Chan
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
| | - Yue-Hua Deng
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
| | - Hsiao-Yu Pai
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
- Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei 110301, Taiwan
| | - Hong-Jian Wei
- Department of Radiation Oncology, Columbia University Irving Medical Center, 630 W. 168th Street, New York, NY, 10032, USA
| | - Ming-Fu Wang
- Department of Food and Nutrition, Providence University, Taichung 433303, Taiwan
| | - Shwu-Huey Wang
- Core Facility Center, Department of Research Development, Taipei Medical University, Taipei 11030, Taiwan
| | - Chia-Yu Wu
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Division of Oral and Maxillofacial Surgery, Department of Dentistry, Taipei Medical University Hospital, Taipei 110301, Taiwan.
| | - Win-Ping Deng
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Stem Cell Research Center, College of Oral Medicine, Taipei Medical University, Taipei 110301, Taiwan.
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, Taipei 242062, Taiwan
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4
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Makowczenko KG, Jastrzebski JP, Kiezun M, Paukszto L, Dobrzyn K, Smolinska N, Kaminski T. Adaptation of the Porcine Pituitary Transcriptome, Spliceosome and Editome during Early Pregnancy. Int J Mol Sci 2023; 24:ijms24065946. [PMID: 36983019 PMCID: PMC10053595 DOI: 10.3390/ijms24065946] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
The physiological mechanisms of the porcine reproduction are relatively well-known. However, transcriptomic changes and the mechanisms accompanying transcription and translation processes in various reproductive organs, as well as their dependence on hormonal status, are still poorly understood. The aim of this study was to gain a principal understanding of alterations within the transcriptome, spliceosome and editome occurring in the pituitary of the domestic pig (Sus scrofa domestica L.), which controls basic physiological processes in the reproductive system. In this investigation, we performed extensive analyses of data obtained by high-throughput sequencing of RNA from the gilts' pituitary anterior lobes during embryo implantation and the mid-luteal phase of the estrous cycle. During analyses, we obtained detailed information on expression changes of 147 genes and 43 long noncoding RNAs, observed 784 alternative splicing events and also found the occurrence of 8729 allele-specific expression sites and 122 RNA editing events. The expression profiles of the selected 16 phenomena were confirmed by PCR or qPCR techniques. As a final result of functional meta-analysis, we acquired knowledge regarding intracellular pathways that induce changes in the processes accompanying transcription and translation regulation, which may induce modifications in the secretory activity of the porcine adenohypophyseal cells.
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Affiliation(s)
- Karol G Makowczenko
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Jan P Jastrzebski
- Department of Plant Physiology, Genetics and Biotechnology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Marta Kiezun
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Lukasz Paukszto
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Plac Lodzki 1, 10-719 Olsztyn, Poland
| | - Kamil Dobrzyn
- Department of Zoology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 5, 10-719 Olsztyn, Poland
| | - Nina Smolinska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland
| | - Tadeusz Kaminski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland
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5
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Buettner JM, Sowoidnich L, Gerstner F, Blanco-Redondo B, Hallermann S, Simon CM. p53-dependent c-Fos expression is a marker but not executor for motor neuron death in spinal muscular atrophy mouse models. Front Cell Neurosci 2022; 16:1038276. [DOI: 10.3389/fncel.2022.1038276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
The activation of the p53 pathway has been associated with neuronal degeneration in different neurological disorders, including spinal muscular atrophy (SMA) where aberrant expression of p53 drives selective death of motor neurons destined to degenerate. Since direct p53 inhibition is an unsound therapeutic approach due carcinogenic effects, we investigated the expression of the cell death-associated p53 downstream targets c-fos, perp and fas in vulnerable motor neurons of SMA mice. Fluorescence in situ hybridization (FISH) of SMA motor neurons revealed c-fos RNA as a promising candidate. Accordingly, we identified p53-dependent nuclear upregulation of c-Fos protein in degenerating motor neurons from the severe SMNΔ7 and intermediate Smn2B/– SMA mouse models. Although motor neuron-specific c-fos genetic deletion in SMA mice did not improve motor neuron survival or motor behavior, p53-dependent c-Fos upregulation marks vulnerable motor neurons in different mouse models. Thus, nuclear c-Fos accumulation may serve as a readout for therapeutic approaches targeting neuronal death in SMA and possibly other p53-dependent neurodegenerative diseases.
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6
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Wang S, Zhang L, Xuan R, Li Q, Ji Z, Chao T, Wang J, Zhang C. Identification and functional analysis of m6A in the mammary gland tissues of dairy goats at the early and peak lactation stages. Front Cell Dev Biol 2022; 10:945202. [PMID: 36330333 PMCID: PMC9623301 DOI: 10.3389/fcell.2022.945202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/04/2022] [Indexed: 12/01/2022] Open
Abstract
N6-methyladenosine (m6A) is the most common reversible epigenetic RNA modification in the mRNA of all higher eukaryotic organisms and plays an important role in the regulation of gene expression and cell function. In this study, m6A-modified methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptome sequencing (RNA-seq) were used to identify the key genes with m6A modification during mammary gland development and lactation in dairy goats. The results showed that m6A methylation occurred at 3,927 loci, which were significantly enriched in the 3′ untranslated region (3′UTR) and the termination codon region. In the early stage and peak stage of lactation, m6A methylation occurred extensively in mammary tissues, and a total of 725 differentially expressed m6A-modified genes were obtained, all negatively correlated with mRNA expression. In addition, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that different methylated genes were mainly involved in the growth and apoptosis of mammary epithelial cells through signaling pathways, such as the mitogen-activated protein kinase (MAPK) and phospholipase D pathways, and then affected the development and lactation of mammary gland. All in all, we identified and analyzed the methylation events related to the development and lactation regulation of mammary gland at the early and peak lactation stages, and provided a theoretical basis to reveal the physiological regulatory system of mammary gland development and lactation in dairy goats.
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Affiliation(s)
- Shujun Wang
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Lu Zhang
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Rong Xuan
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Qing Li
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Zhibin Ji
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
- *Correspondence: Zhibin Ji,
| | - Tianle Chao
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Jianmin Wang
- College of Animal Science and Technology, Shandong Agricultural University, Taian, China
| | - Chunlan Zhang
- College of Biological and Agricultural Engineering, Weifang University, Weifang, China
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7
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Çomaklı S, Kandemir FM, Küçükler S, Özdemir S. Morin mitigates ifosfamide induced nephrotoxicity by regulation of NF-kappaB/p53 and Bcl-2 expression. Biotech Histochem 2022; 97:423-432. [PMID: 35037524 DOI: 10.1080/10520295.2021.2021449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Ifosfamide (IFO) is used for treating childhood solid tumors, but its use is limited by its adverse effects on kidneys. Morin may be used to prevent nephrotoxic and other side effects. We investigated the underlying mechanisms of the protective effects of morin on IFO induced nephrotoxicity. We used 35 male rats divided into five groups of seven: control group, morin group, IFO group, 100 mg/kg morin + IFO group and 200 mg/kg morin + IFO group. We measured kidney tissue oxidant, antioxidant and inflammatory parameters using ELISA, and apoptosis was evaluated using immunohistochemistry and real time PCR. Serum urea, creatinine and kidney injury molecule-1 (KIM-1) levels were increased by IFO treatment; elevated levels were decreased significantly by treatment with both 100 and 200 mg/kg morin. Morin treatment also decreased oxidative stress and lipid oxidation in IFO treated rats. The ameliorative effect of morin on inflammatory response was due to reduced levels of NF-κB and TNF-α. Morin also reduced NF-κB/p53 levels by increasing Bcl-2 expression in IFO treated kidneys. Morin may prevent IFO induced nephrotoxicity via the NF-κB/p53 and Bcl-2 signaling pathways.
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Affiliation(s)
- Selim Çomaklı
- Department of Pathology, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Fatih Mehmet Kandemir
- Department of Biochemistry, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Sefa Küçükler
- Department of Biochemistry, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Selçuk Özdemir
- Department of Genetics, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
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8
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Palanikumar L, Karpauskaite L, Al-Sayegh M, Chehade I, Alam M, Hassan S, Maity D, Ali L, Kalmouni M, Hunashal Y, Ahmed J, Houhou T, Karapetyan S, Falls Z, Samudrala R, Pasricha R, Esposito G, Afzal AJ, Hamilton AD, Kumar S, Magzoub M. Protein mimetic amyloid inhibitor potently abrogates cancer-associated mutant p53 aggregation and restores tumor suppressor function. Nat Commun 2021; 12:3962. [PMID: 34172723 PMCID: PMC8233319 DOI: 10.1038/s41467-021-23985-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 05/26/2021] [Indexed: 02/05/2023] Open
Abstract
Missense mutations in p53 are severely deleterious and occur in over 50% of all human cancers. The majority of these mutations are located in the inherently unstable DNA-binding domain (DBD), many of which destabilize the domain further and expose its aggregation-prone hydrophobic core, prompting self-assembly of mutant p53 into inactive cytosolic amyloid-like aggregates. Screening an oligopyridylamide library, previously shown to inhibit amyloid formation associated with Alzheimer's disease and type II diabetes, identified a tripyridylamide, ADH-6, that abrogates self-assembly of the aggregation-nucleating subdomain of mutant p53 DBD. Moreover, ADH-6 targets and dissociates mutant p53 aggregates in human cancer cells, which restores p53's transcriptional activity, leading to cell cycle arrest and apoptosis. Notably, ADH-6 treatment effectively shrinks xenografts harboring mutant p53, while exhibiting no toxicity to healthy tissue, thereby substantially prolonging survival. This study demonstrates the successful application of a bona fide small-molecule amyloid inhibitor as a potent anticancer agent.
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Affiliation(s)
- L Palanikumar
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Laura Karpauskaite
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Mohamed Al-Sayegh
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Ibrahim Chehade
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Maheen Alam
- Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Sarah Hassan
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Debabrata Maity
- Department of Chemistry, New York University, New York, NY, USA
| | - Liaqat Ali
- Core Technology Platforms, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Mona Kalmouni
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Yamanappa Hunashal
- Chemistry Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.,DAME, Università di Udine, Udine, Italy
| | - Jemil Ahmed
- Department of Chemistry and Biochemistry and Knoebel Institute for Healthy Aging, The University of Denver, Denver, CO, USA
| | - Tatiana Houhou
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Shake Karapetyan
- Physics Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Zackary Falls
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), Buffalo, NY, USA
| | - Ram Samudrala
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), Buffalo, NY, USA
| | - Renu Pasricha
- Core Technology Platforms, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Gennaro Esposito
- Chemistry Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.,INBB, Rome, Italy
| | - Ahmed J Afzal
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | | | - Sunil Kumar
- Department of Chemistry and Biochemistry and Knoebel Institute for Healthy Aging, The University of Denver, Denver, CO, USA.
| | - Mazin Magzoub
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.
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9
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Vasilikos I, Teixeira GQ, Seitz A, Nothelfer J, Haas J, Wilke HJ, Mizaikoff B, Beck J, Hubbe U, Neidlinger-Wilke C. Can UVA-light-activated riboflavin-induced collagen crosslinking be transferred from ophthalmology to spine surgery? A feasibility study on bovine intervertebral disc. PLoS One 2021; 16:e0252672. [PMID: 34081754 PMCID: PMC8174733 DOI: 10.1371/journal.pone.0252672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/19/2021] [Indexed: 11/19/2022] Open
Abstract
Background Collagen cross-links contribute to the mechanical resilience of the intervertebral disc (IVD). UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) is a well-established and effective ophthalmological intervention that increases the mechanical rigidity of the collagen-rich corneal matrix in Keratoconus. This study explores the feasibility, safety and efficacy of translating this intervention in reinforcing the IVD. Methods Annulus fibrosus (AF) cells were isolated from bovine IVDs and treated with different combinations of riboflavin (RF) concentrations (0.05–8 mM) and UVA light intensities (0.3–4 mW/cm2). Metabolic activity (resazurin assay), cell viability (TUNEL assay), and gene expression of apoptosis regulators C-FOS and PT5 were assessed immediately and 24 hours after treatment. Biomechanical effects of UVA-CXL on IVDs were measured by indentation analysis of changes in the instantaneous modulus and by peel-force delamination strength analysis of the AF prior and after treatment. Results Different intensities of UVA did not impair the metabolic activity of AF cells. However, RF affected metabolic activity (p < 0.001). PT53 expression was similar in all RF conditions tested while C-FOS expression decreased 24 hours after treatment. Twenty-four hours after treatment, no apoptotic cells were observed in any condition tested. Biomechanical characterizations showed a significant increase in the annular peel strength of the UVA-CXL group, when compared to controls of UVA and RF alone (p < 0.05). UVA-CXL treated IVDs showed up to 152% higher (p < 0.001) instantaneous modulus values compared to the untreated control. Conclusion This is the first study on UVA-CXL treatment of IVD. It induced significantly increased delamination strength and instantaneous modulus indentation values in intact IVD samples in a structure–function relationship. RF concentrations and UVA intensities utilized in ophthalmological clinical protocols were well tolerated by the AF cells. Our findings suggest that UVA-CXL may be a promising tool to reinforce the IVD matrix.
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Affiliation(s)
- Ioannis Vasilikos
- Department of Neurosurgery, Faculty of Medicine, Medical Center—University of Freiburg, University of Freiburg, Freiburg, Germany
- Laboratory of Experimental Neurosurgery (LENS), Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
| | - Graciosa Q. Teixeira
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Center, University of Ulm, Ulm, Germany
| | - Andreas Seitz
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Center, University of Ulm, Ulm, Germany
| | - Julia Nothelfer
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Center, University of Ulm, Ulm, Germany
| | - Julian Haas
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany
| | - Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Center, University of Ulm, Ulm, Germany
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany
| | - Jürgen Beck
- Department of Neurosurgery, Faculty of Medicine, Medical Center—University of Freiburg, University of Freiburg, Freiburg, Germany
- Laboratory of Experimental Neurosurgery (LENS), Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ulrich Hubbe
- Department of Neurosurgery, Faculty of Medicine, Medical Center—University of Freiburg, University of Freiburg, Freiburg, Germany
- Laboratory of Experimental Neurosurgery (LENS), Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Cornelia Neidlinger-Wilke
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Center, University of Ulm, Ulm, Germany
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Fargesin Inhibits EGF-Induced Cell Transformation and Colon Cancer Cell Growth by Suppression of CDK2/Cyclin E Signaling Pathway. Int J Mol Sci 2021; 22:ijms22042073. [PMID: 33669811 PMCID: PMC7922630 DOI: 10.3390/ijms22042073] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/05/2021] [Accepted: 02/16/2021] [Indexed: 01/15/2023] Open
Abstract
Although the lignan compound fargesin is a major ingredient in Shin-Yi, the roles of fargesin in carcinogenesis and cancer cell growth have not been elucidated. In this study, we observed that fargesin inhibited cell proliferation and transformation by suppression of epidermal growth factor (EGF)-stimulated G1/S-phase cell cycle transition in premalignant JB6 Cl41 and HaCaT cells. Unexpectedly, we found that signaling pathway analyses showed different regulation patterns in which fargesin inhibited phosphatidylinositol 3-kinase/AKT signaling without an alteration of or increase in mitogen activated protein kinase (MAPK) in JB6 Cl41 and HaCaT cells, while both signaling pathways were abrogated by fargesin treatment in colon cancer cells. We further found that fargesin-induced colony growth inhibition of colon cancer cells was mediated by suppression of the cyclin dependent kinase 2 (CDK2)/cyclin E signaling axis by upregulation of p21WAF1/Cip1, resulting in G1-phase cell cycle accumulation in a dose-dependent manner. Simultaneously, the suppression of CDK2/cyclin E and induction of p21WAF1/Cip1 were correlated with Rb phosphorylation and c-Myc suppression. Taken together, we conclude that fargesin-mediated c-Myc suppression inhibits EGF-induced cell transformation and colon cancer cell colony growth by the suppression of retinoblastoma (Rb)-E2F and CDK/cyclin signaling pathways, which are mainly regulated by MAPK and PKB signaling pathways.
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Li B, Jia S, Yue T, Yang L, Huang C, Verkhratsky A, Peng L. Biphasic Regulation of Caveolin-1 Gene Expression by Fluoxetine in Astrocytes: Opposite Effects of PI3K/AKT and MAPK/ERK Signaling Pathways on c-fos. Front Cell Neurosci 2017; 11:335. [PMID: 29163047 PMCID: PMC5671492 DOI: 10.3389/fncel.2017.00335] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/11/2017] [Indexed: 11/13/2022] Open
Abstract
Previously, we reported that fluoxetine acts on 5-HT2B receptor and induces epidermal growth factor receptor (EGFR) transactivation in astrocytes. Recently, we have found that chronic treatment with fluoxetine regulates Caveolin-1 (Cav-1)/PTEN/PI3K/AKT/glycogen synthase kinase 3β (GSK-3β) signaling pathway and glycogen content in primary cultures of astrocytes with bi-phasic concentration dependence. At low concentrations fluoxetine down-regulates Cav-1 gene expression, decreases membrane content of PTEN, increases PI3K activity and increases phosphorylation of GSK-3β and increases its activity; at high concentrations fluoxetine acts on PTEN/PI3K/AKT/GSK-3β in an inverse fashion. Here, we present the data indicating that acute treatment with fluoxetine at lower concentrations down-regulates c-Fos gene expression via PI3K/AKT signaling pathway; in contrast at higher concentrations fluoxetine up-regulates c-Fos gene expression via MAPK/extracellular-regulated kinase (ERK) signaling pathway. However, acute treatment with fluoxetine has no effect on Cav-1 protein content. Similarly, chronic effects of fluoxetine on Cav-1 gene expression are suppressed by inhibitor of PI3K at lower concentrations, but by inhibitor of MAPK at higher concentrations, indicating that the mechanism underlying bi-phasic regulation of Cav-1 gene expression by fluoxetine is opposing effects of PI3K/AKT and MAPK/ERK signal pathways on c-Fos gene expression. The effects of fluoxetine on Cav-1 gene expression at both lower and higher concentrations are abolished by AG1478, an inhibitor of EGFR, indicating the involvement of 5-HT2B receptor induced EGFR transactivation as we reported previously. However, PP1, an inhibitor of Src only abolished the effect by lower concentrations, suggesting the relevance of Src with PI3K/AKT signal pathway during activation of EGFR.
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Affiliation(s)
- Baoman Li
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Shu Jia
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Tingting Yue
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Li Yang
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Chen Huang
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
| | - Alexej Verkhratsky
- Faculty of Life Science, The University of Manchester, Manchester, United Kingdom.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Liang Peng
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, China
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Bugel SM, Wehmas LC, La Du JK, Tanguay RL. Phenotype anchoring in zebrafish reveals a potential role for matrix metalloproteinases (MMPs) in tamoxifen's effects on skin epithelium. Toxicol Appl Pharmacol 2016; 296:31-41. [PMID: 26908177 DOI: 10.1016/j.taap.2016.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/11/2016] [Accepted: 02/16/2016] [Indexed: 10/24/2022]
Abstract
The zebrafish is a powerful alternative model used to link phenotypes with molecular effects to discover drug mode of action. Using a zebrafish embryo-larval toxicity bioassay, we evaluated the effects of tamoxifen--a widely used anti-estrogen chemotherapeutic. Zebrafish exposed to ≥ 10 μM tamoxifen exhibited a unique necrotic caudal fin phenotype that was rapidly induced regardless of developmental life-stage when treatment was applied. To define tamoxifen's bioactivity resulting in this phenotype, targeted gene expression was used to evaluate 100 transcripts involved in tissue remodeling, calcium signaling, cell cycle and cell death, growth factors, angiogenesis and hypoxia. The most robustly misregulated transcripts in the tail were matrix metalloproteinases mmp9 and mmp13a, induced 127 and 1145 fold, respectively. Expression of c-fos, c-jun, and ap1s1 were also moderately elevated (3-7 fold), consistent with AP-1 activity--a transcription factor that regulates MMP expression. Immunohistochemistry confirmed high levels of induction for MMP13a in affected caudal fin skin epithelial tissue. The necrotic caudal fin phenotype was significantly attenuated or prevented by three functionally unique MMP inhibitors: EDTA (metal chelator), GM 6001 (broad MMP inhibitor), and SR 11302 (AP-1 transcription factor inhibitor), suggesting MMP-dependence. SR 11302 also inhibited induction of mmp9, mmp13a, and a putative MMP target, igfbp1a. Overall, our studies suggest that tamoxifen's effect is the result of perturbation of the MMP system in the skin leading to ectopic expression, cytotoxicity, and the necrotic caudal fin phenotype. These studies help advance our understanding of tamoxifen's non-classical mode of action and implicate a possible role for MMPs in tissues such as skin.
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Affiliation(s)
- Sean M Bugel
- Department of Environmental and Molecular Toxicology, Environmental Health Sciences Center, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, United States.
| | - Leah C Wehmas
- Department of Environmental and Molecular Toxicology, Environmental Health Sciences Center, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, United States.
| | - Jane K La Du
- Department of Environmental and Molecular Toxicology, Environmental Health Sciences Center, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, United States.
| | - Robert L Tanguay
- Department of Environmental and Molecular Toxicology, Environmental Health Sciences Center, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, United States.
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Abstract
The predominant function of the tumor suppressor p53 is transcriptional regulation. It is generally accepted that p53-dependent transcriptional activation occurs by binding to a specific recognition site in promoters of target genes. Additionally, several models for p53-dependent transcriptional repression have been postulated. Here, we evaluate these models based on a computational meta-analysis of genome-wide data. Surprisingly, several major models of p53-dependent gene regulation are implausible. Meta-analysis of large-scale data is unable to confirm reports on directly repressed p53 target genes and falsifies models of direct repression. This notion is supported by experimental re-analysis of representative genes reported as directly repressed by p53. Therefore, p53 is not a direct repressor of transcription, but solely activates its target genes. Moreover, models based on interference of p53 with activating transcription factors as well as models based on the function of ncRNAs are also not supported by the meta-analysis. As an alternative to models of direct repression, the meta-analysis leads to the conclusion that p53 represses transcription indirectly by activation of the p53-p21-DREAM/RB pathway.
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Key Words
- CDE, cell cycle-dependent element
- CDKN1A
- CHR, cell cycle genes homology region
- ChIP, chromatin immunoprecipitation
- DREAM complex
- DREAM, DP, RB-like, E2F4, and MuvB complex
- E2F/RB complex
- HPV, human papilloma virus
- NF-Y, Nuclear factor Y
- cdk, cyclin-dependent kinase
- genome-wide meta-analysis
- p53
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Affiliation(s)
- Martin Fischer
- a Molecular Oncology; Medical School ; University of Leipzig ; Leipzig , Germany
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Cyclin-dependent kinase 2 (CDK2) is a key mediator for EGF-induced cell transformation mediated through the ELK4/c-Fos signaling pathway. Oncogene 2015; 35:1170-9. [PMID: 26028036 PMCID: PMC4666830 DOI: 10.1038/onc.2015.175] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 02/03/2015] [Accepted: 03/11/2015] [Indexed: 12/28/2022]
Abstract
Cyclin dependent kinase 2 (CDK2) is a known regulator in the cell cycle control of the G1/S and S/G2 transitions. However, the role of CDK2 in tumorigenesis is controversial. Evidence from knockout mice as well as colon cancer cell lines indicated that CDK2 is dispensable for cell proliferation. In this study, we found that ectopic CDK2 enhances Ras (G12V)-induced foci formation and knocking down CDK2 expression dramatically decreases EGF-induced cell transformation mediated through the down-regulation of c-fos expression. Interestingly, CDK2 directly phosphorylates ELK4 at Thr194 and Ser387 and regulates ELK4 transcriptional activity, which serves as a mechanism to regulate c-fos expression. In addition, ELK4 is over-expressed in melanoma and knocking down ELK4 or CDK2 expression significantly attenuated the malignant phenotype of melanoma cells. Taken together, our study reveals a novel function of CDK2 in EGF-induced cell transformation and the associated signal transduction pathways. This indicates that CDK2 is a useful molecular target for chemoprevention and therapy against skin cancer.
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15
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Platelet-activating factor induces proliferation in differentiated keratinocytes. Mol Cell Biochem 2013; 384:83-94. [PMID: 23975504 DOI: 10.1007/s11010-013-1784-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 08/09/2013] [Indexed: 10/26/2022]
Abstract
Increased levels of platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) are found in several inflammatory dermatoses, but PAF's exact role in epidermis is uncertain. In order to better understand the physiological consequences of excess PAF production in epidermis, we examined the gene regulatory effects of PAF short-term stimulation in differentiated HaCaT keratinocytes by transcriptional profiling. Even though PAF induces COX2 expression, we found that PAF regulates only few genes associated with inflammation in differentiated keratinocytes. Rather, we show that natural PAF rapidly regulates genes involved in proliferation, (anti)-apoptosis and migration, all sub-processes of re-epithelialization and wound healing. Moreover, profiling of phosphorylated kinases, cellular wound-scratch experiments, resazurin assay and flow cytometry cell cycle phase analysis all support a role for PAF in keratinocyte proliferation and epidermal re-epithelialization. In conclusion, these results suggest that PAF acts as an activator of proliferation and may, therefore, function as a connector between inflammation and proliferation in differentiated keratinocytes.
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Regulation of S100A2 expression by TGF-β-induced MEK/ERK signalling and its role in cell migration/invasion. Biochem J 2012; 447:81-91. [PMID: 22747445 DOI: 10.1042/bj20120014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
S100A2, an EF hand calcium-binding protein, is a potential biomarker in several cancers and is also a TGF-β (transforming growth factor-β)-regulated gene in melanoma and lung cancer cells. However, the mechanism of S100A2 regulation by TGF-β and its significance in cancer progression remains largely unknown. In the present study we report the mechanism of S100A2 regulation by TGF-β and its possible role in TGF-β-mediated tumour promotion. Characterization of the S100A2 promoter revealed an AP-1 (activator protein-1) element at positions -1161 to -1151 as being the most critical factor for the TGF-β1 response. Chromatin immunoprecipitation and electrophoretic mobility-shift assays confirmed the functional binding of the AP-1 complex, predominantly JunB, to the S100A2 promoter in response to TGF-β1 in HaCaT keratinocytes. JunB overexpression markedly stimulated the S100A2 promoter which was blocked by the dominant-negative JunB and MEK1 [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase 1] inhibitor, PD98059. Intriguingly, despite the presence of a putative SMAD-binding element, S100A2 regulation by TGF-β1 was found to be SMAD3 independent. Interestingly, p53 protein and TGF-β1 show synergistic regulation of the S100A2 promoter. Finally, knockdown of S100A2 expression compromised TGF-β1-induced cell migration and invasion of Hep3B cells. Together our findings highlight an important link between the TGF-β1-induced MAPK and p53 signalling pathways in the regulation of S100A2 expression and pro-tumorigenic actions.
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Cell type-specific gene expression and editing responses to chronic fluoxetine treatment in the in vivo mouse brain and their relevance for stress-induced anhedonia. Neurochem Res 2012; 37:2480-95. [PMID: 22711334 DOI: 10.1007/s11064-012-0814-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/03/2012] [Accepted: 05/26/2012] [Indexed: 01/11/2023]
Abstract
Recently developed methods for fluorescence-activated cell sorting (FACS) of freshly-isolated brain cells from transgenic mice combining fluorescent signals with cell type-specific markers allow cell-type separation. Based upon previous observations in primary cultures of mouse astrocytes we treated transgenic mice tagged with a neuron-specific or an astrocyte-specific marker with fluoxetine, either acute (10 mg/kg for 2 h) or chronic (10 mg/kg daily for 2 weeks). Acute treatment upregulated cfos and fosB mRNA expression in astrocytes and neurons. Chronic effects on astrocytes replicated those demonstrated in cultures, i.e., upregulation of mRNA and/or protein expression of 5-HT(2B) receptors (5-HT(2B)R), and GluK2 receptors, and of cPLA(2a) and ADAR2, together with increased GluK2 and 5-HT(2B)R editing. Neurons showed increased GluK4 and 5-HT(2C) receptor expression. To further correlate these findings with major depression we compared the changes in gene expression with those in a mouse model of anhedonia. Three out of 4 genes up-regulated in astrocytes by fluoxetine were down-regulated, whereas the neuronally upregulated 5-HT(2C) receptor gene showed no change. References are made to recent review papers discussing potential relations between observed fluoxetine effects and clinical effects of SSRIs, emphasizing that all 5 clinically used SSRIs have identical and virtually equipotent effects on cultured astrocytes.
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Andreu-Vieyra CV, Chen R, Agno JE, Glaser S, Anastassiadis K, Stewart AF, Matzuk MM. MLL2 is required in oocytes for bulk histone 3 lysine 4 trimethylation and transcriptional silencing. PLoS Biol 2010; 8. [PMID: 20808952 PMCID: PMC2923083 DOI: 10.1371/journal.pbio.1000453] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 07/02/2010] [Indexed: 11/19/2022] Open
Abstract
Conditional knockout mouse strategies identify the histone methyltranferase MLL2 as a key player in epigenetic reprogramming of female gametes. During gametogenesis and pre-implantation development, the mammalian epigenome is reprogrammed to establish pluripotency in the epiblast. Here we show that the histone 3 lysine 4 (H3K4) methyltransferase, MLL2, controls most of the promoter-specific chromatin modification, H3K4me3, during oogenesis and early development. Using conditional knockout mutagenesis and a hypomorph model, we show that Mll2 deficiency in oocytes results in anovulation and oocyte death, with increased transcription of p53, apoptotic factors, and Iap elements. MLL2 is required for (1) bulk H3K4me3 but not H3K4me1, indicating that MLL2 controls most promoters but monomethylation is regulated by a different H3K4 methyltransferase; (2) the global transcriptional silencing that preceeds resumption of meiosis but not for the concomitant nuclear reorganization into the surrounded nucleolus (SN) chromatin configuration; (3) oocyte survival; and (4) normal zygotic genome activation. These results reveal that MLL2 is autonomously required in oocytes for fertility and imply that MLL2 contributes to the epigenetic reprogramming that takes place before fertilization. We propose that once this task has been accomplished, MLL2 is not required until gastrulation and that other methyltransferases are responsible for bulk H3K4me3, thereby revealing an unexpected epigenetic control switch amongst the H3K4 methyltransferases during development. It is well established that gametes and early mammalian embryos undergo extensive epigenetic changes, which are changes in phenotype or gene expression that do not entail changes in DNA sequence. However, the machinery responsible for epigenetic modification in these situations is poorly understood. In mice, we conditionally deleted the histone 3 lysine 4 (H3K4) methyltransferase Mll2, an enzyme that alters DNA structure and packaging, either in gametes or in somatic cells of the ovary and also produced a mouse hypomorph expressing low levels of MLL2. We show that MLL2 is required in oocytes during gametogenesis and is also needed as a maternally derived factor during early development. Oocytes deficient in Mll2 display decreased methylation of H3K4 (H3K4me3) and show abnormal maturation and gene expression, in particular of pro-apoptotic factors. In addition, we demonstrate that embryonic genome activation is compromised in the absence of Mll2. Together our results identify MLL2 as one of the key players in the epigenetic reprogramming required for female fertility in the mouse.
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Affiliation(s)
- Claudia V. Andreu-Vieyra
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ruihong Chen
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Julio E. Agno
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Stefan Glaser
- Genomics, BioInnovationsZentrum, Technische Universitaet Dresden, Dresden, Germany
- Walter and Eliza Hall Institute, Melbourne, Australia
| | | | - A. Francis Stewart
- Genomics, BioInnovationsZentrum, Technische Universitaet Dresden, Dresden, Germany
- * E-mail: (MMM); (AFS)
| | - Martin M. Matzuk
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail: (MMM); (AFS)
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Fluoxetine-mediated 5-HT2B receptor stimulation in astrocytes causes EGF receptor transactivation and ERK phosphorylation. Psychopharmacology (Berl) 2008; 201:443-58. [PMID: 18758753 DOI: 10.1007/s00213-008-1306-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 08/12/2008] [Indexed: 10/21/2022]
Abstract
RATIONALE Fluoxetine has relatively high affinity for Gq/11 protein-coupled 5-HT(2) receptors. Part of these receptors in brain are on astrocytes, where fluoxetine causes an increase in free cytosolic calcium concentration ([Ca(2+)](i)) and phosphorylation of extracellular regulated kinase 1 and 2 (ERK(1/2)). OBJECTIVE The objectives of the study are to identify subtype of the 5-HT(2) receptor involved, to establish whether ERK(1/2) phosphorylation is a result of 5-HT(2)-mediated transactivation of epidermal growth factor (EGF) receptors (EGFRs), and to determine signaling pathways up- and downstream of ERK(1/2). MATERIALS AND METHODS Primary cultures of mouse astrocytes, which express all three subtypes of the 5-HT(2) receptor but no 5-HT(2) transporter, were used. ERK(1/2) phosphorylation and c-Fos and FosB protein expression were determined with Western blotting, and c-fos and fosB mRNA expression with reverse transcription polymerase chain reaction. Receptor subtype was investigated with subtype-specific 5-HT antagonists and 5-HT(2B) receptor depletion and signaling pathways by EGFR phosphorylation, using immunoprecipitation and Western blotting, inhibition of protein kinase C (PKC), and [Ca(2+)](i) chelation by BAPTA/AM. RESULTS ERK(1/2) phosphorylation was abolished by SB204741, a universal 5-HT(2) receptor antagonist, and in 5-HT(2B) receptor-depleted cells, but unaffected by 5-HT(2A) or 5-HT(2C) receptor antagonists (M100907 and SB242084). Phosphorylation of ERK(1/2) and EGFRs was abolished by AG 1478, an inhibitor of EGFR tyrosine kinases, and GM 6001, an inhibitor of Zn-dependent metalloproteinases, suggesting growth factor "shedding" and transactivation of EGFRs. Chelation of [Ca(2+)](i) or PKC inhibition with GF 109203X abrogated ERK(1/2) phosphorylation. Up-regulated mRNA and protein expression of c-fos and fosB was abolished by SB204741, AG1478, and by U0126, an inhibitor of ERK phosphorylation by MAP kinase/ERK kinase.
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Jiao S, Liu B, Gao A, Ye M, Jia X, Zhang F, Liu H, Shi X, Huang C. Benzo(a)pyrene-caused increased G1-S transition requires the activation of c-Jun through p53-dependent PI-3K/Akt/ERK pathway in human embryo lung fibroblasts. Toxicol Lett 2008; 178:167-75. [PMID: 18448277 DOI: 10.1016/j.toxlet.2008.03.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 03/12/2008] [Accepted: 03/13/2008] [Indexed: 01/25/2023]
Abstract
Benzo(a)pyrene (B(a)P) is a potent lung carcinogen mainly derived from tobacco smoking and environmental contamination, however, the molecular mechanisms by which it accelerates the cell cycle progression and induces the abnormal cell proliferation are still far away from understood. Our current analysis of human embryo lung fibroblasts (HELF) showed that B(a)P exposure was able to promote cell cycle G(1)-S phase transition. This effect was correlated with c-Jun activation because inhibition of c-Jun by its dominant negative mutant (TAM67) reversed B(a)P action on cell cycle with the down-regulation of expression of cyclin D1, pRb and E2F1. Further study found that overexpression of dominant negative mutants of, PI-3K or Akt, dramatically reduced B(a)P-induced the activation of c-Jun and extracellular signaling regulated kinase (ERK), but not c-Jun NH2 terminal kinase (JNK). Inhibition of p53 by either its inhibitor pifithrin-alpha or p53 siRNA markedly increased B(a)P-induced the activation of c-Jun, Akt and ERK in this context. Take together, our results indicate that c-Jun activation by p53-dependent PI-3K/Akt/ERK pathway is responsible for B(a)P-induced cell cycle alternations in human embryo lung fibroblasts.
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Affiliation(s)
- Shi Jiao
- Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, 29 Nan Wei Road, Beijing, PR China
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Li B, Du T, Li H, Gu L, Zhang H, Huang J, Hertz L, Peng L. Signalling pathways for transactivation by dexmedetomidine of epidermal growth factor receptors in astrocytes and its paracrine effect on neurons. Br J Pharmacol 2008; 154:191-203. [PMID: 18311185 DOI: 10.1038/bjp.2008.58] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Stimulation of astrocytes by the alpha(2)-adrenoceptor agonist dexmedetomidine, a neuroprotective drug, transactivates epidermal growth factor (EGF) receptors. The present study investigates signal pathways leading to release of an EGF receptor ligand and those activated during EGF receptor stimulation, and the response of neurons to dexmedetomidine and to astrocyte-conditioned medium. EXPERIMENTAL APPROACH Phosphorylation of ERK(1/2) was determined by western blotting and immunocytochemistry, and phosphorylation of EGF receptors by immunoprecipitation and western blotting. mRNA expression of fos family was measured by RT-PCR. KEY RESULTS Pertussis toxin (0.2 microg ml(-1)) an inhibitor of betagamma subunit dissociation from Galpha(i) protein, and GF 109203X (500 nM), a protein kinase C inhibitor, abolished ERK(1/2) phosphorylation. PP1 (10 microM), inhibiting Src kinase and GM 6001 (10 microM), an inhibitor of Zn-dependent metalloproteinase, abolished ERK(1/2) phosphorylation by dexmedetomidine (50 nM), but not that by EGF (10 ng ml(-1)), showing Src kinase and metalloproteinase activation during the first stage only; AG 1478 (1 microM), an inhibitor of the EGF receptor tyrosine kinase, abolished ERK(1/2) phosphorylation. Dexmedetomidine-induced EGF receptor phosphorylation was prevented by AG 1478, GM 6001, PP1 and GF 109203X and its induction of cfos and fosB by AG 1478 and by U0126 (10 microM), an inhibitor of ERK phosphorylation, indicating downstream effects of ERK(1/2) phosphorylation. EGF and conditioned medium from dexmedetomidine-treated astrocytes, but not dexmedetomidine itself, induced ERK phosphorylation in primary cultures of cerebellar neurons. CONCLUSIONS AND IMPLICATIONS Dexmedetomidine-induced transactivation pathways were delineated. Its paracrine effect on neurons may account for its neuroprotective effects.
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Affiliation(s)
- B Li
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
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22
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Abstract
The AP-1 transcription factor is mainly composed of Jun, Fos and ATF protein dimers. It mediates gene regulation in response to a plethora of physiological and pathological stimuli, including cytokines, growth factors, stress signals, bacterial and viral infections, as well as oncogenic stimuli. Studies in genetically modified mice and cells have highlighted a crucial role for AP-1 in a variety of cellular events involved in normal development or neoplastic transformation causing cancer. However, emerging evidence indicates that the contribution of AP-1 to determination of cell fates critically depends on the relative abundance of AP-1 subunits, the composition of AP-1 dimers, the quality of stimulus, the cell type and the cellular environment. Therefore, AP-1-mediated regulation of processes such as proliferation, differentiation, apoptosis and transformation should be considered within the context of a complex dynamic network of signalling pathways and other nuclear factors that respond simultaneously.
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Affiliation(s)
- Jochen Hess
- Deutsches Krebsforschungszentrum, Division of Signal Transduction and Growth Control, 69120 Heidelberg, Germany
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23
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Shih A, Zhang S, Cao HJ, Boswell S, Wu YH, Tang HY, Lennartz MR, Davis FB, Davis PJ, Lin HY. Inhibitory effect of epidermal growth factor on resveratrol-induced apoptosis in prostate cancer cells is mediated by protein kinase C-α. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1355.3.11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Resveratrol, a naturally occurring stilbene with antitumor properties, caused mitogen-activated protein kinase [MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2)] activation, nuclear translocation of Ser15-phosphorylated p53, and p53-dependent apoptosis in hormone-insensitive DU145 prostate cancer cells. Exposure of these cells to epidermal growth factor (EGF) for up to 4 hours resulted in brief activation of MAPK followed by inhibition of resveratrol-induced signal transduction, p53 phosphorylation, and apoptosis. Resveratrol stimulated c-fos and c-jun expression in DU145 cells, an effect also suppressed by EGF. An inhibitor of protein kinase C (PKC)-α, -β, and -γ (CGP41251) enhanced Ser15 phosphorylation of p53 by resveratrol in the absence of EGF and blocked EGF inhibition of the resveratrol effect. EGF caused PKC-α/β phosphorylation in DU145 cells, an effect reversed by CGP41251. Activation of PKC by phorbol ester (phorbol 12-myristate 13-acetate) enhanced EGF action on ERK1/2 phosphorylation without significantly altering p53 phosphorylation by resveratrol. DU145 cells transfected with a dominant-negative PKC-α construct showed resveratrol-induced ERK1/2 phosphorylation and Ser15 phosphorylation of p53 but were unresponsive to EGF. Thus, resveratrol and EGF activate MAPK by discrete mechanisms in DU145 cells. The stilbene promoted p53-dependent apoptosis, whereas EGF opposed induction of apoptosis by resveratrol via a PKC-α-mediated mechanism. Resveratrol also induced p53 phosphorylation in LNCaP prostate cancer cells, an effect also inhibited by EGF. Inhibition of PKC activation in LNCaP cells, however, resulted in a reduction, rather than increase, in p53 activation and apoptosis, suggesting that resveratrol-induced apoptosis in these two cell lines occurs through different PKC-mediated and MAPK-dependent pathways.
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Affiliation(s)
- Ai Shih
- 1Research Service, Stratton Veterans Affairs Medical Center,
| | | | | | | | | | - Heng-Yuan Tang
- 1Research Service, Stratton Veterans Affairs Medical Center,
| | | | | | - Paul J. Davis
- 1Research Service, Stratton Veterans Affairs Medical Center,
- 2Ordway Research Institute,
- 4Wadsworth Center, New York State Department of Health, Albany, New York
| | - Hung-Yun Lin
- 1Research Service, Stratton Veterans Affairs Medical Center,
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24
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Nakade K, Zheng H, Ganguli G, Buchwalter G, Gross C, Wasylyk B. The tumor suppressor p53 inhibits Net, an effector of Ras/extracellular signal-regulated kinase signaling. Mol Cell Biol 2004; 24:1132-42. [PMID: 14729959 PMCID: PMC321436 DOI: 10.1128/mcb.24.3.1132-1142.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The tumor suppressor function of p53 is linked to its ability to repress gene expression, but the mechanisms of specific gene repression are poorly understood. We report that wild-type p53 inhibits an effector of the Ras oncogene/mitogen-activated protein (MAP) kinase pathway, the transcription factor Net. Tumor-associated mutant p53s are less efficient inhibitors. p53 inhibits by preventing phosphorylation of Net by MAP kinases. Loss of p53 in vivo leads to increased Net phosphorylation in response to wound healing and UV irradiation of skin. Our results show that p53 can repress specific gene expression by inhibiting Net, a factor implicated in cell cycle entry.
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Affiliation(s)
- Koji Nakade
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 67404 Illkirch cedex, France
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25
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Abstract
The nuclear transcription factor AP-1, composed of dimers of Fos and Jun proteins, has been linked to a startling breadth of cellular events including cell transformation, proliferation, differentiation and apoptosis. AP-1 is often portrayed as a general, nuclear decision-maker that determines life or death cell fates in response to extracellular stimuli. However, it is increasingly clear that the cellular context is critical for determining the contribution of AP-1 to cellular fates, and the role of AP-1 in apoptosis should be considered within the context of a complex network of nuclear factors that respond simultaneously to a wide range of signal transduction pathways. We take a closer look at the evidence for and against a role for AP-1 in inducing apoptosis, drawing on examples of studies in neurons, lymphocytes and hepatocytes. Although AP-1 activation is associated with a large number of apoptotic scenarios, its role in ensuring cell survival seems equally important. It is, therefore, difficult to convict AP-1 as a killer without taking into account the cellular and extracellular context within which it is functioning. Defining the target genes regulated by AP-1 in these different contexts will help to decipher the contribution of AP-1 to cell fate decisions.
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Affiliation(s)
- M Ameyar
- Department of Developmental Biology, Fernbach Building, Institut Pasteur, 25, rue du Docteur-Roux, 75724 Paris cedex 15, France
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26
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Camarda G, Binaschi M, Maggi CA, Goso C. Nuclear factor-kappaB, induced in human carcinoma cell line A2780 by the new anthracycline men 10755, is devoid of transcriptional activity. Int J Cancer 2002; 102:476-82. [PMID: 12432549 DOI: 10.1002/ijc.10745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The new disaccharide anthracycline MEN 10755 induces activation of both NF-kappaB and p53 transcription factors in A2780 cells. Nevertheless, pharmacologic inhibition of NF-kappaB activation does not modify the sensitivity of A2780 cells to MEN 10755 treatment. To better characterize the role of NF-kappaB in MEN 10755-induced cytotoxicity, we analyzed the expression of a number of genes that are known to be regulated by NF-kappaB. None of these genes is modified by MEN 10755 treatment. On the contrary, our results suggest that the p53 DNA damage-responsive pathway is fully activated in A2780 cells, several genes controlled by p53 being up- or downregulated according to the described action of p53 on their promoters. Thus, in the A2780 cell line, the role of p53 in transducing the DNA-damage signal appears to be relevant, whereas NF-kappaB, although activated, appears to be nonfunctional. Other human carcinoma cell lines besides A2780 activate NF-kappaB DNA binding in response to MEN 10755 treatment, but again, this binding does not always lead to target gene activation. These results suggest that other factors, tumor type-specific and different from mere activation, could influence NF-kappaB transcriptional activity. Therefore, care should be taken when considering the pharmacologic inhibition of NF-kappaB as a means to improve anticancer therapy efficacy.
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Affiliation(s)
- Grazia Camarda
- Department of Pharmacology, Menarini Ricerche, Pomezia, Rome, Italy
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27
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Inga A, Storici F, Darden TA, Resnick MA. Differential transactivation by the p53 transcription factor is highly dependent on p53 level and promoter target sequence. Mol Cell Biol 2002; 22:8612-25. [PMID: 12446780 PMCID: PMC139870 DOI: 10.1128/mcb.22.24.8612-8625.2002] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Little is known about the mechanisms that regulate differential transactivation by p53. We developed a system in the yeast Saccharomyces cerevisiae that addresses p53 transactivation capacity from 26 different p53 response elements (REs) under conditions where all other factors, such as chromatin, are kept constant. The system relies on a tightly regulated promoter (rheostatable) that can provide for a broad range of p53 expression. The p53 transactivation capacity toward each 20- to 22-bp-long RE could be ranked by using a simple phenotypic assay. Surprisingly, there was as much as a 1,000-fold difference in transactivation. There was no correlation between the functional rank and statistical predictions of binding energy of the REs. Instead we found that the central sequence element in an RE greatly affects p53 transactivation capacity, possibly because of DNA structural properties. Our results suggest that intrinsic DNA binding affinity and p53 protein levels are important contributors to p53-induced differential transactivation. These results are also relevant to understanding the regulation by other families of transcription factors that recognize several sequence-related response elements and/or have tightly regulated expression. We found that p53 had weak activity towards half the apoptotic REs. In addition, p53 alleles associated with familial breast cancer, previously classified as wild type, showed subtle differences in transactivation capacity towards several REs.
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Affiliation(s)
- Alberto Inga
- Laboratory of Molecular Genetics, Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Francesca Storici
- Laboratory of Molecular Genetics, Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Thomas A. Darden
- Laboratory of Molecular Genetics, Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Michael A. Resnick
- Laboratory of Molecular Genetics, Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
- Corresponding author. Mailing address: National Institute of Environmental Health Sciences (NIEHS), Mail drop D3-01, TW Alexander Dr., P.O. Box 12233, Research Triangle Park, NC 27709. Phone: (919) 541-4480. Fax: (919) 541-7593. E-mail:
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28
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Qian H, Wang T, Naumovski L, Lopez CD, Brachmann RK. Groups of p53 target genes involved in specific p53 downstream effects cluster into different classes of DNA binding sites. Oncogene 2002; 21:7901-11. [PMID: 12420228 DOI: 10.1038/sj.onc.1205974] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2002] [Revised: 08/12/2002] [Accepted: 08/13/2002] [Indexed: 11/09/2022]
Abstract
The tumor suppressor protein p53, once activated, can cause either cell cycle arrest or apoptosis through transactivation of target genes with p53 DNA binding sites (DBS). To investigate the role of p53 DBS in the regulation of this profound, yet poorly understood decision of life versus death, we systematically studied all known and potential p53 DBS. We analysed the DBS separated from surrounding promoter regions in yeast and mammalian assays with and without DNA damage. p53 efficiently utilized the DBS of MDM2 and of genes connected to cell cycle arrest, DNA repair and the death receptor pathway of apoptosis. However, p53 was unable to utilize two-thirds of the isolated DBS, a subset that included almost all DBS of apoptosis-related genes. Neither ASPP2, a p53-interacting protein reported to specifically stimulate p53 transcriptional activity on apoptosis-related promoters, nor DNA damage resulted in p53 utilization of isolated DBS of apoptosis-related genes. Thus, a major regulation of p53 activity occurs at the level of p53 DBS themselves by posing additional requirements for the successful utilization of apoptosis-related DBS.
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Affiliation(s)
- Hua Qian
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 S Euclid Avenue, Box 8069, St Louis, Missouri, MO 63110, USA
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29
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Göhler T, Reimann M, Cherny D, Walter K, Warnecke G, Kim E, Deppert W. Specific interaction of p53 with target binding sites is determined by DNA conformation and is regulated by the C-terminal domain. J Biol Chem 2002; 277:41192-203. [PMID: 12171916 DOI: 10.1074/jbc.m202344200] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcriptional activation of p53-regulated genes is initiated by sequence-specific DNA binding of p53 to target binding sites. Regulation of sequence-specific DNA binding is complex and occurs at various levels. We demonstrate that DNA topology is an important parameter for regulating the selective and highly specific interaction of p53 with its target binding sites. Specific binding of wild-type p53 is greatly enhanced when cognate binding sites are present in a non-linear stem-loop conformation. The C-terminal domain plays a key role in regulating the specific interactions of p53 with target binding sites in a DNA conformation-dependent manner. The C-terminal domain is required for binding to target sites in a non-linear DNA conformation in contrast to the strong inhibitory effects of the C terminus on p53 interaction with linear DNA. We propose that selective binding of p53 to various promoters may be determined by the DNA conformation within p53 cognate sites.
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Affiliation(s)
- Thomas Göhler
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Universität Hamburg, Martinistrasse 52, Hamburg D-20251, Germany
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30
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Inga A, Nahari D, Velasco-Miguel S, Friedberg EC, Resnick MA. A novel p53 mutational hotspot in skin tumors from UV-irradiated Xpc mutant mice alters transactivation functions. Oncogene 2002; 21:5704-15. [PMID: 12173040 DOI: 10.1038/sj.onc.1205779] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2002] [Revised: 06/12/2002] [Accepted: 06/18/2002] [Indexed: 11/09/2022]
Abstract
A mutation in codon 122 of the mouse p53 gene resulting in a T to L amino acid substitution (T122-->L) is frequently associated with skin cancer in UV-irradiated mice that are both homozygous mutant for the nucleotide excision repair (NER) gene Xpc (Xpc(-/-)) and hemizygous mutant for the p53 gene. We investigated the functional consequences of the mouse T122-->L mutation when expressed either in mammalian cells or in the yeast Saccharomyces cerevisiae. Similar to a non-functional allele, high expression of the T122-->L allele in p53(-/-) mouse embryo fibroblasts and human Saos-2 cells failed to suppress growth. However, the T122-->L mutant p53 showed wild-type transactivation levels with Bax and MDM2 promoters when expressed in either cell type and retained transactivation of the p21 and the c-Fos promoters in one cell line. Using a recently developed rheostatable p53 induction system in yeast we assessed the T122-->L transactivation capacity at low levels of protein expression using 12 different p53 response elements (REs). Compared to wild-type p53 the T122-->L protein manifested an unusual transactivation pattern comprising reduced and enhanced activity with specific REs. The high incidence of the T122-->L mutant allele in the Xpc(-/-) background suggests that both genetic and epigenetic conditions may facilitate the emergence of particular functional p53 mutations. Furthermore, the approach that we have taken also provides for the dissection of functions that may be retained in many p53 tumor alleles.
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Affiliation(s)
- Alberto Inga
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, PO Box 12233, Research Triangle Park, North Carolina, NC 27709, USA
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31
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Xu H, el-Gewely MR. P53-responsive genes and the potential for cancer diagnostics and therapeutics development. BIOTECHNOLOGY ANNUAL REVIEW 2002; 7:131-64. [PMID: 11686042 DOI: 10.1016/s1387-2656(01)07035-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
P53 protein regulates cell responses to DNA damage to keep genomic stability by transactivation and trans-repression of its downstream target genes. P53 protein also has activators, inactivators, or co-factors via interaction with other proteins. Both the p53-regulated genes and interacted proteins form a huge network. As tumors usually escape from proliferating controls by means of accumulation of genetic alterations, p53 is one of the most important tumor suppressor genes that can be targeted for diagnosis, prognosis, and therapeutic intervention. Reviewing the p53-network is of great importance. In this review, we are focusing on cancer-related p53 downstream-regulated genes. Various methods dealing with the discovery of p53-regulated genes by the detection of gene expression have been applied. Recently high throughput functional genomics methods, such as DNA microarray, serial analysis of gene expression (SAGE), differential display, and protein two-dimensional gel electrophoresis, have provided a wealth of information on the dynamics of cell context responses. Hundreds of genes have been discovered whose transcriptions are regulated by p53 protein. They were grouped, based on their functions, into sub-classes including cell-cycle regulation, DNA repair, angiogenesis, metastasis, and multidrug resistance. P53 plays a pivotal role in keeping genomic stability and tumor suppression. The deeper we investigate the cell responses as mediated by p53, the more complex p53-network becomes. However, understanding p53-network, offers great opportunities to develop more sensitive and accurate diagnostic/prognostic tools, as well as more efficient therapies for cancer.
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Affiliation(s)
- H Xu
- Department of Biotechnology, Institute of Medical Biology, University of Tromsø, 9037 Tromsø, Norway
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32
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Zörnig M, Hueber A, Baum W, Evan G. Apoptosis regulators and their role in tumorigenesis. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1551:F1-37. [PMID: 11591448 DOI: 10.1016/s0304-419x(01)00031-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It has become clear that, together with deregulated growth, inhibition of programmed cell death (PCD) plays a pivotal role in tumorigenesis. In this review, we present an overview of the genes and mechanisms involved in PCD. We then summarize the evidence that impaired PCD is a prerequisite for tumorigenesis, as indicated by the fact that more and more neoplastic mutations appear to act by interfering with PCD. This has made the idea of restoration of corrupted 'death programs' an intriguing new area for potential cancer therapy.
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Affiliation(s)
- M Zörnig
- Georg-Speyer-Haus, Frankfurt, Germany.
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33
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Abstract
Changes in gene expression were examined in p53(-/-) and p53(+/+) mouse cells after ultraviolet (UV) irradiation. Differential display was used to identify differentially expressed gene(s) in UV-treated p53(-/-) and p53(+/+) cells. One of the differentially expressed genes was EGR-1 (early growth response gene-1), which was shown to be induced only in p53(-/-) cells. The induction of this gene by UV was detected as early as 0.5 h, peaked at 2 h, and returned to normal levels by 4 h. De novo protein synthesis was not required for UV-induced EGR-1 expression in p53(-/-) cells. Pretreatment of p53(-/-) cells with suramin, an inhibitor of growth factor receptors, completely suppressed UV-induced EGR-1 expression, suggesting that the induction may be mediated via the growth factor receptors. The presence of wild-type p53 suppressed the induction of EGR-1 after UV treatment. Overexpression of EGR-1 promoted the UV-induced transformation in p53(+/+) cells, but not in p53(-/-) cells. These data suggested that EGR-1 may be an important player in the UV responses of mammalian cells and may influence UV-induced transformation.
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Affiliation(s)
- W Zhang
- Laboratory for Cancer Research, College of Pharmacy, Rutgers, the State University of New Jersey, 164 Frelinghuysen Road, Piscataway, New Jersey 08854, USA
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34
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Yang X, Taylor L, Polgar P. p53 down-regulates human bradykinin B1 receptor gene expression. J Cell Biochem 2001; 82:38-45. [PMID: 11400161 DOI: 10.1002/jcb.1117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The tumor suppressor, p53, has been shown to transcriptionally activate or silence a number of target genes. As an activator, p53 relies on its specific consensus sequence within the promoter. It is not clear whether p53 requires a specific DNA binding site in its action as a gene repressor. This report demonstrates that the human BKB1R gene is a p53 target. Expression of p53 in transiently transfected SV40-transformed IMR90 cells strongly suppressed luciferase reporter activity driven by a 1.8 kb BKB1R promoter as well as its minigene. These down-regulations were p53 dose-dependent. p53 reduced both basal and induced promoter activities of the minigene. Expression of p53 abolished the inducibility of the minigene. Induction of endogenous p53 expression by etoposide also inhibited promoter activity and minigene inducibility. Replacing the region containing both the putative p53 binding site and the TATA-box with a basal adenovirus promoter in the 1.8 kb promoter construct did not prevent p53 from inhibiting BKB1R promoter activity. Thus suppression by p53 is not mediated by competition with the TATA-binding protein and is not through interaction with the putative p53-binding site. p53 also does not appear to suppress BKB1R gene expression through interaction with c-Jun which functions in the inducibility of this gene [Yang et al., 2001].
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MESH Headings
- Binding Sites/drug effects
- Binding Sites/genetics
- Cell Line, Transformed
- Dose-Response Relationship, Drug
- Down-Regulation/genetics
- Etoposide/pharmacology
- Gene Expression/drug effects
- Gene Expression/genetics
- Genes, jun/genetics
- Genes, p53/drug effects
- Genes, p53/genetics
- Humans
- Promoter Regions, Genetic/genetics
- Receptor, Bradykinin B1
- Receptors, Bradykinin/drug effects
- Receptors, Bradykinin/genetics
- Receptors, Bradykinin/physiology
- TATA Box/drug effects
- TATA Box/genetics
- Tumor Suppressor Protein p53/genetics
- Tumor Suppressor Protein p53/metabolism
- Tumor Suppressor Protein p53/pharmacology
- Up-Regulation
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Affiliation(s)
- X Yang
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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35
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Leypoldt F, Lewerenz J, Methner A. Identification of genes up-regulated by retinoic-acid-induced differentiation of the human neuronal precursor cell line NTERA-2 cl.D1. J Neurochem 2001; 76:806-14. [PMID: 11158252 DOI: 10.1046/j.1471-4159.2001.00079.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The human teratocarcinoma cell line NTERA-2 cl.D1 (NT2 cells) can be induced with retinoic acid and cell aggregation to yield postmitotic neurones. This seems to model the in vivo situation, as high concentrations of retinoic acid, retinoic acid binding proteins, and receptors have been detected in the embryonic CNS and the developing spinal cord suggesting a role for retinoic acid in neurogenesis. Suppression subtractive hybridization was used to detect genes up-regulated by this paradigm of neuronal differentiation. Microfibril-associated glycoprotein 2 was found to be drastically up-regulated and has not been implicated in neuronal differentiation before. Suppression subtractive hybridization also identified DYRK4, a homologue of the Drosophila gene minibrain. Minibrain mutations result in specific defects in the development of the fly central nervous system. In adult rats, DYRK4 is only expressed in testis, but our results suggest an additional role for DYRK4 in neuronal differentiation. We have shown that suppression subtractive hybridization in conjunction with an efficient screening procedure is a valuable tool to produce a repertoire of differentially expressed genes and propose a new physiological role for several identified genes and expressed sequence tags.
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Affiliation(s)
- F Leypoldt
- Zentrum für Molekulare Neurobiologie, Hamburg, Germany
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36
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Sengupta S, Vonesch JL, Waltzinger C, Zheng H, Wasylyk B. Negative cross-talk between p53 and the glucocorticoid receptor and its role in neuroblastoma cells. EMBO J 2000; 19:6051-64. [PMID: 11080152 PMCID: PMC305812 DOI: 10.1093/emboj/19.22.6051] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The tumour suppressor p53 and the glucocorticoid receptor (GR) respond to different types of stress. We found that dexamethasone-activated endogenous and exogenous GR inhibit p53-dependent functions, including transactivation, up- (Bax and p21(WAF1/CIP1)) and down- (Bcl2) regulation of endogenous genes, cell cycle arrest and apoptosis. GR forms a complex with p53 in vivo, resulting in cytoplasmic sequestration of both p53 and GR. In neuroblastoma (NB) cells, cytoplasmic retention and inactivation of wild-type p53 involves GR. p53 and GR form a complex that is dissociated by GR antagonists, resulting in accumulation of p53 in the nucleus, activation of p53-responsive genes, growth arrest and apoptosis. These results suggest that molecules that efficiently disrupt GR-p53 interactions would have a therapeutic potential for the treatment of neuroblastoma and perhaps other diseases in which p53 is sequestered by GR.
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Affiliation(s)
- S Sengupta
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, BP 163, 67404 Illkirch cedex, France
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37
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Eichhorst ST, Müller M, Li-Weber M, Schulze-Bergkamen H, Angel P, Krammer PH. A novel AP-1 element in the CD95 ligand promoter is required for induction of apoptosis in hepatocellular carcinoma cells upon treatment with anticancer drugs. Mol Cell Biol 2000; 20:7826-37. [PMID: 11003676 PMCID: PMC86378 DOI: 10.1128/mcb.20.20.7826-7837.2000] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The CD95 (also called APO-1 or Fas) system plays a major role in the induction of apoptosis in lymphoid and nonlymphoid tissues in response to a variety of extracellular signals, including chemotherapeutic drugs. Here we report that the CD95 ligand (CD95L) is upregulated in hepatoma cells upon treatment with antineoplastic drugs. Upregulation by different chemotherapeutic drugs is functionally relevant for drug-induced apoptosis and is mediated by transcriptional mechanisms. The MEKK1/JNKK pathway and a novel AP-1 element in the CD95L promoter downstream of the TATA box are required for CD95L upregulation. Thus, understanding the mechanisms of CD95-mediated apoptosis through CD95L upregulation upon treatment of hepatocellular carcinomas with chemotherapeutic drugs may contribute to the improvement of anticancer chemotherapy.
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Zhu J, Chen X. MCG10, a novel p53 target gene that encodes a KH domain RNA-binding protein, is capable of inducing apoptosis and cell cycle arrest in G(2)-M. Mol Cell Biol 2000; 20:5602-18. [PMID: 10891498 PMCID: PMC86022 DOI: 10.1128/mcb.20.15.5602-5618.2000] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
p53, a tumor suppressor, inhibits cell proliferation by inducing cellular genes involved in the regulation of the cell cycle. MCG10, a novel cellular p53 target gene, was identified in a cDNA subtraction assay with mRNA isolated from a p53-producing cell line. MCG10 can be induced by wild-type but not mutant p53 and by DNA damage via two potential p53-responsive elements in the promoter of the MCG10 gene. The MCG10 gene contains 10 exons and is located at chromosome 3p21, a region highly susceptible to aberrant chromosomal rearrangements and deletions in human neoplasia. The MCG10 gene locus encodes at least two alternatively spliced transcripts, MCG10 and MCG10as. The MCG10 and MCG10as proteins contain two domains homologous to the heterogeneous nuclear ribonucleoprotein K homology (KH) domain. By generating cell lines that inducibly express either wild-type or mutated forms of MCG10 and MCG10as, we found that MCG10 and MCG10as can suppress cell proliferation by inducing apoptosis and cell cycle arrest in G(2)-M. In addition, we found that MCG10 and MCG10as, through their KH domains, can bind poly(C) and that their RNA-binding activity is necessary for inducing apoptosis and cell cycle arrest. Furthermore, we found that the level of the poly(C) binding MCG10 protein is increased in cells treated with the DNA-damaging agent camptothecin in a p53-dependent manner. These results suggest that the MCG10 RNA-binding protein is a potential mediator of p53 tumor suppression.
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Affiliation(s)
- J Zhu
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA
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Saifudeen Z, Du H, Dipp S, El-Dahr SS. The bradykinin type 2 receptor is a target for p53-mediated transcriptional activation. J Biol Chem 2000; 275:15557-62. [PMID: 10748162 DOI: 10.1074/jbc.m909810199] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The bradykinin type 2 receptor (BK2) is a developmentally regulated G protein-coupled receptor that mediates diverse actions such as vascular reactivity, salt and water excretion, inflammatory responses, and cell growth. However, little is known regarding regulation of the BK2 gene. We report here that the rat BK2 receptor is transcriptionally regulated by the tumor suppressor protein p53. The 5'-flanking region of the rat BK2 gene contains two p53-like binding sites: a sequence at -70 base pairs (P1 site) that is conserved in the murine and human BK2 genes; and a sequence at -707 (P2) that is not. The P1 and P2 motifs bind specifically to p53, as assessed by gel mobility shift assays. Transient transfection into HeLa cells of a CAT reporter construct driven by 1.2-kilobases of the BK2 gene 5'-flanking region demonstrated that the BK2 promoter is dose dependently activated by co-expression of wild-type p53. Co-expression of a dominant negative mutant p53 suppresses the activation of BK2 by wild-type p53. Promoter truncation localized the p53-responsive element to the region between -38 and -94 base pairs encompassing the p53-binding P1 sequence. Furthermore, p53-mediated activation of the BK2 promoter is augmented by the transcriptional co-activators, CBP/p300. Interestingly, removal of the P2 site by truncation or site-directed deletion amplifies p53-mediated activation of the BK2 promoter. These results demonstrate that the rat BK2 promoter is a target for p53-mediated activation and suggest a new physiological role for p53 in the regulation of G protein-coupled receptor gene expression.
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Affiliation(s)
- Z Saifudeen
- Department of Pediatrics, Section of Pediatric Nephrology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Blattner C, Kannouche P, Litfin M, Bender K, Rahmsdorf HJ, Angulo JF, Herrlich P. UV-Induced stabilization of c-fos and other short-lived mRNAs. Mol Cell Biol 2000; 20:3616-25. [PMID: 10779351 PMCID: PMC85654 DOI: 10.1128/mcb.20.10.3616-3625.2000] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Irradiation of cells with short-wavelength ultraviolet light (UVC) changes the program of gene expression, in part within less than 15 min. As one of the immediate-early genes in response to UV, expression of the oncogene c-fos is upregulated. This immediate induction is regulated at the transcriptional level and is transient in character, due to the autocatalyzed shutoff of transcription and the rapid turnover of c-fos mRNA. In an experiment analyzing the kinetics of c-fos mRNA expression in murine fibroblasts irradiated with UVC, we found that, in addition to the initial transient induction, c-fos mRNA accumulated in a second wave starting at 4 to 5 h after irradiation, reaching a maximum at 8 h, and persisting for several more hours. It was accompanied by an increase in Fos protein synthesis. The second peak of c-fos RNA was caused by an UV dose-dependent increase in mRNA half-life from about 10 to 60 min. With similar kinetics, the mRNAs of other UV target genes (i.e., the Kin17 gene, c-jun, IkappaB, and c-myc) were stabilized (e.g., Kin17 RNA from 80 min to more than 8 h). The delayed response was not due to autocrine cytokine secretion with subsequent autostimulation of the secreting cells or to UV-induced growth factor receptor activation. Cells unable to repair UVC-induced DNA damage responded to lower doses of UVC with an even greater accumulation of c-fos and Kin17 mRNAs than repair-proficient wild-type cells, suggesting that a process in which a repair protein is involved regulates mRNA stability. Although resembling the induction of p53, a DNA damage-dependent increase in p53 was not a necessary intermediate in the stabilization reaction, since cells derived from p53 knockout mice showed the same pattern of c-fos and Kin17 mRNA accumulation as wild-type cells. The data indicate that the signal flow induced by UV radiation addresses not only protein stability (p53) and transcription but also RNA stability, a hitherto-unrecognized level of UV-induced regulation.
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Affiliation(s)
- C Blattner
- Forschungszentrum Karlsruhe, Institute of Toxicology and Genetics, 76021 Karlsruhe, Germany
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Jimenez GS, Khan SH, Stommel JM, Wahl GM. p53 regulation by post-translational modification and nuclear retention in response to diverse stresses. Oncogene 1999; 18:7656-65. [PMID: 10618705 DOI: 10.1038/sj.onc.1203013] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
p53 activation by diverse stresses involves post-translational modifications that alter its structure and result in its nuclear accumulation. We will discuss several unresolved topics regarding p53 regulation which are currently under investigation. DNA damage is perhaps the best-studied stress which activates p53, and recent data implicate phosphorylation at N-terminal serine residues as critical in this process. We discuss recent data regarding the potential kinases which modify p53 and the possible role of the resulting phosphorylation events. By contrast, much less is understood about agents which disrupt the mitotic spindle. The cell cycle phase, induction signal, and biochemical mechanism of the reversible arrest induced by microtubule disruption are currently under investigation. Finally, a key event in response to any genotoxic stress is the accumulation of p53 in the nucleus. The factors which determine the steady state level of p53 are starting to be elucidated, but the mechanisms responsible for nuclear accumulation and nuclear export remain controversial. We discuss new studies revealing a mechanism for nuclear retention of p53, and the potential contributions of MDM2 to this process.
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Affiliation(s)
- G S Jimenez
- Gene Expression Laboratory, The Salk Institute, 10010 N. Torrey Pines Road, La Jolla, California, CA 92037, USA
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Loging WT, Reisman D. Inhibition of the putative tumor suppressor gene TIMP-3 by tumor-derived p53 mutants and wild type p53. Oncogene 1999; 18:7608-15. [PMID: 10602522 DOI: 10.1038/sj.onc.1203135] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The p53 gene is a tumor suppressor that regulates the expression of genes required for cell cycle arrest or apoptosis. Mutations in p53 have been observed in over 60% of all human cancers. Certain classes of mutant p53 proteins maintain some of their activities or acquire novel activities and thus may contribute to the transformed phenotype. By carrying out an analysis of differential gene expression using cDNA expression arrays, we compared the expression patterns of cells expressing no p53 to isogenic lines expressing the codon 248 Arg to Trp mutant p53 allele (R248W). In this report, we show that the R248W and D281G p53 mutants, two of the more commonly occurring mutations, as well as wild type p53, repress transcription of the tissue inhibitor of metalloproteinases type 3 (TIMP-3) gene by greater than tenfold. TIMP-3 expression has been observed to be repressed in many tumors and its reduced expression is thought to contribute to tumor metastasis and invasiveness by allowing increased activity of metalloproteinases in the extracellular matrix. Since mutant forms of p53 tend to be expressed at greatly elevated levels in many human tumors, the retention of their ability to repress TIMP-3 illustrate one mechanism by which mutant forms of the p53 gene may contribute to tumorigenesis.
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Affiliation(s)
- W T Loging
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, SC 29208, USA
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Abstract
Recent data suggest that additional factors, other than UV radiation, are involved in the etiology of non-melanoma skin cancer. These include alterations in the tumor suppressor genes, p53, p16$L*I*U$LINK4a$L*I$L/CDKN2A, p21$L*I*U$LWAF1/CIP1$L*I$L and the PTCH gene, as well as cytokines. Papillomavirus infections have been implicated in the etiology of non-melanoma skin cancer. The interaction of tumor suppressor genes and cytokines with the oncoproteins of high-risk mucosal HPV types have been studied in detail, but very little is known about the cutaneous HPV types. We have studied the effect of UV radiation on the URRs of HPV 1, 2, 3, 5, 7, 20, 23, 27, 38, 41, and 77. Neither the CAT-expression and promoter activity of these HPV types, nor presence or absence of wild-type or mutated p53 in the cell lines used, could be related to the DNA sequence homology between the different HPV types or their biological behavior.
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Affiliation(s)
- E M de Villiers
- Division for Tumour-virus Characterization, Research Programme Applied Tumour-virology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 242, Heidelberg, 69120, Germany
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Kohn KW. Molecular interaction map of the mammalian cell cycle control and DNA repair systems. Mol Biol Cell 1999; 10:2703-34. [PMID: 10436023 PMCID: PMC25504 DOI: 10.1091/mbc.10.8.2703] [Citation(s) in RCA: 390] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Eventually to understand the integrated function of the cell cycle regulatory network, we must organize the known interactions in the form of a diagram, map, and/or database. A diagram convention was designed capable of unambiguous representation of networks containing multiprotein complexes, protein modifications, and enzymes that are substrates of other enzymes. To facilitate linkage to a database, each molecular species is symbolically represented only once in each diagram. Molecular species can be located on the map by means of indexed grid coordinates. Each interaction is referenced to an annotation list where pertinent information and references can be found. Parts of the network are grouped into functional subsystems. The map shows how multiprotein complexes could assemble and function at gene promoter sites and at sites of DNA damage. It also portrays the richness of connections between the p53-Mdm2 subsystem and other parts of the network.
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Affiliation(s)
- K W Kohn
- Laboratory of Molecular Pharmacology, Division of Basic Sciences, National Cancer Institute, Bethesda, Maryland 20892, USA.
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