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Vetterkind S, Lee E, Sundberg E, Poythress RH, Tao TC, Preuss U, Morgan KG. Par-4: a new activator of myosin phosphatase. Mol Biol Cell 2010; 21:1214-24. [PMID: 20130087 PMCID: PMC2847525 DOI: 10.1091/mbc.e09-08-0711] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We show here for the first time that the pro-apoptotic protein Par-4 binds to and activates myosin phosphatase (MP). During agonist stimulation, Par-4 facilitates ZIPK targeting and inhibitory phosphorylation of MP, however, phosphorylation of Par-4 is required for MP inhibition. Our model presents Par-4 as an amplifier of the MP activity range. Myosin phosphatase (MP) is a key regulator of myosin light chain (LC20) phosphorylation, a process essential for motility, apoptosis, and smooth muscle contractility. Although MP inhibition is well studied, little is known about MP activation. We have recently demonstrated that prostate apoptosis response (Par)-4 modulates vascular smooth muscle contractility. Here, we test the hypothesis that Par-4 regulates MP activity directly. We show, by proximity ligation assays, surface plasmon resonance and coimmunoprecipitation, that Par-4 interacts with the targeting subunit of MP, MYPT1. Binding is mediated by the leucine zippers of MYPT1 and Par-4 and reduced by Par-4 phosphorylation. Overexpression of Par-4 leads to increased phosphatase activity of immunoprecipitated MP, whereas small interfering RNA knockdown of endogenous Par-4 significantly decreases MP activity and increases MYPT1 phosphorylation. LC20 phosphorylation assays demonstrate that overexpression of Par-4 reduces LC20 phosphorylation. In contrast, a phosphorylation site mutant, but not wild-type Par-4, interferes with zipper-interacting protein kinase (ZIPK)-mediated MP inhibition. We conclude from our results Par-4 operates through a “padlock” model in which binding of Par-4 to MYPT1 activates MP by blocking access to the inhibitory phosphorylation sites, and inhibitory phosphorylation of MYPT1 by ZIPK requires “unlocking” of Par-4 by phosphorylation and displacement of Par-4 from the MP complex.
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Affiliation(s)
- Susanne Vetterkind
- Department of Health Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, Boston, MA 02215, USA
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Acharya M, Lingenfelter DJ, Huang L, Gage PJ, Walter MA. Human PRKC apoptosis WT1 regulator is a novel PITX2-interacting protein that regulates PITX2 transcriptional activity in ocular cells. J Biol Chem 2009; 284:34829-38. [PMID: 19801652 PMCID: PMC2787345 DOI: 10.1074/jbc.m109.006684] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 10/01/2009] [Indexed: 11/06/2022] Open
Abstract
Mutations in the homeobox transcription factor PITX2 result in Axenfeld-Rieger syndrome (ARS), which is associated with anterior segment dysgenesis and an increased risk of glaucoma. To understand the pathogenesis of the defects resulting from PITX2 mutations, it is essential to know the normal functions of PITX2 and its interaction with the network of proteins in the eye. Yeast two-hybrid screening was performed using a cDNA library from a human trabecular meshwork primary cell line to detect novel PITX2-interacting proteins and study their role in ARS pathogenesis. After screening of approximately 1 x 10(6) clones, one putative interacting protein was identified named PRKC apoptosis WT1 regulator (PAWR). This interaction was further confirmed by retransformation assay in yeast cells as well as co-immunoprecipitation in ocular cells and nickel pulldown assay in vitro. PAWR is reportedly a proapoptotic protein capable of selectively inducing apoptosis primarily in cancer cells. Our analysis indicates that the homeodomain and the adjacent inhibitory domain in PITX2 interact with the C-terminal leucine zipper domain of PAWR. Endogenous PAWR and PITX2 were found to be located in the nucleus of ocular cells and to co-localize in the mesenchyme of the iridocorneal angle of the developing mouse eye, consistent with a role in the development of the anterior segment of the eye. PAWR was also found to inhibit PITX2 transcriptional activity in ocular cells. These data suggest PAWR is a novel PITX2-interacting protein that regulates PITX2 activity in ocular cells. This information sheds new light in understanding ARS and associated glaucoma pathogenesis.
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Affiliation(s)
| | - David J. Lingenfelter
- the Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - LiJia Huang
- From the Departments of Medical Genetics and
| | - Philip J. Gage
- the Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Michael A. Walter
- From the Departments of Medical Genetics and
- Ophthalmology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada and
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Abstract
Tumor suppressors function in a coordinated regulatory network, and their inactivation is a key step in carcinogenesis. The tumor suppressor Par-4 is a novel integral player in the PTEN network. Thus, Par-4 is absent in a high percentage of human prostate carcinomas, and its loss is concomitantly associated with PTEN loss. Genetic ablation of Par-4 induces fully invasive prostate carcinomas in PTEN-heterozygous mice. In contrast, Par-4 deficiency alone, like PTEN heterozygosis, results in lesions that are unable to progress beyond the benign neoplastic stage known as PIN. At this PIN transition, the mutual induction of Par-4 and PTEN is an additional regulatory step in preventing cancer progression. Par-4 deficiency cooperates with PTEN haploinsufficiency in prostate cancer initiation and progression and their simultaneous inactivation, in addition to enhancing Akt activation, sets in motion a unique mechanism involving the synergistic activation of NFkappaB. These results suggest that the concurrent interruption of complementary signaling pathways targeting PI3K/Akt and NFkappaB activation could provide new and effective strategies for cancer therapy.
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Affiliation(s)
- Maria T Diaz-Meco
- Department of Cancer and Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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Burikhanov R, Zhao Y, Goswami A, Qiu S, Schwarze SR, Rangnekar VM. The tumor suppressor Par-4 activates an extrinsic pathway for apoptosis. Cell 2009; 138:377-88. [PMID: 19632185 DOI: 10.1016/j.cell.2009.05.022] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2008] [Revised: 01/14/2009] [Accepted: 05/01/2009] [Indexed: 12/12/2022]
Abstract
Prostate apoptosis response-4 (Par-4) is a proapoptotic protein with intracellular functions in the cytoplasm and nucleus. Unexpectedly, we noted Par-4 protein is spontaneously secreted by normal and cancer cells in culture, and by Par-4 transgenic mice that are resistant to spontaneous tumors. Short exposure to endoplasmic reticulum (ER) stress-inducing agents further increased cellular secretion of Par-4 by a brefeldin A-sensitive pathway. Secretion occurred independently of caspase activation and apoptosis. Interestingly, extracellular Par-4 induced apoptosis by binding to the stress response protein, glucose-regulated protein-78 (GRP78), expressed at the surface of cancer cells. The interaction of extracellular Par-4 and cell surface GRP78 led to apoptosis via ER stress and activation of the FADD/caspase-8/caspase-3 pathway. Moreover, apoptosis inducible by TRAIL, which also exerts cancer cell-specific effects, is dependent on extracellular Par-4 signaling via cell surface GRP78. Thus, Par-4 activates an extrinsic pathway involving cell surface GRP78 receptor for induction of apoptosis.
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Affiliation(s)
- Ravshan Burikhanov
- Department of Radiation Medicine, University of Kentucky, Lexington, KY 40536, USA
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55
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Boosen M, Vetterkind S, Kubicek J, Scheidtmann KH, Illenberger S, Preuss U. Par-4 is an essential downstream target of DAP-like kinase (Dlk) in Dlk/Par-4-mediated apoptosis. Mol Biol Cell 2009; 20:4010-20. [PMID: 19625447 DOI: 10.1091/mbc.e09-02-0173] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prostate apoptosis response-4 (Par-4) was initially identified as a gene product up-regulated in prostate cancer cells undergoing apoptosis. In rat fibroblasts, coexpression of Par-4 and its interaction partner DAP-like kinase (Dlk, which is also known as zipper-interacting protein kinase [ZIPK]) induces relocation of the kinase from the nucleus to the actin filament system, followed by extensive myosin light chain (MLC) phosphorylation and induction of apoptosis. Our analyses show that the synergistic proapoptotic effect of Dlk/Par-4 complexes is abrogated when either Dlk/Par-4 interaction or Dlk kinase activity is impaired. In vitro phosphorylation assays employing Dlk and Par-4 phosphorylation mutants carrying alanine substitutions for residues S154, T155, S220, or S249, respectively, identified T155 as the major Par-4 phosphorylation site of Dlk. Coexpression experiments in REF52.2 cells revealed that phosphorylation of Par-4 at T155 by Dlk was essential for apoptosis induction in vivo. In the presence of the Par-4 T155A mutant Dlk was partially recruited to actin filaments but resided mainly in the nucleus. Consequently, apoptosis was not induced in Dlk/Par-4 T155A-expressing cells. In vivo phosphorylation of Par-4 at T155 was demonstrated with a phospho-specific Par-4 antibody. Our results demonstrate that Dlk-mediated phosphorylation of Par-4 at T155 is a crucial event in Dlk/Par-4-induced apoptosis.
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Affiliation(s)
- Meike Boosen
- Institute of Genetics, University of Bonn, D-53117 Bonn, Germany
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56
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Hussain S, Romio L, Saleem M, Mathieson P, Serrano M, Moscat J, Diaz-Meco M, Scambler P, Koziell A. Nephrin deficiency activates NF-kappaB and promotes glomerular injury. J Am Soc Nephrol 2009; 20:1733-43. [PMID: 19497968 DOI: 10.1681/asn.2008111219] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Increasing evidence implicates activation of NF-kappaB in a variety of glomerular diseases, but the mechanisms involved are unknown. Here, upregulation of NF-kappaB in the podocytes of transgenic mice resulted in glomerulosclerosis and proteinuria. Absence of the podocyte protein nephrin resulted in NF-kappaB activation, suggesting that nephrin negatively regulates the NF-kappaB pathway. Signal transduction assays supported a functional relationship between nephrin and NF-kappaB and suggested the involvement of atypical protein kinase C (aPKCzeta/lambda/iota) as an intermediary. We propose that disruption of the slit diaphragm leads to activation of NF-kappaB; subsequent upregulation of NF-kappaB-driven genes results in glomerular damage mediated by NF-kappaB-dependent pathways. In summary, nephrin may normally limit NF-kappaB activity in the podocyte, suggesting a mechanism by which it might discourage the evolution of glomerular disease.
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Affiliation(s)
- Sagair Hussain
- Molecular Medicine Unit, Institute of Child Health, London, UK.
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57
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Libich DS, Schwalbe M, Kate S, Venugopal H, Claridge JK, Edwards PJB, Dutta K, Pascal SM. Intrinsic disorder and coiled-coil formation in prostate apoptosis response factor 4. FEBS J 2009; 276:3710-28. [PMID: 19490121 DOI: 10.1111/j.1742-4658.2009.07087.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Prostate apoptosis response factor-4 (Par-4) is an ubiquitously expressed pro-apoptotic and tumour suppressive protein that can both activate cell-death mechanisms and inhibit pro-survival factors. Par-4 contains a highly conserved coiled-coil region that serves as the primary recognition domain for a large number of binding partners. Par-4 is also tightly regulated by the aforementioned binding partners and by post-translational modifications. Biophysical data obtained in the present study indicate that Par-4 primarily comprises an intrinsically disordered protein. Bioinformatic analysis of the highly conserved Par-4 reveals low sequence complexity and enrichment in polar and charged amino acids. The high proteolytic susceptibility and an increased hydrodynamic radius are consistent with a largely extended structure in solution. Spectroscopic measurements using CD and NMR also reveal characteristic features of intrinsic disorder. Under physiological conditions, the data obtained show that Par-4 self-associates via the C-terminal domain, forming a coiled-coil. Interruption of self-association by urea also resulted in loss of secondary structure. These results are consistent with the stabilization of the coiled-coil motif through an intramolecular association.
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Affiliation(s)
- David S Libich
- Centre for Structural Biology, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
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58
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Interaction of the replication proteins and the capsid protein of porcine circovirus type 1 and 2 with host proteins. Virology 2009; 386:122-31. [DOI: 10.1016/j.virol.2008.12.039] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 12/02/2008] [Accepted: 12/26/2008] [Indexed: 01/08/2023]
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59
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Lee JW, Liu PF, Hsu LP, Chen PR, Chang CH, Shih WL. EBV LMP-1 negatively regulates expression and pro-apoptotic activity of Par-4 in nasopharyngeal carcinoma cells. Cancer Lett 2009; 279:193-201. [PMID: 19250735 DOI: 10.1016/j.canlet.2009.01.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 12/24/2008] [Accepted: 01/27/2009] [Indexed: 12/19/2022]
Abstract
Latent membrane protein-1 (LMP-1) of the Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC), and in this study we sought to determine whether the pro-apoptotic activity of prostate apoptosis response-4 (Par-4) is modulated by LMP-1 in NPC cells. We found that LMP-1 diminished the pro-apoptotic activity of Par-4 and negatively regulated Par-4 protein by de novo synthesis; moreover, although LMP-1 accelerated a Par-4 activator, PKA, we demonstrated that LMP-1 also activated the PI3K/Akt pathway and increased Bcl-2 expression to suppress the activity of Par-4. Consequently, our results revealed a novel negative action of LMP-1 on the pro-apoptosis protein Par-4 by the coordination of multiple signaling pathways.
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Affiliation(s)
- Jeng-Woei Lee
- Department and Institute of Life Science, College of Life Science, Tzu-Chi University, No. 701, Zhongyang Rd., Sec. 3, Hualien 97004, Taiwan.
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60
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Finsterbusch T, Mankertz A. Porcine circoviruses--small but powerful. Virus Res 2009; 143:177-83. [PMID: 19647885 DOI: 10.1016/j.virusres.2009.02.009] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Accepted: 02/15/2009] [Indexed: 01/31/2023]
Abstract
When porcine circovirus type 1 (PCV1) was isolated more than 40 years ago as a non-pathogenic contaminant of a porcine kidney cell line, enthusiasm and curiosity kept within reasonable limits. Virologists became more interested, when a second variant was isolated and termed PCV2, because PCV2 is linked to postweaning multisystemic wasting disease (PMWS), a new emerging multifactorial disease in swine. Both PCV1 and PCV2 are small and rather simply organized and express only few proteins. Therefore, it was expected that the factor(s) triggering PMWS should be easily identified, but more than one decade of PCV research has not yet singled out a molecule inducing the disease onset. Unravelling the molecular features of PCV and the channels through which the virus interacts with its host are key to manage, prevent and treat PMWS and other PCV-associated diseases. Since we have learned many aspects of the molecular biology of PCV in the last years, it is time for a résumé!
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Affiliation(s)
- Tim Finsterbusch
- Division of Viral Infections (FG12), Robert Koch-Institute, 13353 Berlin, Germany
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61
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Abstract
Par-4 is a tumor suppressor protein with a pro-apoptotic function. Epigenetic silencing of Par-4 is seen in diverse tumors and Par-4 knockout mice develop spontaneous tumors in various tissues. Endogenous Par-4 is essential for sensitization of cells to diverse apoptotic stimuli, whereas ectopic expression of Par-4 can selectively induce apoptosis in cancer cells. The cancer-specific pro-apoptotic action of Par-4 resides in its centrally located SAC domain. This review emphasizes the role of Par-4/SAC in apoptosis and tumor resistance. SAC transgenic mice display normal development and life span, and, most importantly, are resistant to spontaneous, as well as oncogene-induced, autochthonous tumors. The tumor resistant phenotype and undetectable toxicity of SAC in vivo suggests the SAC domain possesses tremendous therapeutic potential.
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Affiliation(s)
- Yanming Zhao
- Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536, USA
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62
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Goswami A, Qiu S, Dexheimer TS, Ranganathan P, Burikhanov R, Pommier Y, Rangnekar VM. Par-4 binds to topoisomerase 1 and attenuates its DNA relaxation activity. Cancer Res 2008; 68:6190-8. [PMID: 18676842 DOI: 10.1158/0008-5472.can-08-0831] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The regulation of DNA relaxation by topoisomerase 1 (TOP1) is essential for DNA replication, transcription, and recombination events. TOP1 activity is elevated in cancer cells, yet the regulatory mechanism restraining its activity is not understood. We present evidence that the tumor suppressor protein prostate apoptosis response-4 (Par-4) directly binds to TOP1 and attenuates its DNA relaxation activity. Unlike camptothecin, which binds at the TOP1-DNA interface to form cleavage complexes, Par-4 interacts with TOP1 via its leucine zipper domain and sequesters TOP1 from the DNA. Par-4 knockdown by RNA interference enhances DNA relaxation and gene transcription activities and promotes cellular transformation in a TOP1-dependent manner. Conversely, attenuation of TOP1 activity either by RNA interference or Par-4 overexpression impedes DNA relaxation, cell cycle progression, and gene transcription activities and inhibits transformation. Collectively, our findings suggest that Par-4 serves as an intracellular repressor of TOP1 catalytic activity and regulates DNA topology to suppress cellular transformation.
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Affiliation(s)
- Anindya Goswami
- Department of Radiation Medicine, Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536, USA
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63
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Lu C, Chen JQ, Zhou GP, Wu SH, Guan YF, Yuan CS. Multimolecular complex of Par-4 and E2F1 binding to Smac promoter contributes to glutamate-induced apoptosis in human- bone mesenchymal stem cells. Nucleic Acids Res 2008; 36:5021-32. [PMID: 18660514 PMCID: PMC2528162 DOI: 10.1093/nar/gkn426] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Neural cells undergo glutamate-induced apoptosis in ischaemic brain tissue, in which prostate apoptosis response-4 gene (Par-4) is involved. Human-bone mesenchymal stem cells can be utilized as an effective therapy for ischemic brain injury. In this study, we found that glutamate could induce apoptosis in human-bone mesenchymal stem cells, accompanied by increased expression of Par-4 gene and Smac release from mitochondria. Repressing Par-4 expression attenuated the glutamate-induced apoptosis. Both Par-4 protein and E2F1 protein could bind to E2F1-binding BS3 site on Smac promoter and participated in the formation of a proteins-DNA complex. Moreover, in the complex, E2F1, not Par-4, was found to be directly bound to the Smac promoter, suggesting that Par-4 exerted indirectly its transcriptional control on the Smac gene though interacting with E2F1. Expression of full-length Par-4 in human-bone mesenchymal cells resulted in increased activity of the Smac promoter. In addition, the indirect transcripional regulation of Par-4 on Smac depended on its COOH terminus-mediated interaction between Par-4 and E2F1. We conclude that the formation of proteins-DNA complex, containing Par-4 protein, E2F1 protein and the Smac promoter, contributes to the pro-apoptotic effect on glutamate-treated human-bone mesenchymal stem cells.
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Affiliation(s)
- Chao Lu
- Department of Pediatrics, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, People's Republic of China.
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64
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Par-4 inhibits Akt and suppresses Ras-induced lung tumorigenesis. EMBO J 2008; 27:2181-93. [PMID: 18650932 DOI: 10.1038/emboj.2008.149] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Accepted: 07/07/2008] [Indexed: 12/20/2022] Open
Abstract
The atypical PKC-interacting protein, Par-4, inhibits cell survival and tumorigenesis in vitro, and its genetic inactivation in mice leads to reduced lifespan, enhanced benign tumour development and low-frequency carcinogenesis. Here, we demonstrate that Par-4 is highly expressed in normal lung but reduced in human lung cancer samples. We show, in a mouse model of lung tumours, that the lack of Par-4 dramatically enhances Ras-induced lung carcinoma formation in vivo, acting as a negative regulator of Akt activation. We also demonstrate in cell culture, in vivo, and in biochemical experiments that Akt regulation by Par-4 is mediated by PKCzeta, establishing a new paradigm for Akt regulation and, likely, for Ras-induced lung carcinogenesis, wherein Par-4 is a novel tumour suppressor.
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65
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Vetterkind S, Morgan KG. The pro-apoptotic protein Par-4 facilitates vascular contractility by cytoskeletal targeting of ZIPK. J Cell Mol Med 2008; 13:887-95. [PMID: 18505470 PMCID: PMC2700217 DOI: 10.1111/j.1582-4934.2008.00374.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Par-4 (prostate apoptosis response 4) is a pro-apoptotic protein and tumour suppressor that was originally identified as a gene product up-regulated during apoptosis in prostate cancer cells. Here, we show, for the first time, that Par-4 is expressed and co-localizes with the actin filament bundles in vascular smooth muscle. Furthermore, we demonstrate that targeting of ZIPK to the actin filaments, as observed upon PGF-2α stimulation, is inhibited by the presence of a cell permeant Par-4 decoy peptide. The same decoy peptide also significantly inhibits PGF-2α induced contractions of smooth muscle tissue. Moreover, knockdown of Par-4 using antisense morpholino nucleotides results in significantly reduced contractility, and myosin light chain and myosin phosphatase target subunit phosphorylation. These results indicate that Par-4 facilitates contraction by targeting ZIPK to the vicinity of its substrates, myosin light chain and MYPT, which are located on the actin filaments. These results identify Par-4 as a novel regulator of myosin light chain phosphorylation in differentiated, contractile vascular smooth muscle.
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66
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Schittenhelm J, Beschorner R, Simon P, Tabatabai G, Herrmann C, Schlaszus H, Capper D, Weller M, Meyermann R, Mittelbronn M. Diagnostic value of WT1 in neuroepithelial tumours. Neuropathol Appl Neurobiol 2008; 35:69-81. [PMID: 18466223 DOI: 10.1111/j.1365-2990.2008.00957.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Currently, clinical trials using WT1 (Wilms tumour gene) peptide vaccines are conducted in haematopoietic malignancies and solid cancers. Single reports showed that the Wilms tumour gene product WT1 is also expressed in astrocytic neoplasms. Our aim was to investigate WT1 expression in a large cohort of various neuroepithelial tumours of different World Health Organization (WHO) grades and in normal central nervous system (CNS) tissue specimens to test its potential value as a diagnostic marker. METHODS Specimens were assessed by RT-PCR, Western blotting and immunohistochemistry. The samples investigated in our study consisted of 334 human neuroepithelial tumours, among those 33 oligodendrogliomas, 219 astrocytomas (including 105 glioblastomas) and 47 ependymomas. RESULTS Our results showed a de novo WT1 expression in neuroepithelial tumours. In diffuse astrocytomas and ependymomas, WT1 expression increased significantly with the grade of malignancy. In contrast, no significant difference was seen between WHO grade-II and -III oligodendrogliomas. Controlling for WHO grade, the comparison of oligodendrogliomas with ependymal and astrocytic tumours showed higher expression values for the latter. CONCLUSIONS Our study shows that WT1 is expressed de novo in numerous neuroepithelial tumours and increases with the grade of malignancy. These results suggest an important role of WT1 in tumourigenesis and progression in human brain tumours.
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Affiliation(s)
- J Schittenhelm
- Institute of Brain Research, University of Tuebingen, Tuebingen, Germany
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67
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Sera T, Hiasa Y, Mashiba T, Tokumoto Y, Hirooka M, Konishi I, Matsuura B, Michitaka K, Udaka K, Onji M. Wilms' tumour 1 gene expression is increased in hepatocellular carcinoma and associated with poor prognosis. Eur J Cancer 2008; 44:600-8. [PMID: 18255279 DOI: 10.1016/j.ejca.2008.01.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 12/21/2007] [Accepted: 01/07/2008] [Indexed: 01/29/2023]
Abstract
BACKGROUND/AIMS Wilms' tumour 1 gene (WT1) was originally isolated as a tumour-suppressor gene. We investigated the expression of WT1 in hepatocellular carcinoma (HCC; T) and in non-cancerous hepatic tissues (non-tumour: NT) from patients with chronic liver diseases, and then examined the role of WT1 in the carcinogenesis or prognosis of HCC. METHODS The expression of WT1 in T and NT from 50 patients with HCC was investigated using Western blotting, immunohistochemistry and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). We also examined whether WT1 expression was related to clinicopathological factors in individual patients in addition to prognostic factors in 50 patients with HCC and in 26 without HCC. RESULTS Western blotting and immunohistochemical staining showed that WT1 was overexpressed in T compared with NT (P<0.001) and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) showed that WT1 mRNA expression was similarly increased. Overexpressed WT1 in HCC was significantly associated with T factors at the TNM stage, and short doubling time of HCC. Univariate and multivariate analyses revealed that WT1 overexpression was an independent prognostic factor for HCC. The disease-free survival period in patients with overexpressed WT1 in NT tissues was significantly reduced. CONCLUSION The expression of WT1 is increased more in HCC than in non-tumour tissues. Moreover, overexpressed WT1 was associated with tumour growth, and resulted in a worsening prognosis of HCC. Our findings from NT tissues revealed that WT1 overexpression might contribute to oncogenic potential.
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Affiliation(s)
- Toshiki Sera
- Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Sitsukawa, Toon, Ehime 791-0295, Japan
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68
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Gonzalez IH, Santana P, Gonzalez-Robayna I, Ferrer M, Morales V, Blanco FL, Fanjul LF. Regulation of the expression of prostate apoptosis response protein 4 (Par-4) in rat granulosa cells. Apoptosis 2008; 12:769-79. [PMID: 17219052 DOI: 10.1007/s10495-006-0019-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The par-4 gene, directs the expression of a protein in the rat ventral prostate after apoptotic stimuli but not growth stimulatory, growth arresting or necrotic signals. Since Par-4 expression appears to be ubiquitous we investigated the possibility of Par-4 having a role in the rat ovary granulosa cells apoptotic death. Par-4 mRNA was detected by RT-PCR with oligonucleotides designed to prime Par-4 leucine zipper in the ovaries of 12 day old rats and reached the higher levels in 24 days old rats. In situ hybridization analysis revealed that Par-4 expression is restricted to granulosa cells. PMSG priming of 24 day old rats for 2 days greatly reduced Par-4 expression in granulosa cells as determined by in situ hybridization, RT-PCR of mRNA and protein immunodetection with Western blot. Granulosa cells placed in serum-fee culture, exhibited increased levels of Par-4 mRNA and protein, in good correlation with the degree of apoptosis. The culture-induced increases in Par-4 are significantly prevented by FSH. Transient transfection of granulosa cells with Par-4 leucine zipper domain that functions as a dominant-negative regulator of Par-4 activity resulted in lower rates of apoptosis while overexpression of the full length Par-4 counteracted FSH effects on apoptosis. Par-4 association with PKCzeta which is supposed to inhibit this kinase mediated antiapoptotic way is also prevented by FSH and, FSH antiapoptotic effects are counteracted by a PKCzeta specific inhibitor. These findings indicate that FSH by suppressing Par-4 expression in the ovary activates PKCzeta-dependent antiapoptotic pathway and suggest that Par-4 is part of the mechanism underlying granulosa cells apoptotic demise.
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Affiliation(s)
- Inmaculada Hernandez Gonzalez
- Departamento de Bioquímica, Biología Molecular y Fisiología, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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Rong Y, Cheng L, Ning H, Zou J, Zhang Y, Xu F, Liu L, Chang Z, Fu XY. Wilms' tumor 1 and signal transducers and activators of transcription 3 synergistically promote cell proliferation: a possible mechanism in sporadic Wilms' tumor. Cancer Res 2007; 66:8049-57. [PMID: 16912181 DOI: 10.1158/0008-5472.can-06-1172] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transcription factor Wilms' tumor 1 (WT1) was originally identified as a tumor suppressor for Wilms' tumor, but it is also overexpressed in a variety of cancer cells, suggesting a potential oncogenic function of WT1. It is important to understand molecular mechanisms underlying these dual functions of WT1 in tumorigenesis. In the current study, we report a synergistic role for signal transducers and activators of transcription 3 (STAT3) and WT1 in tumor development, including Wilms' tumor. STAT3 interacts with WT1 through its conserved domains both in vitro and in vivo. When STAT3 is activated, expression of WT1 enhances STAT3 transcriptional activity. Overexpression of WT1 and STAT3CA in NIH 3T3 increases the expression level of STAT3 target genes, including cyclin D1 and Bcl-xL, which results in an advantage of cell proliferation. Our results suggest that in the presence of activated STAT3, WT1 promotes cell proliferation instead of suppressing cell proliferation. Strikingly, STAT3 translocates to the nucleus and interacts with WT1 in a variety of primary Wilms' tumor cells, raising the hypothesis that WT1 and activated STAT3 in Wilms' tumor accelerate tumorigenesis.
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Affiliation(s)
- Yu Rong
- Department of Biological Sciences and Biotechnology and Institute of Biomedicine, Tsinghua University, Beijing 10084, China
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70
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Lee JW, Lee KF, Hsu HY, Hsu LP, Shih WL, Chu YC, Hsiao WT, Liu PF. Protein expression and intracellular localization of prostate apoptosis response-4 (Par-4) are associated with apoptosis induction in nasopharyngeal carcinoma cell lines. Cancer Lett 2007; 257:252-62. [PMID: 17881119 DOI: 10.1016/j.canlet.2007.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 07/03/2007] [Accepted: 08/01/2007] [Indexed: 10/22/2022]
Abstract
Prostate apoptosis response-4 (Par-4) is a proapoptotic gene that selectively induces cell death in most cancer cells. In addition to the increased percentage of apoptotic cells, caspase-3 activity, and poly (ADP-ribose) polymerase (PARP) cleavage, we demonstrate that elevated expression of Par-4 and nuclear entry resulted in apoptosis of nasopharyngeal carcinoma (NPC) cell lines either in serum deprivation or by ectopic overexpression of Par-4. Moreover, disassociation from the Par-4/Akt complex was correlated with the induced proapoptotic ability of Par-4. Therefore, our data suggest that the cytoplasmic localization and expression level of endogenous Par-4 in NPC cells are not sufficient to augment apoptosis.
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Affiliation(s)
- Jeng-Woei Lee
- Department and Institute of Life Science, College of Life Science, Tzu-Chi University, 701, Sec. 3, Chung-Yang Road, Hualien 97071, Taiwan.
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71
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Kabbani N, Levenson R. A proteomic approach to receptor signaling: Molecular mechanisms and therapeutic implications derived from discovery of the dopamine D2 receptor signalplex. Eur J Pharmacol 2007; 572:83-93. [PMID: 17662712 DOI: 10.1016/j.ejphar.2007.06.059] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 06/14/2007] [Accepted: 06/18/2007] [Indexed: 12/23/2022]
Abstract
Recent research in cell signaling has shown that the assembly of G protein coupled receptors into signaling complexes or signalplexes represents the primary mechanism by which receptor-mediated signaling is established and maintained. In this review, we summarize the current state of knowledge regarding protein interactions that comprise the dopamine D2 receptor signalplex within the brain. Studies based on conventional and advanced two-hybrid methodologies, as well as bioinformatic and computational analysis of sequence information from completed genomes have demonstrated interactions between dopamine D2 receptors and a cohort of dopamine receptor interacting proteins (DRIPs). DRIP interactions appear to regulate key aspects of receptor function including the signaling and membrane trafficking of dopamine D2 receptors. Disruptions or modifications of the signalplex, using membrane permeant competing peptide or dominant negative approaches, may represent promising new strategies for the selective targeting of the dopamine D2 receptor in cells and in native tissue. DRIP interactions provide a novel platform for understanding the mechanisms of dopamine receptor signaling, and for the potential development of novel treatments for brain disease.
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Affiliation(s)
- Nadine Kabbani
- Department of Neuroscience, Pasteur Institute, 75015 Paris, France.
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72
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Val P, Martinez-Barbera JP, Swain A. Adrenal development is initiated by Cited2 and Wt1 through modulation of Sf-1 dosage. Development 2007; 134:2349-58. [PMID: 17537799 DOI: 10.1242/dev.004390] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
It has been proposed that the mammalian adrenal cortex and gonad are derived from the same primordium present during early urogenital development. Molecular pathways involved in the differentiation of the adrenal cortex from the adrenogonadal primordium (AGP) have yet to be determined. Here we show in mice that the transcription co-factor Cited2 is required for the specification of the adrenal cortex from the AGP. We present genetic and molecular evidence demonstrating that Cited2 interacts with the transcription factor Wt1 to stimulate expression of the nuclear hormone receptor Sf-1 (Nr5a1) in the AGP prior to the separation between gonad and adrenal cortex. We show a direct correlation between the expression levels of Sf-1 in the AGP and the defects in adrenal development found in mice with different Cited2 and Wt1 mutant backgrounds. Analysis of embryos heterozygous for mutations in both Sf-1 and Cited2 confirmed that these genes act in the same pathway during adrenal development. Our studies reveal a regulatory mechanism in which Cited2 acts as a Wt1 co-factor to increase, at a critical time in embryogenesis, the levels of the essential transcription factor Sf-1 in the AGP above the threshold required to determine adrenal development. These results highlight the importance of transcription factor dosage in organogenesis and the role of transcription co-factors such as Cited2 in determining the levels of these factors.
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Affiliation(s)
- Pierre Val
- Section of Gene Function and Regulation, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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73
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Stoll R, Lee BM, Debler EW, Laity JH, Wilson IA, Dyson HJ, Wright PE. Structure of the Wilms tumor suppressor protein zinc finger domain bound to DNA. J Mol Biol 2007; 372:1227-45. [PMID: 17716689 DOI: 10.1016/j.jmb.2007.07.017] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 07/11/2007] [Accepted: 07/12/2007] [Indexed: 11/22/2022]
Abstract
The zinc finger domain of the Wilms tumor suppressor protein (WT1) contains four canonical Cys(2)His(2) zinc fingers. WT1 binds preferentially to DNA sequences that are closely related to the EGR-1 consensus site. We report the structure determination by both X-ray crystallography and NMR spectroscopy of the WT1 zinc finger domain in complex with DNA. The X-ray structure was determined for the complex with a cognate 14 base-pair oligonucleotide, and composite X-ray/NMR structures were determined for complexes with both the 14 base-pair and an extended 17 base-pair DNA. This combined approach allowed unambiguous determination of the position of the first zinc finger, which is influenced by lattice contacts in the crystal structure. The crystal structure shows the second, third and fourth zinc finger domains inserted deep into the major groove of the DNA where they make base-specific interactions. The DNA duplex is distorted in the vicinity of the first zinc finger, with a cytidine twisted and tilted out of the base stack to pack against finger 1 and the tip of finger 2. By contrast, the composite X-ray/NMR structures show that finger 1 continues to follow the major groove in the solution complexes. However, the orientation of the helix is non-canonical, and the fingertip and the N terminus of the helix project out of the major groove; as a consequence, the zinc finger side-chains that are commonly involved in base recognition make no contact with the DNA. We conclude that finger 1 helps to anchor WT1 to the DNA by amplifying the binding affinity although it does not contribute significantly to binding specificity. The structures provide molecular level insights into the potential consequences of mutations in zinc fingers 2 and 3 that are associated with Denys-Drash syndrome and nephritic syndrome. The mutations are of two types, and either destabilize the zinc finger structure or replace key base contact residues.
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Affiliation(s)
- Raphael Stoll
- Department of Molecular Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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74
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Moreno-Bueno G, Fernandez-Marcos PJ, Collado M, Tendero MJ, Rodriguez-Pinilla SM, Garcia-Cao I, Hardisson D, Diaz-Meco MT, Moscat J, Serrano M, Palacios J. Inactivation of the candidate tumor suppressor par-4 in endometrial cancer. Cancer Res 2007; 67:1927-34. [PMID: 17332319 DOI: 10.1158/0008-5472.can-06-2687] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recently, it has been shown that mice deficient in the proapoptotic protein prostate apoptosis response 4 (Par-4) are specifically prone to develop endometrial carcinomas. Based on this, we have examined here the possible role of Par-4 as a tumor suppressor gene in human endometrial cancer. Using cDNA arrays, quantitative reverse transcription-PCR, and immunohistochemistry, we detected Par-4 down-regulation in approximately 40% of endometrial carcinomas. This alteration was not associated with phosphatase and tensin homologue (PTEN), K-RAS, or beta-catenin mutations, but was more frequent among tumors showing microsatellite instability (MSI) or among tumors that were estrogen receptor positive. Mutational analysis of the complete coding sequence of Par-4 in endometrial cancer cell lines (n = 6) and carcinomas (n = 69) detected a mutation in a single carcinoma, which was localized in exon 3 [Arg (CGA) 189 (TGA) Stop]. Interestingly, Par-4 promoter hypermethylation was detected in 32% of the tumors in association with low levels of Par-4 protein and was more common in MSI-positive carcinomas. Par-4 promoter hypermethylation and silencing was also detected in endometrial cancer cell lines SKUT1B and AN3CA, and reexpression was achieved by treatment with the demethylating agent 5'-aza-2'-deoxycytidine. Together, these data show that Par-4 is a relevant tumor suppressor gene in human endometrial carcinogenesis.
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Affiliation(s)
- Gema Moreno-Bueno
- Breast and Gynecological Cancer Group, Tumor Suppression Group, Spanish National Cancer Center (CNIO), 3 Melchior Fernandez Almagro Street, Madrid E-28029, Spain
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75
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Yang L, Han Y, Suarez Saiz F, Saurez Saiz F, Minden MD. A tumor suppressor and oncogene: the WT1 story. Leukemia 2007; 21:868-76. [PMID: 17361230 DOI: 10.1038/sj.leu.2404624] [Citation(s) in RCA: 329] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Wilms' tumor 1 (WT1) gene encodes a transcription factor important for normal cellular development and cell survival. The initial discovery of WT1 as the causative gene in an autosomal-recessive condition identified it as a tumor suppressor gene whose mutations are associated with urogenital disease and the development of kidney tumors. However, this view is not in keeping with the frequent finding of wild-type, full-length WT1 in human leukemia, breast cancer and several other cancers including the majority of Wilms' tumors. Rather, these observations suggest that in those conditions, WT1 has an oncogenic role in tumor formation. In this review, we explore the literature supporting both views of WT1 in human cancer and in particular human leukemias. To understand the mechanism by which WT1 can do this, we will also examine its functional activity as a transcription factor and the influence of protein partners on its dual behavior.
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Affiliation(s)
- L Yang
- Department of Cellular and Molecular Biology, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
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76
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Abstract
Aberrant methylation patterns of genomic DNA are well-studied epigenetic mutations in cancer. Hypermethylation of CpG islands in tumor-suppressor genes promotes oncogenesis and hypomethylation of global genomic DNA affects genomic stability. Cancer is recognized as a genetic and epigenetic disease. However, it is not clear how epigenetic regulatory factors, including histone modification enzymes, chromatin components and other factors are involved in carcinogenesis. To gain insights into the molecular mechanisms mediated by these factors at the early stage of hepatocarcinogenesis and hepatotoxicity induced by chemicals, we investigated gene expression profiles by DNA microarray and Western blot analyses. We prepared RNA and nuclear extracts from livers with hyperplastic nodules expressing Glutathione S-transferase placental form (GST-P) and compared findings with those of normal liver. GST-P is a phase II detoxification enzyme and a well-known tumor marker. We identified several epigenetic regulatory factors that showed dysregulated expression during chemically induced hepatocarcinogenesis. Here I review the characterization and functions of these factors and discuss the mechanisms of tumor marker gene expression during chemical hepatocarcinogenesis.
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Affiliation(s)
- Shigehiro Osada
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
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77
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Ahmed MM, Sheldon D, Fruitwala MA, Venkatasubbarao K, Lee EY, Gupta S, Wood C, Mohiuddin M, Strodel WE. Downregulation of PAR-4, a pro-apoptotic gene, in pancreatic tumors harboring K-ras mutation. Int J Cancer 2007; 122:63-70. [PMID: 17893871 DOI: 10.1002/ijc.23019] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Oncogenic ras is known to inhibit cell death and growth inhibitory genes and activate prosurvival genes. Proapoptotic gene PAR-4, has been found to be downregulated by oncogenic ras. Since pancreatic tumors harbor a high incidence of K-ras point mutations, we hypothesized that oncogenic K-ras might influence the function and expression of PAR-4. PAR-4 expression levels were analyzed in 4 established pancreatic tumor cell lines, 10 normal pancreatic tissues, 44 frozen tumor tissues and 25 paraffin-embedded pancreatic adenocarcinoma samples by Real Time RT-PCR, Western blot analysis and immunohistochemistry. K-ras mutational status was analyzed by allele-specific oligonucleotide-hybridization. Expression levels of PAR-4 were correlated with the K-ras mutational status and clinical characteristics. Further, modulation of endogenous PAR-4 was tested by transiently expressing oncogenic ras in a wild-type K-ras pancreatic cancer cell line, BxPC-3. Three cell lines with K-ras mutations showed low levels of PAR-4 when compared to a normal pancreatic tissue. Of 44 frozen tumors, 16 showed appreciable upregulation of Par mRNA and 27 showed significant downregulation of PAR-4 mRNA when compared to normal pancreatic tissue and 1 had levels equivalent to normal pancreatic tissue. Of 25 paraffin-embedded tumors, 9 showed downregulation of PAR-4 protein and this downregulation of PAR-4 correlated significantly with K-ras mutational status (p < 0.00002). In addition, the presence of PAR-4 mRNA or protein expression in pancreatic tumors correlated with prolonged survival. Transient overexpression of oncogenic ras in wild-type K-ras BxPC-3 cells significantly downregulated the endogenous PAR-4 protein levels and conferred accelerated growth. Thus, downregulation or loss of PAR-4 expression by oncogenic ras may provide a selective survival advantage for pancreatic tumors, through inhibition of proapoptotic pathway mediated by PAR-4.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/metabolism
- Down-Regulation
- Gene Expression Regulation, Neoplastic
- Genes, ras/genetics
- Humans
- Mutation/genetics
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Receptors, Thrombin/genetics
- Receptors, Thrombin/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Cells, Cultured
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Affiliation(s)
- Mansoor M Ahmed
- Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA
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78
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Srinivasan S, Ranga RS, Burikhanov R, Han SS, Chendil D. Par-4-dependent apoptosis by the dietary compound withaferin A in prostate cancer cells. Cancer Res 2006; 67:246-53. [PMID: 17185378 DOI: 10.1158/0008-5472.can-06-2430] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Deletion or mutation of the androgen receptor (AR) renders prostate tumors refractory to apoptosis by androgen ablation, the mainstay of prostate cancer therapy. To identify novel therapeutics that can induce apoptosis regardless of the AR status of prostate cancer cells, we screened dietary herbal compounds using a reporter assay for the prostate apoptosis response-4 (Par-4) gene, which induces p53- and PTEN-independent and cancer-selective apoptosis. One of the compounds, withaferin A (WA), a major constituent of the dietary compound Withania somnifera, induced Par-4-dependent apoptosis in androgen-refractory prostate cancer cells and regression of PC-3 xenografts in nude mice. Interestingly, restoration of wild-type AR in PC-3 (AR negative) cells abrogated both Par-4 induction and apoptosis by WA. Individually, WA and anti-androgens induced neither Par-4 nor apoptosis in androgen-responsive prostate cancer cells, yet in combination, WA and anti-androgen synergistically induced Par-4 and apoptosis in androgen-responsive prostate cancer cells. Thus, when judiciously combined with anti-androgens, WA inhibits survival of both androgen-responsive and androgen-refractory prostate cancer cells by a Par-4-dependent mechanism. As Par-4 up-regulation induces apoptosis in most tumor cells, our findings can be extended to high-throughput screens to identify synergistic combinations for both therapy-sensitive and therapy-resistant cancers.
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Affiliation(s)
- Sowmyalakshmi Srinivasan
- Department of Clinical Sciences, College of Health Sciences, University of Kentucky, 900 South Limestone Street, Lexington, KY 40536, USA
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79
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Osada S, Naganawa A, Misonou M, Tsuchiya S, Tamba S, Okuno Y, Nishikawa JI, Satoh K, Imagawa M, Tsujimoto G, Sugimoto Y, Nishihara T. Altered gene expression of transcriptional regulatory factors in tumor marker-positive cells during chemically induced hepatocarcinogenesis. Toxicol Lett 2006; 167:106-13. [PMID: 16997513 DOI: 10.1016/j.toxlet.2006.08.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 08/29/2006] [Accepted: 08/29/2006] [Indexed: 11/25/2022]
Abstract
Glutathione-S-transferase placental form (GST-P) is markedly and specifically inducible in rat chemical hepatocarcinogenesis and is a reliable marker protein for pre-neoplasia. To gain insights into the molecular mechanisms at the early stage of hepatocarcinogenesis and hepatotoxicity, we investigated the gene expression profile by DNA microarray analysis. We prepared RNA from GST-P-positive foci in three individual rats and compared with normal liver sections from three individual rats, and labeled RNA was individually hybridized onto Affymetrix GeneChip Rat Expression Array 230A. DNA microarray analysis showed distinctly different profiles of dysregulated gene expression and supported the previous finding that some enzymes involved in metabolism and detoxification are overexpressed and suppressed. Here we discovered that several DNA-binding transcription factors and cofactors, including sterol-regulatory-element binding protein 1 (SREBP1) and Wilms' tumour 1 (WT1)-interacting protein, and their target genes were dysregulated in GST-P-positive foci. Moreover, genes involved in chromatin components, histone modification enzymes, and centrosome duplication were highly expressed. These genes were not previously known to be up-regulated during chemically induced hepatocarcinogenesis. DNA microarray analysis using RNA prepared from tumor marker-positive foci and control tissues provided a candidate gene link to the early stage of carcinogenesis and hepatotoxicity.
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Affiliation(s)
- Shigehiro Osada
- Laboratory of Environmental Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-Oka, Suita, Osaka 565-0871, Japan.
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80
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Luke MPS, Sui G, Liu H, Shi Y. Yin Yang 1 Physically Interacts with Hoxa11 and Represses Hoxa11-dependent Transcription. J Biol Chem 2006; 281:33226-32. [PMID: 16963455 DOI: 10.1074/jbc.m606584200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Yin Yang 1 (YY1) plays an indispensable role in embryonic development. YY1 contains an evolutionarily conserved, 22-amino acid segment, the PHO homology region (PHR), which is located within its central domain (spacer) and has been shown previously to participate in the recruitment of Polycomb group of proteins and in YY1-mediated transcription. In this report, we show that the PHR physically interacts with several Abd-B-type Hox proteins. Although ectopic expression of Hoxa11 enhanced target promoter activity, overexpression of YY1 repressed this effect, which was abrogated by YY1 siRNA and the histone deacetylase inhibitor trichostatin A. We have further demonstrated that this suppression effect was the result of YY1-dependent recruitment of HDAC2 to the Hoxa11 target promoter. Taken together, our findings show that YY1 represses Hoxa11-dependent transcription via interactions with the Hox proteins and HDAC recruitment, providing a link between an Abd-type Hox protein and a Polycomb group protein at the level of direct protein-protein interactions. These findings not only provide a novel insight into YY1 function but also identify a new regulation of homeotic protein-mediated transcriptional regulation in general.
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81
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Abstract
Prostate apoptosis response-4 (Par-4) is a unique pro-apoptotic protein that selectively induces apoptosis in cancer cells. Moreover, Par-4 sensitizes cells to the action of diverse apoptotic stimuli and causes tumor regression. This review discusses the prominent structural and functional features of Par-4 and the multiple levels of regulation of its apoptotic function, all of which can be utilized to develop targeted cancer therapy.
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Affiliation(s)
- Padhma Ranganathan
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536, USA
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82
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Netinatsunthorn W, Hanprasertpong J, Dechsukhum C, Leetanaporn R, Geater A. WT1 gene expression as a prognostic marker in advanced serous epithelial ovarian carcinoma: an immunohistochemical study. BMC Cancer 2006; 6:90. [PMID: 16606472 PMCID: PMC1479357 DOI: 10.1186/1471-2407-6-90] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Accepted: 04/11/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND WT1 is a tumor suppressor gene responsible for Wilms' tumor. WT1 reactivity is limited to ovarian serous carcinomas. Recent studies have shown that WT1 plays an important role in the progression of disease and indicates a poorer prognosis of human malignancies such as acute myeloid leukemia and breast cancer. The aims of this study were to determine the survival and recurrence-free survival of women with advanced serous epithelial ovarian carcinoma in relation to WT1 gene expression. METHODS The study accrued women over an 18-year period, from 1987-2004. During the study period, 163 patients were diagnosed with advanced serous epithelial ovarian carcinoma and had undergone complete post-operative chemotherapy, but the final study group comprised 99 patients. The records of these women were reviewed and the paraffin-embedded tissue of these women stained with WT1 immunostaining. Survival analysis was performed using Kaplan-Meier and Cox regression methods. RESULTS Fifty patients showed WT1 staining and forty-nine did not. Five-year survival of non-staining and staining groups were 39.4% and 10.7% (p < 0.00005); five-year recurrence-free survival of these groups were 29.8% and < or = 7.5% (p < 0.00005), respectively. For survival the HR of WT1 staining, adjusted for residual tumor and chemotherapy response, was 1.98 (95% CI 1.28-3.79), and for recurrence-free survival the HR was 3.36 (95% CI 1.60-7.03). The HR for recurrence-free survival was not confounded by any other variables. CONCLUSION This study suggests that expression of WT1 gene may be indicative of an unfavorable prognosis in patients with advanced serous epithelial ovarian carcinoma.
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Affiliation(s)
- Wirote Netinatsunthorn
- Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla, Thailand
| | - Jitti Hanprasertpong
- Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla, Thailand
| | - Chavaboon Dechsukhum
- Department of Pathology, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla, Thailand
| | - Roengsak Leetanaporn
- Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla, Thailand
| | - Alan Geater
- Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla, Thailand
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83
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Affar EB, Luke MPS, Gay F, Calvo D, Sui G, Weiss RS, Li E, Shi Y. Targeted Ablation of Par-4 Reveals a Cell Type–Specific Susceptibility to Apoptosis-Inducing Agents. Cancer Res 2006; 66:3456-62. [PMID: 16585168 DOI: 10.1158/0008-5472.can-05-0964] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The prostate apoptosis response-4 (Par-4) protein has been shown to function as an effector of cell death in response to various apoptotic stimuli, and down-regulation of this protein has been suggested to be a key event during tumorigenesis. Several studies suggest an essential function for the COOH-terminal leucine repeats/death domain of Par-4 in mediating apoptosis. We investigated the biological role of this domain in vivo by generating knock-out mice expressing a Par-4 mutant protein lacking the COOH terminus domain. We found that the Par-4 mutant mice are viable and fertile with no overt phenotype, thus excluding an essential role for the COOH terminus domain of Par-4 in embryogenesis and developmental apoptosis. To determine the requirement of Par-4 for apoptosis, we treated primary fibroblasts with various stimuli that trigger mitochondria and membrane receptor cell death pathways. Fibroblasts isolated from Par-4 mutant mice are as sensitive as the wild-type cells to these apoptosis-inducing agents. Similar effects were observed following RNA interference (RNAi)-mediated knockdown of Par-4 in these cells. In contrast, RNAi-mediated depletion of Par-4 in HeLa cells resulted in a significant inhibition of apoptosis induced by various proapoptotic agents. Taken together, our findings provide strong genetic evidence that the proapoptotic function of Par-4 is dependent on the cellular context and raise the possibility that alterations of Par-4 function may occur during carcinogenesis.
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Affiliation(s)
- El Bachir Affar
- Department of Pathology, Harvard Medical School, 77 Louis Pasteur Avenue, Boston, MA 02115, USA
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84
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Reese BE, Krissinger D, Yun JK, Billingsley ML. Elucidation of stannin function using microarray analysis: implications for cell cycle control. Gene Expr 2006; 13:41-52. [PMID: 16572589 PMCID: PMC6032450 DOI: 10.3727/000000006783991944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Stannin (Snn) is a highly conserved, vertebrate protein whose cellular function is unclear. We have recently demonstrated in human umbilical vein endothelial cells (HUVECs) that Snn gene expression is significantly induced by tumor necrosis factor-alpha (TNF-alpha) in a protein kinase C-epsilon (PKC-epsilon)-dependent manner. In HUVEC, TNF-alpha stimulation of HUVECs results in altered gene expression, and a slowing or halting of cell growth. An initial set of experiments established that Snn knockdown via siRNA, prior to TNF-alpha treatment, resulted in a significant inhibition of HUVEC growth compared to TNF-alpha treatment alone. In order to assess how Snn may be involved in TNF-alpha signaling in HUVEC growth arrest, we performed microarray analysis of TNF-alpha-stimulated HUVECs with and without Snn knockdown via siRNA. The primary comparison made was between TNF-alpha-stimulated HUVECs and TNF-alpha-exposed HUVECs that had Snn knocked down via Snn-specific siRNAs. Ninety-six genes were differentially expressed between these two conditions. Of particular interest was the significant upregulation of several genes associated with control of cell growth and/or the cell cycle, including interleukin-4, p29, WT1/PRKC, HRas-like suppressor, and MDM4. These genes act upon cyclin D1 and/or p53, both of which are key regulators of the G1 phase of the cell cycle. Functional studies further supported the role of Snn in cell growth, as cell cycle analysis using flow cytometry shows a significant increase of G1 cell cycle arrest in HUVECs with Snn knockdown in response to TNF-alpha treatment. Together these studies suggest a functional role of Snn in regulation of TNF-alpha-induced signaling associated with HUVEC growth arrest.
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Affiliation(s)
- Brian E Reese
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
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85
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Boosen M, Vetterkind S, Koplin A, Illenberger S, Preuss U. Par-4-mediated recruitment of Amida to the actin cytoskeleton leads to the induction of apoptosis. Exp Cell Res 2005; 311:177-91. [PMID: 16229834 DOI: 10.1016/j.yexcr.2005.09.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 08/26/2005] [Accepted: 09/08/2005] [Indexed: 12/13/2022]
Abstract
Par-4 (prostate apoptosis response-4) sensitizes cells to apoptotic stimuli, but the exact mechanisms are still poorly understood. Using Par-4 as bait in a yeast two-hybrid screen, we identified Amida as a novel interaction partner, a ubiquitously expressed protein which has been suggested to be involved in apoptotic processes. Complex formation of Par-4 and Amida occurs in vitro and in vivo and is mediated via the C-termini of both proteins, involving the leucine zipper of Par-4. Amida resides mainly in the nucleus but displays nucleo-cytoplasmic shuttling in heterokaryons. Upon coexpression with Par-4 in REF52.2 cells, Amida translocates to the cytoplasm and is recruited to actin filaments by Par-4, resulting in enhanced induction of apoptosis. The synergistic effect of Amida/Par-4 complexes on the induction of apoptosis is abrogated when either Amida/Par-4 complex formation or association of these complexes with the actin cytoskeleton is impaired, indicating that the Par-4-mediated relocation of Amida to the actin cytoskeleton is crucial for the pro-apoptotic function of Par-4/Amida complexes in REF52.2 cells. The latter results in enhanced phosphorylation of the regulatory light chain of myosin II (MLC) as has previously been shown for Par-4-mediated recruitment of DAP-like kinase (Dlk), suggesting that the recruitment of nuclear proteins involved in the regulation of apoptotic processes to the actin filament system by Par-4 represents a potent mechanism how Par-4 can trigger apoptosis.
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Affiliation(s)
- Meike Boosen
- Institute of Genetics, University of Bonn, Römerstr. 164, D-53117 Bonn, Germany
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86
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Minn AH, Pise-Masison CA, Radonovich M, Brady JN, Wang P, Kendziorski C, Shalev A. Gene expression profiling in INS-1 cells overexpressing thioredoxin-interacting protein. Biochem Biophys Res Commun 2005; 336:770-8. [PMID: 16143294 DOI: 10.1016/j.bbrc.2005.08.161] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 08/20/2005] [Indexed: 10/25/2022]
Abstract
Thioredoxin-interacting protein (TXNIP) is overexpressed in diabetes and has deleterious effects on pancreatic beta-cells and the cardiovascular system. TXNIP is a regulator of the cellular redox state, but has also been suggested to act as a transcriptional repressor. However, the genes and pathways regulated by TXNIP remain unknown. We therefore compared gene expression in INS-1 insulinoma beta-cells overexpressing TXNIP and control LacZ-overexpressing cells using the Affymetrix 230A rat chip. Analysis with the Bayes methodology revealed 98 differentially expressed genes, 90 of which were down-regulated, consistent with the predicted role of TXNIP as a repressor. Using the PathwayAssist software, we found that affected genes were involved in cell death/survival and insulin secretion, and confirmed these findings by real-time RT-PCR and by functional studies. Thus, aside from regulating the cellular redox, TXNIP does modulate overall gene transcription and thereby may further enhance beta-cell death and impair insulin secretion.
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Affiliation(s)
- Alexandra H Minn
- Department of Medicine, University of Wisconsin-Madison, WI, USA
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87
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Abstract
Wilms' tumour, or nephroblastoma, is a common childhood tumour that is intimately linked to early kidney development and is often associated with persistent embryonic renal tissue and other kidney abnormalities. WT1, the first gene found to be inactivated in Wilms' tumour, encodes a transcription factor that functions as both a tumour suppressor and a critical regulator of renal organogenesis. Our understanding of the roles of WT1 in tumour formation and organogenesis have advanced in parallel, providing a striking example of the intersection between tumour biology, cellular differentiation and normal organogenesis.
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Affiliation(s)
- Miguel N Rivera
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
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88
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García-Cao I, Duran A, Collado M, Carrascosa MJ, Martín-Caballero J, Flores JM, Diaz-Meco MT, Moscat J, Serrano M. Tumour-suppression activity of the proapoptotic regulator Par4. EMBO Rep 2005; 6:577-83. [PMID: 15877079 PMCID: PMC1369092 DOI: 10.1038/sj.embor.7400421] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 03/17/2005] [Accepted: 04/13/2005] [Indexed: 11/09/2022] Open
Abstract
The proapoptotic protein encoded by Par4 (prostate apoptosis response 4) has been implicated in tumour suppression, particularly in the prostate. We report here that Par4-null mice are prone to develop tumours, both spontaneously and on carcinogenic treatment. The endometrium and prostate of Par4-null mice were particularly sensitive to the development of proliferative lesions. Most (80%) Par4-null females presented endometrial hyperplasia by 9 months of age, and a significant proportion (36%) developed endometrial adenocarcinomas after 1 year of age. Similarly, Par4-null males showed a high incidence of prostate hyperplasia and prostatic intraepithelial neoplasias, and were extraordinarily sensitive to testosterone-induced prostate hyperplasia. Finally, the uterus and prostate of young Par4-null mice have increased levels of the apoptosis inhibitor XIAP (X-chromosome-linked inhibitor of apoptosis), supporting the previously proposed function of Par4 as an inhibitor of the (zeta)PKC (atypical protein kinase)-NF-(kappa)B (nuclear factor-(kappa)B)-XIAP pathway. These data show that Par4 has an important role in tumour suppression, with a particular relevance in the endometrium and prostate.
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Affiliation(s)
- Isabel García-Cao
- Spanish National Cancer Center (CNIO), 3 Melchor Fernandez Almagro Street, Madrid 28029, Spain
| | - Angeles Duran
- Center of Molecular Biology ‘Severo Ochoa' (UAM-CSIC), Madrid 28049, Spain
| | - Manuel Collado
- Spanish National Cancer Center (CNIO), 3 Melchor Fernandez Almagro Street, Madrid 28029, Spain
| | | | - Juan Martín-Caballero
- Spanish National Cancer Center (CNIO), 3 Melchor Fernandez Almagro Street, Madrid 28029, Spain
| | - Juana M. Flores
- Department of Animal Surgery and Medicine, Complutense University, Madrid 28040, Spain
| | - Maria T. Diaz-Meco
- Center of Molecular Biology ‘Severo Ochoa' (UAM-CSIC), Madrid 28049, Spain
| | - Jorge Moscat
- Center of Molecular Biology ‘Severo Ochoa' (UAM-CSIC), Madrid 28049, Spain
| | - Manuel Serrano
- Spanish National Cancer Center (CNIO), 3 Melchor Fernandez Almagro Street, Madrid 28029, Spain
- Tel: +34 917 328 032; Fax: +34 917 328 028; E-mail:
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89
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Haferlach T, Kohlmann A, Schnittger S, Dugas M, Hiddemann W, Kern W, Schoch C. Global approach to the diagnosis of leukemia using gene expression profiling. Blood 2005; 106:1189-98. [PMID: 15878973 DOI: 10.1182/blood-2004-12-4938] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractAccurate diagnosis and classification of leukemias are the bases for the appropriate management of patients. The diagnostic accuracy and efficiency of present methods may be improved by the use of microarrays for gene expression profiling. We analyzed gene expression profiles in 937 bone marrow and peripheral blood samples from 892 patients with all clinically relevant leukemia subtypes and from 45 nonleukemic controls by U133A and U133B GeneChip arrays. For each subgroup, differentially expressed genes were calculated. Class prediction was performed using support vector machines. Prediction accuracy was estimated by 10-fold cross-validation and was assessed for robustness in a 100-fold resampling approach using randomly chosen test sets consisting of one third of the samples. Applying the top 100 genes of each subgroup, an overall prediction accuracy of 95.1% was achieved that was confirmed by resampling (median, 93.8%; 95% confidence interval, 91.4%-95.8%). In particular, acute myeloid leukemia (AML) with t(15;17), AML with t(8;21), AML with inv(16), chronic lymphatic leukemia (CLL), and pro–B-cell acute lymphoblastic leukemia (pro–B-ALL) with t(11q23) were classified with 100% sensitivity and 100% specificity. Accordingly, cluster analysis completely separated all 13 subgroups analyzed. Gene expression profiling can predict all clinically relevant subentities of leukemia with high accuracy.
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Affiliation(s)
- Torsten Haferlach
- Laboratory for Leukemia Diagnostics, Department of Internal Medicine III, Ludwig-Maximilians-University, Marchioninistr 15, 81377 Munich.
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90
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Park SK, Nguyen MD, Fischer A, Luke MPS, Affar EB, Dieffenbach PB, Tseng HC, Shi Y, Tsai LH. Par-4 Links Dopamine Signaling and Depression. Cell 2005; 122:275-87. [PMID: 16051151 DOI: 10.1016/j.cell.2005.05.031] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 02/03/2005] [Accepted: 05/27/2005] [Indexed: 11/19/2022]
Abstract
Prostate apoptosis response 4 (Par-4) is a leucine zipper containing protein that plays a role in apoptosis. Although Par-4 is expressed in neurons, its physiological role in the nervous system is unknown. Here we identify Par-4 as a regulatory component in dopamine signaling. Par-4 directly interacts with the dopamine D2 receptor (D2DR) via the calmodulin binding motif in the third cytoplasmic loop. Calmodulin can effectively compete with Par-4 binding in a Ca2+-dependent manner, providing a route for Ca2+-mediated downregulation of D2DR efficacy. To examine the importance of the Par-4/D2DR interaction in dopamine signaling in vivo, we used a mutant mouse lacking the D2DR interaction domain of Par-4, Par-4DeltaLZ. Primary neurons from Par-4DeltaLZ embryos exhibit an enhanced dopamine-cAMP-CREB signaling pathway, indicating an impairment in dopamine signaling in these cells. Remarkably, Par-4DeltaLZ mice display significantly increased depression-like behaviors. Collectively, these results provide evidence that Par-4 constitutes a molecular link between impaired dopamine signaling and depression.
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Affiliation(s)
- Sang Ki Park
- Department of Pathology, Howard Hughes Medical Institute, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
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91
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Bieberich E. Integration of glycosphingolipid metabolism and cell-fate decisions in cancer and stem cells: review and hypothesis. Glycoconj J 2005; 21:315-27. [PMID: 15514480 DOI: 10.1023/b:glyc.0000046274.35732.47] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The metabolism of glycosphingolipids is strictly regulated during the mitotic cell cycle. Before the G1-to-S transition, the ceramide and glucosylceramide concentration is elevated. Ceramide induces apoptosis synergistically with the pro-apoptotic protein prostate apoptosis response 4 (PAR-4) that may be asymmetrically inherited during cell division. Only one daughter cell dies shortly after mitosis, a mechanism we suggested to regulate the number of neural stem cells during embryonic development. The progeny cells, however, may protect themselves by converting ceramide to glucosylceramide and other glycosphingolipids. In particular, complex gangliosides have been found to sustain cell survival and differentiation. The cell cycle may thus be a turning point for (glyco)sphingolipid metabolism and explain rapid changes of the sphingolipid composition in cells that undergo mitotic cell-fate decisions. In the proposed model termed "Shiva cycle", progression through the cell cycle, differentiation, or apoptosis may rely on a delicate balance of (glyco)sphingolipid second messengers that modulate the retinoblastoma-dependent G1-to-S transition or caspase-dependent G1-to-apoptosis program. Ceramide-induced cell cycle delay at G0/G1 is either followed by ceramide-induced apoptosis or by conversion of ceramide to glucosylceramide, a proposed key regulatory rheostat that rescues cells from re-entry into a life/death decision at G1-to-S. We propose a mechanistic model for sphingolpid-induced protein scaffolds ("slip") that regulate cell-fate decisions and will discuss the biological consequences and pharmacological potential of manipulating the (glyco)sphingolipid-dependent cell fate program in cancer and stem cells.
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Affiliation(s)
- Erhard Bieberich
- Institute of Molecular Medicine and Genetics, School of Medicine, Medical College of Georgia, 1120 15th Street Room CB-2803, Augusta, GA 30912, USA.
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92
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Vetterkind S, Illenberger S, Kubicek J, Boosen M, Appel S, Naim HY, Scheidtmann KH, Preuss U. Binding of Par-4 to the actin cytoskeleton is essential for Par-4/Dlk-mediated apoptosis. Exp Cell Res 2005; 305:392-408. [PMID: 15817164 DOI: 10.1016/j.yexcr.2005.01.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Revised: 01/07/2005] [Accepted: 01/12/2005] [Indexed: 12/13/2022]
Abstract
Prostate apoptosis response-4 (Par-4) is a 38-kDa protein originally identified as a gene product upregulated in prostate cancer cells undergoing apoptosis. Cell death mediated by Par-4 and its interaction partner DAP like kinase (Dlk) is characterized by dramatic changes of the cytoskeleton. To uncover the role of the cytoskeleton in Par-4/Dlk-mediated apoptosis, we analyzed Par-4 for a direct association with cytoskeletal structures. Confocal fluorescence microscopy revealed that endogenous Par-4 is specifically associated with stress fibers in rat fibroblasts. In vitro cosedimentation analyses and in vivo FRET analyses showed that Par-4 directly binds to F-actin. Actin binding is mediated by the N-terminal 266 amino acids, but does not require the C-terminal region of Par-4 containing the leucine zipper and the death domain. Furthermore, the interaction of Par-4 with actin filaments leads to the formation of actin bundles in vitro and in vivo. In rat fibroblasts, this microfilament association is essential for the pro-apoptotic function of Par-4, since both disruption of the actin cytoskeleton by cytochalasin D treatment and overexpression of Par-4 constructs impaired in actin binding result in a significant decrease of apoptosis induction by Par-4 and Dlk. We propose a model, in which Par-4 recruits Dlk to stress fibers, leading to enhanced phosphorylation of the regulatory light chain of myosin II (MLC) and to the induction of apoptosis.
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Affiliation(s)
- Susanne Vetterkind
- Institute of Genetics, University of Bonn, Römerstr. 164, D-53117 Bonn, Germany
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93
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Mattson MP. Prostate apoptosis response-4 (Par-4): an emerging target for Alzheimer’s and Parkinson’s diseases and stroke. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728222.4.1.51] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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94
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Cresswell KS, Clarke CJP, Jackson JT, Darcy PK, Trapani JA, Johnstone RW. Biochemical and growth regulatory activities of the HIN-200 family member and putative tumor suppressor protein, AIM2. Biochem Biophys Res Commun 2005; 326:417-24. [PMID: 15582594 DOI: 10.1016/j.bbrc.2004.11.048] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Indexed: 01/23/2023]
Abstract
The human HIN-200 family member AIM2 was originally identified in a screen for suppressors of melanoma tumorigenicity following introduction of chromosome 6 into the UACC903 human melanoma cell line. Although the AIM2 protein contained many of the conserved structural motifs common to other HIN-200 proteins, the biochemical characteristics of AIM2 and the ability of overexpressed AIM2 to phenocopy the effect of introduction of chromosome 6 in the UACC903 cells had not been assessed. Herein we demonstrated that AIM2 was localised within the nucleus of transfected or interferon-treated human cells. In addition, AIM2 could homodimerise via the amino-terminal (PAAD/DAPIN) region and heterodimerise with the related IFI 16 protein. However, overexpressed AIM2 did not significantly affect the growth or survival of UACC903 cells or another human melanoma cell line. These data indicate that AIM2 has many of the biochemical and structural characteristics of HIN-200 proteins, however, its expression is not sufficient to induce a tumor-suppressor-like phenotype.
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Affiliation(s)
- Kim S Cresswell
- The Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne, 3002 Vic., Australia
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95
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Abstract
Cardiovascular disease is the most important cause of morbidity and mortality in developed countries, causing twice as many deaths as cancer in the USA. The major cardiovascular diseases, including coronary artery disease (CAD), myocardial infarction (MI), congestive heart failure (CHF) and common congenital heart disease (CHD), are caused by multiple genetic and environmental factors, as well as the interactions between them. The underlying molecular pathogenic mechanisms for these disorders are still largely unknown, but gene expression may play a central role in the development and progression of cardiovascular disease. Microarrays are high-throughput genomic tools that allow the comparison of global expression changes in thousands of genes between normal and diseased cells/tissues. Microarrays have recently been applied to CAD/MI, CHF and CHD to profile changes in gene expression patterns in diseased and non-diseased patients. This same technology has also been used to characterise endothelial cells, vascular smooth muscle cells and inflammatory cells, with or without various treatments that mimic disease processes involved in CAD/MI. These studies have led to the identification of unique subsets of genes associated with specific diseases and disease processes. Ongoing microarray studies in the field will provide insights into the molecular mechanism of cardiovascular disease and may generate new diagnostic and therapeutic markers.
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Affiliation(s)
- Stephen Archacki
- Center for Molecular Genetics, Department of Molecular Cardiology, Lerner Research Institute; Center for Cardiovascular Genetics, Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Biological, Geological and Environmental Sciences Cleveland State University, Cleveland, OH 44115, USA
| | - Qing Wang
- Center for Molecular Genetics, Department of Molecular Cardiology, Lerner Research Institute; Center for Cardiovascular Genetics, Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Biological, Geological and Environmental Sciences Cleveland State University, Cleveland, OH 44115, USA
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96
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Renshaw J, Orr RM, Walton MI, te Poele R, Williams RD, Wancewicz EV, Monia BP, Workman P, Pritchard-Jones K. Disruption of WT1 gene expression and exon 5 splicing following cytotoxic drug treatment: Antisense down-regulation of exon 5 alters target gene expression and inhibits cell survival. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1467.3.11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Deregulated expression of the Wilms' tumor gene (WT1) has been implicated in the maintenance of a malignant phenotype in leukemias and a wide range of solid tumors through interference with normal signaling in differentiation and apoptotic pathways. Expression of high levels of WT1 is associated with poor prognosis in leukemias and breast cancer. Using real-time (Taqman) reverse transcription-PCR and RNase protection assay, we have shown up-regulation of WT1 expression following cytotoxic treatment of cells exhibiting drug resistance, a phenomenon not seen in sensitive cells. WT1 is subject to alternative splicing involving exon 5 and three amino acids (KTS) at the end of exon 9, producing four major isoforms. Exon 5 splicing was disrupted in all cell lines studied following a cytotoxic insult probably due to increased exon 5 skipping. Disruption of exon 5 splicing may be a proapoptotic signal because specific targeting of WT1 exon 5–containing transcripts using a nuclease-resistant antisense oligonucleotide (ASO) killed HL60 leukemia cells, which were resistant to an ASO targeting all four alternatively spliced transcripts simultaneously. K562 cells were sensitive to both target-specific ASOs. Gene expression profiling following treatment with WT1 exon 5–targeted antisense showed up-regulation of the known WT1 target gene, thrombospondin 1, in HL60 cells, which correlated with cell death. In addition, novel potential WT1 target genes were identified in each cell line. These studies highlight a new layer of complexity in the regulation and function of the WT1 gene product and suggest that antisense directed to WT1 exon 5 might have therapeutic potential.
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Affiliation(s)
| | - Rosanne M. Orr
- 2Cancer Research UK Centre of Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom and
| | - Michael I. Walton
- 2Cancer Research UK Centre of Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom and
| | - Robert te Poele
- 2Cancer Research UK Centre of Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom and
| | | | | | | | - Paul Workman
- 2Cancer Research UK Centre of Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom and
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97
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Shichishima T, Noji H. A new aspect of the molecular pathogenesis of paroxysmal nocturnal hemoglobinuria. ACTA ACUST UNITED AC 2004; 7:211-27. [PMID: 14972783 DOI: 10.1080/1024533021000024094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematologic disorder which is manifest by complement-mediated hemolysis, venous thrombosis, and bone marrow failure. Complement-mediated hemolysis in PNH is explained by the deficiency of glycosylphosphatidylinositol (GPI)-anchored proteins, CD55 and CD59 on erythrocyte surfaces. All the PNH patients had phosphatidylinositol glycan-class A (PIG-A) gene abnormalities in various cell types, indicating that PIG-A gene mutations cause the defects in GPI-anchored proteins that are essential for the pathogenesis of PNH. In addition, a PIG-A gene abnormality results in a PNH clone. Bone marrow failure causes cytopenias associated with a proliferative decrease of its hematopoietic stem cells and appears to be related to a pre-leukemic state. Although it is unclear how a PNH clone expands in bone marrow, it is considered that the most important hypothesis implicates negative selection of a PNH clone, but it does not explain the changes in the clinical features at the terminal stage of PNH. Recently, it has been suggested that an immune mechanism, in an HLA-restricted manner, plays an important role in the occurrence or selection of a PNH clone and GPI may be a target for cytotoxic-T lymphocytes. Also, it has been indicated that the Wilms' tumor gene (WT1) product is related to a PNH clone, but the significance of WT1 expression is not clear because of the functional diversity of the gene. To elucidate this problem, it is important to know the pathophysiology of bone marrow failure in detail and how bone marrow failure affects hematopoietic stem cells and immune mechanisms in bone marrow failure syndromes.
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Affiliation(s)
- Tsutomu Shichishima
- First Department of Internal Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan
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98
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Discenza MT, Pelletier J. Insights into the physiological role of WT1 from studies of genetically modified mice. Physiol Genomics 2004; 16:287-300. [PMID: 14966251 DOI: 10.1152/physiolgenomics.00164.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Discenza, Maria Teresa, and Jerry Pelletier. Insights into the physiological role of WT1 from studies of genetically modified mice. Physiol Genomics 16: 287-300, 2004; 10.1152/physiolgenomics.00164.2003.—The identification of WT1 gene mutations in children with WAGR and Denys-Drash syndromes pointed toward a role for WT1 in genitourinary system development. Biochemical analysis of the different WT1 protein isoforms showed that WT1 is a transcription factor and also has the ability to bind RNA. Analysis of WT1 complexes identified several target genes and protein partners capable of interacting with WT1. Some of these studies placed WT1, its downstream targets, and protein partners in a transcriptional regulatory network that controls urogenital system development. We review herein studies on WT1 knockout and transgenic models that have been instrumental in defining a physiological role for WT1 in normal and abnormal urogenital development.
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99
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Srichai MB, Konieczkowski M, Padiyar A, Konieczkowski DJ, Mukherjee A, Hayden PS, Kamat S, El-Meanawy MA, Khan S, Mundel P, Lee SB, Bruggeman LA, Schelling JR, Sedor JR. A WT1 co-regulator controls podocyte phenotype by shuttling between adhesion structures and nucleus. J Biol Chem 2004; 279:14398-408. [PMID: 14736876 DOI: 10.1074/jbc.m314155200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glomerular podocyte differentiation state is critical for filtration barrier function and is regulated by WT1, a zinc finger transcription factor. A yeast two-hybrid assay identified a novel, WT1-interacting protein (WTIP) that maps to human chromosome 19q13.1, a region with genes linked to familial focal segmental glomerulosclerosis. The domain structure of WTIP is similar to the zyxin subfamily of cytosolic LIM domain-containing proteins, which contain three carboxyl-terminal LIM protein-protein interaction domains and a proline-rich, pre-LIM region with a nuclear export signal. Other LIM domain-containing proteins (zyxin and mouse muscle LIM protein) did not interact with WT1 in two-hybrid assays, and WTIP did not interact with an unrelated transcription factor, LMX1B. WTIP mRNA was detected in cultured podocytes and was developmentally regulated, with expression peaking in mouse kidney at embryonic day 15-16 (E15-E16) in kidney but persisting into adulthood. In situ hybridization demonstrated WTIP expression in developing E15 glomeruli and in cultured podocytes. The partial WTIP clone, which interacted with WTIP in the two-hybrid assay, co-localized with WT1 in nuclei, co-precipitated with WT1, and inhibited WT1-dependent transcriptional activation of the amphiregulin promoter. In contrast, full-length WTIP was excluded from cell nuclei, but after the addition of leptomycin B, an inhibitor of Crm1-mediated nuclear export, it accumulated in the nucleus and co-precipitated with WT1 in whole cell lysates. Epitope-tagged WTIP co-localized with the adaptor protein CD2AP (CMS) in podocyte actin spots and with Mena at cell-cell junctions. We propose that WTIP monitors slit diaphragm protein assembly as part of a multiple protein complex, linking this specialized adhesion junction to the actin cytoskeleton, and shuttles into the nucleus after podocyte injury, providing a mechanism whereby changes in slit diaphragm structure modulate gene expression.
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Affiliation(s)
- Manakan B Srichai
- Departments of Medicine and Physiology and Biophysics, School of Medicine, Case Western Reserve University and Rammelkamp Center for Research and Education, MetroHealth System Campus, Cleveland, Ohio 44109-1998, USA
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100
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Abstract
Prostate cancer is associated with the inability of prostatic epithelial cells to undergo apoptosis rather than with increased cell proliferation. Prostate apoptosis response-4 (Par-4) is a unique pro-apoptotic molecule that is capable of selectively inducing apoptosis in cancer cells when over-expressed, sensitizing the cells to diverse apoptotic stimuli and causing regression of tumors in animal models. This review discusses the salient functions of Par-4 that can be harnessed to prostate cancer therapy.
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Affiliation(s)
- Sushma Gurumurthy
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536, USA
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