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McKinney AJ, Holmen SL. Animal models of melanoma: a somatic cell gene delivery mouse model allows rapid evaluation of genes implicated in human melanoma. CHINESE JOURNAL OF CANCER 2011; 30:153-62. [PMID: 21352692 PMCID: PMC4013311 DOI: 10.5732/cjc.011.10007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 01/10/2011] [Accepted: 01/26/2011] [Indexed: 01/13/2023]
Abstract
The increasing incidence and mortality associated with advanced stages of melanoma are cause for concern. Few treatment options are available for advanced melanoma and the 5-year survival rate is less than 15%. Targeted therapies may revolutionize melanoma treatment by providing less toxic and more effective strategies. However, maximizing effectiveness requires further understanding of the molecular alterations that drive tumor formation, progression, and maintenance, as well as elucidating the mechanisms of resistance. Several different genetic alterations identified in human melanoma have been recapitulated in mice. This review outlines recent progress made in the development of mouse models of melanoma and summarizes what these findings reveal about the human disease. We begin with a discussion of traditional models and conclude with the recently developed RCAS/TVA somatic cell gene delivery mouse model of melanoma.
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Affiliation(s)
- Andrea J McKinney
- Department of Drug and Target Discovery, Nevada Cancer Institute, Las Vegas, NV 89135, USA
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102
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Brown CY, Sadlon T, Gargett T, Melville E, Zhang R, Drabsch Y, Ling M, Strathdee CA, Gonda TJ, Barry SC. Robust, reversible gene knockdown using a single lentiviral short hairpin RNA vector. Hum Gene Ther 2011; 21:1005-17. [PMID: 20615123 DOI: 10.1089/hum.2009.107] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Manipulation of gene expression is an invaluable tool to study gene function in vitro and in vivo. The application of small inhibitory RNAs to knock down gene expression provides a relatively simple, elegant, but transient approach to study gene function in many cell types as well as in whole animals. Short hairpin structures (shRNAs) are a logical advance as they can be expressed continuously and are hence suitable for stable gene knockdown. Drug-inducible systems have now been developed; however, application of the technology has been hampered by persistent problems with low or transient expression, leakiness or poor inducibility of the short hairpin, and lack of reversibility. We have developed a robust, versatile, single lentiviral vector tool that delivers tightly regulated, fully reversible, doxycycline-responsive knockdown of target genes (FOXP3 and MYB), using single short hairpin RNAs. To demonstrate the capabilities of the vector we targeted FOXP3 because it plays a critical role in the development and function of regulatory T cells. We also targeted MYB because of its essential role in hematopoiesis and implication in breast cancer progression. The versatility of this vector is hence demonstrated by knockdown of distinct genes in two biologically separate systems.
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Affiliation(s)
- Cheryl Y Brown
- Women's and Children's Health Research Institute, Adelaide, South Australia 5006, Australia
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103
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Haubensak W, Kunwar PS, Cai H, Ciocchi S, Wall NR, Ponnusamy R, Biag J, Dong HW, Deisseroth K, Callaway EM, Fanselow MS, Lüthi A, Anderson DJ. Genetic dissection of an amygdala microcircuit that gates conditioned fear. Nature 2010; 468:270-6. [PMID: 21068836 PMCID: PMC3597095 DOI: 10.1038/nature09553] [Citation(s) in RCA: 614] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 10/06/2010] [Indexed: 12/12/2022]
Abstract
The role of different amygdala nuclei (neuroanatomical subdivisions) in processing Pavlovian conditioned fear has been studied extensively, but the function of the heterogeneous neuronal subtypes within these nuclei remains poorly understood. We used molecular genetic approaches to map the functional connectivity of a subpopulation of GABAergic neurons, located in the lateral subdivision of the central amygdala (CEl), which express protein kinase C-delta (PKCδ). Channelrhodopsin-2 assisted circuit mapping in amygdala slices and cell-specific viral tracing indicate that PKCδ+ neurons inhibit output neurons in the medial CE (CEm), and also make reciprocal inhibitory synapses with PKCδ− neurons in CEl. Electrical silencing of PKCδ+ neurons in vivo suggests that they correspond to physiologically identified units that are inhibited by the conditioned stimulus (CS), called CEloff units (Ciocchi et al, this issue). This correspondence, together with behavioral data, defines an inhibitory microcircuit in CEl that gates CEm output to control the level of conditioned freezing.
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Affiliation(s)
- Wulf Haubensak
- Division of Biology 216-76, California Institute of Technology, Pasadena, California 91125, USA
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104
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Monosynaptic circuit tracing in vivo through Cre-dependent targeting and complementation of modified rabies virus. Proc Natl Acad Sci U S A 2010; 107:21848-53. [PMID: 21115815 DOI: 10.1073/pnas.1011756107] [Citation(s) in RCA: 262] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We describe a powerful system for revealing the direct monosynaptic inputs to specific cell types in Cre-expressing transgenic mice through the use of Cre-dependent helper virus and a modified rabies virus. We generated helper viruses that target gene expression to Cre-expressing cells, allowing us to control initial rabies virus infection and subsequent monosynaptic retrograde spread. Investigators can use this system to elucidate the connections onto a desired cell type in a high-throughput manner, limited only by the availability of Cre mouse lines. This method allows for identification of circuits that would be extremely tedious or impossible to study with other methods and can be used to build subcircuit maps of inputs onto many different types of cells within the same brain region. Furthermore, by expressing various transgenes from the rabies genome, this system also has the potential to allow manipulation of targeted neuronal circuits without perturbing neighboring cells.
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105
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Xu J, Jin C, Hao S, Luo G, Fu D. Pancreatic cancer: gene therapy approaches and gene delivery systems. Expert Opin Biol Ther 2010; 10:73-88. [PMID: 19857184 DOI: 10.1517/14712590903321454] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
IMPORTANCE OF THE FIELD Due to the absence of early diagnosis, the highly invasive and metastatic features and the lack of effective therapeutic modalities, the prognosis of patients with pancreatic cancer is poor. Gene therapy is currently regarded as a potential and promising therapeutic modality for pancreatic cancer. AREAS COVERED IN THIS REVIEW This article summarizes an update of gene therapy approaches and reviews the latest progress in gene delivery systems that have been tested on pancreatic cancer. WHAT THE READER WILL GAIN The treatment effectiveness of gene combination therapy is better than that of the regulation of single-gene or single gene therapy approaches. Naked DNA is limited because of degradation by intracellular and extracellular nucleases. Virus vectors show high transfection efficiency but are limited due to immunogenicity, inflammatory response and potential carcinogenicity. Non-viral vectors, such as cationic polymers or inorganic nanoparticles, show an important feature that they can be easily modified, and the progress of materials science will provide more and better non-viral vectors, accordingly improving the efficiency and safety of gene therapy, which will make them the most promising vectors for pancreatic cancer.
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Affiliation(s)
- Jin Xu
- Fudan University, Pancreatic Disease Institution, Huashan Hospital, Department of General Surgery, Shanghai, China
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106
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VanBrocklin MW, Robinson JP, Lastwika KJ, Khoury JD, Holmen SL. Targeted delivery of NRASQ61R and Cre-recombinase to post-natal melanocytes induces melanoma in Ink4a/Arflox/lox mice. Pigment Cell Melanoma Res 2010; 23:531-41. [PMID: 20444198 PMCID: PMC2906690 DOI: 10.1111/j.1755-148x.2010.00717.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have developed a somatic cell gene delivery mouse model of melanoma that allows for the rapid validation of genetic alterations identified in this disease. A major advantage of this system is the ability to model the multi-step process of carcinogenesis in immune-competent mice without the generation and cross breeding of multiple strains. We have used this model to evaluate the role of RAS isoforms in melanoma initiation in the context of conditional Ink4a/Arf loss. Mice expressing the tumor virus A (TVA) receptor specifically in melanocytes under control of the dopachrome tautomerase (DCT) promoter were crossed to Ink4a/Arf(lox/lox) mice and newborn DCT-TVA/Ink4a/Arf(lox/lox) mice were injected with retroviruses containing activated KRAS, NRAS and/or Cre-recombinase. No mice injected with viruses containing KRAS and Cre or NRAS alone developed tumors; however, more than one-third of DCT-TVA/Ink4a/Arf(lox/lox) mice injected with NRAS and Cre viruses developed melanoma and two-thirds developed melanoma when NRAS and Cre expression was linked.
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107
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Abstract
Nuclear factor-kappaB (NF-kappaB) and p53 critically determine cancer development and progression. Defining the cross talk between these transcription factors can expand our knowledge on molecular mechanisms of tumorigenesis. Here, we show that induction of replicational stress activates NF-kappaB p65 and triggers its interaction with p53 in the nucleus. Experiments with knockout cells show that p65 and p53 are both required for enhanced NF-kappaB activity during S-phase checkpoint activation involving ataxia-telangiectasia mutated and checkpoint kinase-1. Accordingly, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) also triggers formation of a transcriptionally active complex containing nuclear p65 and p53 on kappaB response elements. Gene expression analyses revealed that, independent of NF-kappaB activation in the cytosol, TNF-induced NF-kappaB-directed gene expression relies on p53. Hence, p53 is unexpectedly necessary for NF-kappaB-mediated gene expression induced by atypical and classical stimuli. Remarkably, data from gain- and loss-of function approaches argue that anti-apoptotic NF-kappaB p65 activity is constitutively evoked by a p53 hot-spot mutant frequently found in tumors. Our observations suggest explanations for the outstanding question why p53 mutations rather than p53 deletions arise in tumors of various origins.
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108
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Reddy JP, Li Y. The RCAS-TVA system for introduction of oncogenes into selected somatic mammary epithelial cells in vivo. J Mammary Gland Biol Neoplasia 2009; 14:405-9. [PMID: 19936988 DOI: 10.1007/s10911-009-9157-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 11/06/2009] [Indexed: 01/20/2023] Open
Abstract
We have reported the use of the RCAS-TVA system to model sporadic tumorigenesis upon oncogenic activation in somatic mammary epithelial cells in the mouse. Here we review the advantages of this approach as compared to conventional mouse models with transgenic oncogene expression. We also in detail describe the RCAS-TVA method for introducing genes into somatic mammary epithelial cells engineered to express the avian receptor tva. This method may be particularly useful in modeling oncogenic activation and subsequent tumorigenesis in distinct breast epithelial cell sub-populations, including progenitor cells.
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Affiliation(s)
- Jay P Reddy
- Lester & Sue Smith Breast Center & Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA
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109
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Nagl F, Schönhofer K, Seidler B, Mages J, Allescher HD, Schmid RM, Schneider G, Saur D. Retinoic acid-induced nNOS expression depends on a novel PI3K/Akt/DAX1 pathway in human TGW-nu-I neuroblastoma cells. Am J Physiol Cell Physiol 2009; 297:C1146-56. [PMID: 19726747 DOI: 10.1152/ajpcell.00034.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) acts as a neurotransmitter and intracellular signaling molecule in the central and peripheral nervous system. NO regulates multiple processes like neuronal development, plasticity, and differentiation and is a mediator of neurotoxicity. The nNOS gene is highly complex with 12 alternative first exons, exon 1a-1l, transcribed from distinct promoters, leading to nNOS variants with different 5'-untranslated regions. Transcriptional control of the nNOS gene is not understood in detail. To investigate regulation of nNOS gene expression by retinoic acid (RA), we used the human neuroblastoma cell line TGW-nu-I as a model system. We show that RA induces nNOS transcription in a protein synthesis-dependent fashion. We identify the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway and the atypical orphan nuclear receptor DAX1 (NR0B1) as critical mediators involved in RA-induced nNOS gene transcription. RA treatment increases DAX1 expression via PI3K/Akt signaling. Upregulation of DAX1 expression in turn induces nNOS transcription in response to RA. These results identify nNOS as a target gene of a novel RA/PI3K/Akt/DAX1-dependent pathway in human neuroblastoma cells and stress the functional importance of the transcriptional regulator DAX1 for nNOS gene expression in response to RA treatment.
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Affiliation(s)
- Florian Nagl
- II. Medizinische Klinik, Technische Universität München, 81675 Munich, Germany
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110
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von Burstin J, Eser S, Paul MC, Seidler B, Brandl M, Messer M, von Werder A, Schmidt A, Mages J, Pagel P, Schnieke A, Schmid RM, Schneider G, Saur D. E-cadherin regulates metastasis of pancreatic cancer in vivo and is suppressed by a SNAIL/HDAC1/HDAC2 repressor complex. Gastroenterology 2009; 137:361-71, 371.e1-5. [PMID: 19362090 DOI: 10.1053/j.gastro.2009.04.004] [Citation(s) in RCA: 279] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2008] [Revised: 03/16/2009] [Accepted: 04/02/2009] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Early metastasis is a hallmark of pancreatic ductal adenocarcinoma and responsible for >90% of pancreatic cancer death. Because little is known about the biology and genetics of the metastatic process, we desired to elucidate molecular pathways mediating pancreatic cancer metastasis in vivo by an unbiased forward genetic approach. METHODS Highly metastatic pancreatic cancer cell populations were selected by serial in vivo passaging of parental cells with low metastatic potential and characterized by global gene expression profiling, chromatin immunoprecipitation, and in vivo metastatic assay. RESULTS In vivo selection of highly metastatic pancreatic cancer cells induced epithelial-mesenchymal transition (EMT), loss of E-cadherin expression, and up-regulation of mesenchymal genes such as Snail. Genetic inactivation of E-cadherin in parental cells induced EMT and increased metastasis in vivo. Silencing of E-cadherin in highly metastatic cells is mediated by a transcriptional repressor complex containing Snail and histone deacetylase 1 (HDAC1) and HDAC2. In line, mesenchymal pancreatic cancer specimens and primary cell lines from genetically engineered Kras(G12D) mice showed HDAC-dependent down-regulation of E-cadherin and high metastatic potential. Finally, transforming growth factor beta-driven E-cadherin silencing and EMT of human pancreatic cancer cells depends on HDAC activity. CONCLUSIONS We provide the first in vivo evidence that HDACs and Snail play an essential role in silencing E-cadherin during the metastatic process of pancreatic cancer cells. These data link the epigenetic HDAC machinery to EMT and metastasis and provide preclinical evidence that HDACs are promising targets for antimetastatic therapy.
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111
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Asimakopoulos F, Varmus HE. Cell-specific transduction of Prdm1-expressing lineages mediated by a receptor for avian leukosis virus subgroup B. J Virol 2009; 83:4835-43. [PMID: 19279099 PMCID: PMC2682090 DOI: 10.1128/jvi.02254-08] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 03/02/2009] [Indexed: 02/01/2023] Open
Abstract
The transcription factor Blimp-1 has emerged as a regulator of cell fate in embryonic (germ cell) and adult (B- and T-cell immune effector and epithelial) lineages. It has also been proposed to act as a tumor suppressor in B-cell malignancy. Here, we present a novel in vivo system enabling the targeted genetic manipulation of cells expressing Prdm1, the gene encoding Blimp-1. We created bacterial artificial chromosome-transgenic mice expressing the avian leukosis virus (ALV) receptor TVB, fused to monomeric red fluorescent protein, under regulation by Prdm1 transcriptional elements, and we achieved transduction of TVB-expressing lymphocytes by ALV vectors bearing a subgroup B envelope. The system presented here incorporates a number of innovations. First, it is the first mammalian transgenic system that employs the ALV receptor TVB, thus expanding the flexibility and scope of ALV-mediated gene delivery. Second, it represents the first ALV-based system that allows gene transfer and expression into in vivo-activated mature lymphocytes, a cell type that has traditionally presented formidable challenges to efficient retroviral transduction. Third, Prdm1:TVB-mRFP transgenic animals could provide an invaluable tool for exploring the diverse roles of Blimp-1 in lineage commitment, immune regulation, and tumorigenesis.
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Affiliation(s)
- Fotis Asimakopoulos
- Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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112
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Mayr U, Werder AV, Seidler B, Reindl W, Bajbouj M, Schmid RM, Schneider G, Saur D. RCAS-Mediated Retroviral Gene Delivery: A Versatile Tool for the Study of Gene Function in a Mouse Model of Pancreatic Cancer. Hum Gene Ther 2008; 19:896-906. [DOI: 10.1089/hum.2008.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Ulrich Mayr
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Alexander von Werder
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Barbara Seidler
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Wolfgang Reindl
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Monther Bajbouj
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Roland M. Schmid
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Günter Schneider
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Dieter Saur
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, 81675 Munich, Germany
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