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Brewer BJ, Payen C, Raghuraman MK, Dunham MJ. Origin-dependent inverted-repeat amplification: a replication-based model for generating palindromic amplicons. PLoS Genet 2011; 7:e1002016. [PMID: 21437266 PMCID: PMC3060070 DOI: 10.1371/journal.pgen.1002016] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Bonita J Brewer
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA.
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Notch2 is required for progression of pancreatic intraepithelial neoplasia and development of pancreatic ductal adenocarcinoma. Proc Natl Acad Sci U S A 2010; 107:13438-43. [PMID: 20624967 DOI: 10.1073/pnas.1002423107] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Pancreatic cancer is one of the most fatal malignancies lacking effective therapies. Notch signaling is a key regulator of cell fate specification and pancreatic cancer development; however, the role of individual Notch receptors and downstream signaling is largely unknown. Here, we show that Notch2 is predominantly expressed in ductal cells and pancreatic intraepithelial neoplasia (PanIN) lesions. Using genetically engineered mice, we demonstrate the effect of conditional Notch receptor ablation in KrasG12D-driven pancreatic carcinogenesis. Deficiency of Notch2 but not Notch1 stops PanIN progression, prolongs survival, and leads to a phenotypical switch toward anaplastic pancreatic cancer with epithelial-mesenchymal transition. By expression profiling, we identified increased Myc signaling regulated by Notch2 during tumor development, placing Notch2 as a central regulator of PanIN progression and malignant transformation. Our study supports the concept of distinctive roles of individual Notch receptors in cancer development.
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Abstract
Pancreatic cancer is a leading cause of cancer death. This devastating disease has the horrible honour of close to equal incidence and mortality rates. Late diagnosis and a constitutive resistance to every chemotherapy approach are responsible for this scenario. However, molecular biology tools in cooperation with translational efforts have dissected several secrets that underlie pancreatic cancer. Progressive acquisition of malignant, invasive phenotypes from pre-malignant lesions, recent revelations on core signalling pathways and new targeted designed trials offer a better future for pancreatic cancer patients. This review will summarise recent advances in the molecular biology of pancreatic cancer.
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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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Siveke JT, Lubeseder-Martellato C, Lee M, Mazur PK, Nakhai H, Radtke F, Schmid RM. Notch signaling is required for exocrine regeneration after acute pancreatitis. Gastroenterology 2008; 134:544-55. [PMID: 18242220 DOI: 10.1053/j.gastro.2007.11.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Accepted: 10/18/2007] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS The mechanisms for tissue regeneration and renewal after acute pancreatitis are not well understood but may involve activation of Notch signaling. To study the effect of Notch signaling ablation during acute experimental pancreatitis, we used a chemical and genetic approach to ablate Notch signaling in cerulein-induced pancreatitis in mice. METHODS Acute pancreatitis was induced by cerulein treatment in mice treated with the gamma-secretase inhibitor dibenzazepine or in conditional Notch1 knockout mice. Mice were characterized using immunohistologic, biochemical, and molecular methods. To investigate Notch and beta-catenin interaction, acinar 266-6 cells were analyzed using transfection and biochemical assays. RESULTS Loss of Notch signaling results in impaired regeneration after acute pancreatitis with fewer mature acinar cells in dibenzazepine-treated and Notch1-deficient mice in the regenerative phase 3 days after induction. beta-catenin expression was increased and prolonged during exocrine regeneration. Crosstalk between Notch and beta-catenin-mediated signaling was identified, with Notch1-IC inhibiting beta-catenin-mediated transcriptional activity. This inhibition was dependent on a functional RAM domain. CONCLUSIONS Inhibition of Notch signaling in vivo leads to impaired regeneration of the exocrine pancreas after acute pancreatitis. Our results suggest an interaction of Notch and Wnt signaling in pancreatic acinar cells, providing evidence for a role of these pathways in the regulation of the maturation process of acinar cells.
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Affiliation(s)
- Jens T Siveke
- Second Department of Internal Medicine, Klinikum rechts der Isar, Technical University of Munich, München, Germany
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Mitsui F, Dobashi Y, Imoto I, Inazawa J, Kono K, Fujii H, Ooi A. Non-incidental coamplification of Myc and ERBB2, and Myc and EGFR, in gastric adenocarcinomas. Mod Pathol 2007; 20:622-31. [PMID: 17431415 DOI: 10.1038/modpathol.3800777] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study was conducted to assess the frequencies of protein overexpression and gene amplification of Myc and to identify the mechanisms of Myc gene amplification, especially with regards to its possible coamplification with ERBB2 or EGFR in gastric adenocarcinomas. By immunohistochemical analysis of a total of 300 formalin-fixed and paraffin-embedded gastric adenocarcinomas, the nuclear overexpression of MYC was found in 47 tumors (16%). A fluorescence in situ hybridization (FISH) analysis revealed that nine (19%) of the 47 tumors with protein overexpression had cancer cells with high levels of Myc amplification, whereas only seven (6%) of the 122 tumors without protein overexpression showed high-level Myc gene amplification. Such Myc amplification was significantly correlated with positive nuclear protein overexpression. The coamplification of ERBB2 or EGFR with Myc that was found in six and four cases, respectively, is believed to be non-incidental because those frequencies were significantly higher than the individual frequencies observed for the total examined cases (ERBB2: 7%; EGFR: 4%). The high levels of gene amplification of these three genes, as visualized by FISH, could be broadly classified into two typical types, namely, 'multiple scattered signals' and 'large clustered signals'. Using two-color FISH, the coexistence of coamplified Myc and ERBB2, or Myc and EGFR, within single nuclei in various combinations of amplification types and copy numbers, could be ascertained in all nine cases, including one in which the synchronous 'multiple scattered type' coamplification of Myc and ERBB2 was observed. In three tumors, coamplification of ERBB2 and EGFR was found; however, ERBB2- and EGFR-amplified cell populations were separate and mutually exclusive. We propose that the non-incidental coamplification of Myc and either ERBB2 or EGFR occurred through translocation and subsequent rearrangement.
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Affiliation(s)
- Fumihiko Mitsui
- Department of Pathology, School of Medicine, University of Yamanashi, Yamanashi, Japan
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Buchholz M, Schatz A, Wagner M, Michl P, Linhart T, Adler G, Gress TM, Ellenrieder V. Overexpression of c-myc in pancreatic cancer caused by ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway. EMBO J 2006; 25:3714-24. [PMID: 16874304 PMCID: PMC1538549 DOI: 10.1038/sj.emboj.7601246] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 05/23/2006] [Accepted: 06/26/2006] [Indexed: 12/25/2022] Open
Abstract
The nuclear factor of activated T cell (NFAT) proteins are a family of Ca2+/calcineurin-responsive transcription factors primarily recognized for their central roles in T lymphocyte activation and cardiac valve development. We demonstrate that NFATc1 is commonly overexpressed in pancreatic carcinomas and enhances the malignant potential of tumor cells through transcriptional activation of the c-myc oncogene. Activated NFATc1 directly binds to a specific element within the proximal c-myc promoter and upregulates c-myc transcription, ultimately resulting in increased cell proliferation and enhanced anchorage-independent growth. Conversely, c-myc transcription and anchorage-dependent and -independent cell growth is significantly attenuated by inhibition of Ca2+/calcineurin signaling or siRNA-mediated knock down of NFATc1 expression. Together, these results demonstrate that ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway is an important mechanism of oncogenic c-myc activation in pancreatic cancer.
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Affiliation(s)
- Malte Buchholz
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
| | - Alexandra Schatz
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Martin Wagner
- Clinical GI research, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Patrick Michl
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Thomas Linhart
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Guido Adler
- Clinical GI research, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Thomas M Gress
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
| | - Volker Ellenrieder
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
- Innere Medizin, SP Gastroenterologie, Universitaet Marburg, Baldingerstraβe, 35043 Marburg, Germany. Tel.: +49 6421 286 2318; Fax: +49 6421 286 8922; E-mail:
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Tepel J, Kruse ML, Kapischke M, Haye S, Sipos B, Kremer B, Kalthoff H. Adjuvant treatment of pancreatic carcinoma in a clinically adapted mouse resection model. Pancreatology 2006; 6:240-7. [PMID: 16543775 DOI: 10.1159/000092027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Accepted: 09/08/2004] [Indexed: 12/11/2022]
Abstract
BACKGROUND The high rate of local recurrence after radical resection of pancreatic adenocarcinoma fosters intensive efforts to develop new approaches for adjuvant treatment. The established animal models show significant limitations in simulating an adjuvant therapeutic setting. For optimal approximation to the clinical situation we therefore improved a murine orthotopic human xenotransplantation model. METHODS Subtotal pancreatectomy in mice was performed after orthotopic inoculation of human pancreatic cancer cells and manifestation of solid tumours. The natural course of disease, tumour growth and metastases were analysed. Gemcitabine as a cytotoxic drug was tested in vitro on the cell line used in this model and the effect of adjuvant treatment with gemcitabine in vivo was investigated. RESULTS All tumour-resected animals showed local recurrence. Organ metastases occurred in 67% in resected compared to 25% of non-resected animals. Gemcitabine in vitro was ineffective, but as adjuvant monotherapy resulted in a highly significant reduction of tumour weight and metastatic events. CONCLUSION Subtotal pancreatectomy for xenotransplanted pancreatic cancer in SCID beige mice is feasible. Due to high rates of local recurrence and increased organ metastases, this model offers a relevant option for preclinical adjuvant testing, especially as in vitro and in vivo effects of cytotoxic drugs differ enormously.
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Affiliation(s)
- Juergen Tepel
- Clinic for General Surgery and Thoracic Surgery, University Hospital of Schleswig-Holstein, Kiel, Germany.
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Sharif A, Prévot V, Renault-Mihara F, Allet C, Studler JM, Canton B, Chneiweiss H, Junier MP. Transforming growth factor alpha acts as a gliatrophin for mouse and human astrocytes. Oncogene 2006; 25:4076-85. [PMID: 16532035 DOI: 10.1038/sj.onc.1209443] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Astrocyte death has been implicated in several neuropathological diseases, but the identification of molecules susceptible of promoting astrocyte survival has been elusive. We investigated whether transforming growth factor alpha (TGFalpha), an erbB1/EGFR ligand, which promotes glioma progression and affects astrocyte metabolism at embryonic and adult stages, regulates astrocyte survival. Primary serum-free astrocyte cultures from post-natal mouse and fetal human cortices were used. Transforming growth factor alpha protected both species of astrocytes from staurosporine-induced apoptosis. In serum-free medium, mouse astrocytes did not survive beyond 2 months while TGFalpha-treated astrocytes survived up to 12 months. Transforming growth factor alpha also promoted long-term survival of human astrocytes. We additionally extended TGFalpha proliferative effects to human astrocytes. After 3 days of permanent application, TGFalpha induced a major downregulation of both erbB1 and erbB2. This downregulation did not impair the functional activation of the receptors, as ascertained by their tyrosine phosphorylation and the continuous stimulation of both ERK/MAPK and PI3K/Akt pathways up to 7 days, the longest time examined. The full cellular effects of TGFalpha required activation of both transduction pathways. Enhanced proliferation and survival thus define TGFalpha as a gliatrophin for mammalian astrocytes. These results demonstrate that in normal, non-transformed astrocytes, sustained and functional erbBs activation is achieved without bypassing ligand-induced receptors downregulation.
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Affiliation(s)
- A Sharif
- Inserm U752, Paris F-75013, France
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Saur D, Seidler B, Schneider G, Algül H, Beck R, Senekowitsch-Schmidtke R, Schwaiger M, Schmid RM. CXCR4 expression increases liver and lung metastasis in a mouse model of pancreatic cancer. Gastroenterology 2005; 129:1237-50. [PMID: 16230077 DOI: 10.1053/j.gastro.2005.06.056] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2005] [Accepted: 06/16/2005] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Expression of the Gi-protein-coupled chemokine receptor CXCR4 has recently been linked to increased proliferation, invasion, and migration of human pancreatic cancer cell lines. However, the relevance of CXCR4 for organ-specific pancreatic cancer metastasis in vivo remains unclear. Here, we have studied the role of CXCR4 in vivo using noninvasive imaging of targeted metastasis in a mouse model of pancreatic cancer. METHODS Functional expression of the chemokine receptors CXCR4 and CCR7 was achieved by stable transfection of murine TD-2 pancreatic cancer cells and analyzed by flow cytometry, calcium flux, migration, and proliferation assays. The metastatic potential of the different stable TD-2 cell clones was assessed by tail vein metastatic assays in nude mice using in vivo bioluminescent imaging. RESULTS Native TD-2 cells display very low abundant CXCR4 and CCR7 expression and show poor metastatic potential after tail vein injection. To study the role of CXCR4 in pancreatic cancer metastasis, we selected stable TD-2 cell clones with similar CXCR4 expression levels as human pancreatic cancer cell lines derived from metastatic lesions. CXCR4, but not CCR7, expression dramatically increased the in vivo metastatic potential of TD-2 cells, resulting in liver and lung metastasis in nude mice. Systemic administration of the selective CXCR4 inhibitor AMD 3100 effectively blocked the enhanced metastatic potential of CXCR4-expressing pancreatic cancer cells. CONCLUSIONS These results indicate that CXCR4 expression mediates organ-specific metastasis of pancreatic cancer cells and provide preclinical evidence that blockade of the CXCL12/CXCR4 axis is a target for antimetastatic therapy.
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Affiliation(s)
- Dieter Saur
- Department of Internal Medicine 2, Technical University of Munich, Germany.
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Park SJ, Armstrong S, Kim CH, Yu M, Robertson K, Kelley MR, Lee SH. Lack of EGF receptor contributes to drug sensitivity of human germline cells. Br J Cancer 2005; 92:334-41. [PMID: 15655552 PMCID: PMC2361860 DOI: 10.1038/sj.bjc.6602315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Germline mutations have been associated with generation of various types of tumour. In this study, we investigated genetic alteration of germline tumours that affect the drug sensitivity of cells. Although all germline tumour cells we tested were hypersensitive to DNA-damaging drugs, no significant alteration was observed in their DNA repair activity or the expression of DNA repair proteins. In contrast, germline tumours expressed very low level of epidermal growth factor receptor (EGFR) compared to drug-resistant ovarian cancer cells. An immunohistochemical analysis indicated that most of the primary germline tumours we tested expressed very low level of EGFR. In accordance with this, overexpression of EGFR in germline tumour cells showed an increase in drug resistance, suggesting that a lack of EGFR, at least in part, contributes to the drug sensitivity of germline tumours.
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Affiliation(s)
- S-J Park
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Schreiner B, Baur DM, Fingerle AA, Zechner U, Greten FR, Adler G, Sipos B, Klöppel G, Hameister H, Schmid RM. Pattern of secondary genomic changes in pancreatic tumors of Tgf alpha/Trp53+/- transgenic mice. Genes Chromosomes Cancer 2003; 38:240-8. [PMID: 14506698 DOI: 10.1002/gcc.10285] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Trp53(+/-) mice overexpressing Tgfalpha in a pancreas-specific manner represent a well-established animal model for pancreatic cancer. In this study we analyzed 38 pancreatic adenocarcinomas of these mice for secondary genomic changes by comparative genomic hybridization (CGH), loss of heterozygosity (LOH) analysis, real-time PCR, and methylation-specific analysis. CGH screening of the tumors revealed a recurrent pattern of genomic changes. In more than 50% of the tumors, chromosome 11 was affected. The gain of the proximal part spans about 16 cM, including the genes for Egfr, Rel, and Stk10. The distal part of chromosome 11, which contains the Trp53 locus, was deleted. LOH analysis proved that almost all tumors segregate the wild-type Trp53 allele. The Cdkn2a locus on chromosome 4 was inactivated by hypermethylation in 55% of all tumors. In addition, two other changes were detected in a mutually exclusive manner: overrepresentation of part of chromosome 15, or more rarely, loss of the distal part of chromosome 14. Together these data suggest the induction of a uniform pattern of secondary genomic changes in this transgenic tumor model for pancreatic cancer.
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