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Morelli T, Neiva R, Nevins ML, McGuire MK, Scheyer ET, Oh TJ, Braun TM, Nör JE, Bates D, Giannobile WV. Angiogenic biomarkers and healing of living cellular constructs. J Dent Res 2011; 90:456-62. [PMID: 21248359 DOI: 10.1177/0022034510389334] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The use of intra-oral soft-tissue-engineered devices has demonstrated potential for oral mucosa regeneration. The aim of this study was to investigate the temporal expression of angiogenic biomarkers during wound healing of soft tissue reconstructive procedures comparing living cellular constructs (LCC) with autogenous free gingival grafts. Forty-four human participants bilaterally lacking sufficient zones of attached keratinized gingiva were randomly assigned to soft tissue surgery plus either LCC or autograft. Wound fluid samples were collected at baseline and weeks 1, 2, 3, and 4 post-operatively and analyzed for a panel of angiogenic biomarkers: angiogenin (ANG), angiostatin (ANT), PDGF-BB, VEGF, FGF-2, IL-8, TIMP-1, TIMP-2, GM-CSF, and IP-10. Results demonstrated a significant increase in expression of ANT, PDGF-BB, VEGF, FGF-2, and IL-8 for the LCC group over the autograft group at the early stages of wound repair. Although angiogenic biomarkers were modestly elevated for the LCC group, no clinical correlation with wound healing was found. This human investigation demonstrates that, during early wound-healing events, expression of angiogenic-related biomarkers is up-regulated in sites treated with LCC compared with autogenous free gingival grafts, which may provide a safe and effective alternative for regenerating intra-oral soft tissues (ClinicalTrials.gov number, NCT01134081).
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102
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Liu J, Jin T, Chang S, Czajka-Jakubowska A, Zhang Z, Nör JE, Clarkson BH. The effect of novel fluorapatite surfaces on osteoblast-like cell adhesion, growth, and mineralization. Tissue Eng Part A 2010; 16:2977-86. [PMID: 20412028 DOI: 10.1089/ten.tea.2009.0632] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is increasing demand for biomedical implants to correct skeletal defects caused by trauma, disease, or genetic disorder. In this study, the MG-63 cells were grown on metals coated with ordered and disordered fluorapatite (FA) crystal surfaces to study the biocompatibility, initial cellular response, and the underlying mechanisms during this process. The long-term growth and mineralization of the cells were also investigated. After 3 days, the cell numbers on etched metal surface are significantly higher than those on the ordered and disordered FA surfaces, but the initial adherence of a greater number of cells did not lead to earlier mineral formation at the cell-implant interface. Of the 84 cell adhesion and matrix-focused pathway genes, an up- or down-regulation of a total of 15 genes such as integrin molecules, integrin alpha M and integrin alpha 7 and 8 was noted, suggesting a modulating effect on these adhesion molecules by the ordered FA surface compared with the disordered. Osteocalcin expression and the mineral nodule formation are most evident on the FA surfaces after osteogenic induction (OI) for 7 weeks. The binding of the ordered FA surfaces to the metal, with and without OI, was significantly higher than that of the disordered FA surfaces with OI. Most significantly, even without the OI supplement, the MG-63 cells grown on FA crystal surfaces start to differentiate and mineralize, suggesting that the FA crystal could be a simple and bioactive implant coating material.
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103
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Krishnamurthy S, Dong Z, Vodopyanov D, Imai A, Helman JI, Prince ME, Wicha MS, Nör JE. Endothelial cell-initiated signaling promotes the survival and self-renewal of cancer stem cells. Cancer Res 2010; 70:9969-78. [PMID: 21098716 DOI: 10.1158/0008-5472.can-10-1712] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent studies have demonstrated that cancer stem cells play an important role in the pathobiology of head and neck squamous cell carcinomas (HNSCC). However, little is known about functional interactions between head and neck cancer stem-like cells (CSC) and surrounding stromal cells. Here, we used aldehyde dehydrogenase activity and CD44 expression to sort putative stem cells from primary human HNSCC. Implantation of 1,000 CSC (ALDH+CD44+Lin-) led to tumors in 13 (out of 15) mice, whereas 10,000 noncancer stem cells (ALDH-CD44-Lin-) resulted in 2 tumors in 15 mice. These data demonstrated that ALDH and CD44 select a subpopulation of cells that are highly tumorigenic. The ability to self-renew was confirmed by the observation that ALDH+CD44+Lin- cells sorted from human HNSCC formed more spheroids (orospheres) in 3-D agarose matrices or ultra-low attachment plates than controls and were serially passaged in vivo. We observed that approximately 80% of the CSC were located in close proximity (within 100-μm radius) of blood vessels in human tumors, suggesting the existence of perivascular niches in HNSCC. In vitro studies demonstrated that endothelial cell-secreted factors promoted self-renewal of CSC, as demonstrated by the upregulation of Bmi-1 expression and the increase in the number of orospheres as compared with controls. Notably, selective ablation of tumor-associated endothelial cells stably transduced with a caspase-based artificial death switch (iCaspase-9) caused a marked reduction in the fraction of CSC in xenograft tumors. Collectively, these findings indicate that endothelial cell-initiated signaling can enhance the survival and self-renewal of head and neck CSC.
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MESH Headings
- Aldehyde Dehydrogenase/metabolism
- Animals
- Apoptosis/drug effects
- Carcinoma, Squamous Cell/blood supply
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Line, Tumor
- Cell Proliferation
- Cell Survival
- Cells, Cultured
- Endothelial Cells/metabolism
- Head and Neck Neoplasms/blood supply
- Head and Neck Neoplasms/metabolism
- Head and Neck Neoplasms/pathology
- Humans
- Hyaluronan Receptors/metabolism
- Immunohistochemistry
- Isoenzymes/metabolism
- Mice
- Mice, SCID
- Microscopy, Confocal
- Neoplasms, Experimental/blood supply
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Neoplastic Stem Cells/metabolism
- Neovascularization, Pathologic
- Signal Transduction
- Tacrolimus/analogs & derivatives
- Tacrolimus/pharmacology
- Transplantation, Heterologous
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104
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Kim JK, Shukla R, Casagrande L, Sedgley C, Nör JE, Baker JR, Hill EE. Differentiating dental pulp cells via RGD-dendrimer conjugates. J Dent Res 2010; 89:1433-8. [PMID: 20929719 DOI: 10.1177/0022034510384870] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Traumatic dental injuries are often irreversible, underscoring the need for therapies that protect dental pulp cells and enhance their regeneration. We hypothesized that generation 5 poly amido amine (PAMAM) dendrimers (G5), functionalized with fluorescein isothiocyanate (FL) and αVβ3-specific, cyclic arginine-glycine-aspartic acid (RGD) peptides, will bind to dental pulp cells (DPCs) and modulate their differentiation. Dental pulp cells and mouse odontoblast-like cells (MDPC-23) (±) treated with G5-FL-RGD were analyzed via Western blot, RT-PCR, and quantitative PCR. Transcription of dental differentiation markers was as follows: Dentin matrix protein (DMP-1), dentin sialoprotein (DSPP), and matrix extracellular phosphoglycoprotein (MEPE) as well as vascular endothelial growth factor (VEGF) all increased via the JNK pathway. Long-term G5-RGD treatment of dental pulp cells resulted in enhanced mineralization as examined via Von Kossa assay, suggesting that PAMAM dendrimers conjugated to cyclic RGD peptides can increase the odontogenic potential of these cells.
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105
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Nedel F, Soki FN, Conde MCM, Zeitlin BD, Tarquinio SBC, Nör JE, Seixas FK, Demarco FF. Comparative analysis of two colorimetric assays in dental pulp cell density. Int Endod J 2010; 44:59-64. [PMID: 20880134 DOI: 10.1111/j.1365-2591.2010.01796.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AIM To compare and contrast two colorimetric assays used for the measurement of proliferation using two dental pulp cell types: dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF). METHODOLOGY Dental pulp stem cells or HDPF were seeded at 0.25×10(4) cells per well in 96-well plates. Cell proliferation was evaluated after 24-72h. At the end of the experimental period, the sulforhodamine B (SRB) assay or a water-soluble tetrazolium salt (WST-1) assay was performed. Optical densities were determined in a microplate reader (Genius; TECAN). Data were analysed by Student's t-test (comparison between cell types) and one-way anova followed by Tukey test (time-point intervals). Pearson' correlation tests were performed to compare the two assays for each cell line. RESULTS Both assays showed that DPSC had higher proliferation rates than HDPF. A positive significant correlation between the two colorimetric assays tested for both cell types DPSC (Pearson's correlation coefficient=0.847; P<0.05) and HDPF (Pearson's correlation coefficient=0.775; P<0.05). CONCLUSION Both tests demonstrated similar trends of cell proliferation, and thus are both appropriate for the evaluation of DPSC and HDPF. The choice of assay is therefore one of the practical applications. SRB stained plates can be dried and stored so may have utility in laboratories where data may require review or when access to analytical equipment is limited. WST-1 assays have the benefit of both ease and speed and may have utility in laboratories requiring either high throughput or rapid analyses.
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106
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Hegen A, Blois A, Tiron CE, Hellesøy M, Micklem DR, Nör JE, Akslen LA, Lorens JB. Efficient in vivo vascularization of tissue-engineering scaffolds. J Tissue Eng Regen Med 2010; 5:e52-62. [PMID: 20865694 DOI: 10.1002/term.336] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 05/20/2010] [Indexed: 12/24/2022]
Abstract
The success of tissue engineering depends on the rapid and efficient formation of a functional blood vasculature. Adult blood vessels comprise endothelial cells and perivascular mural cells that assemble into patent tubules ensheathed by a basement membrane during angiogenesis. Using individual vessel components, we characterized intra-scaffold microvessel self-assembly efficiency in a physiological in vivo tissue engineering implant context. Primary human microvascular endothelial and vascular smooth muscle cells were seeded at different ratios in poly-L-lactic acid (PLLA) scaffolds enriched with basement membrane proteins (Matrigel) and implanted subcutaneously into immunocompromised mice. Temporal intra-scaffold microvessel formation, anastomosis and perfusion were monitored by immunohistochemical, flow cytometric and in vivo multiphoton fluorescence microscopy analysis. Vascularization in the tissue-engineering context was strongly enhanced in implants seeded with a complete complement of blood vessel components: human microvascular endothelial and vascular smooth muscle cells in vivo assembled a patent microvasculature within Matrigel-enriched PLLA scaffolds that anastomosed with the host circulation during the first week of implantation. Multiphoton fluorescence angiographic analysis of the intra-scaffold microcirculation showed a uniform, branched microvascular network. 3D image reconstruction analysis of human pulmonary artery smooth muscle cell (hPASMC) distribution within vascularized implants was non-random and displayed a preferential perivascular localization. Hence, efficient microvessel self-assembly, anastomosis and establishment of a functional microvasculture in the native hypoxic in vivo tissue engineering context is promoted by providing a complete set of vascular components.
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107
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Demarco FF, Casagrande L, Zhang Z, Dong Z, Tarquinio SB, Zeitlin BD, Shi S, Smith AJ, Nör JE. Effects of morphogen and scaffold porogen on the differentiation of dental pulp stem cells. J Endod 2010; 36:1805-11. [PMID: 20951292 DOI: 10.1016/j.joen.2010.08.031] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 08/06/2010] [Accepted: 08/06/2010] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Dental pulp tissue engineering is an emerging field that can potentially have a major impact on oral health. However, the source of morphogens required for stem cell differentiation into odontoblasts and the scaffold characteristics that are more conducive to odontoblastic differentiation are still unclear. This study investigated the effect of dentin and scaffold porogen on the differentiation of human dental pulp stem cells (DPSCs) into odontoblasts. METHODS Poly-L-lactic acid (PLLA) scaffolds were prepared in pulp chambers of extracted human third molars using salt crystals or gelatin spheres as porogen. DPSCs seeded in tooth slice/scaffolds or control scaffolds (without tooth slice) were either cultured in vitro or implanted subcutaneously in immunodefficient mice. RESULTS DPSCs seeded in tooth slice/scaffolds but not in control scaffolds expressed putative odontoblastic markers (DMP-1, DSPP, and MEPE) in vitro and in vivo. DPSCs seeded in tooth/slice scaffolds presented lower proliferation rates than in control scaffolds between 7 and 21 days (p < 0.05). DPSCs seeded in tooth slice/scaffolds and transplanted into mice generated a tissue with morphological characteristics similar to those of human dental pulps. Scaffolds generated with gelatin or salt porogen resulted in similar DPSC proliferation. The porogen type had a relatively modest impact on the expression of the markers of odontoblastic differentiation. CONCLUSIONS Collectively, this work shows that dentin-related morphogens are important for the differentiation of DPSC into odontoblasts and for the engineering of dental pulp-like tissues and suggest that environmental cues influence DPSC behavior and differentiation potential.
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108
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Zeitlin BD, Spalding AC, Campos MS, Ashimori N, Dong Z, Wang S, Lawrence TS, Nör JE. Metronomic small molecule inhibitor of Bcl-2 (TW-37) is antiangiogenic and potentiates the antitumor effect of ionizing radiation. Int J Radiat Oncol Biol Phys 2010; 78:879-87. [PMID: 20675079 DOI: 10.1016/j.ijrobp.2010.04.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 01/27/2023]
Abstract
PURPOSE To investigate the effect of a metronomic (low-dose, high-frequency) small-molecule inhibitor of Bcl-2 (TW-37) in combination with radiotherapy on microvascular endothelial cells in vitro and in tumor angiogenesis in vivo. METHODS AND MATERIALS Primary human dermal microvascular endothelial cells were exposed to ionizing radiation and/or TW-37 and colony formation, as well as capillary sprouting in three-dimensional collagen matrices, was evaluated. Xenografts vascularized with human blood vessels were engineered by cotransplantation of human squamous cell carcinoma cells (OSCC3) and human dermal microvascular endothelial cells seeded in highly porous biodegradable scaffolds into the subcutaneous space of immunodeficient mice. Mice were treated with metronomic TW-37 and/or radiation, and tumor growth was evaluated. RESULTS Low-dose TW-37 sensitized primary endothelial cells to radiation-induced inhibition of colony formation. Low-dose TW-37 or radiation partially inhibited endothelial cell sprout formation, and in combination, these therapies abrogated new sprouting. Combination of metronomic TW-37 and low-dose radiation inhibited tumor growth and resulted in significant increase in time to failure compared with controls, whereas single agents did not. Notably, histopathologic analysis revealed that tumors treated with TW-37 (with or without radiation) are more differentiated and showed more cohesive invasive fronts, which is consistent with less aggressive phenotype. CONCLUSIONS These results demonstrate that metronomic TW-37 potentiates the antitumor effects of radiotherapy and suggest that patients with head and neck cancer might benefit from the combination of small molecule inhibitor of Bcl-2 and radiation therapy.
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109
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Aranha AMF, Zhang Z, Neiva KG, Costa CAS, Hebling J, Nör JE. Hypoxia enhances the angiogenic potential of human dental pulp cells. J Endod 2010; 36:1633-7. [PMID: 20850667 DOI: 10.1016/j.joen.2010.05.013] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Accepted: 05/25/2010] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Trauma can result in the severing of the dental pulp vessels, leading to hypoxia and ultimately to pulp necrosis. Improved understanding of mechanisms underlying the response of dental pulp cells to hypoxic conditions might lead to better therapeutic alternatives for patients with dental trauma. The purpose of this study was to evaluate the effect of hypoxia on the angiogenic response mediated by human dental pulp stem cells (DPSCs) and human dental pulp fibroblasts (HDPFs). METHODS DPSCs and HDPFs were exposed to experimental hypoxic conditions. Hypoxia-inducible transcription factor-1alpha (HIF-1alpha) was evaluated by Western blot and immunocytochemistry, whereas vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) expression was evaluated by enzyme-linked immunosorbent assay. YC-1, an inhibitor of HIF-1alpha, was used to evaluate the functional effect of this transcriptional factor on hypoxia-induced VEGF expression. Conditioned medium from hypoxic and normoxic pulp cells was used to stimulate human dermal microvascular endothelial cells (HDMECs). HDMEC proliferation was measured by WST-1 assay, and angiogenic potential was evaluated by a capillary sprouting assay in 3-dimensional collagen matrices. RESULTS Hypoxia enhanced HIF-1alpha and VEGF expression in DPSCs and HDPFs. In contrast, hypoxia did not induce bFGF expression in pulp cells. YC-1 partially inhibited hypoxia-induced HIF-1alpha and VEGF in these cells. The growth factor milieu of hypoxic HDPFs (but not hypoxic DPSCs) induced endothelial cell proliferation and sprouting as compared with medium from normoxic cells. CONCLUSIONS Collectively, these data demonstrate that hypoxia induces complex and cell type-specific pro-angiogenic responses and suggest that VEGF (but not bFGF) participates in the revascularization of hypoxic dental pulps.
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110
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Sakai VT, Zhang Z, Dong Z, Neiva KG, Machado MAAM, Shi S, Santos CF, Nör JE. SHED differentiate into functional odontoblasts and endothelium. J Dent Res 2010; 89:791-6. [PMID: 20395410 DOI: 10.1177/0022034510368647] [Citation(s) in RCA: 268] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Studies on mechanisms underlying the differentiation of dental pulp stem cells are critical for the understanding of the biology of odontogenesis and for dental tissue engineering. Here, we tested the hypothesis that stem cells from exfoliated deciduous teeth (SHED) differentiate into functional odontoblasts and endothelial cells. SHED were seeded in tooth slice/scaffolds and implanted subcutaneously into immunodeficient mice. SHED differentiated into functional odontoblasts that generated tubular dentin, as determined by tetracycline staining and confocal microscopy. These cells also differentiated into vascular endothelial cells, as determined by beta-galactosidase staining of LacZ-tagged SHED. In vitro, vascular endothelial growth factor (VEGF) induced SHED to express VEGFR2, CD31, and VE-Cadherin (markers of endothelium) and to organize into capillary-like sprouts. VEGF induced ERK and AKT phosphorylation (indicative of differentiation), while inhibiting phosphorylation of STAT3 (indicative of 'stemness'). Collectively, this work demonstrates that SHED can differentiate into angiogenic endothelial cells and odontoblasts capable of generating tubular dentin.
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111
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Kaneko T, Okiji T, Kaneko R, Suda H, Nör JE. Gene expression analysis of immunostained endothelial cells isolated from formaldehyde-fixated paraffin embedded tumors using laser capture microdissection--a technical report. Microsc Res Tech 2010; 72:908-12. [PMID: 19425073 DOI: 10.1002/jemt.20734] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Laser capture microdissection (LCM) allows microscopic procurement of specific cell types from tissue sections that can then be used for gene expression analysis. In conventional LCM, frozen tissues stained with hematoxylin are normally used to the molecular analysis. Recent studies suggested that it is possible to carry out gene expression analysis of formaldehyde-fixated paraffin embedded (FFPE) tissues that were stained with hematoxylin. However, it is still unclear if quantitative gene expression analyses can be performed from LCM cells from FFPE tissues that were subjected to immunostaining to enhance identification of target cells. In this proof-of-principle study, we analyzed by reverse transcription-PCR (RT-PCR) and real time PCR the expression of genes in factor VIII immunostained human endothelial cells that were dissected from FFPE tissues by LCM. We observed that immunostaining should be performed at 4 degrees C to preserve the mRNA from the cells. The expression of Bcl-2 in the endothelial cells was evaluated by RT-PCR and by real time PCR. Glyceraldehyde-3-phosphate dehydrogenase and 18S were used as house keeping genes for RT-PCR and real time PCR, respectively. This report unveils a method for quantitative gene expression analysis in cells that were identified by immunostaining and retrieved by LCM from FFPE tissues. This method is ideally suited for the analysis of relatively rare cell types within a tissue, and should improve on our ability to perform differential diagnosis of pathologies as compared to conventional LCM.
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112
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Zeitlin BD, Ellis LM, Nör JE. Inhibition of Vascular Endothelial Growth Factor Receptor-1/Wnt/{beta}-catenin Crosstalk Leads to Tumor Cell Death. Clin Cancer Res 2009; 15:7453-7455. [PMID: 20008844 PMCID: PMC2796551 DOI: 10.1158/1078-0432.ccr-09-2578] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two genes are considered synthetic lethal if mutation of either alone allows cell viability, whereas simultaneous mutation leads to cell death. A synthetic lethal screen unveiled the dependency of Wnt/beta-catenin-addicted colorectal cancer cells on vascular endothelial growth factor receptor-1 kinase activity and suggested a novel therapeutic approach for this malignancy. (Clin Cancer Res 2009;15(24):7453-5).
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113
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Soden RI, Botero TM, Hanks CT, Nör JE. Angiogenic signaling triggered by cariogenic bacteria in pulp cells. J Dent Res 2009; 88:835-40. [PMID: 19767581 DOI: 10.1177/0022034509341946] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The inflammation observed in the dental pulp of teeth with deep caries lesions is characterized by a significant increase in blood vessel density. It is known that lipoteichoic acid (LTA) from Gram-positive cariogenic bacteria induces expression of vascular endothelial growth factor (VEGF) in dental pulp cells. The hypothesis underlying this study was that LTA induces VEGF expression in dental pulp cells through TLR2 and PI3k/Akt signaling. Odontoblast-like cells (MDPC-23) and undifferentiated pulp cells (OD-21) were exposed to LTA from Streptococcus sanguis, and the role of TLR2, PI3K/Akt, and IKK signaling in LTA-induced VEGF expression was evaluated. These studies demonstrated that TLR2 signaling through the PI3K-Akt pathway is necessary for LTA-induced VEGF expression in pulp cells. In contrast, inhibition of IKK signaling did not prevent VEGF up-regulation in response to LTA. Understanding signaling pathways triggered by cariogenic bacteria may reveal novel therapeutic targets for the clinical management of pulpitis.
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114
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Dong Z, Nör JE. Transcriptional targeting of tumor endothelial cells for gene therapy. Adv Drug Deliv Rev 2009; 61:542-53. [PMID: 19393703 DOI: 10.1016/j.addr.2009.02.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 02/05/2009] [Indexed: 12/21/2022]
Abstract
It is well known that angiogenesis plays a critical role in the pathobiology of tumors. Recent clinical trials have shown that inhibition of angiogenesis can be an effective therapeutic strategy for patients with cancer. However, one of the outstanding issues in anti-angiogenic treatment for cancer is the development of toxicities related to off-target effects of drugs. Transcriptional targeting of tumor endothelial cells involves the use of specific promoters for selective expression of therapeutic genes in the endothelial cells lining the blood vessels of tumors. Recently, several genes that are expressed specifically in tumor-associated endothelial cells have been identified and characterized. These discoveries have enhanced the prospectus of transcriptionally targeting tumor endothelial cells for cancer gene therapy. In this manuscript, we review the promoters, vectors, and therapeutic genes that have been used for transcriptional targeting of tumor endothelial cells, and discuss the prospects of such approaches for cancer gene therapy.
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115
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Ashimori N, Zeitlin BD, Zhang Z, Warner K, Turkienicz IM, Spalding AC, Teknos TN, Wang S, Nör JE. TW-37, a small-molecule inhibitor of Bcl-2, mediates S-phase cell cycle arrest and suppresses head and neck tumor angiogenesis. Mol Cancer Ther 2009; 8:893-903. [PMID: 19372562 DOI: 10.1158/1535-7163.mct-08-1078] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Members of the Bcl-2 family play a major role in the pathobiology of head and neck cancer. We have shown that Bcl-2 orchestrates a cross talk between tumor cells and endothelial cells that have a direct effect on the progression of head and neck squamous cell carcinoma (HNSCC). Notably, Bcl-2 is significantly up-regulated in the tumor-associated endothelial cells compared with the endothelial cells of normal oral mucosa in patients with HNSCC. Here, we evaluated the effect of TW-37, a small-molecule inhibitor of Bcl-2, on the cell cycle and survival of endothelial cells and HNSCC and on the progression of xenografted tumors. TW-37 has an IC50 of 1.1 micromol/L for primary human endothelial cells and averaged 0.3 micromol/L for head and neck cancer cells (OSCC3, UM-SCC-1, and UM-SCC-74A). The combination of TW-37 and cisplatin showed enhanced cytotoxic effects for endothelial cells and HNSCC in vitro, compared with single drug treatment. Notably, whereas cisplatin led to an expected G2-M cell cycle arrest, TW-37 mediated an S-phase cell cycle arrest in endothelial cells and in HNSCC. In vivo, TW-37 inhibited tumor angiogenesis and induced tumor apoptosis without significant systemic toxicities. Combination of TW-37 and cisplatin enhanced the time to tumor failure (i.e., 4-fold increase in tumor volume), compared with either drug given separately. Collectively, these data reveal that therapeutic inhibition of Bcl-2 function with TW-37 is sufficient to arrest endothelial cells and HNSCC in the S phase of the cell cycle and to inhibit head and neck tumor angiogenesis.
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Casagrande L, Falster CA, Di Hipolito V, De Góes MF, Straffon LH, Nör JE, de Araujo FB. Effect of adhesive restorations over incomplete dentin caries removal: 5-year follow-up study in primary teeth. JOURNAL OF DENTISTRY FOR CHILDREN (CHICAGO, ILL.) 2009; 76:117-122. [PMID: 19619424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the effect of the materials used for indirect pulp treatment (IPT) on the long-term outcome of primary molar teeth. METHODS Forty-eight teeth with deep carious lesions, but without signs and symptoms of irreversible pulpitis, were randomly divided into 2 groups, according to the material placed on the demineralized dentin remain: (1) experimental group, adhesive system (Scotchbond Multipurpose); and (2) control group, calcium hydroxide liner (Dycal). Both groups were followed by a resin restoration application. RESULTS After 4 to 5 years, the clinical and radiographic success rates between groups were similar (group 1=14 of 15; group 2=8 of 10; P=0.350). Subsequent to exfoliation, scanning electron microscopy revealed the presence of a hybrid layer at the resin-dentin interface and a microtensile bond strength of 9.63 MPa (group 1). Histological analysis showed that the pulp health status was similar in both groups. CONCLUSIONS Indirect pulp treatment has a high clinical and radiographic long-term success rate in primary teeth and is not material-dependent.
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117
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Garcia MB, Carrilho MR, Nör JE, Anauate-Netto C, Anido-Anido A, Amore R, Tjäderhane L, Bretz WA. Chlorhexidine Inhibits the Proteolytic Activity of Root and Coronal Carious Dentin in vitro. Caries Res 2009; 43:92-6. [PMID: 19321985 DOI: 10.1159/000209340] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 01/12/2009] [Indexed: 11/19/2022] Open
Abstract
The purpose of this study was to evaluate the effect of chlorhexidine on the proteolytic activity of carious coronal and root dentin collected from patients. Sound dentin from freshly extracted human teeth was used as a control. Dentin fragments were mixed with a synthetic substrate for proteolytic enzymes (N-benzoyl-DL-arginine-naphthylamide--BANA) and the suspensions mixed with either 0.12% chlorhexidine digluconate or distilled water. These mixtures were incubated for 18 h at 37 degrees C, color was developed by the addition of 0.1% Fast Garnet and their optical density was recorded spectrophotometrically. BANA hydrolysis measured by the optical density of incubated specimens was detected in all tested groups, but was significantly higher for carious than for sound dentin (p < 0.05). The proteolytic activity was reduced for carious coronal and root dentin by chlorhexidine (p < 0.05; 50 and 30%, respectively). Chlorhexidine also reduced the proteolytic activity in sound root dentin (p < 0.05; 20%). Conversely, changes in the proteolytic activity of sound coronal dentin were not observed in the presence of chlorhexidine. The reduction in proteolytic activity by chlorhexidine was significantly higher in carious coronal dentin than in carious root dentin (p < 0.05). In conclusion, part of the effect of chlorhexidine in controlling caries progression in humans may be due to a decrease in the proteolytic activity of carious coronal and root dentin. Because of the prolonged incubation time in the present study, similar results may be obtained clinically with prolonged dentin exposure to chlorhexidine, e.g. chlorhexidine-containing varnishes.
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Mullane EM, Dong Z, Sedgley CM, Hu JCC, Botero TM, Holland GR, Nör JE. Effects of VEGF and FGF2 on the revascularization of severed human dental pulps. J Dent Res 2009; 87:1144-8. [PMID: 19029083 DOI: 10.1177/154405910808701204] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The long-term outcome of replanted avulsed permanent teeth is frequently compromised by lack of revascularization, resulting in pulp necrosis. The purpose of this study was to evaluate the effects of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF-2) on the revascularization of severed human dental pulps. Tooth slices were prepared from non-carious human molars and treated with 0-50 ng/mL rhVEGF(165) or rhFGF-2 for 7 days in vitro. Both angiogenic factors enhanced pulp microvessel density compared with untreated controls (p < 0.05). Tooth slices were also treated with 0 or 50 ng/mL rhVEGF(165) for one hour prior to implantation into the subcutaneous space of immunodeficient mice. Treatment with rhVEGF(165) increased pulp microvessel density in vivo (p < 0.05). These results demonstrate that rhVEGF(165) enhanced neovascularization of severed human dental pulps and suggest that topical application of an angiogenic factor prior to replantation might be beneficial for the treatment of avulsed teeth.
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119
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Miyazawa M, Dong Z, Zhang Z, Neiva KG, Cordeiro MM, Oliveira DT, Nör JE. Effect of PTK/ZK on the angiogenic switch in head and neck tumors. J Dent Res 2009; 87:1166-71. [PMID: 19029087 DOI: 10.1177/154405910808701213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transformation of small avascular masses of tumor cells into rapidly progressive cancers is triggered by the angiogenic switch, a process that involves vascular endothelial growth factor (VEGF) signaling. We have shown that VEGF enhances the survival and angiogenic potential of endothelial cells by activating the Bcl-2-CXCL8 signaling axis. The purpose of this study was to evaluate the effect of a small-molecule inhibitor of VEGF receptors (PTK/ZK) on the initial stages of head and neck tumor angiogenesis. In vitro, PTK/ZK blocked head and neck tumor cell (OSCC3 or UM-SCC-17B)-induced Bcl-2 and CXCL8 expression in endothelial cells. Oral administration of PTK/ZK decreased xenograft head and neck tumor microvessel density, and inhibited Bcl-2 and CXCL8 expression in tumor-associated endothelial cells. Analysis of these data demonstrates that PTK/ZK blocks downstream targets of VEGF signaling in endothelial cells, and suggests that PTK/ZK may inhibit the angiogenic switch in head and neck tumors.
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Yasuda Y, Inuyama H, Maeda H, Akamine A, Nör JE, Saito T. Cytotoxicity of one-step dentin-bonding agents toward dental pulp and odontoblast-like cells. J Oral Rehabil 2008; 35:940-6. [PMID: 18976265 DOI: 10.1111/j.1365-2842.2008.01885.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to compare the cytotoxicity of five one-step dentin-bonding agents on human dental pulp and odontoblast-like cells (MDPC-23). Photopolymerized and unpolymerized samples of these dentin-bonding agents were prepared and incubated with dental pulp or MDPC-23 cells. After 24 or 72 h of incubation, the number of unstained cells with trypan blue was counted. The staining of cells with trypan blue stands for a cytotoxicity. The pulp cell and MDPC-23 cytotoxicity of polymerized sample treatment increased in the order of AQ Bond Plus (AQ)<Clearfil Tri-S Bond (TS)=G-bond (GB)<Absolute (AB)<Adper Prompt (AP) for 24 and 72 h. The pulp cell cytotoxicity of unpolymerized sample treatment for 24 h increased in the order of AQ<GB = AB<TS<AP. The MDPC-23 cytotoxicity of unpolymerized sample treatment for 24 h increased in the order of AQ<GB<TS = AB<AP. Whether polymerized or unpolymerized, AQ was the least cytotoxic agent, while AP was the strongest. All polymerized dentin-bonding agents exhibited lower cytotoxicity by 2-65% than their unpolymerized counterparts. The appearance of the cytotoxicity of dentin-bonding agents was time-dependent, and cell viability was lower at 72 h by 2-46% than at 24 h. The cytotoxicity to MDPC-23 cells was about 5-24% higher than that to pulp cells. These results indicate that one-step dentin-bonding agents differ markedly in their cytotoxicity. Differential cytotoxic effects of one-step dentin-bonding agents should be considered during clinical application of operative restoration.
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121
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Zeitlin BD, Zeitlin IJ, Nör JE. Expanding circle of inhibition: small-molecule inhibitors of Bcl-2 as anticancer cell and antiangiogenic agents. J Clin Oncol 2008; 26:4180-8. [PMID: 18757333 DOI: 10.1200/jco.2007.15.7693] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The specific targeting of diseases, particularly cancer, is a primary aim in drug development, as specificity reduces unwelcome effects on healthy tissue and increases drug efficacy at the target site. Drug specificity can be increased by improving the delivery system or by selecting drugs with affinity for a molecular ligand specific to the disease state. The role of the prosurvival Bcl-2 protein in maintaining the normal balance between apoptosis and cellular survival has been recognized for more than a decade. Bcl-2 is vital during development, much less so in adults. It has also been noted that some cancers evade apoptosis and obtain a survival advantage through aberrant expression of Bcl-2. The new and remarkably diverse class of drugs, small-molecule inhibitors of Bcl-2 (molecular weight approximately 400 to 800 Daltons), is examined herein. We present the activities of these compounds along with clinical observations, where available. The effects of Bcl-2 inhibition on attenuation of tumor cell growth are discussed, as are studies revealing the potential for Bcl-2 inhibitors as antiangiogenic agents. Despite an enormous body of work published for the Bcl-2 family of proteins, we are still learning exactly how this group of molecules interacts and indeed what they do. The small-molecule inhibitors of Bcl-2, in addition to their therapeutic potential, are proving to be an important investigative tool for understanding the function of Bcl-2.
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Song W, Dong Z, Jin T, Mantellini MG, Núñez G, Nör JE. Cancer gene therapy with iCaspase-9 transcriptionally targeted to tumor endothelial cells. Cancer Gene Ther 2008; 15:667-75. [PMID: 18566614 DOI: 10.1038/cgt.2008.38] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antiangiogenic therapies have shown varying results partly because each tumor type secretes a distinct panel of angiogenic factors to sustain its own microvascular network. In addition, recent evidence demonstrated that tumors develop resistance to antiangiogenic therapy by turning on alternate angiogenic pathways when one pathway is therapeutically inhibited. Here, we test the hypothesis that expression of a caspase-based artificial death switch in tumor-associated endothelial cells will disrupt tumor blood vessels and slow down tumor progression irrespective of tumor type. Adenoviral vectors expressing inducible Caspase-9 (iCaspase-9) under transcriptional regulation with the endothelial cell-specific vascular endothelial growth factor receptor-2 (VEGFR2) promoter (Ad-hVEGFR2-iCaspase-9) induced apoptosis of proliferating human dermal microvascular endothelial cells (HDMECs), but not human tumor cells (UM-SCC-17B, head and neck squamous cell carcinoma; HepG2, hepatocellular carcinoma; PC-3, prostate adenocarcinoma; SLK, Kaposi's sarcoma; MCF-7, breast adenocarcinoma). Notably, apoptosis was dependent upon activation of iCaspase-9 with the dimerizer drug AP20187. Local delivery of Ad-hVEGFR2-iCaspase-9 followed by intraperitoneal injection of AP20187 ablated tumor microvessels and inhibited xenografted tumor growth in all tumor models evaluated here. We conclude that a cancer gene therapy strategy based on a transcriptionally targeted viral vector expressing an inducible caspase allows for selective and controlled ablation of microvessels of histopathologically diverse tumor types.
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123
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Kaneko T, Okiji T, Kaneko R, Nör JE, Suda H. Antigen-presenting cells in human radicular granulomas. J Dent Res 2008; 87:553-7. [PMID: 18502964 DOI: 10.1177/154405910808700617] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Substantial numbers of dendritic cells have been detected in radicular granulomas. To test the hypothesis that local antigen presentation from dendritic cells to T-cells is involved critically in immunological responses within radicular granulomas, we compared characteristics of dendritic cells and macrophages by morphological and biological analyses. Under light microscopy, HLA-DR+ and CD68+ cells showed diverse profiles, including dendritic-shaped cells. Transmission electron microscopy revealed that HLA-DR+ dendritic cells, with long cytoplasmic processes and lacking distinct phagosomes, were concentrated in the lymphocyte-rich area. HLA-DR alpha-chain, CD83, and CD86 mRNAs from HLA-DR+ dendritic cells, and CD28 mRNA from CD28+ T-cells were up-regulated in lymphocyte-rich area. Scanning electron microscopy demonstrated that the density of gold particles on dendritic cells was higher than that on HLA-DR+ macrophages. These results suggest that dendritic cells in radicular granulomas are associated with local defense reactions as stronger antigen-presenting cells, as compared with macrophages.
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Zeitlin BD, Joo E, Dong Z, Warner K, Wang G, Nikolovska-Coleska Z, Wang S, Nör JE. Antiangiogenic effect of TW37, a small-molecule inhibitor of Bcl-2. Cancer Res 2007; 66:8698-706. [PMID: 16951185 DOI: 10.1158/0008-5472.can-05-3691] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bcl-2 is an antiapoptotic protein that is up-regulated in several tumor types, and its expression levels have strong correlation to development of resistance to therapy and poor prognosis. We have shown recently that Bcl-2 also functions as a proangiogenic signaling molecule that activates a nuclear factor-kappaB-mediated pathway resulting in up-regulation of the angiogenic chemokines CXCL1 and CXCL8 by neovascular endothelial cells. Here, we evaluate the antiangiogenic effect of the novel small-molecule inhibitor of Bcl-2 (TW37) developed using a structure-based design strategy. We observed that TW37 has an IC(50) of 1.8 mumol/L for endothelial cells but showed no cytotoxic effects for fibroblasts at concentrations up to 50 mumol/L. The mechanism of TW37-induced endothelial cell death was apoptosis, in a process mediated by mitochondrial depolarization and activation of caspase-9 and caspase-3. The effect of TW37 on endothelial cell apoptosis was not prevented by coexposure to the growth factor milieu secreted by tumor cells. Inhibition of the angiogenic potential of endothelial cells (i.e., migration and capillary sprouting assays) and expression of the angiogenic chemokines CXCL1 and CXCL8 were accomplished at subapoptotic TW37 concentrations (0.005-0.05 micromol/L). Notably, administration of TW37 i.v. resulted in a decrease in the density of functional human microvessels in the severe combined immunodeficient mouse model of human angiogenesis. In conclusion, we describe functionally separate proapoptotic and antiangiogenic mechanisms for a small-molecule inhibitor of Bcl-2 and show the potential for Bcl-2 inhibition as a target for antiangiogenic therapy.
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125
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Grando Mattuella L, Poli de Figueiredo JA, Nör JE, de Araujo FB, Medeiros Fossati AC. Vascular endothelial growth factor receptor-2 expression in the pulp of human primary and young permanent teeth. J Endod 2007; 33:1408-12. [PMID: 18037047 DOI: 10.1016/j.joen.2007.08.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 08/15/2007] [Accepted: 08/29/2007] [Indexed: 10/22/2022]
Abstract
The purpose of this study was to evaluate the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in endothelial cells within the dental pulp of human primary and young permanent teeth and the spatial distribution of VEGFR-2-positive cells. Nine sound primary teeth and 4 sound young permanent teeth were evaluated by immunohistochemistry with a human anti-VEGFR-2 antibody. Stained tissue sections were analyzed qualitatively under light microscopy. Here we observed that endothelial cells of both primary and permanent teeth showed positive immunostaining for VEGFR-2. Notably, VEGFR-2-positive cells in the primary teeth tended to be found close to the subodontoblastic layer, whereas the spatial distribution of VEGFR-2 immunostaining in the permanent teeth was more uniform. In conclusion, VEGFR-2 was expressed in the microvascular endothelial cells of both primary and young permanent teeth, which suggests that these cells are capable of responding to the morphogenetic and survival signals mediated by VEGF.
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126
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Kaneko T, Zhang Z, Mantellini MG, Karl E, Zeitlin B, Verhaegen M, Soengas MS, Lingen M, Strieter RM, Nunez G, Nör JE. Bcl-2 Orchestrates a Cross-talk between Endothelial and Tumor Cells that Promotes Tumor Growth. Cancer Res 2007; 67:9685-93. [DOI: 10.1158/0008-5472.can-07-1497] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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127
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Jain HV, Nör JE, Jackson TL. Modeling the VEGF–Bcl-2–CXCL8 Pathway in Intratumoral Agiogenesis. Bull Math Biol 2007; 70:89-117. [PMID: 17701379 DOI: 10.1007/s11538-007-9242-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 05/31/2007] [Indexed: 01/24/2023]
Abstract
Recent experiments show that vascular endothelial growth factor (VEGF) is the crucial mediator of downstream events that ultimately lead to enhanced endothelial cell survival and increased vascular density within many tumors. The newly discovered pathway involves up-regulation of the anti-apoptotic protein Bcl-2, which in turn leads to increased production of interleukin-8 (CXCL8). The VEGF-Bcl-2-CXCL8 pathway suggests new targets for the development of anti-angiogenic strategies including short interfering RNA (siRNA) that silence the CXCL8 gene and small molecule inhibitors of Bcl-2. In this paper, we present and validate a mathematical model designed to predict the effect of the therapeutic blockage of VEGF, CXCL8, and Bcl-2 at different stages of tumor progression. In agreement with experimental observations, the model predicts that curtailing the production of CXCL8 early in development can result in a delay in tumor growth and vascular development; however, it has little effect when applied at late stages of tumor progression. Numerical simulations also show that blocking Bcl-2 up-regulation, either at early stages or after the tumor has fully developed, ensures that both microvascular and tumor cell density stabilize at low values representing growth control. These results provide insight into those aspects of the VEGF-Bcl-2-CXCL8 pathway, which independently and in combination, are crucial mediators of tumor growth and vascular development. Continued quantitative modeling in this direction may have profound implications for the development of novel therapies directed against specific proteins and chemokines to alter tumor progression.
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128
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Dong Z, Zeitlin BD, Song W, Sun Q, Karl E, Spencer DM, Jain HV, Jackson T, Núñez G, Nör JE. Level of endothelial cell apoptosis required for a significant decrease in microvessel density. Exp Cell Res 2007; 313:3645-57. [PMID: 17720154 PMCID: PMC2080879 DOI: 10.1016/j.yexcr.2007.07.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 07/22/2007] [Accepted: 07/23/2007] [Indexed: 12/15/2022]
Abstract
Endothelial cell apoptosis plays a critical role in the disruption of blood vessels mediated by natural inhibitors of angiogenesis and by anti-vascular drugs. However, the proportion of endothelial cells required to mediate a significant decrease in microvessel density is unknown. A system based on an inducible caspase (iCaspase-9) offers a unique opportunity to address this question. The dimerizer drug AP20187 induces apoptosis of human dermal microvascular endothelial cells stably transduced with iCaspase-9 (HDMEC-iCaspase-9), but not control cells (HDMEC-LXSN). Here, we generated blood vessels containing several HDMEC-iCaspase-9:HDMEC-LXSN ratios, and developed a mathematical modeling involving a system of differential equations to evaluate experimentally inaccessible ratios. A significant decrease in capillary sprouts was observed when at least 17% of the endothelial cells underwent apoptosis in vitro. Exposure to vascular endothelial growth factor (VEGF(165)) did not prevent apoptosis of HDMEC-iCaspase-9, but increased the apoptotic requirement for sprout disruption. In vivo experiments showed the requirement of at least 22% apoptotic endothelial cells for a significant decrease in microvascular density. The combined use of biological experimentation with mathematical modeling allowed us to conclude that apoptosis of a relatively small proportion of endothelial cells is sufficient to mediate a significant decrease in microvessel density.
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129
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Dong Z, Neiva KG, Jin T, Zhang Z, Hall DE, Mooney DJ, Polverini PJ, Nör JE. Quantification of human angiogenesis in immunodeficient mice using a photon counting-based method. Biotechniques 2007; 43:73-7. [PMID: 17695255 DOI: 10.2144/000112457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Testing new antiangiogenic drugs for cancer treatment requires the use of animal models, since stromal cells and extracellular matrices mediate signals to endothelial cells that cannot be fully reproduced in vitro. Most methods used for analysis of antiangiogenic drugs in vivo utilized histologic examination of tissue specimens, which often requires large sample sizes to obtain reliable quantitative data. Furthermore, these assays rely on the analysis of murine vasculature that may not be correlated with the responses of human endothelial cells. Here, we engineered human blood vessels in immunodeficient mice with human endothelial cells expressing luciferase, demonstrated that these cells line functional blood vessels, and quantified angiogenesis over time using a photon counting-based method. In a proof-of-principle experiment with PTK/ZK, a small molecule inhibitor of vascular endothelial growth factor (VEGF) tyrosine kinase receptors, a strong correlation was observed between the decrease in bioluminescence (9.12-fold) in treated mice and the actual decrease in microvessel density (9.16-fold) measured after retrieval of the scaffolds and immunohistochemical staining of endothelial cells. The method described here allows for quantitative and noninvasive investigation into the effects of anti-cancer drugs on human angiogenesis in a murine host.
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130
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Gonçalves SB, Dong Z, Bramante CM, Holland GR, Smith AJ, Nör JE. Tooth Slice–Based Models for the Study of Human Dental Pulp Angiogenesis. J Endod 2007; 33:811-4. [PMID: 17804317 DOI: 10.1016/j.joen.2007.03.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 03/16/2007] [Accepted: 03/17/2007] [Indexed: 10/23/2022]
Abstract
Treatment of avulsed young permanent teeth aims to revascularize the dental pulp. The study of therapeutic strategies for avulsed teeth has been hindered by the scarcity of experimental models. The purpose of this work is to characterize two model systems to study dental pulp revascularization. Tooth slices from human third molars were prepared with a sterile diamond saw. The tooth slices were cultured in vitro for up to 7 days. Immunohistochemical staining with Factor VIII showed an increase in microvascular density in pulps treated with 50 ng/mL rhVEGF(165) as compared with untreated controls (p < 0.05). Alternatively, tooth slices were prepared and immediately implanted subcutaneously in immunodeficient mice. Pulp vitality and vascularization were confirmed by histological analysis and terminal deoxynucleotide transferase dUTP nick end labeling assays 7 days after implantation. The models presented here may be valuable in the assessment of angiogenesis-based therapeutic strategies for the dental pulp.
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131
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Karl E, Zhang Z, Dong Z, Neiva KG, Soengas MS, Koch AE, Polverini PJ, Núñez G, Nör JE. Unidirectional crosstalk between Bcl-xL and Bcl-2 enhances the angiogenic phenotype of endothelial cells. Cell Death Differ 2007; 14:1657-66. [PMID: 17572663 DOI: 10.1038/sj.cdd.4402174] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Expression of Bcl-x(L) correlates with the clinical outcomes of patients with cancer. While the role of Bcl-2 in angiogenesis is becoming increasingly evident, the function of Bcl-x(L) in angiogenesis is unclear. Here, we showed that epidermal growth factor (EGF) induces in vitro capillary sprouting and Bcl-x(L) expression in primary endothelial cells. Bcl-x(L)-transduced human dermal microvascular endothelial cells (HDMEC-Bcl-x(L)), but not empty vector control cells, spontaneously organize into capillary-like sprouts. Searching for a mechanism to explain these responses, we observed that Bcl-x(L) induced expression of the pro-angiogenic chemokines CXC ligand-1 (CXCL1) and CXC ligand-8 (CXCL8), and that blockade of CXC receptor-2 (CXCR2) signaling inhibited spontaneous sprouting of HDMEC-Bcl-x(L). Bcl-x(L) led to Bcl-2 upregulation, but Bcl-2 did not upregulate Bcl-x(L), suggesting the existence of a unidirectional crosstalk from Bcl-x(L) to Bcl-2. EGF and Bcl-x(L) activate the mitogen-activated protein kinase/ERK pathway resulting in upregulation of vascular endothelial growth factor (VEGF), a known inducer of Bcl-2 in endothelial cells. Inhibition of VEGF receptor signaling in HDMEC-Bcl-x(L) prevented Bcl-2 upregulation and demonstrated the function of a VEGF-mediated autocrine loop. Bcl-2 downregulation by RNAi blocked CXCL1 and CXCL8 expression downstream of Bcl-x(L), and markedly decreased angiogenesis in vivo. We conclude that Bcl-x(L) functions as a pro-angiogenic signaling molecule controlling Bcl-2 and VEGF expression. These results emphasize a complex interplay between Bcl-2 family members beyond their classical roles in apoptosis.
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Marchi JJ, de Araujo FB, Fröner AM, Straffon LH, Nör JE. Indirect pulp capping in the primary dentition: a 4 year follow-up study. J Clin Pediatr Dent 2007; 31:68-71. [PMID: 17315796 DOI: 10.17796/jcpd.31.2.y4um5076341226m5] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Evaluate clinical and radiographic changes in primary teeth submitted to indirect pulp capping (IPC) over a 48-month-period. METHODS Twenty seven primary molars with deep caries, but without preoperative signs of irreversible pulpits, were treated with IPC. The teeth were randomly divided into two groups, according to the material used for protection of the dentin-pulp complex. (1) a calcium hydroxide liner (Dycal) and (2) glass ionomer cement (Vitremer). RESULTS After 48 months, Group-1 showed a success rate of 88.8% and Group-2 of 93%. No statistical significant difference between the groups was observed (P = 0.62). CLINICAL SIGNIFICANCE The results of this study suggested that indirect pulp capping in primary teeth arrests the progression of the underlying caries, regardless of the material used as a liner.
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Abstract
AbstractFor many years, operative dentistry has been using regenerative approaches to treat dental disease. The use of calcium hydroxide to stimulate reparative or reactionary dentin is clearly an example of such a therapeutic strategy. The advent of tissue engineering is allowing dentistry to move forward in the use of regeneration as an underlying principle for the treatment of dental disease. Tissue engineering is a multi-disciplinary science that brings together biology, engineering and clinical sciences with developing new tissues and organs. It is based on fundamental principles that involve the identification of appropriate cells, the development of conducive scaffolds and an understanding of the morphogenic signals required to induce cells to regenerate the tissues that were lost. This review is focused on the presentation and discussion of existing literature that covers the engineering of enamel, dentin and pulp, as well on the engineering of entire teeth. There are clearly major roadblocks to overcome before such strategies move to the clinic and are used regularly to treat patients. However, existing evidence strongly suggests that the engineering of new dental structures to replace tissues lost during the process of caries or trauma will have a place in the future of operative dentistry.
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134
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Botero TM, Shelburne CE, Holland GR, Hanks CT, Nör JE. TLR4 Mediates LPS-Induced VEGF Expression in Odontoblasts. J Endod 2006; 32:951-5. [PMID: 16982271 DOI: 10.1016/j.joen.2006.03.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Revised: 03/10/2006] [Accepted: 03/17/2006] [Indexed: 11/20/2022]
Abstract
Lipopolysaccharide (LPS) from gram-negative bacteria cell walls such as Prevotella intermedia and Escherichia coli induce vascular endothelial growth factor (VEGF) expression in odontoblasts, but not in undifferentiated dental pulp cells. CD14 and TLR4 are responsible for LPS signaling in macrophages, but their expression levels and function in dental pulp cells are unknown. We showed here that murine odontoblast-like cells (MDPC-23) express CD14 and TLR4 by immunohistochemistry and flow cytometry. In contrast, undifferentiated dental pulp cells (OD-21) presented low or no expression of these two receptors. MDPC-23 cells showed CD14 and TLR4 up-regulation upon exposure to LPS, as determined by real time PCR. Dominant negative murine TLR4 (DN-mTLR4) transfected MDPC-23 cells did not show upregulated VEGF expression in response to LPS stimulation. These results demonstrate that odontoblast-like cells express CD14 and TLR4, and that LPS-induced VEGF expression is mediated, at least in part, by TLR4 signaling.
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Mantellini MG, Botero T, Yaman P, Dennison JB, Hanks CT, Nör JE. Adhesive resin and the hydrophilic monomer HEMA induce VEGF expression on dental pulp cells and macrophages. Dent Mater 2006; 22:434-40. [PMID: 16182358 DOI: 10.1016/j.dental.2005.04.039] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Accepted: 04/07/2005] [Indexed: 01/21/2023]
Abstract
Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis by inducing endothelial cell proliferation, migration and survival. Direct pulp capping with an adhesive resin system was shown to induce local increase in blood vessel density and lack of dentin bridging. However, the mechanisms involved in the increase in blood vessel density observed near the pulp exposures capped with an adhesive resin are largely unknown. OBJECTIVES.: To investigate the effect of an adhesive resin or one of its hydrophilic monomers (HEMA), in the expression of VEGF by pulp cells. METHODS.: Mouse odontoblast-like cells (MDPC-23), undifferentiated pulp cells (OD-21), gingival fibroblasts, and macrophages were exposed to SingleBond (3M) or to 0-1000nM HEMA. VEGF expression was evaluated by ELISA and semi-quantitative RT-PCR. RESULTS AND SIGNIFICANCE.: VEGF expression was upregulated in MDPC-23 cells exposed to HEMA (p<0.001) or to SingleBond (p<0.018), and in macrophages exposed to HEMA (p<0.001) or SingleBond (p=0.001). In contrast, VEGF expression remained unchanged in undifferentiated pulp cells (OD-21), or fibroblasts exposed to either HEMA or Single Bond (p>0.05). Treatment with SingleBond or HEMA did not affect VEGF expression at the mRNA level of any cell type evaluated here, suggesting that the induction of VEGF expression in these cells is regulated primarily at the post-transcriptional level. These findings suggest that VEGF is involved in the regulation of pulp neovascularization observed in response to the application of adhesive resins at site of pulp exposure.
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Holland SJ, Powell MJ, Franci C, Chan EW, Friera AM, Atchison RE, McLaughlin J, Swift SE, Pali ES, Yam G, Wong S, Lasaga J, Shen MR, Yu S, Xu W, Hitoshi Y, Bogenberger J, Nör JE, Payan DG, Lorens JB. Multiple roles for the receptor tyrosine kinase axl in tumor formation. Cancer Res 2005; 65:9294-303. [PMID: 16230391 DOI: 10.1158/0008-5472.can-05-0993] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A focus of contemporary cancer therapeutic development is the targeting of both the transformed cell and the supporting cellular microenvironment. Cell migration is a fundamental cellular behavior required for the complex interplay between multiple cell types necessary for tumor development. We therefore developed a novel retroviral-based screening technology in primary human endothelial cells to discover genes that control cell migration. We identified the receptor tyrosine kinase Axl as a novel regulator of endothelial cell haptotactic migration towards the matrix factor vitronectin. Using small interfering RNA-mediated silencing and overexpression of wild-type or mutated receptor proteins, we show that Axl is a key regulator of multiple angiogenic behaviors including endothelial cell migration, proliferation, and tube formation in vitro. Moreover, using sustained, retrovirally delivered short hairpin RNA (shRNA) Axl knockdown, we show that Axl is necessary for in vivo angiogenesis in a mouse model. Furthermore, we show that Axl is also required for human breast carcinoma cells to form a tumor in vivo. These findings indicate that Axl regulates processes vital for both neovascularization and tumorigenesis. Disruption of Axl signaling using a small-molecule inhibitor will hence simultaneously affect both the tumor and stromal cell compartments and thus represents a unique approach for cancer therapeutic development.
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MESH Headings
- Animals
- Breast Neoplasms/blood supply
- Breast Neoplasms/enzymology
- Cell Growth Processes/physiology
- Cell Line, Tumor
- Cell Movement/genetics
- Cell Transformation, Neoplastic/metabolism
- Cells, Cultured
- Chemotaxis/drug effects
- Chemotaxis/physiology
- Coculture Techniques
- Endothelial Cells/cytology
- Endothelial Cells/enzymology
- Humans
- Mice
- Mice, SCID
- Neovascularization, Pathologic/enzymology
- Neovascularization, Pathologic/genetics
- Neovascularization, Physiologic/genetics
- Neovascularization, Physiologic/physiology
- Oncogene Proteins/antagonists & inhibitors
- Oncogene Proteins/biosynthesis
- Oncogene Proteins/genetics
- Oncogene Proteins/physiology
- Proto-Oncogene Proteins
- RNA, Small Interfering/genetics
- Receptor Protein-Tyrosine Kinases/antagonists & inhibitors
- Receptor Protein-Tyrosine Kinases/biosynthesis
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor Protein-Tyrosine Kinases/physiology
- Signal Transduction
- Transfection
- Transplantation, Heterologous
- Vitronectin/pharmacology
- Axl Receptor Tyrosine Kinase
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137
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Barros JA, Myaki SI, Nör JE, Peters MC. Effect of bur type and conditioning on the surface and interface of dentine. J Oral Rehabil 2005; 32:849-56. [PMID: 16202050 DOI: 10.1111/j.1365-2842.2005.01507.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this in vitro study was to evaluate the surface and resin-dentine interface characteristics of permanent tooth dentine cut with diamond or carbide burs and treated with phosphoric acid (PA) or an acidic conditioner. Labial surfaces of permanent incisors were prepared into dentine with high-speed carbide or diamond burs and divided into two halves. Phosphoric acid 36% was applied on one half and non-rinse conditioner (NRC) was applied on the other half. Ten randomly selected scanning electron microscopy (SEM) fields from each specimen (n = 15) were evaluated. Occlusal surfaces of third molars were divided in two halves for evaluation of the resin-dentine interface. The halves were randomly assigned to one of each conditioner and restored with Prime & Bond NT/Spectrum. Ten specimens were analysed by SEM to evaluate hybrid layer formation and interfacial seal. We observed that surfaces prepared with carbide bur presented less residual smear plugs (P < 0.05) than surfaces prepared with diamond burs. Surfaces conditioned with NRC, which is a smear layer modifier, presented more residual smear plugs than surfaces conditioned with PA (P < 0.05). Treatment with PA resulted in more sealed interfaces than specimens treated with NRC. Within the limitations of this study the results showed that carbide burs leave a surface that is more conducive to bonding than diamond burs.
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138
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Addison CL, Nör JE, Zhao H, Linn SA, Polverini PJ, Delaney CE. The response of VEGF-stimulated endothelial cells to angiostatic molecules is substrate-dependent. BMC Cell Biol 2005; 6:38. [PMID: 16262896 PMCID: PMC1291360 DOI: 10.1186/1471-2121-6-38] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Accepted: 10/31/2005] [Indexed: 11/12/2022] Open
Abstract
Background The microenvironment surrounding cells can exert multiple effects on their biological responses. In particular the extracellular matrix surrounding cells can profoundly influence their behavior. It has been shown that the extracellular matrix composition in tumors is vastly different than that found in normal tissue with increased amounts of certain matrices such as collagen I. It has been previously demonstrated that VEGF stimulation of endothelial cells growing on type I collagen results in the induction of bcl-2 expression and enhanced endothelial cell survival. We sought to investigate whether this increased endothelial cell survival resulted in the failure of angiostatic molecules to inhibit angiogenesis. Results We now demonstrate that VEGF-induced survival on collagen I impairs the ability of three known angiostatic molecules, TSP-1, IP-10 and endostatin to inhibit endothelial cell proliferation. Apoptosis of endothelial cells, growing on collagen I, induced by TSP-1 and IP-10 was also inhibited following VEGF stimulation. In contrast, endostatin induced apoptosis in these same cells. Further analysis determined that endostatin did not decrease the expression of bcl-2 nor did it increase activation of caspase-3 in the presence of VEGF. Alternatively, it appeared that in the presence of VEGF, endostatin induced the activation of caspase-8 in endothelial cells grown on collagen I. Furthermore, only endostatin had the ability to inhibit VEGF-induced sprout formation in collagen I gels. Conclusion These data suggest that TSP-1, IP-10 and endostatin inhibit endothelial cells via different mechanisms and that only endostatin is effective in inhibiting angiogenic activities in the presence of collagen I. Our results suggest that the efficacy of angiostatic treatments may be impaired depending on the context of the extracellular matrix within the tumor environment and thus could impede the efficacy of angiostatic therapies.
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139
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Karl E, Warner K, Zeitlin B, Kaneko T, Wurtzel L, Jin T, Chang J, Wang S, Wang CY, Strieter RM, Nunez G, Polverini PJ, Nör JE. Bcl-2 acts in a proangiogenic signaling pathway through nuclear factor-kappaB and CXC chemokines. Cancer Res 2005; 65:5063-9. [PMID: 15958549 DOI: 10.1158/0008-5472.can-05-0140] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vascular endothelial growth factor (VEGF) induces expression of Bcl-2 in tumor-associated microvascular endothelial cells. We have previously reported that up-regulated Bcl-2 expression in microvascular endothelial cells is sufficient to enhance intratumoral angiogenesis and to accelerate tumor growth. We initially attributed these results to Bcl-2-mediated endothelial cell survival. However, in recent experiments, we observed that conditioned medium from Bcl-2-transduced human dermal microvascular endothelial cells (HDMEC-Bcl-2) is sufficient to induce potent neovascularization in the rat corneal assay, whereas conditioned medium from empty vector controls (HDMEC-LXSN) does not induce angiogenesis. These results cannot be attributed to the role of Bcl-2 in cell survival. To understand this unexpected observation, we did gene expression arrays that revealed that the expression of the proangiogenic chemokines interleukin-8 (CXCL8) and growth-related oncogene-alpha (CXCL1) is significantly higher in HDMEC exposed to VEGF and in HDMEC-Bcl-2 than in controls. Inhibition of Bcl-2 expression with small interfering RNA-Bcl-2, or the inhibition of Bcl-2 function with small molecule inhibitor BL-193, down-regulated CXCL8 and CXCL1 expression and caused marked decrease in the angiogenic potential of endothelial cells without affecting cell viability. Nuclear factor-kappaB (NF-kappaB) is highly activated in HDMEC exposed to VEGF and HDMEC-Bcl-2 cells, and genetic and chemical approaches to block the activity of NF-kappaB down-regulated CXCL8 and CXCL1 expression levels. These results reveal a novel function for Bcl-2 as a proangiogenic signaling molecule and suggest a role for this pathway in tumor angiogenesis.
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140
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Dienst A, Grunow A, Unruh M, Rabausch B, Nör JE, Fries JWU, Gottstein C. Specific Occlusion of Murine and Human Tumor Vasculature by VCAM-1–Targeted Recombinant Fusion Proteins. ACTA ACUST UNITED AC 2005; 97:733-47. [PMID: 15900043 DOI: 10.1093/jnci/dji130] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The tumor vasculature is increasingly recognized as a target for cancer therapy. We developed and evaluated recombinant fusion proteins targeting the coagulation-inducing protein soluble tissue factor (sTF) to the luminal tumor endothelial antigen vascular cell adhesion molecule 1 (VCAM-1, CD106). METHODS We generated fusion proteins consisting of sTF fused to antibody fragments directed against mouse or human VCAM-1 and characterized them in vitro by flow cytometry, surface plasmon resonance, and two-stage coagulation assays. Their therapeutic effects were tested in three human xenograft tumor models: L540rec Hodgkin lymphoma, Colo677 small-cell lung carcinoma, and Colo677/HDMEC small-cell lung carcinoma with human vasculature. Toxicity was analyzed by histologic examination of organs and determination of laboratory blood parameters. RESULTS The fusion proteins bound VCAM-1 with nanomolar affinities and had the same coagulation activity as an sTF standard. Xenograft tumor-bearing mice treated with fusion protein (FP) alone or in combination with lipopolysaccharide (FP/L) or doxorubicin (FP/D) exhibited tumor-selective necrosis (L540rec tumors: 74% tumor necrosis [95% confidence interval {CI} = 55% to 93%] with FP/L versus 13% tumor necrosis [95% CI = 4% to 22%] with vehicle; Colo677 tumors: 26% [95% CI = 16% to 36%] with FP versus 8% [95% CI = 2% to 14%] with vehicle); tumor growth delay (Colo677/HDMEC: mean tumor weights after 3 days = 42 mg in FP-treated mice versus 71 mg in vehicle-treated mice, difference = 29 mg, 95% CI = 8 to 100, Mann-Whitney P = .008); and some tumor regressions (one of seven FP-treated Colo677 tumor-bearing mice and two of seven FP/D-treated mice). The fusion protein was well tolerated. CONCLUSIONS Recombinant tissue factor-based fusion proteins directed against an intraluminal tumor endothelial cell marker induce tumor-selective intravascular coagulation, tumor tissue necrosis, and tumor growth delay.
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141
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Song W, Sun Q, Dong Z, Spencer DM, Núñez G, Nör JE. Antiangiogenic gene therapy: disruption of neovascular networks mediated by inducible caspase-9 delivered with a transcriptionally targeted adenoviral vector. Gene Ther 2005; 12:320-9. [PMID: 15616606 DOI: 10.1038/sj.gt.3302306] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The activation of an inducible caspase (iCaspase-9) mediates apoptosis of neovascular endothelial cells, and overcomes the prosurvival effect of vascular endothelial growth factor or basic fibroblast growth factor. The potential utilization of direct activation of caspases as an antiangiogenic strategy for treatment of angiogenesis-dependent diseases (eg cancer) requires expression of the inducible caspase primarily in the tumor endothelium. The objective of this work was to develop and characterize a transcriptionally targeted adenoviral vector that mediates expression of iCaspase-9 specifically in neovascular endothelial cells. We observed that adenoviral vectors containing the human VEGFR2 promoter induced reporter gene expression primarily in proliferating human dermal microvascular endothelial cells (HDMEC). HDMEC transduced with recombinant adenoviral vectors containing iCaspase-9 under regulation of the VEGFR2 promoter (Ad-hVEGFR2-iCaspase-9) and exposed to a cell-permeable dimerizer drug (AP20187), presented higher caspase-3 activity and apoptosis than controls (P < or = 0.05). Using the SCID Mouse Model of Human Angiogenesis, we observed that local delivery of Ad-hVEGFR2-iCaspase-9 followed by intraperitoneal injection of AP20187 resulted in endothelial cell apoptosis and local ablation of microvessels. We believe that this constitutes the first report of a transcriptionally targeted antiangiogenic adenoviral vector that mediates neovascular disruption upon activation of a caspase-based artificial death switch.
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142
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Moghaddame-Jafari S, Mantellini MG, Botero TM, McDonald NJ, Nör JE. Effect of ProRoot MTA on Pulp Cell Apoptosis and Proliferation In Vitro. J Endod 2005; 31:387-91. [PMID: 15851935 DOI: 10.1097/01.don.0000145423.89539.d7] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ProRoot Mineral Trioxide Aggregate (MTA) has been indicated as a pulp capping material. The purpose of this study was to evaluate the effect of tooth-colored (white) MTA on pulp cell apoptosis and cell cycle. Mouse odontoblast-like cells (MDPC-23) and undifferentiated pulp cells (OD-21) were exposed to 0 to 100 mg MTA for 24 h. Propidium iodide staining followed by flow cytometry demonstrated that MTA did not induce apoptosis of MDPC-23 or OD-21 (p > 0.05). Cell cycle analysis showed that MTA induced a modest (but significant) increase in the percentage of MDPC-23 in the S and G2 phases, and OD-21 in the S phase of cell cycle, as compared to untreated controls (p </= 0.05). In conclusion, MTA induced proliferation, and not apoptosis, of pulp cells in vitro. These findings suggest a potential mechanism to explain the regenerative effect observed in the dentin-pulp complex when MTA was used for direct pulp capping.
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143
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Hernandez EP, Botero TM, Mantellini MG, McDonald NJ, Nör JE. Effect of ProRootR MTA mixed with chlorhexidine on apoptosis and cell cycle of fibroblasts and macrophages in vitro*. Int Endod J 2005; 38:137-43. [PMID: 15667636 DOI: 10.1111/j.1365-2591.2004.00922.x] [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] [Indexed: 11/27/2022]
Abstract
AIM To compare the percentage of apoptotic cells and the cell cycle profile of fibroblasts and macrophages exposed to either ProRoot mineral trioxide aggregate (MTA) mixed with chlorhexidine (CHX), or exposed to ProRoot MTA mixed with sterile water. METHODOLOGY Mouse gingival fibroblasts or mouse macrophages were seeded in six-well plates and allowed to attach overnight. Freshly mixed or set (allowed to dry for 24 h) specimens of tooth-coloured (white) ProRoot MTA were prepared with 0.12% CHX gluconate (MTA/CHX) or with sterile water (MTA/H2O). The cells were exposed for 24 h to the MTA specimens, which were placed over permeable membrane inserts to avoid direct contact with the cells. Untreated cells served as controls. Propidium iodide staining followed by flow cytometry was used to evaluate the effects of ProRoot MTA on cell apoptosis and cell cycle. Statistical analyses were performed by one-way anova followed by post-hoc tests with the use of the SigmaStat 2.0 software, and significance was determined at P < or = 0.05. RESULTS MTA specimens containing CHX induced apoptosis of macrophages and fibroblasts (P < 0.05). In contrast, no change in the proportion of apoptotic cells was observed when sterile water was used to prepare the specimens (P > 0.05). Cell cycle analysis showed that exposure to MTA/CHX decreased the percentage of fibroblasts and macrophages in S phase (DNA synthesis) as compared with exposure to MTA/H2O (P < 0.05). CONCLUSION This in vitro study demonstrated that the substitution of CHX for sterile water in MTA increases its cytotoxicity. This suggests that the potentially beneficial antimicrobial effect of CHX may be accompanied by an increase in the cytotoxicity of the resulting MTA-based material.
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144
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Nör JE, DiPietro L, Murphy-Ullrich JE, Hynes RO, Lawler J, Polverini PJ. Activation of Latent TGF-β1 by Thrombospondin-1 is a Major Component of Wound Repair. ORAL BIOSCIENCES & MEDICINE : OBM 2005; 2:153-161. [PMID: 21822445 PMCID: PMC3150167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE: Thrombospondin 1 (TSP1) is a matrix glycoprotein that regulates cell adhesion, migration, and proliferation, and is a natural inhibitor of angiogenesis. Recent evidence suggests that TSP1 is a major physiologic activator of latent transforming growth factor-β1 (TGF-β1), and that TGF-β1 is important for wound healing. The purpose of this study was to examine whether excisional wound healing in TSP1-deficient mice is compromised as a result of deficient TGF-β1 activation. MATERIALS AND METHODS: Punch wounds were made on the dorsum of TSP1 deficient and wild-type mice and the area of granulation tissue, number of microvessels, and inflammatory cell infiltration was evaluated over a period of 28 days. RESULTS: TSP1 deficient mice showed impaired wound healing with persistent granulation tissue, decreased collagen content over time, and delayed arrival of macrophages compared to wild-type littermates. The number of microvessels in wounds of TSP1-deficient mice was approximately two-fold greater than in wild-type littermates 10 days after injury. Topical application of TSP1, or KRFK (a peptide derived from TSP1 that activates latent TGF-β1), to wounds of TSP1-deficient mice rescued wild-type patterns of wound repair and partially recovered local levels of TGF-β1 expression. Topical application of anti-TGF-β neutralizing antibody impaired the ability of KRFK to rescue normal patterns of wound neovascularization in TSP1-deficient mice. CONCLUSIONS: These results demonstrate that TSP1 plays a key role in the orchestration of wound healing, and that TSP1-mediated activation of local TGF-β1 is an important step in this process.
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145
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Polverini PJ, Nör JE, Peters MC, Mooney DJ. Growth of human blood vessels in severe combined immunodeficient mice. A new in vivo model system of angiogenesis. METHODS IN MOLECULAR MEDICINE 2003; 78:161-77. [PMID: 12825270 DOI: 10.1385/1-59259-332-1:161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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146
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Mantellini MG, Botero TM, Yaman P, Dennison JB, Hanks CT, Nör JE. Adhesive resin induces apoptosis and cell-cycle arrest of pulp cells. J Dent Res 2003; 82:592-6. [PMID: 12885841 DOI: 10.1177/154405910308200804] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The application of an adhesive resin near or directly over the pulp was shown to induce pulp inflammation and lack of dentin regeneration. We hypothesize that the absence of dentin bridging is due to adhesive-resin-induced apoptosis of cells responsible for pulp healing and dentin regeneration. Mouse odontoblast-like cells (MDPC-23), undifferentiated pulp cells (OD-21), or macrophages (RAW 264.7) were exposed to SingleBond polymerized for 0-40 seconds. Annexin V and propidium iodide assays demonstrated that SingleBond induced apoptosis of MDPC-23, OD-21, and macrophages. The proportion of apoptotic cells was dependent on the degree of adhesive resin polymerization. Adhesive-resin-induced death of pulp cells was associated with activation of the pro-apoptotic cysteine protease Caspase-3. Interestingly, most cells exposed to adhesive resin that did not undergo apoptosis showed cell-cycle arrest. We conclude that an adhesive resin induces apoptosis and cell-cycle arrest of cells involved in the regeneration of the dentin-pulp complex in vitro.
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147
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Telles PDS, Hanks CT, Machado MAAM, Nör JE. Lipoteichoic acid up-regulates VEGF expression in macrophages and pulp cells. J Dent Res 2003; 82:466-70. [PMID: 12766200 DOI: 10.1177/154405910308200612] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis, vascular permeability, and edema. Up-regulation of VEGF expression in the dental pulp may result in increased intra-pulpal pressure, and contribute to pain and irreversible tissue damage. Lipoteichoic acid (LTA) is an amphiphilic molecule from Gram-positive bacteria that has been associated with the pathogenesis of pulpitis. To investigate if LTA regulates expression of VEGF, we exposed mouse odontoblast-like cells (MDPC-23), undifferentiated pulp cells (OD-21), fibroblasts, or macrophages to streptococcal LTA, and evaluated VEGF expression by ELISA and RT-PCR. LTA induced up to a nine-fold increase in VEGF protein expression in macrophages, a 2.4-fold increase in MDPC-23, and a 1.6-fold increase in OD-21 as compared with controls. In contrast, LTA did not induce VEGF expression in fibroblasts. VEGF mRNA expression remained constant upon exposure to LTA, which suggests that VEGF regulation in these cells is primarily post-transcriptional. This work constitutes the first demonstration that lipoteichoic acid is sufficient to induce expression of a pro-angiogenic factor.
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148
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Botero TM, Mantellini MG, Song W, Hanks CT, Nör JE. Effect of lipopolysaccharides on vascular endothelial growth factor expression in mouse pulp cells and macrophages. Eur J Oral Sci 2003; 111:228-34. [PMID: 12786954 DOI: 10.1034/j.1600-0722.2003.00041.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Vascular endothelial growth factor (VEGF), a potent pro-angiogenic factor, might regulate the neovascularization observed in the pulp of teeth with deep caries. The purpose of this in vitro study was to evaluate the effect of bacterial lipopolysaccharides (LPS) on VEGF expression in dental pulp cells. Mouse odontoblast-like cells (MDPC-23) or undifferentiated pulp cells (OD-21) were exposed to 0-20 microg ml-1Escherichia coli LPS or 0-80 microg ml-1Prevotella intermedia LPS. As controls, mouse macrophages or gingival fibroblasts were exposed to LPS, since these cells are known to secrete VEGF. The VEGF expression was evaluated by reverse transcriptase polymerase chain reaction or enzyme-linked immunosorbent assay. The baseline expression levels of VEGF protein were higher in MDPC-23 and OD-21 than in fibroblasts or macrophages. Vascular endothelial growth factor protein expression was upregulated in MDPC-23 and macrophages exposed to E. coli LPS, but not in OD-21 cells or fibroblasts. Higher concentrations of P. intermedia LPS were required to induce VEGF expression in MDPC-23 cells. Treatment with LPS did not affect VEGF expression at the mRNA level in any of the cells evaluated. These results demonstrate that bacterial LPS upregulates VEGF expression in odontoblast-like cells and macrophages, and suggest that the regulation of VEGF expression occurs primarily at a post-transcriptional level.
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149
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Falster CA, Araujo FB, Straffon LH, Nör JE. Indirect pulp treatment: in vivo outcomes of an adhesive resin system vs calcium hydroxide for protection of the dentin-pulp complex. Pediatr Dent 2002; 24:241-8. [PMID: 12064499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
PURPOSE The purpose of this prospective and randomized in vivo study was to compare the clinical and radiographic outcomes of an adhesive resin system vs a calcium hydroxide liner for protection of the dentin-pulp complex of primary molars treated with indirect pulp treatment. METHODS Forty-eight primary molars with deep occlusal caries, but without preoperative signs and symptoms of irreversible pulpitis, received indirect pulp treatment and were restored with a composite resin (Z100). The teeth were randomly divided into 2 groups according to the material used for protection of the dentin-pulp complex: (1) adhesive resin system (Scotchbond MultiPurpose); and (2) calcium hydroxide liner (Dycal). These teeth were evaluated clinically and radiographicaly for 2 years. RESULTS After 2 years, 83% (19/23) of the teeth treated with calcium hydroxide and 96% (24/25) of teeth treated with only the adhesive resin system presented a successful outcome, as determined by clinical and radiographic examination. Interradicular and/or periapical lesions were the most predominant signs of treatment failure, since 3 out of 23 teeth treated with calcium hydroxide and 1 out of 25 teeth treated with only adhesive resin presented this outcome. One tooth treated with the calcium hydroxide liner was diagnosed with internal root resorption at the 18-month examination. Of the 5 teeth diagnosed from radiographs as a failure of the indirect pulp treatment, none presented clinical signs/symptoms of pulpitis or necrosis such as the presence of fistula, enhanced tooth mobility, or pain. CONCLUSIONS This study demonstrates that protection of the dentin-pulp complex of primary molars with an adhesive resin system results in similar clinical and radiographic 2-year outcomes as compared to calcium hydroxide when indirect pulp treatment is performed in Class I composite restorations.
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150
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Nör JE, Hu Y, Song W, Spencer DM, Núñez G. Ablation of microvessels in vivo upon dimerization of iCaspase-9. Gene Ther 2002; 9:444-51. [PMID: 11938459 DOI: 10.1038/sj.gt.3301671] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2001] [Accepted: 01/13/2002] [Indexed: 01/06/2023]
Abstract
Anti-angiogenic therapies based on targeted disruption of the tumor microvascular network have been proposed for cancer treatment. Inhibitors of the endothelial cell pro-survival pathway mediated by VEGF were shown to activate caspases and cause microvascular regression, but the efficacy of this strategy can be hindered by the engagement of redundant survival pathways. Alternatively, if direct activation of an apical pro-apoptotic caspase is sufficient to disrupt microvessels in vivo, such a strategy could potentially override upstream endothelial cell survival inputs and disrupt tumor neovascular networks. Here, we fused caspase-9 to a mutated FKBP12 domain to express an inducible caspase-9 molecule (iCaspase-9) that can be activated by a cell-permeable dimerizer drug, and transduced this construct into primary endothelial cells. We found that drug-induced dimerization of iCaspase-9 is sufficient to activate endogenous caspase-3 and trigger apoptosis even when endothelial cells are treated with the pro-survival factors VEGF or bFGF. A single intraperitoneal injection of the dimerizer drug induced apoptosis of endothelial cells expressing iCaspase-9 and elimination of human microvessels engineered in immunodeficient mice. These results demonstrate that the activation of iCaspase-9 disrupts microvessels in vivo, and suggest a novel anti-angiogenic strategy based on the expression and controlled activation of an inducible death gene in neovascular endothelial cells.
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