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Annals of Hematology 08/2012; · 2.62 Impact Factor
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ABSTRACT: An important feature of abdominal aortic aneurysm (AAA) is the destruction of vessel wall, especially elastin and collagen. Besides matrix metalloproteinases, cathepsins are the most potent elastolytic enzymes. The expression of cathepsins with known elastolytic and collagenolytic activities in the individual cells within AAA has not yet been determined. The vessel wall of 32 AAA patients and 10 organ donors was analysed by immunohistochemistry for expression of cathepsins B, D, K, L and S, and cystatin C in all cells localized within AAA. Luminal endothelial cells (ECs) of AAA were positive for cathepsin D and partially for cathepsins B, K and S. Endothelial cells of the neovessels and smooth muscle cells in the media were positive for all cathepsins tested, especially for cathepsin B. In the inflammatory infiltrate all cathepsins were expressed in the following pattern: B > D = S > K = L. Macrophages showed the highest staining intensity for all cathepsins. Furthermore, weak overall expression of cystatin C was observed in all the cells localized in the AAA with the exception of the ECs. There is markedly increased expression of the various cathepsins within the AAA wall compared to healthy aorta. Our data are broadly consistent with a role for cathepsins in AAA; and demonstrate expression of cathepsins D, B and S in phagocytic cells in the inflammatory infiltrate; and also may reveal a role for cathepsin B in lymphocytes.
International Journal of Experimental Pathology 08/2012; 93(4):252-8. · 2.57 Impact Factor
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Carolin Beck,
Guido Piontek,
Anna Haug,
Murat Bas,
Andreas Knopf,
Thomas Stark,
Martin Mißlbeck, Martina Rudelius,
Rudolf Reiter,
Markus Brandstetter,
Anja Pickhard
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ABSTRACT: BACKGROUND: In this study, we investigated the role of the kallikrein-kinin-system in head and neck squamous cell carcinoma (HNSCC) and its implication on tumour survival, invasion, migration and response to radiotherapy. METHODS: The expression of BKB2R was studied in a series of 180 tumour samples to determine the functional significance of BKB2R in HNSCC. Additionally, four different HNSCC cell lines were treated with an irradiation dose of 8Gy following bradykinin receptor stimulation or blockage. Tumour cell survival was tested using a colony formation assay. The invasive potential of tumour cells was assessed using Matrigel invasion chambers, the cells' ability to migrate was determined with a wound-healing assay. To examine the biochemical activation of BKB2R, the epidermal growth factor receptor (EGFR) and its downstream pathways, western blot analyses were conducted. RESULTS: Immunohistochemistry revealed an over-expression of BKB2R in HNSCC tumour cells in comparison to normal peritumoural tissue. Blocking the BKB2R at irradiated tumour cells led to a reduced response to radiotherapy of tumour cells and led to an activation of the EGFR and its downstream pathways, known mediators of tumour cell survival, migration and invasion. Bradykinin stimulation also resulted in a better tumour cell survival, but these effects were achieved via an EGFR-independent signalling. CONCLUSIONS: Our results demonstrate that the kallikrein-kinin-system is involved in survival, invasion and migration of HNSCC cells.
Oral Oncology 06/2012; · 2.86 Impact Factor
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Marie-Luise von Brühl,
Konstantin Stark,
Alexander Steinhart,
Sue Chandraratne,
Ildiko Konrad,
Michael Lorenz,
Alexander Khandoga,
Anca Tirniceriu,
Raffaele Coletti,
Maria Köllnberger, [......], Martina Rudelius,
Christian Schulz,
Katrin Echtler,
Volker Brinkmann,
Markus Schwaiger,
Klaus T Preissner,
Denisa D Wagner,
Nigel Mackman,
Bernd Engelmann,
Steffen Massberg
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ABSTRACT: Deep vein thrombosis (DVT) is a major cause of cardiovascular death. The sequence of events that promote DVT remains obscure, largely as a result of the lack of an appropriate rodent model. We describe a novel mouse model of DVT which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of DVT in humans. We demonstrate by intravital two-photon and epifluorescence microscopy that blood monocytes and neutrophils crawling along and adhering to the venous endothelium provide the initiating stimulus for DVT development. Using conditional mutants and bone marrow chimeras, we show that intravascular activation of the extrinsic pathway of coagulation via tissue factor (TF) derived from myeloid leukocytes causes the extensive intraluminal fibrin formation characteristic of DVT. We demonstrate that thrombus-resident neutrophils are indispensable for subsequent DVT propagation by binding factor XII (FXII) and by supporting its activation through the release of neutrophil extracellular traps (NETs). Correspondingly, neutropenia, genetic ablation of FXII, or disintegration of NETs each confers protection against DVT amplification. Platelets associate with innate immune cells via glycoprotein Ibα and contribute to DVT progression by promoting leukocyte recruitment and stimulating neutrophil-dependent coagulation. Hence, we identified a cross talk between monocytes, neutrophils, and platelets responsible for the initiation and amplification of DVT and for inducing its unique clinical features.
Journal of Experimental Medicine 03/2012; 209(4):819-35. · 13.85 Impact Factor
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ABSTRACT: The a disintegrin and metalloprotease (ADAM) family of metalloproteases possesses a proteolytic function and activates various inflammatory factors. Their expression pattern in an abdominal aortic aneurysm (AAA) is as yet unknown. The aim of this study was to make a detailed analysis of the expression of ADAMs 8, 9, 10, 12, 15 and 17, and their tissue inhibitors of metalloprotease (TIMP)-1 and TIMP-3 in patients with AAA.
The aortic vessel walls of AAA patients (n=20) and non-aneurysmal aortic specimens (n=10) were obtained by conventional surgical repair and autopsy. SYBR green-based real-time PCR, histology and immunohistochemistry were performed on all samples.
Quantitative expression analysis and the localisation of various ADAMs in AAA.
ADAMs tested in our study were expressed in both AAA and control aorta without any significant differences between the groups. In contrast, expression of TIMP-1 was significantly reduced in AAA compared to control vessels. Smooth muscle cells (SMCs), neovessels and macrophages were positive for all ADAMs and TIMPs tested. Infiltrates were negative for TIMP-3, and luminal endothelial cells were positive for ADAMs 15 and 17. A significant positive correlation was observed between ADAMs 10, 12, 15, 17, TIMP-3 and SMCs.
ADAMs are constitutively expressed in normal aortic vessel walls and AAA, particularly in SMCs.
Journal of Vascular Research 03/2012; 49(3):198-206. · 2.65 Impact Factor
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ABSTRACT: Most atherosclerotic lesions are vascularized, so neovessels may also contribute to plaque progression and vulnerability, but their precise role of neovessels in atherosclerosis is still unknown. The aim of this study was to analyze the possible relationships among neovascularization, relevant angiogenic factors, and plaque vulnerability in patients with advanced carotid artery stenosis.
The study group comprised 56 patients (stable: n=28, unstable: n=28) with advanced carotid artery stenosis (>70%). Immunohistochemistry was performed for smooth muscle, endothelial, and inflammatory cells, macrophages, vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), platelet-derived growth factor (PDGF), and angiopoietin-1,-2 (Ang-1,-2). Furthermore, the concentrations of angiogenic factors were measured in serum. Quantitative expression analysis was performed by SYBR-Green-based real-time polymerase chain reaction. Compared with stable carotid lesions, unstable carotid lesions showed 1.8-fold increase in neovascularization (P=0.013), which significantly correlated with accumulation of inflammatory cells (factor 1.9, P<0.001). In unstable lesions, compared with stable lesions, VEGF was 1.7-fold increased (P=0.032) and Ang-1 was 1.9-fold reduced (P=0.029). Furthermore, VEGF was higher in the blood of patients with unstable plaques than in stable plaques (0.32 ± 0.22 vs. 0.22 ± 0.16 ng/ml; P=0.002). Significant correlations were observed between plaque vulnerability, VEGF, neovascularization and inflammatory cells.
Our results show a close association between neovascularization, expression of angiogenic factors, inflammation, and plaque vulnerability in patients with advanced carotid stenosis.
Circulation Journal 03/2012; 76(5):1274-82. · 3.77 Impact Factor
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Ken Herrmann,
Andreas K Buck,
Tibor Schuster, Martina Rudelius,
Hans-Jürgen Wester,
Nicolas Graf,
Christine Scheuerer,
Christian Peschel,
Markus Schwaiger,
Tobias Dechow,
Ulrich Keller
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ABSTRACT: Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma. Proliferation activity is considered an important prognostic marker. Immunohistochemical analysis from core biopsy or lymph node may not represent the proliferation rate. We investigated the in vivo proliferation marker 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) to characterize MCL.
Eight untreated MCL patients were recruited prospectively. (18)F-FLT PET/CT was performed 45 min after injection of (18)F-FLT. (18)F-FDG PET/CT served as reference. Mean (18)F-FLT standardized uptake values were assessed per lesion and compared with respective (18)F-FDG uptake. Correlation of mean (18)F-FLT and (18)F-FDG uptake in the hottest lesion to Ki67 immunostaining was performed. Five patients underwent repetitive early (18)F-FLT PET.
All lymphoma lesions identified by (18)F-FDG PET/CT showed increased (18)F-FLT uptake. Semiquantitative analysis revealed a high mean (18)F-FLT standardized uptake value of 9.9 (range, 5.5-15.9). Mean (18)F-FLT uptake and Ki67 expressions showed a strong positive correlation.
PET using (18)F-FLT as a biomarker for proliferative activity showed a high sensitivity for MCL. (18)F-FLT uptake shows a correlation with proliferation. Our results warrant further analysis of (18)F-FLT PET in MCL.
Journal of Nuclear Medicine 11/2011; 52(12):1898-902. · 6.38 Impact Factor
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ABSTRACT: The transcription factor c-Myc (or "Myc") is a master regulator of pathways driving cell growth and proliferation. MYC is deregulated in many human cancers, making its downstream target genes attractive candidates for drug development. We report the unexpected finding that B-cell lymphomas from mice and patients exhibit a striking correlation between high levels of Myc and checkpoint kinase 1 (Chk1).
By in vitro cell biology studies as well as preclinical studies using a genetically engineered mouse model, we evaluated the role of Chk1 in Myc-overexpressing cells.
We show that Myc indirectly induces Chek1 transcript and protein expression, independently of DNA damage response proteins such as ATM and p53. Importantly, we show that inhibition of Chk1, by either RNA interference or a novel highly selective small molecule inhibitor, results in caspase-dependent apoptosis that affects Myc-overexpressing cells in both in vitro and in vivo mouse models of B-cell lymphoma.
Our data suggest that Chk1 inhibitors should be further evaluated as potential drugs against Myc-driven malignancies such as certain B-cell lymphoma/leukemia, neuroblastoma, and some breast and lung cancers.
Clinical Cancer Research 09/2011; 17(22):7067-79. · 7.74 Impact Factor
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Alexander Hoellein,
Anja Pickhard,
Fabienne von Keitz,
Stephanie Schoeffmann,
Guido Piontek, Martina Rudelius,
Anja Baumgart,
Stefan Wagenpfeil,
Christian Peschel,
Tobias Dechow,
Henning Bier,
Ulrich Keller
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ABSTRACT: Squamous cell cancer of the head and neck (SCCHN) is the sixth leading cause for cancer deaths worldwide. Despite extense knowledge of risk factors and pathogenesis about 50 percent of all patients and essentially every patient with metastatic SCCHN eventually die from this disease. We analyzed the clinical data and performed immunohistochemistry for Epidermal growth factor receptor (EGFR) and Aurora kinase A (Aurora-A) expression in 180 SCCHN patients. Patients characterized by elevated EGFR and elevated Aurora-A protein expression in tumor tissue represent a risk group with poor disease-free and overall survival (EGFR(low)Aurora-A(low) versus EGFR(high)Aurora-A(high), p = 0.024). Treating SCCHN cell lines with a pan-Aurora kinase inhibitor resulted in defective cytokinesis, polyploidy and apoptosis, which was effective irrespective of the EGFR status. Combined Aurora kinase and EGFR targeting using a monoclonal anti-EGFR antibody was more effective compared to single EGFR and Aurora kinase inhibition. Comparing pan-Aurora kinase and Aurora-A targeting hints towards a strong and clinically relevant biological effect mediated via Aurora kinase B. Taken together, our findings characterize a new poor risk group in SCCHN patients defined by elevated EGFR and Aurora-A protein expression. Our results demonstrate that combined targeting of EGFR and Aurora kinases represents a therapeutic means to activate cell cycle checkpoints and apoptosis in SCCHN.
Oncotarget 08/2011; 2(8):599-609. · 4.78 Impact Factor
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ABSTRACT: The Pim kinases are weak oncogenes. However, when co-expressed with a strong oncogene, such as c-Myc, Pim kinases potentiate the oncogenic effect resulting in an acceleration of tumorigenesis. In this study we show that the least studied Pim kinase, Pim-3, is encoded by a gene directly regulated by c-Myc via binding to one of the conserved E-boxes within the Pim3 gene. Accordingly, lymphomas arising in Myc-transgenic mice and Burkitt lymphoma cell lines exhibit elevated levels of Pim-3. Interestingly, inhibition of Pim kinases by a novel pan-Pim kinase inhibitor, Pimi, in Myc-induced lymphoma results in cell death that appears independent of caspases. The data indicate that Pim kinase inhibition could be a viable treatment strategy in certain human lymphomas that rely on Pim-3 kinase expression.
Oncotarget 06/2011; 2(6):448-60. · 4.78 Impact Factor
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Ken Herrmann,
Andreas K Buck,
Tibor Schuster,
Alexandra Junger,
Hinrich A Wieder,
Nicolas Graf,
Ingo Ringshausen, Martina Rudelius,
Hans-Jürgen Wester,
Markus Schwaiger,
Ulrich Keller,
Tobias Dechow
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ABSTRACT: R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone)-like chemotherapy is the standard therapy in aggressive B-cell lymphoma. (18)F-FDG PET has high prognostic implications at treatment completion but is limited as an early predictor. Here, we present the results of a prospective study correlating the initial uptake of the in vivo proliferation marker 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) with the clinical outcome of patients with aggressive non-Hodgkin lymphoma treated with R-CHOP.
Sixty-six eligible patients were evaluated prospectively with (18)F-FLT PET before R-CHOP. PET was performed 45 min after injection of 300-370 MBq of (18)F-FLT. Mean and maximum standardized uptake values (SUVs) were calculated on a lesion-by-lesion basis. Response was assessed at the end of therapy. International Prognostic Index (IPI) scores and clinical parameters (Ann Arbor stage, lactate dehydrogenase, performance status, extranodal disease) were determined in all patients. Response was assessed according to revised response criteria after the end of therapy. After treatment, patients were followed in intervals from 4 wk to 6 mo (mean follow-up, 23.1 mo [range, 1-63 mo]), and progression-free and overall survival were determined.
All lymphoma lesions identified by a reference method ((18)F-FDG PET/CT or multislice CT of the trunk) showed increased focal tracer uptake (mean (18)F-FLT SUV, 7.3 ± 2.5). Response assessment revealed progressive disease in 4, partial response in 3, and complete response (CR) in the remaining 55 patients. The IPI score was predictive for achieving CR (P = 0.034). Importantly, initial mean SUV was also significantly higher in patients who showed progressive disease and partial response than in patients who achieved CR (P = 0.049). In addition, we found a significant correlation between IPI score and initial (18)F-FLT uptake.
Taken together, high (18)F-FLT uptake is a negative predictor of response to R-CHOP treatment in aggressive B-cell non-Hodgkin lymphoma and correlates with the IPI score. Thus, (18)F-FLT PET may represent a useful tool for implementing risk-adapted treatment in these patients.
Journal of Nuclear Medicine 05/2011; 52(5):690-6. · 6.38 Impact Factor
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ABSTRACT: Matrix metalloproteinases participate in remodeling of extracellular matrix, which is central to the development of aortic stenosis. Synthesis of certain matrix metalloproteinases is induced by the glycoprotein extracellular matrix metalloproteinase inducer. We investigated whether extracellular matrix metalloproteinase inducer and membrane-type 1 matrix metalloproteinase are abundant in calcific aortic valve and their role in the pathogenesis of this condition.
Sixteen patients who underwent surgery for aortic stenosis (n = 12) or heart transplantation for ischemic cardiomyopathy (n = 4) were reviewed. Expression of extracellular matrix metalloproteinase inducer and membrane-type 1 matrix metalloproteinase proteins was assessed by Western blot (n = 4 per group), immunohistochemistry for aortic stenosis (n = 12) and ischemic cardiomyopathy (n = 2), and in situ zymography (n = 3 per group). Functional relevance was investigated using an artificial valve model.
Extracellular matrix metalloproteinase inducer and membrane-type 1 matrix metalloproteinase were abundant in all stenotic valves. Control valves did not stain for either protein. Double immunofluorescence colocalized extracellular matrix metalloproteinase inducer and membrane-type 1 matrix metalloproteinase to macrophages. On Western blotting, both proteins were more abundant in stenotic valves than in control valves. In situ zymography demonstrated greater gelatinolytic activity in stenotic valves than in control valves. Silencing of the extracellular matrix metalloproteinase inducer gene using small interfering RNA reduced migration of monocytes in an artificial valve model.
Extracellular matrix metalloproteinase inducer and membrane-type 1 matrix metalloproteinase were demonstrated on macrophages in stenotic aortic valves, into which extracellular matrix metalloproteinase inducer may promote monocyte immigration. The latter protein may therefore represent a potential target to reduce the development of aortic stenosis.
The Journal of thoracic and cardiovascular surgery 12/2010; 142(1):191-8. · 3.41 Impact Factor
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ABSTRACT: Genetically modified natural killer (NK) cells that recognize tumor-associated surface antigens have recently shown promise as a novel approach for cancer immunotherapy. To determine NK cell therapy response early, a real-time, noninvasive method to quantify NK cell homing to the tumor is desirable. The purpose of this study was to evaluate if MR imaging could provide a noninvasive, in vivo diagnosis of NK cell accumulation in epithelial cell adhesion molecule (EpCAM)-positive prostate cancers in a rat xenograft model. Genetically engineered NK-92-scFv(MOC31)-ζ cells, which express a chimeric antigen receptor specific to the tumor-associated EpCAM antigen, and nontargeted NK-92 cells were labeled with superparamagnetic particles of iron-oxides (SPIO) ferumoxides. Twelve athymic rats with implanted EpCAM positive DU145 prostate cancers received intravenous injections of 1.5×10(7) SPIO labeled NK-92 and NK-92-scFv(MOC31)-ζ cells. EpCAM-positive prostate cancers demonstrated a progressive and a significant decline in contrast-to-noise-ratio data at 1 and 24 h after injection of SPIO-labeled NK-92-scFv(MOC31)-ζ cells. Conversely, tumor contrast-to-noise-ratio data did not change significantly after injection of SPIO-labeled parental NK-92 cells. Histopathology confirmed an accumulation of the genetically engineered NK-92-scFv(MOC31)-ζ cells in prostate cancers. Thus, the presence or absence of a tumor accumulation of therapeutic NK cells can be monitored with cellular MR imaging. EpCAM-directed, SPIO labeled NK-92-scFv(MOC31)-ζ cells accumulate in EpCAM-positive prostate cancers.
Magnetic Resonance in Medicine 10/2010; 65(3):756-63. · 2.96 Impact Factor
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Jürgen den Hollander,
Sara Rimpi,
Joanne R Doherty, Martina Rudelius,
Andreas Buck,
Alexander Hoellein,
Marcus Kremer,
Nikolas Graf,
Markus Scheerer,
Mark A Hall,
Andrei Goga,
Nikolas von Bubnoff,
Justus Duyster,
Christian Peschel,
John L Cleveland,
Jonas A Nilsson,
Ulrich Keller
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ABSTRACT: Myc oncoproteins promote continuous cell growth, in part by controlling the transcription of key cell cycle regulators. Here, we report that c-Myc regulates the expression of Aurora A and B kinases (Aurka and Aurkb), and that Aurka and Aurkb transcripts and protein levels are highly elevated in Myc-driven B-cell lymphomas in both mice and humans. The induction of Aurka by Myc is transcriptional and is directly mediated via E-boxes, whereas Aurkb is regulated indirectly. Blocking Aurka/b kinase activity with a selective Aurora kinase inhibitor triggers transient mitotic arrest, polyploidization, and apoptosis of Myc-induced lymphomas. These phenotypes are selectively bypassed by a kinase inhibitor-resistant Aurkb mutant, demonstrating that Aurkb is the primary therapeutic target in the context of Myc. Importantly, apoptosis provoked by Aurk inhibition was p53 independent, suggesting that Aurka/Aurkb inhibitors will show efficacy in treating primary or relapsed malignancies having Myc involvement and/or loss of p53 function.
Blood 09/2010; 116(9):1498-505. · 9.90 Impact Factor
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ABSTRACT: To evaluate a combined indocyanine green-enhanced optical imaging/radiography system for the detection of arthritic joints in a rat model of antigen-induced arthritis.
Arthritis of the knee and ankle joints was induced in 6 Harlan rats, using peptidoglycan-polysaccharide polymers. Three rats served as untreated controls. Optical imaging of the knee and ankle joints was done with an integrated optical imaging/radiography system before and up to 24 hours following intravenous injection of 10 mg/kg indocyanine green. The fluorescence signal intensities of arthritic and normal joints were compared for significant differences, using generalized estimating equation models. Specimens of knee and ankle joints were further processed and evaluated by histology.
Immediately after administration, indocyanine green provided a significant increase in the fluorescence signal of arthritic joints compared with baseline values (P < 0.05). The fluorescence signal of arthritic joints was significantly higher compared with that of nonarthritic control joints at 1-720 minutes after intravenous injection (P < 0.05). Fusion of indocyanine green-enhanced optical imaging and radiography allowed for anatomic coregistration of the inflamed tissue with the associated joint. Hematoxylin and eosin staining confirmed marked synovial inflammation of arthritic joints and the absence of inflammation in control joints.
Indocyanine green-enhanced optical imaging is a clinically applicable tool for detection of arthritic tissue. Using relatively high doses of indocyanine green, long-term enhanced fluorescence of arthritic joints can be achieved. This may facilitate simultaneous evaluations of multiple joints in a clinical setting. Fusion of indocyanine green-enhanced optical imaging scans with radiography increases anatomic resolution.
Arthritis & Rheumatism 08/2010; 62(8):2322-7. · 7.87 Impact Factor
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ABSTRACT: To assess the capability of the folate receptor (FR)-targeted ultrasmall superparamagnetic iron oxide (USPIO) P1133 to provide FR-specific enhancement of breast cancers on magnetic resonance (MR) images.
This study was approved by the institutional Animal Care and Use Committee. The FR-targeted contrast agent P1133 was incubated with various FR-positive human breast cancer cell lines, with and without free folic acid (FFA) as a competitor. Labeling efficiencies were evaluated with MR imaging and inductively coupled plasma mass spectrometry. Subsequently, six athymic rats with implanted FR-positive MDA-MB-231 breast cancers underwent MR imaging at 3 T before and up to 1 hour and 24 hours after injection of P1133. Six athymic rats with implanted FR-positive MDA-MB-231 cancers injected with the non-FR-targeted USPIO P904 and nine athymic rats with implanted FR-negative A549 lung cancers injected with P1133 (n = 6) or P904 (n = 3) served as controls. Data of the in vitro studies were compared for significant differences with the Wilcoxon test for two independent samples. Tumor signal-to-noise-ratios (SNRs) were compared between different experimental groups by using the Kruskal-Wallis test and were correlated with histopathologic findings. Differences with P < .05 were considered significant.
FR-positive breast cancer cells showed a significant P1133 uptake which was inhibited by FFA. MDA-MB-231 cells showed the highest level of P1133 uptake and the strongest T2 effect on MR images. In vivo, all tumors showed an initial perfusion effect. At 24 hours after injection, only MDA-MB-231 tumors injected with P1133 showed significantly decreased SNR data compared with baseline data (P < .05). MR findings were confirmed by using histopathologic findings.
The FR-targeted USPIO P1133 demonstrates a specific retention in FR-positive breast cancers. Because FR expression correlates with tumor aggressiveness and prognosis, persistent P1133 tumor enhancement may be used as a noninvasive indicator for tumors with poor outcome.
Radiology 05/2010; 255(2):527-35. · 5.73 Impact Factor
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Natasa Anastasov,
Irina Bonzheim, Martina Rudelius,
Margit Klier,
Therese Dau,
Daniela Angermeier,
Justus Duyster,
Stefania Pittaluga,
Falko Fend,
Mark Raffeld,
Leticia Quintanilla-Martinez
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ABSTRACT: Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma is characterized by the t(2;5) chromosomal translocation, resulting in the expression of a fusion protein formed of nucleophosmin (NPM) and ALK. Recently, we reported the abnormal expression of the transcription factor CCAAT/enhancer binding protein-beta (C/EBPbeta) in ALK-positive anaplastic large cell lymphomas, and demonstrated its dependence on NPM-ALK activity.
In this study, the role of C/EBPbeta in proliferation and survival of ALK-positive anaplastic large cell lymphomas was investigated, as well as the mechanism of its expression and activity. Highly effective short hairpin RNA sequences and/or pharmacological inhibitors were used to abrogate the expression or activity of C/EBPbeta, signal transducer and activator of transcription 3 (STAT3), AKT, extracellular signal-related kinase 1/2 (ERK1/2) and mammalian target of rapamycin (mTOR).
Interference with C/EBPbeta expression resulted in a dramatic decrease in cell proliferation in ALK-positive anaplastic large cell lymphomas, with a mild induction of apoptosis after 6 days. Down-regulation of STAT3 resulted in a marked decrease in C/EBPbeta mRNA and protein levels with impairment in cell proliferation and viability, underscoring the important role of these two proteins in ALK-mediated oncogenesis. Additionally, we demonstrated that reduction of ERK1/2 activity led to C/EBPbeta Thr(235) dephosphorylation and moderate growth retardation. The AKT/mTOR signaling pathway did not have any influence on C/EBPbeta expression or C/EBPbeta phosphorylation.
These findings reveal the convergence of STAT3 and ERK1/2 signaling pathways activated by NPM-ALK in mediating the regulation of C/EBPbeta expression, a transcription factor central to NPM-ALK transformation.
Haematologica 12/2009; 95(5):760-7. · 6.42 Impact Factor
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Katrin Echtler,
Konstantin Stark,
Michael Lorenz,
Sandra Kerstan,
Axel Walch,
Luise Jennen, Martina Rudelius,
Stefan Seidl,
Elisabeth Kremmer,
Nikla R Emambokus,
Marie-Luise von Bruehl,
Jon Frampton,
Berend Isermann,
Orsolya Genzel-Boroviczény,
Christian Schreiber,
Julinda Mehilli,
Adnan Kastrati,
Markus Schwaiger,
Ramesh A Shivdasani,
Steffen Massberg
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ABSTRACT: The ductus arteriosus (DA) is a fetal shunt vessel between the pulmonary artery and the aorta that closes promptly after birth. Failure of postnatal DA closure is a major cause of morbidity and mortality particularly in preterm neonates. The events leading to DA closure are incompletely understood. Here we show that platelets have an essential role in DA closure. Using intravital microscopy of neonatal mice, we observed that platelets are recruited to the luminal aspect of the DA during closure. DA closure is impaired in neonates with malfunctioning platelet adhesion or aggregation or with defective platelet biogenesis. Defective DA closure resulted in a left-to-right shunt with increased pulmonary perfusion, pulmonary vascular remodeling and right ventricular hypertrophy. Our findings indicate that platelets are crucial for DA closure by promoting thrombotic sealing of the constricted DA and by supporting luminal remodeling. A retrospective clinical study revealed that thrombocytopenia is an independent predictor for failure of DA closure in preterm human newborns, indicating that platelets are likely to contribute to DA closure in humans.
Nature medicine 12/2009; 16(1):75-82. · 27.14 Impact Factor
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ABSTRACT: In this study a multiscore analysis of various biomarkers including matrix metalloproteinases (MMPs), inflammatory factors and other clinical parameters was performed to establish a set of reliable biomarkers for improved detection of plaque instability in patients with advanced carotid stenosis.
Study patients (n = 101) were classified as histologically stable (n = 37) or unstable (n = 64). Serum levels of MMP-1, -2, -3, -7, -8, -9, MMP inhibitors TIMP-1, -2, and inflammatory factors such as tumor necrosis factor (TNF-alpha), interleukin (IL)-1beta, -6, -8, -10, and -12 were measured by ELISA assays. Multiscore analysis was performed using multiple receiver operating characteristics analysis and determination of appropriate cutoff values.
Circulating levels of MMP-1, -7, TIMP-1, TNF-alpha, and IL-8 were significantly enhanced in patients with unstable plaques compared to individuals with stable lesions, mean differences being 1.2 (p = 0.032), 2.5 (p = 0.004), 30.0 (p = 0.014), 1.3 (p = 0.047), and 2.2 (p = 0.033), respectively. The combination of MMP-1, -7, TIMP-1 and IL-8 demonstrated the highest positive predictive value of 89.4% and negative predictive value of 60.1% for patients correctly classified as individuals with unstable and stable carotid lesions by means of blood sample analysis.
Multiple relevant biomarkers that play a decisive role in plaque instability can improve the correct determination of vulnerable carotid plaques in patients with advanced carotid artery stenosis.
Cerebrovascular Diseases 10/2009; 28(6):601-10. · 2.72 Impact Factor
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ABSTRACT: Mantle cell lymphoma (MCL) has one of the poorest prognoses of the non-Hodgkin's lymphomas, and novel therapeutic approaches are needed. We wished to determine whether Nutlin-3, a novel small-molecule murine double minute 2 (MDM2) antagonist that efficiently activates TP53, might be effective in inducing cell death in MCL.
MCL cell lines with known TP53 status were treated with Nutlin-3, and biological and biochemical consequences were studied. Synergies with the prototypic genotoxic agent doxorubicin and the novel proteasome inhibitor bortezomib were assessed.
Nutlin-3 resulted in a reduction in cell proliferation/viability (IC50 < 10 micromol/L), an increase in the apoptotic fraction, and cell cycle arrest in wild-type (wt) TP53 Z-138 and Granta 519 cells. These effects were accompanied by TP53 accumulation and induction of TP53-dependent proteins p21, MDM2, Puma, and Noxa. Cell cycle arrest was characterized by suppression of S phase and an increase in the G0-G1 and G2-M fractions and accompanied by suppression of total and phosphorylated retinoblastoma protein and a decrease in G2-M-associated proteins cyclin B and CDC2. The combination of Nutlin-3 with doxorubicin or bortezomib was synergistic in wt-TP53 MCL cells. Nutlin-3 also induced cell cycle arrest and reduced cell viability in the mutant TP53 MINO cells but at a significantly higher IC50 (22.5 micromol/L). These effects were associated with induction of the TP53 homologue p73, slight increases in p21 and Noxa, and caspase activation. Nutlin-3 and bortezomib synergistically inhibited cell growth of MINO.
These findings suggest that the MDM2 antagonist Nutlin-3 may be an effective agent in the treatment of MCL with or without wt-TP53.
Clinical Cancer Research 02/2009; 15(3):933-42. · 7.74 Impact Factor
