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  • 1
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  83. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie; 20120516-20120520; Mainz; DOC12hnod046 /20120404/
    Publication Date: 2012-04-05
    Keywords: ddc: 610
    Language: English
    Type: conferenceObject
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  • 2
    Abstract: Significant progress has been made in recent years toward realizing the potential of natural killer (NK) cells for cancer immunotherapy. NK cells can respond rapidly to transformed and stressed cells and have the intrinsic potential to extravasate and reach their targets in almost all body tissues. In addition to donor-derived primary NK cells, also the established NK cell line NK-92 is being developed for adoptive immunotherapy, and general safety of infusion of irradiated NK-92 cells has been established in phase I clinical trials with clinical responses observed in some of the cancer patients treated. To enhance their therapeutic utility, NK-92 cells have been modified to express chimeric antigen receptors (CARs) composed of a tumor-specific single chain fragment variable antibody fragment fused via hinge and transmembrane regions to intracellular signaling moieties such as CD3zeta or composite signaling domains containing a costimulatory protein together with CD3zeta. CAR-mediated activation of NK cells then bypasses inhibitory signals and overcomes NK resistance of tumor cells. In contrast to primary NK cells, CAR-engineered NK-92 cell lines suitable for clinical development can be established from molecularly and functionally well-characterized single cell clones following good manufacturing practice-compliant procedures. In preclinical in vitro and in vivo models, potent antitumor activity of NK-92 variants targeted to differentiation antigens expressed by hematologic malignancies, and overexpressed or mutated self-antigens associated with solid tumors has been found, encouraging further development of CAR-engineered NK-92 cells. Importantly, in syngeneic mouse tumor models, induction of endogenous antitumor immunity after treatment with CAR-expressing NK-92 cells has been demonstrated, resulting in cures and long-lasting immunological memory protecting against tumor rechallenge at distant sites. Here, we summarize the current status and future prospects of CAR-engineered NK-92 cells as off-the-shelf cellular therapeutics, with special emphasis on ErbB2 (HER2)-specific NK-92 cells that are approaching clinical application.
    Type of Publication: Journal article published
    PubMed ID: 28572802
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  • 3
    Keywords: APOPTOSIS ; CANCER ; CELLS ; EXPRESSION ; GROWTH ; carcinoma ; CELL ; Germany ; INHIBITION ; THERAPY ; HEPATOCELLULAR-CARCINOMA ; PROTEIN ; TISSUE ; LINES ; MICE ; PATIENT ; IMPACT ; INDUCTION ; CELL-LINES ; treatment ; hepatocellular carcinoma ; resistance ; AGE ; metastases ; NUDE-MICE ; CELL-LINE ; chemotherapy ; leukemia ; LINE ; MODULATION ; p53 ; CANCER-PATIENTS ; CARCINOMAS ; CISPLATIN ; CANCER PATIENTS ; cell lines ; CANCER-THERAPY ; protein expression ; P53 STATUS ; GEMCITABINE ; RE ; cancer therapy ; GENDER ; dexamethasone ; GLUCOCORTICOID-INDUCED APOPTOSIS ; NAUSEA ; HISTOLOGY ; corticosteroids ; GLUCOCORTICOIDS ; correlation ; GAMMA-IRRADIATION ; viability ; 5-FU ; xenograft
    Abstract: The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone cotreatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients. (c) 2005 Elsevier Ireland Ltd. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 16338063
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  • 4
    Keywords: CELLS ; IN-VITRO ; CELL ; Germany ; MICROSCOPY ; imaging ; TOOL ; TIME ; MRI ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; PARTICLES ; RELAXATION ; ASSAY ; MASS-SPECTROMETRY ; STEM-CELLS ; PROGENITOR CELLS ; self-assembled monolayers ; surface modification ; CLUSTER ; CHEMISTRY ; RE ; INCREASE ; GELS ; ASSAYS ; INTERNALIZATION ; NANOPARTICLES ; USA ; uptake ; MR CONTRAST AGENTS ; progenitor cell ; PROGENITOR-CELL ; CONJUGATION ; BIOSEPARATIONS ; DISPERSIONS
    Abstract: In this study silica- and alkoxysilane-coated ultrasmall superparamagnetic iron oxide (USPIO) particles were synthesized, and their ability to label immortalized progenitor cells for magnetic resonance imaging (MRI) was compared. USPIO particles were synthesized by coprecipitation of ferric and ferrous salts. Subsequently, the particles were coated with silica, (3-aminopropyl)trimethoxysilane (APTMS), and [N-(2-aminoethyl)-3-aminopropyl]trimethoxysilane (AEAPTMS). The size of the USPIO particles was about 10 nm without a significant increase in diameter after coating. The highest T-2 relaxivity was achieved for silica-coated USPIO particles, 339.80 +/- 0.22 s(-1) mM(-1), as compared with APTMS- and AEAPTMS-coated ones, reaching 134.40 +/- 0.01 and 84.79 +/- 0.02 s(-1) mM(-1), respectively. No toxic effects on the cells could be detected by trypan blue, TUNEL, and MTS assays. Uptake of USPIO particles was evaluated by Prussian blue staining, transmission electron microscopy, T-2-MR relaxometry, and mass spectrometry. It was found that cell uptake of the different USPIO particles increased for longer incubation times and higher doses. Maximum cellular iron concentrations of 42.1 +/- 4.0 pg/cell (silica-coated USPIO particles), 37.1 +/- 3.5 pg/cell (APTMS-coated USPIO particles), and 32.7 +/- 4.0 pg/cell (AEAPTMS-coated USPIO particles) were achieved after incubation of the cells with USPIO particles at a dose of 3 mu mol/mL for 6 h. The decrease of the T-2 relaxation time of the cell pellets was most pronounced for cells incubated with silica-coated USPIO particles followed by APTMS- and AEAPTMS-coated particles, respectively. In gelatin gels even small clusters of labeled cells were detected by 1.5 T MRI, and significant changes in the T-2 relaxation times of the gels were determined for 10000 labeled cells/mL for all particles. In summary, as compared with APTMS- and AEAPTMS-coated particles, silica-coated USPIO particles provide the highest T-2 relaxivity and most effectively reduce the T-2 relaxation time of immortalized progenitor cells after internalization. This suggests silica-coated USPIO particles are most suited for cell labeling approaches in MRI
    Type of Publication: Journal article published
    PubMed ID: 17241069
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  • 5
    Keywords: RECEPTOR ; APOPTOSIS ; CANCER ; CELLS ; IN-VITRO ; tumor ; AGENTS ; carcinoma ; CELL ; Germany ; IN-VIVO ; INHIBITION ; THERAPY ; VITRO ; VIVO ; SAMPLES ; TUMORS ; TIME ; PATIENT ; INDUCTION ; cell cycle ; CELL-CYCLE ; CYCLE ; treatment ; PROGRESSION ; resistance ; INDUCED APOPTOSIS ; PLASMA ; prostate cancer ; PROSTATE-CANCER ; chemotherapy ; ACUTE LYMPHOBLASTIC-LEUKEMIA ; DERIVATIVES ; HEPATOMA-CELLS ; EPITHELIAL-CELLS ; CARCINOMAS ; PHARMACOKINETICS ; AGENT ; SINGLE ; ONCOLOGY ; RE ; EX-VIVO ; SOLID TUMORS ; MEDIATED APOPTOSIS ; MOLECULAR-MECHANISMS ; LEVEL ; analysis ; methods ; PLASMA-LEVELS ; dexamethasone ; PROMOTION ; USA ; GLUCOCORTICOIDS ; prospective ; in vivo ; clinical study
    Abstract: Background: Glucocorticoids have been used widely in conjunction with cancer therapy due to their ability to induce apoptosis in hematological cells and to prevent nausea and emesis. However, recent data including ours, suggest induction of therapy resistance by glucocorticoids in solid tumors, although it is unclear whether this happens only in few carcinomas or is a more common cell type specific phenomenon. Material and Methods: We performed an overall statistical analysis of our new and recent data obtained with 157 tumor probes evaluated in vitro, ex vivo and in vivo. The effect of glucocorticoids on apoptosis, viability and cell cycle progression under diverse clinically important questions was examined. Results: New in vivo results demonstrate glucocorticoid - induced chemotherapy resistance in xenografted prostate cancer. In an overall statistical analysis we found glucocorticoid - induced resistance in 89% of 157 analysed tumor samples. Resistance is common for several cytotoxic treatments and for several glucocorticoid - derivatives and due to an inhibition of apoptosis, promotion of viability and cell cycle progression. Resistance occurred at clinically achievable peak plasma levels of patients under anti - emetic glucocorticoid therapy and below, lasted for a long time, after one single dose, but was reversible upon removal of glucocorticoids. Two nonsteroidal alternative anti - emetic agents did not counteract anticancer treatment and may be sufficient to replace gluco corticoids in cotreatment of carcinoma patients. Conclusion: These data demonstrate the need for prospective clinical studies as well as for detailed mechanistic studies of GC - induced cell - type specific pro - and anti - apoptotic signalling
    Type of Publication: Journal article published
    PubMed ID: 17224649
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  • 6
    Abstract: The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone co-treatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients.
    Type of Publication: Journal article published
    PubMed ID: 16338063
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  • 7
    Keywords: EXPRESSION ; TUMORS ; ABERRATIONS ; METHYLATION ; EMBRYONIC STEM-CELLS ; MULTIFORME ; HIGH-GRADE GLIOMAS ; TELOMERES ; INTEGRATED GENOMIC ANALYSIS ; ATRX
    Abstract: Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases(1-4). To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (alpha-thalassaemia/mental retardation syndrome X-linked)(5) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres(6,7), were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n = 784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis
    Type of Publication: Journal article published
    PubMed ID: 22286061
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  • 8
    Abstract: BACKGROUND: Glioblastoma (GBM) is the most common and malignant intracranial tumor in adults and currently incurable. To specifically target natural killer (NK) cell activity to GBM, we employed NK-92/5.28.z cells that are continuously expanding human NK cells expressing an ErbB2-specific chimeric antigen receptor (CAR). METHODS: ErbB2 expression in 56 primary tumors, four primary cell cultures, and seven established cell lines was assessed by immunohistochemistry and flow cytometry. Cell killing activity of NK-92/5.28.z cells was analyzed in in vitro cytotoxicity assays. In vivo antitumor activity was evaluated in NOD-SCID IL2Rgamma(null) (NSG) mice carrying orthotopic human GBM xenografts (6 to 11 mice per group) and C57BL/6 mice carrying subcutaneous and orthotopic ErbB2-expressing murine GBM tumors (5 to 8 mice per group). Statistical tests were two-sided. RESULTS: We found elevated ErbB2 protein expression in 41% of primary GBM samples and in the majority of GBM cell lines investigated. In in vitro assays, NK-92/5.28.z in contrast to untargeted NK-92 cells lysed all ErbB2-positive established and primary GBM cells analyzed. Potent in vivo antitumor activity of NK-92/5.28.z was observed in orthotopic GBM xenograft models in NSG mice, leading to a marked extension of symptom-free survival upon repeated stereotactic injection of CAR NK cells into the tumor area (median survival of 200.5 days upon treatment with NK-92/5.28.z vs 73 days upon treatment with parental NK-92 cells, P 〈 .001). In immunocompetent mice, local therapy with NK-92/5.28.z cells resulted in cures of transplanted syngeneic GBM in four of five mice carrying subcutaneous tumors and five of eight mice carrying intracranial tumors, induction of endogenous antitumor immunity, and long-term protection against tumor rechallenge at distant sites. CONCLUSIONS: Our data demonstrate the potential of ErbB2-specific NK-92/5.28.z cells for adoptive immunotherapy of glioblastoma, justifying evaluation of this approach for the treatment of ErbB2-positive GBM in clinical studies.
    Type of Publication: Journal article published
    PubMed ID: 26640245
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  • 9
    Abstract: Chromothripsis is a recently discovered form of genomic instability, characterized by tens to hundreds of clustered DNA rearrangements resulting from a single dramatic event. Telomere dysfunction has been suggested to play a role in the initiation of this phenomenon, which occurs in a large number of tumor entities. Here, we show that telomere attrition can indeed lead to catastrophic genomic events, and that telomere patterns differ between cells analyzed before and after such genomic catastrophes. Telomere length and telomere stabilization mechanisms diverge between samples with and without chromothripsis in a given tumor subtype. Longitudinal analyses of the evolution of chromothriptic patterns identify either stable patterns between matched primary and relapsed tumors, or loss of the chromothriptic clone in the relapsed specimen. The absence of additional chromothriptic events occurring between the initial tumor and the relapsed tumor sample points to telomere stabilization after the initial chromothriptic event which prevents further shattering of the genome.
    Type of Publication: Journal article published
    PubMed ID: 26856307
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  • 10
    Abstract: Epidermal growth factor receptor (EGFR) and its mutant form EGFRvIII are overexpressed in a large proportion of glioblastomas (GBM). Immunotherapy with an EGFRvIII-specific vaccine has shown efficacy against GBM in clinical studies. However, immune escape by antigen-loss variants and lack of control of EGFR wild-type positive clones limit the usefulness of this approach. Chimeric antigen receptor (CAR)-engineered natural killer (NK) cells may represent an alternative immunotherapeutic strategy. For targeting to GBM, we generated variants of the clinically applicable human NK cell line NK-92 that express CARs carrying a composite CD28-CD3zeta domain for signaling, and scFv antibody fragments for cell binding either recognizing EGFR, EGFRvIII, or an epitope common to both antigens. In vitro analysis revealed high and specific cytotoxicity of EGFR-targeted NK-92 against established and primary human GBM cells, which was dependent on EGFR expression and CAR signaling. EGFRvIII-targeted NK-92 only lysed EGFRvIII-positive GBM cells, while dual-specific NK cells expressing a cetuximab-based CAR were active against both types of tumor cells. In immunodeficient mice carrying intracranial GBM xenografts either expressing EGFR, EGFRvIII or both receptors, local treatment with dual-specific NK cells was superior to treatment with the corresponding monospecific CAR NK cells. This resulted in a marked extension of survival without inducing rapid immune escape as observed upon therapy with monospecific effectors. Our results demonstrate that dual targeting of CAR NK cells reduces the risk of immune escape and suggest that EGFR/EGFRvIII-targeted dual-specific CAR NK cells may have potential for adoptive immunotherapy of glioblastoma.
    Type of Publication: Journal article published
    PubMed ID: 27141401
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