Mature dendritic cells (DCs) represent cellular adjuvants for optimal antigen presentation in cancer vaccines. Recently, a combination of prostaglandin E (PGE) with Toll-like receptor agonists (TLR-P) was proposed as a new standard to generate superior cytokine-producing DCs with high migratory capacity. Here, we compare TLR-P DCs with conventional DCs matured only with the proinflammatory cytokines TNFα and IL-1ß (CDCs), focussing on the interaction of resulting DCs with CD8 T-cells.
View Article and Find Full Text PDFHigh-grade gliomas (HGG) exert systemic immunosuppression, which is of particular importance as immunotherapeutic strategies such as therapeutic vaccines are increasingly used to treat HGGs. In a first cohort of 61 HGG patients we evaluated a panel of 30 hematological and 34 plasma biomarkers. Then, we investigated in a second cohort of 11 relapsed HGG patients receiving immunomodulation with metronomic cyclophosphamide upfront to a DC-based vaccine whether immune abnormalities persisted and whether they hampered induction of IFNγ T-cell responses.
View Article and Find Full Text PDFBackground Aims: CD8(+) T cells are part of the adaptive immune system and, as such, are responsible for the elimination of tumor cells. Dendritic cells (DC) are professional antigen-presenting cells (APC) that activate CD8(+) T cells. Effector CD8(+) T cells in turn mediate the active immunotherapeutic response of DC vaccination against the aggressive glioblastoma (GBM).
View Article and Find Full Text PDFBackground Aims: Atypical rhabdoid/teratoid tumors (AT/RT) are the most common brain tumors in infants and associated with a dismal prognosis. Although intensification of first-line therapy has resulted in improvement of overall survival, novel treatment strategies are needed. Because immunotherapy has resulted in remarkable results in several adult tumor entities, incorporation of immunotherapy into AT/RT treatment offers a novel alternative.
View Article and Find Full Text PDFAim: To characterize molecular mechanisms underlying photocatalytic cell death of head and neck squamous cell carcinoma (HNSCC) by zinc oxide nanoparticles (ZnO-NPs).
Materials & Methods: Human HNSCC-derived FaDu cells were incubated with ZnO-NPs followed by UVA-1 irradiation. Cytotoxicity was assessed by MTT assay and annexin-V propidium iodide test.
Background Aims: Adipose-derived stem cells (ASCs) are a promising mesenchymal cell source for tissue engineering approaches. To obtain an adequate cell amount, in vitro expansion of the cells may be required in some cases. To monitor potential contraindications for therapeutic applications in humans, DNA strand breaks and chromosomal aberrations in ASCs during in vitro expansion were examined.
View Article and Find Full Text PDFNanoparticles (NPs) are frequently applied in biomedical applications. The use of human mesenchymal stem cells (hMSC) in biomedicine is pivotal, especially in oncology and tissue engineering. Titanium dioxide (TiO2) and zinc oxide (ZnO) NPs are interesting agents in experimental oncology and stem cells are discussed to be a potential vehicle for NPs to tumor sites.
View Article and Find Full Text PDFIntroduction: Adipose tissue-derived stem cells (ASCs) have become the primary focus of tissue engineering research. To understand their functions and behavior in in vitro and in vivo models, it is mandatory to track the implanted cells and distinguish them from the resident or host cells. A common labeling method is the use of fluorescent dyes, e.
View Article and Find Full Text PDFVarious hypotheses on the origin of cancer stem cells (CSCs) exist, including that CSCs develop from transformed human bone marrow mesenchymal stem cells (hBMSC). Since the polyether antibiotic salinomycin selectively kills CSCs, the present study aims to elucidate the effects of salinomycin on normal hBMSC. The immunophenotype of hBMSC after salinomycin exposure was observed by flow cytometry.
View Article and Find Full Text PDFStrahlenther Onkol
January 2013
Background And Purpose: Osteopontin (OPN) is a multifunctional protein overexpressed in many cancers and is involved in tumor progression and metastasis. In lung cancer, elevated OPN expression is associated with an unfavorable prognosis. Therefore, inhibition of OPN is an attractive approach for improving survival.
View Article and Find Full Text PDFIntroduction: Chondrogenic differentiation of adipose-derived stem cells (ASCs) has proven to be feasible. To compensate for laryngeal palsy or cartilage defects after surgery or trauma using tissue engineering, a formable and stable scaffold material is mandatory.
Methods: ASCs were seeded in fibrin-polyurethane scaffolds and cultured in chondrogenic differentiation medium adding the growth factors TGF-b1, TGF-b3, and BMP-2 for up to 35 days.
After surgery, wound healing begins with a well-orchestrated integration of several cytokines, cells, and extracellular matrix. Some studies show an involvement of stem cells in wound healing. However, little is known about the mechanism that leads to the migration of stem cells.
View Article and Find Full Text PDFDespite increasing application of zinc oxide nanoparticles (ZnO-NPs) for industrial purposes, data about potential toxic properties is contradictory. The current study focused on the cyto- and genotoxicity of ZnO-NPs in comparison to ZnO powder in primary human nasal mucosa cells cultured in the air-liquid interface. Additionally, IL-8 secretion as a marker for pro-inflammatory effects was measured.
View Article and Find Full Text PDFSilver nanoparticles (Ag-NPs) are the most frequent commercialized nanomaterial currently. Due to a distinct lack of information on hazardous properties of Ag-NPs in human cells, a study was conducted to evaluate Ag-NP induced DNA damage, cell death and functional impairment in human mesenchymal stem cells (hMSCs). Initially, Ag-NPs and their cellular distribution were characterized by transmission electron microscopy (TEM).
View Article and Find Full Text PDFORL J Otorhinolaryngol Relat Spec
May 2011
Multipotent stromal cells have become of increasing interest due to their potential to provide therapeutic approaches for autologous tissue repair. However, these cells are not well defined in the guinea pig, which represents an important model in hearing research. Adipose-tissue-derived stem cells (ADSC) and bone-marrow-derived stem cells (BMSC) were isolated from different donor sites, and growth curves were generated to judge the proliferation potential.
View Article and Find Full Text PDFBackground Aims: The chondrogenic differentiation potential of mesenchymal stromal cells (MSC), as well as their immunosuppressive properties, have been studied extensively. So far, only a few studies have addressed the question of whether MSC still retain their immunosuppressive qualities after transdifferentiation. In particular, the expression of immunogenic markers, such as human leukocyte antigen (HLA)-DR, after differentiation has never been investigated.
View Article and Find Full Text PDFA growing number of studies are reporting beneficial effects of the transplantation of alleged cardiac stem cells into diseased hearts after myocardial infarction. However, the mechanisms by which transplanted cells might help to promote repair of cardiac tissue are not understood and might involve processes different from the differentiation of transplanted cells into cardiomyocytes. We have compared the effects exerted by skeletal myoblasts (which are not able to form new cardiomyocytes) and ESC-derived cardiomyocytes after implantation into infarcted mouse hearts by echocardiographic follow-up and histological analysis and related these effects to the release of cardioactive cytokines.
View Article and Find Full Text PDFDuring embryogenesis, various cell types can be programmed by potent inducers to follow distinct differentiation paths. In adult life, this ability seems to be restricted to specific multipotent cells. We have identified two cell populations from adult murine bone marrow which express various "stemness" genes.
View Article and Find Full Text PDFMesenchymal stem cells (MSCs) or mesenchymal adult stem cells (MASCs) that are present in the stroma of several organs have been proposed to contribute to the regeneration of different tissues including liver, blood, heart, and skeletal muscle. Yet, it remains unclear whether MSCs can be programmed to differentiate cell-autonomously into fully functional cells or whether they are recruited by surrounding cells via fusion and thereby acquire specialized cellular functions. Here, we demonstrate that Wnt signaling molecules activate the expression of distinct sets of genes characteristic for cardiac and skeletal muscle cells in MASCs.
View Article and Find Full Text PDFNeuroblastoma (NB) cells reportedly accumulate wild-type p53 exclusively in the cytoplasm. However, immunofluorescence assays with five different antibodies showed that p53 accumulates in the nucleus of up to 10% of NB cells. PAb1801 detected cytoplasmic 'punctate structures' which were also found in p53-null cells, rendering this antibody unsuitable for p53 detection.
View Article and Find Full Text PDFHuman SV40-transformed cells contain high levels of stabilized p53 of which only a fraction is complexed with the SV40 large tumor antigen (T-antigen). This raises the question whether the p53 which is not complexed with T-antigen retains some biological activity. Two human SV40-transformed cell lines, BEAS and SV80, were investigated.
View Article and Find Full Text PDFStimulation of NIH3T3 cells with platelet-derived growth factor (PDGF)-BB enhances expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen and a key mediator of tumor angiogenesis. Here, we identified cis-acting VEGF promoter elements and trans-acting factors which are involved in PDGF-stimulated VEGF expression. By 5'-deletion and transient transfection analysis, a G + C-rich region at -85 to -50 of the human VEGF promoter was shown to be necessary and sufficient for both PDGF inducible and basal expression.
View Article and Find Full Text PDFEpothilone A, a novel macrolide antibiotic, is produced by the myxobacterium Sorangium cellulosum. Similarly to paclitaxel (Taxol), epothilone A inhibits cell proliferation and induces apoptosis by binding to tubulin and stabilizing of microtubuli. Like paclitaxel, epothilone A induced apoptosis in neuroblastoma cells which exhibit constitutive cytoplasmic sequestration of p53 and, hence, an impaired DNA-damage-dependent apoptosis.
View Article and Find Full Text PDFIn this study, we investigated the functional role of the transcription factor AP-1 in hypoxia-induced expression of the vascular endothelial growth factor (VEGF) by using dexamethasone as an inhibitor of AP-1 activity. Phorbol ester and platelet-derived growth factor (PDGF) cause an increase in VEGF mRNA expression, which is strongly suppressed in the presence of dexamethasone, whereas hypoxia-induced VEGF expression is not inhibited by dexamethasone. Studies using a VEGF promoter luciferase construct show that the phorbol ester and PDGF-induced VEGF expression is mediated at least in part by transcriptional activation of the VEGF promoter, whereas no transcriptional activation is seen under hypoxic conditions.
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