'Cancer stem cells' (CSCs) are tumor cells with stem cell properties hypothesized to be responsible for tumorigenesis, metastatis, and resistance to treatment, and have been identified in different tumors including cutaneous melanoma, using stem cell markers such as CD133. This study explored expression of CD133 and other putative stem cell markers in uveal melanoma. Eight uveal melanoma cell lines were subjected to flow-cytometric (fluorescence-activated cell sorting) analysis of CD133 and other stem cell markers. Eight paraffin-embedded tumors were analyzed by immunohistochemistry for CD133, Pax6, Musashi, nestin, Sox2, ABCB5, and CD68 expressions. Ocular, uveal melanoma, and hematopoietic stem cell distributions of C-terminal and N-terminal CD133 mRNA splice variants were compared by reverse-transcription PCR. Fluorescence-activated cell sorting analysis revealed a population of CD133-positive/nestin-positive cells in cell lines Mel270, OMM 2.3, and OMM2.5. All cell lines studied were positive for nestin, CXCR-4, CD44, and c-kit. Immunohistochemistry identified cells positive for CD133, Pax6, Musashi, nestin, Sox2, ABCB5, and CD68 predominantly at the invading tumor front. C-terminal primers interacting with CD133 splice variant s2 detected a novel variant lacking exon 27. Differential expression of CD133 splice variants was found in iris, ciliary body, retina, and retinal pigment epithelium/choroid as well as in uveal melanoma cell lines. mRNA for nestin, Sox2, and Musashi was present in all studied cell lines. Uveal melanoma such as cutaneous melanoma may therefore contain CSCs. Further experiments are needed to isolate stem cell marker-positive cells, to evaluate their functional properties and to explore therapeutical approaches to these putative CSCs in uveal melanoma.

Worldwide, cardiovascular disease results in an estimated 14.3 million deaths per year, giving rise to an increased demand for alternative and advanced treatment. Current approaches include medical management, cardiac transplantation, device therapy, and, most recently, stem cell therapy. Research into cell-based therapies has shown this option to be a promising alternative to the conventional methods. In contrast to early trials, modern approaches now attempt to isolate specific stem cells, as well as increase their numbers by means of amplifying in a culture environment. The method of delivery has also been improved to minimize the risk of micro-infarcts and embolization, which were often observed after the use of coronary catheterization. The latest approach entails direct, surgical, transepicardial injection of the stem cell mixture, as well as the use of tissue-engineered meshes consisting of embedded progenitor cells.

Transplantation of bone marrow derived stem cells is currently being used as a therapy for ischemic heart disease. An important aspect in clinical studies is the inability to track the fate of the transplanted cells. In this study, our aim was to assess a clinically applicable technique by using 1.5-Tesla Magnetic Resonance Imaging [MRI] of nano-particle labeled, transplanted bone marrow derived mononuclear cells (MNCs) in a porcine model of myocardial infarction.

CD133+ cells are hemangioblasts that have capacity to generate into both hematopoietic and endothelial cells (ECs). Hypoxia/normoxia has shown to be the regulator of the balance between stemness and differentiation. In this study we performed Agilent's whole human genome oligo microarray analysis and examined the differentiation potential of the bone-marrow-derived CD133+ cells after hypoxic/normoxic preconditioning of CD133+ cells. Results showed that there was no significant increase in erythroid colony forming unit (CFU-E) and CFU-granulocyte, erythrocyte, monocyte, and megakaryocyte formation with cells treated under hypoxia/normoxia. However, a significant increment of EC forming unit at 24 h (143.2 +/- 8.0%) compared to 0 h (100 +/- 11.4%) was observed in CFU-EC analysis. Reverse transcription-polymerase chain reaction and immunostaining analysis showed that the differentiated cells diminished hematopoietic stem cell surface markers and acquired the gene markers and functional phenotype of ECs. The transcriptome profile revealed a cluster of 232 downregulated and 498 upregulated genes in cells treated for 24 h under hypoxia. The upregulated genes include angiogenic genes, angiogenic growth factor genes, angiogenic cytokine and chemokine genes, as well as angiogenic-positive regulatory genes, including FGFBP1, PDGFB, CCL15, CXCL12, CXCL6, IL-6, PTN, EREG, ERBB2, EDG5, FGF3, FHF2, GDF15, JUN, L1CAM, NRG1, NGFR, and PDGFB. On the other hand, angiogenesis inhibitors and related genes, including IL12A, MLLT7, STAB1, and TIMP2, are downregulated. Taken together, hypoxic/normoxic preconditioning may lead to the differentiation of CD133+ cells toward endothelial lineage, which may improve the current clinical trial studies.

BACKGROUND:Dendritic cells (DCs) are applied worldwide in several clinical studies of immune therapy of malignancies, autoimmune diseases, and transplantations. Most legislative bodies are demanding high standards for cultivation and transduction of cells. Closed-cell cultivating systems like cell culture bags would simplify and greatly improve the ability to reach these cultivation standards. We investigated if a new polyolefin cell culture bag enables maturation and adenoviral modification of human DCs in a closed system and compare the results with standard polystyrene flasks.STUDY DESIGN AND METHODS:Mononuclear cells were isolated from HLA-A*0201-positive blood donors by leukapheresis. A commercially available separation system (CliniMACS, Miltenyi Biotec) was used to isolate monocytes by positive selection using CD14-specific immunomagnetic beads. The essentially homogenous starting cell population was cultivated in the presence of granulocyte-macrophage-colony-stimulating factor and interleukin-4 in a closed-bag system in parallel to the standard flask cultivation system. Genetic modification was performed on Day 4. After induction of maturation on Day 5, mature DCs could be harvested and cryopreserved on Day 7. During the cultivation period comparative quality control was performed using flow cytometry, gene expression profiling, and functional assays.RESULTS:Both flasks and bags generated mature genetically modified DCs in similar yields. Surface membrane markers, expression profiles, and functional testing results were comparable. The use of a closed-bag system facilitated clinical applicability of genetically modified DCs.CONCLUSIONS:The polyolefin bag-based culture system yields DCs qualitatively and quantitatively comparable to the standard flask preparation. All steps including cryopreservation can be performed in a closed system facilitating standardized, safe, and reproducible preparation of therapeutic cells.

Objectives: Transplantation of bone marrow derived cells is currently under clinical evaluation as a therapy for non-ischemic congestive heart disease. An important aspect in clinical studies is the inability to track the fate of the transplanted cells. We aimed to assess a clinically applicable technique using an 3-Tesla Magnetic Resonance Imaging [MRI] and CliniMAC® nano-particle labelled transplanted CD-133+ cells in murine hearts.

Objectives: Hypoxic preconditioning regulates stem cell stemness and differentiation. CD133+ cells were among the first cell types used in clinical trial for cell therapy in myocardial regeneration. CD133+ cells could give rise to both hematopoietic and endothelial cells. In our current study, we investigate the effect of hypoxic treatment on the global transcriptome profile and endothelial differentiation capacity of CD133+ cells.

Objective: HMGB1 protein (High-mobility group box 1) is a DNA-binding protein that mediates inflammatory responses in various organ systems. Recent studies indicate that HMGB1 is a strong chemokine for stem cell recruitment and tissue regeneration after injury. However, the underlying mechanism is still unclear. In this study we aimed to evaluate the effects of extracellular HMGB1 on mesenchymal stem cell migration, proliferation and angiogenesis in vitro and in vivo in rat acute myocardial infarction model by gene therapy approach.

Neural stem cells (NSCs) are potential sources for cell therapy of neurodegenerative diseases and for drug screening. Despite their potential benefits, ethical and practical considerations limit the application of NSCs derived from human embryonic stem cells (ES) or adult brain tissue. Thus, alternative sources are required to satisfy the criteria of ready accessibility, rapid expansion in chemically defined media and reliable induction to a neuronal fate. We isolated somatic stem cells from the human periodontium that were collected during minimally invasive periodontal access flap surgery as part of guided tissue regeneration therapy. These cells could be propagated as neurospheres in serum-free medium, which underscores their cranial neural crest cell origin. Culture in the presence of epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2) under serum-free conditions resulted in large numbers of nestin-positive/Sox-2-positive NSCs. These periodontium-derived (pd) NSCs are highly proliferative and migrate in response to chemokines that have been described as inducing NSC migration. We used immunocytochemical techniques and RT-PCR analysis to assess neural differentiation after treatment of the expanded cells with a novel induction medium. Adherence to substrate, growth factor deprivation, and retinoic acid treatment led to the acquisition of neuronal morphology and stable expression of markers of neuronal differentiation by more than 90% of the cells. Thus, our novel method might provide nearly limitless numbers of neuronal precursors from a readily accessible autologous adult human source, which could be used as a platform for further experimental studies and has potential therapeutic implications.

Objective: Erythropoetin (Epo) has angiogenetic, cytoprotective and anti-inflammatory properties. In this study we investigated the beneficial effect of a local Epoetin-a administration in combination with a mesenchymal stem cell therapy in a rat myocardial infarction model.

Mesenchymal stromal cells (MSCs) are non- hematopoietic multipotent cells which can be derived from bone marrow mononuclear cells either by plastic adherence (PA-MSCs) or by a positive selection with antibodies against cell surface antigens expressed by MSC-progenitor cells (CD271, CD73, CD146, CD105, CD166, SSEA-4 and recently GD2). In this study, we compare the phenotype, proliferation potential, differentiation potential, the cytokine expression pattern and inhibitory potential of MSC- derived by plastic adherence and MSCs derived from positively selected CD271+ bone marrow mononuclear cells (BM-MNCs). According to CFU-F assay, the enriched CD271+ BM cells possess a significantly higher frequency (2952 per 1×106 BM cells) compared to PA-MSCs (21 per 1×106 BM cells). Phenotypically, both populations expressed high levels of common MSC antigens such as CD73, CD105, CD44, CD166, CD90, HLA-Class I and were negative for CD34, CD133, and CD14. Compared to PA-MSCs, CD271+ BM cells after the isolation express high levels of the hematopoietic antigen CD45 which is down- regulated within the first passage and HLA-DR, which remains constant through many passages. These cells have a 10- to 1000-fold higher proliferation capacity compared to PA- MSCs. However, both populations differentiated in vitro along adipogenic, chondrogenic and osteogenic lineage. In MLR, both populations significantly suppressed the proliferation of PHA- stimulated allogeneic T- lymphocytes at the ratio 10: 1 (MSCs:T-cells). However, CD271+ BM- derived MSCs were more efficient in secreting IFN-γ, IL-1β, IL-2, IL-4, GM-CSF and TNF-α, whereas PA- MSCs secreted significantly more IL-6 and IL-8 than CD271+ BM- derived MSCs. Ongoing in vivo studies with immunodeficient NOD/SCID mice will show the whole potential of both population in the improvement of engraftment of mobilized peripheral blood hemaatopoietic CD133+ cells. Based on their higher frequency and proliferation capacity we suggest that CD271+ BM- cells may represent a better source than PA- MSCs in order to generate bulk quantities of MSCs for clinical applications.

Engraftment of mesenchymal stem cells (MSCs) derived from adult bone marrow has been proposed as a potential therapeutic approach for postinfarction left ventricular dysfunction. However, limited cell viability after transplantation into the myocardium has restricted its regenerative capacity. In this study, we genetically modified MSCs with an antiapoptotic Bcl-2 gene and evaluated cell survival, engraftment, revascularization, and functional improvement in a rat left anterior descending ligation model via intracardiac injection. Rat MSCs were manipulated to overexpress the Bcl-2 gene. In vitro, the antiapoptotic and paracrine effects were assessed under hypoxic conditions. In vivo, the Bcl-2 gene-modified MSCs (Bcl-2-MSCs) were injected after myocardial infarction. The surviving cells were tracked after transplantation. Capillary density was quantified after 3 weeks. The left ventricular function was evaluated by pressure-volume loops. The Bcl-2 gene protected MSCs against apoptosis. In vitro, Bcl-2 overexpression reduced MSC apoptosis by 32% and enhanced vascular endothelial growth factor secretion by more than 60% under hypoxic conditions. Transplantation with Bcl-2-MSCs increased 2.2-fold, 1.9-fold, and 1.2-fold of the cellular survival at 4 days, 3 weeks, and 6 weeks, respectively, compared with the vector-MSC group. Capillary density in the infarct border zone was 15% higher in Bcl-2-MSC transplanted animals than in vector-MSC treated animals. Furthermore, Bcl-2-MSC transplanted animals had 17% smaller infarct size than vector-MSC treated animals and exhibited functional recovery remarkably. Our current findings support the premise that transplantation of antiapoptotic gene-modified MSCs may have values for mediating substantial functional recovery after acute myocardial infarction.

Background Siglec-7, a sialic acid binding inhibitory receptor expressed by NK cells is masked in vivo by a so far unknown ligand. It shows a strong binding prevalence for α-2,8-linked disialic acids in vitro . Results Here we describe the expression of PSA-NCAM (α-2,8-linked polysialic acid modified NCAM) on functional adult peripheral blood natural killer cells and examine its possible role in masking Siglec-7. Unmasking of Siglec-7 using Clostridium perfringens neuraminidase massively reduces NK cell cytotoxicity. By contrast a specific removal of PSA using Endo-NF does not lead to a reduction of NK cell cytotoxicity. Conclusion The results presented here therefore indicate that PSA-NCAM is not involved in masking Siglec-7.

We report the case of a 58-year-old man with end-stage non-ischemic cardiomyopathy. Baseline transthoracic echocardiography (TTE) and cardiac magnetic resonance (cMRI) revealed a markedly depressed left ventricle systolic function. He underwent autologous CD133+ BM-derived cell transplantation through a minimally invasive approach. During surgery 19 x 10(6) BM-derived stem cells were injected by the transepimyocardial route. Six months after the operation TTE and cMRI showed a clear improvement in left ventricular contractility.

Neural stem cells are a potential source of cells for cell therapy of neurodegenerative diseases or drug screening. Ethical and practical considerations limit the application of neural stem cells derived from human embryonic stem cells or adult brain tissue. Therefore, alternative sources of adult human neural stem cells are of high interest for basic research as well as potential clinical use. These sources have to satisfy the demands of easy accession, rapid expansion in serum-free media and reliable induction to a neural fate.

Objectives: The pro-angiogenic potential of endothelial and hematopoietic progenitor cells may vary according to their origin and source. Therefore, cells from umbilical cord blood (UCBC) and bone marrow (BMC) have different characteristics. In this study we compared the pro-angiogenic and functional effects of CD133+ UCBCs and BMCs in a myocardial injury NOD/scid mouse model.

Bone marrow remains the most frequently used source of adult stem cells, but its angiogenic and possibly also myogenic potentials are likely to regress with increasing donor age and morbidity. Recently, cord blood has been suggested as a readily available source for non-embryonic stem cells with high regenerative capacity. We first tested the capacity of mononuclear cells obtained from human umbilical cord blood (UCBmn) to migrate to the heart on IV delivery in NOD/Scid mice. As evidenced by the presence of human DNA by PCR analysis, UCBmn cells migrated to the heart in 50% of the mice with myocardial infarctions, but in none of the sham-operated control mice. In UCBmn cell-positive injured hearts, the infarct size was smaller and capillary density higher in the ischemic myocardium. By immunohistology, we observed endothelial cell differentiation of UCBmn cells in the heart but there was no colocalization of UCB cell-specific antibodies with markers of myocyte-type cells. In a second series of experiments, we injected 5 X 10(5) UCB cells enriched for CD133 directly into the necrotic myocardium of NOD/Scid mice. Comparisons were performed with an equivalent number of CD133(+) bone marrow (BM) cells or a sham injection in the respective control groups. Both BMCD133+ and UCBCD133+ cells abolished postoperative mortality and improved capillary density in the injured myocardium, but only BMCD133+ cells led to a detectable improvement in myocardial contractility in vivo. We conclude that human UCB cells facilitated neovascularization of ischemic myocardium, but their capacity for formation of contractile neotissue needs further investigation.