Mesenchymal stem cells (MSCs) possess self-renewal and multipotential differentiation abilities, and they are thought to be one of the most reliable stem cell sources for a variety of cell therapies. Recently, cell therapy using MSCs has been studied as a novel therapeutic approach for cancers that show refractory progress and poor prognosis. MSCs from different tissues have different properties. However, the effect of different MSC properties on their application in anticancer therapies has not been thoroughly investigated. In this study, to characterize the anticancer therapeutic application of MSCs from different sources, we established two different kinds of human MSCs: umbilical cord blood-derived MSCs (UCB-MSCs) and adipose-tissue-derived MSCs (AT-MSCs). We used these MSCs in a coculture assay with primary glioblastoma multiforme (GBM) cells to analyze how MSCs from different sources can inhibit GBM growth. We found that UCB-MSCs inhibited GBM growth and caused apoptosis, but AT-MSCs promoted GBM growth. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling assay clearly demonstrated that UCB-MSCs promoted apoptosis of GBM via tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL was expressed more highly by UCBMSCs than by AT-MSCs. Higher mRNA expression levels of angiogenic factors (vascular endothelial growth factor, angiopoietin 1, platelet-derived growth factor, and insulin-like growth factor) and stromal-derived factor-1 (SDF-1/CXCL12) were observed in AT-MSCs, and highly vascularized tumors were developed when ATMSCs and GBM were cotransplanted. Importantly, CXCL12 inhibited TRAIL activation of the apoptotic pathway in GBM, suggesting that AT-MSCs may support GBM development in vivo by at least two distinct mechanisms-promoting angiogenesis and inhibiting apoptosis. The opposite effects of AT-MSCs and UCBMSCs on GBM clearly demonstrate that differences must be considered when choosing a stem cell source for safety in clinical application.

Umbilical cord blood (UCB) has been used as a potential source of various kinds of stem cells, including hematopoietic stem cells, mesenchymal stem cells, and endothelial progenitor cells (EPCs), for a variety of cell therapies. Recently, EPCs were introduced for restoring vascularization in ischemic tissues. An appropriate procedure for isolating EPCs from UCB is a key issue for improving therapeutic efficacy and eliminating the unexpected expansion of nonessential cells. Here we report a novel method for isolating EPCs from UCB by a combination of negative immunoselection and cell culture techniques. In addition, we divided EPCs into 2 subpopulations according to the aldehyde dehydrogenase (ALDH) activity. We found that EPCs with low ALDH activity (Alde-Low) possess a greater ability to proliferate and migrate compared to those with high ALDH activity (Alde- High IntroductionEndothelial progenitor cells (EPCs) were originally identified as a population of stem cells in human peripheral blood (PB) and characterized by the expression of CD34, KDR (VEGFR-2), and CD133 markers. 1-3 Subsequently, EPCs have been isolated from other sources, such as bone marrow (BM), fetal liver, and umbilical cord blood (UCB). [4][5][6] Recent studies have shown that EPCs are a potential tool for therapeutic angiogenesis in the treatment of patients suffering from severe limb ischemia or myocardial infarction. 7 EPCs have been identified as contributors to vessel development in both normal physiological processes such as wound healing and pathological processes such as cancer. 8 The definition of an EPC has been controversial and hence the method to isolate EPCs has been variable among investigators. 9 Several studies have demonstrated that there are 2 distinct types of EPCs, the so-called early and late EPCs, which appear sequentially. 10 Early EPCs, likely originating from monocytic/dendritic cells, are characterized by the expression of CD45 and CD14, together with some endothelial cell (EC) markers, and have a short lifespan of 3 to 4 weeks. On the other hand, late EPCs rapidly grow out from mononuclear cells with a cobblestone-like morphology and are characterized by EC markers such as CD31, CD34, VEGFR2, and VE-cadherin, but are negative for myeloid markers. 10 However, Yoder et al have recently demonstrated that progeny of the CD45 ϩ CD14 ϩ cells that coexpress EC markers are not endothelial progenitor cells but hematopoietic-derived myeloid progenitor cells. 11 Alternatively, Ingram et al divided ECs into several subpopulations according to their clonogenic and proliferative potential. 12 They identified a population of highly proliferative endothelial potential-colony-forming cells (HPP-ECFCs), which form secondary and ternary colonies in human UCB. Given the therapeutic usefulness of EPCs, the effective isolation of highly proliferative EPCs is centrally important for the generation of reliable and safe cell-based therapy.Aldehyde dehydrogenase (ALDH) is an enzyme responsible for oxidizing intercellular aldehydes. 13 This ...

Two laws aiming to provide a new legal framework to promote regenerative medicine, while ensuring the efficacy and safety of the treatments, came into effect in Japan on November 25, 2014. The scope of these laws is briefly described here.

Rationale: New strategies in the field of cardiac regeneration are directed at identifying proliferation-inducing substances to induce regrowth of myocardium. Current screening assays utilize neonatal cardiomyocytes and markers for cytokinesis, such as Aurora B-kinase. However, detection of cardiomyocyte division is complicated because of cell cycle variants, in particular, binucleation. Objective: To analyze the process of cardiomyocyte binucleation to identify definitive discriminators for cell cycle variants and authentic cardiomyocyte division. Methods and Results: Herein, we demonstrate by direct visualization of the contractile ring and midbody in Myh6 (myosin, heavy chain 6)-eGFP (enhanced green fluorescent protein)-anillin transgenic mice that cardiomyocyte binucleation starts by formation of a contractile ring. This is followed by irregular positioning of the midbody and movement of the 2 nuclei into close proximity to each other. In addition, the widespread used marker Aurora B-kinase was found to also label binucleating cardiomyocytes, complicating the interpretation of existing screening assays. Instead, atypical midbody positioning and the distance of daughter nuclei on karyokinesis are bona fide markers for cardiomyocyte binucleation enabling to unequivocally discern such events from cardiomyocyte division in vitro and in vivo. Conclusions: The 2 criteria provide a new method for identifying cardiomyocyte division and should be considered in future studies investigating cardiomyocyte turnover and regeneration after injury, in particular in the postnatal heart to prevent the assignment of false positive proliferation events.