StemCellGateway.net

Author(s): Satoshi Hashino

Abstract:

A 27-year-old man with advanced colon cancer that was resistant to conventional chemoradiotherapies was treated with reduced-intensity allogeneic peripheral blood stem cell transplantation (PBSCT). After obtaining complete donor-type chimerism, there was an apparent graft-versus-tumor effect accompanied by severe hepatic graft-versus-host disease (GVHD) showing hyperbilirubinemia, resulting in a stable disease condition that lasted for 18 months, which had not been seen previously in his previous disease history. The antitumor effect observed in this patient was insuffi cient for the patient to achieve complete remission, because the disease was at an already widespread and treatment-resistant stage. He fi nally died of hepatic failure due to extensive liver GVHD 65 months after the diagnosis of the advanced colon cancer and 29 months after the allogeneic PBSCT. Prospective studies are necessary to achieve better clinical results in patients with advanced colon cancer.

Author(s): Letterio S. Politi

Abstract:

The efficacy of therapies based on neural stem cells (NSC) has been demonstrated in preclinical models of several central nervous system (CNS) diseases. Before any potential human application of such promising therapies can be envisaged, there are some important issues that need to be solved. The most relevant one is the requirement for a noninvasive technique capable of monitoring NSC delivery, homing to target sites and trafficking. Knowledge of the location and temporospatial migration of either transplanted or genetically modified NSC is of the utmost importance in analyzing mechanisms of correction and cell distribution, Further, such a technique may represent a crucial step toward clinical application of NSC-based approaches in humans, for both designing successful protocols and monitoring their outcome. Among the diverse imaging approaches available for noninvasive cell tracking, such as nuclear medicine techniques, fluorescence and bioluminescence, magnetic resonance imaging (MRI) has unique advantages. Its high temporospatial resolution, high sensitivity and specificity render MRI one of the most promising imaging modalities available, since it allows dynamic visualization of migration of transplanted cells in animal models and patients during clinically useful time periods. Different cellular and molecular labeling approaches for MRI depiction of NSC are described and discussed in this review, as well as the most relevant issues to be considered in optimizing molecular imaging techniques for clinical application.

Author(s): Kenichi Teramoto

Abstract:

With the development of regeneration medicine, many researchers have attempted hepatic differentiation from nonhepatic-origin cell sources. The differentiation of embryonic stem (ES) cells into hepatocyte-like cells has been reported in several papers. Mouse ES cells have shown a potential to develop into hepatocyte-like cells in vitro on the basis of hepatic gene expression after adding several growth factors. We transplanted cultured embryoid body (EB) cells (male) into female mice. A liver specimen of the recipient was examined by immunohistochemical staining for albumin and fluorescence in situ hybridization for the Y chromosome after transplantation. Both Y chromosome- and albumin-positive cells were recognized in the recipient female liver, and were considered to be hepatocyte-like cells derived from ES cells containing the Y chromosome. Many groups, including ourselves, have studied hepatocyte-like cell differentiation from umbilical cord blood cells (UBCs). We cultured nucleated cells isolated from UBCs. Using immunostaining, ALBpositive and CK-19-positive cells were recognized in the culture. Dual staining of ALB and CK-19 demonstrated that ALB was coexpresed with CK-19, suggesting the existence of hepatic progenitors. In this review, we consider recent studies of the differentiation of hepatocytes from nonhepatic origins, especially ES cells and umbilical cord blood.

Author(s): S. Gronthos

Abstract:

 

Periodontal disease leads to destruction of the connective tissues responsible for restraining teeth within the jaw. To date, various conventional therapies for periodontal regeneration have shown limited and variable clinical outcomes. Recent studies have suggested that newly identified human periodontal ligament stem cells (PDLSCs) may offer an alternate and more reliable strategy for the treatment of periodontal disease using a cell-based tissue engineering approach. In the PDLSCs derived from ovine periodontal ligament using immunomagnetic bead selection, based on expression of the mesenchymal stem cell-associated antigen CD106 (vascular cell adhesion molecule 1). These CD106⁺ ovine PDLSCs demonstrated the capacity to form adherent clonogenic clusters of fibroblast-like cells when plated at low densities in vitro. Ex vivo- expanded ovine PDLSCs exhibited a high proliferation rate in vitro expressed a phenotype (CD44^+_, CD166^+_,CBFA-1⁺, collagen-I⁺ bone sialoprotein⁺) consistent with human- derived PDLSCs. Furthermore, cultured ovine PDLSCs expressed high transcript levels of the ligament/ tendon-specific early transcription factor scleraxis. Importantly, ex vivo- expanded ovine PDLSCs demonstrated the capacity to regenerate both cementum-like mineral and periodontal ligament when transplanted into NOD/SCID mice. The results from the present study suggest that ovine PDLSCs may potentially be used as a novel cellular therapy to facilitate successful and more predictable regeneration of periodontal tissue using an ovine preclinical model of periodontal disease as a prelude to human clinical studies.

 

Author(s): Virginie Sottile

Abstract: Recent publications have suggested the existence of germ stem cells in the mouse at postnatal stages. The mechanism of de novo oocyte formation is proposed to involve a contribution from the bone marrow to the germ cell pool, via the bloodstream. Critical examination of the data underpinning these contentious claims is under way from a reproductive biology perspective but little has been said about the nature of this elusive bone marrow population with germ cell potential. Furthermore, whereas the prospect of marrow-derived germ cells may appear propitious for fertility applications, its wider impact on transplantation medicine remains to be considered. This paper examines the evidence leading to the current debate and considers the implications of such findings for the field of bone marrow transplantation.

Author(s): Shikhar Vohra

Abstract:

Immortalized  cells are often used to model the behavior of osteogenic cells on orthopaedic and dental biomaterials. In the current study we compared the adhesive behavior of two osteosarcoma cell lines, MG-63 and Saos-2, with that of mesenchymal stem cells (MSCs) on hydroxyapatite (HA). It was found that osteosarcoma cells demonstrated maximal binding to fibronectin-coated HA, while MSCs alternately preferred HA coated with collagen-I. Interesting, the binding of MG-63 and Saos-2 cells to fibronectin was mediated by both α5 and αv-containing integrin heterodimers, whereas only v integrins were used by MSCs. Cell spreading was also markedly different for the three cell types. Osteosarcoma cells exhibited optimal spreading on fibronectin, but poor spreading on HA disks coated with fetal bovine serum. In contrast, MSCs spread very well on serumcoated surfaces, but less extensively on fibronectin. Finally, we evaluated integrin expression and found that MSCs have higher levels of 2 integrin subunits relative to MG-63 or Saos-2 cells, which may explain the enhanced adhesion of MSCs on collagen-coated HA. Collectively our results suggest that osteosarcoma cells utilize different mechanisms than MSCs during initial attachment to protein-coated HA thereby calling into question the suitability of these cell lines as in vitro models for cell/biomaterial interactions.

 

Author(s): M. Engelhardt

Abstract:

Purpose Despite the availability of combined-modality treatment for Ewing sarcoma (ES) and soft tissue sarcomas (STS), results from independent groups still indicate a poor prognosis for high-risk and metastasized patients. The benefit of high-dose chemotherapy (HDCT) with autologous peripheral blood stem cell transplantation (ASCT) as compared to standard treatment is not defined.
 Methods Here, we report of HDCT in 35 consecutive adult patients with poor-risk ES or rhabdomyosarcoma (n = 11) and STS (n = 24) undergoing ASCT between July 1992 and March 2003. At a median follow-up of 100.6 months after ASCT, 11 patients are alive, with nine in sustained complete remission (CR) and each one in partial remission (PR) and stable disease. Median overall survival (OS) from ASCT was 17.1 months. Response to pretreatment, Karnofsky index > 80%, R₀ resection and first-line ASCT were associated with long-term OS (p < 0.05).
Conclusion These data indicate that (1) patients achieving a CR or PR following induction, with preserved performance status and  R₀ resection may benefit from ASCT and (2) that this can be an useful therapeutic modality in a subset of patients, in some achieving remarkable responses.

Author(s): Kazuhiro Ikegame

Abstract: We present a case of adenovirus (ADV) infection in a patient who had undergone nonmyeloablative stem cell transplantation (NST). A 50-year-old man with chronic myelogenous leukemia in the second chronic phase underwent NST from an HLA 2-loci–mismatched sibling. ADV hemorrhagic cystitis developed and progressed to lethal pneumonia.ADV was isolated from urine, bronchoalveolar lavage fluid, and postmortem specimens of kidney and liver. Because there are few reports of lethal pneumonia associated with ADV in Japan, we present the case and discuss the cause of and therapy for the infection.

Author(s): I. I. Selezneva

Author(s): Seng Cheong Loke

Abstract: Very few registries worldwide focus on clinical outcomes of stem cell therapy (SCT) as the large number of applications and rapid development of the field complicates registry design considerably. The National Stem Cell Therapy Patient Registry of Malaysia aims to accommodate this by using a main protocol which covers the overall design and administration of the registry, and condition-specific sub-protocols which deal with outcome measures. The registry will start with a few sub-protocols covering existing modes of SCT in Malaysia, with new sub-protocols released periodically as the need arises.

Author(s): Minal Patel

Abstract: Traditionally, nuclear reprogramming of cells has been performed by transferring somatic cell nuclei into oocytes, by combining somatic and pluripotent cells together through cell fusion and through genetic integration of factors through somatic cell chromatin. All of these techniques changes gene expression which further leads to a change in cell fate. Here we discuss recent advances in generating induced pluripotent stem cells, different reprogramming methods and clinical applications of iPS cells. Viral vectors have been used to transfer transcription factors (Oct4, Sox2, c-myc, Klf4, and nanog) to induce reprogramming of mouse fibroblasts, neural stem cells, neural progenitor cells, keratinocytes, B lymphocytes and meningeal membrane cells towards pluripotency. Human fibroblasts, neural cells, blood and keratinocytes have also been reprogrammed towards pluripotency. In this review we have discussed the use of viral vectors for reprogramming both animal and human stem cells. Currently, many studies are also involved in finding alternatives to using viral vectors carrying transcription factors for reprogramming cells. These include using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. Applications of these techniques have been discussed in detail including its advantages and disadvantages. Finally, current clinical applications of induced pluripotent stem cells and its limitations have also been reviewed. Thus, this review is a summary of current research advances in reprogramming cells into induced pluripotent stem cells.

Author(s): José Becerra

Abstract: Recent advances in stem cell research have highlighted the role played by such cells and their environment (the stem cell niche) in tissue renewal and homeostasis. The control and regulation of stem cells and their niche are remaining challenges for cell therapy and regenerative medicine on several tissues and organs. These advances are important for both, the basic knowledge of stem cell regulation, and their practical translational applications into clinical medicine. This article is primarily concerned with the mesenchymal stem cells (MSCs) and it reviews the current aspects of their own niche. We discuss on the need for a deeper understanding of the identity of this cell type and its microenvironment in order to improve the effectiveness of any cell therapy for regenerative medicine. Ex vivo reproduction of the conditions of the natural stem cell niche, when necessary, would provide success to tissue engineering. The first challenge of regenerative medicine is to find cells able to replace and/or repair the lost function of tissues and organs by disease or aging and the trophic and immunomodulatory effects recently found for MSCs open up for new opportunities. If MSCs are pericytes, as it has been proposed, perhaps it may explain the ubiquity of these cells and their possible role in miscellaneous repairs throughout the body opening for new chances for extensive tissue repair.