Fibroin-Based Material from Natural Silk Can Be Associated with Alginate and Mesenchymal Progenitor Cells

2008 ◽  
Vol 396-398 ◽  
pp. 437-440 ◽  
Author(s):  
Leandra S. Baptista ◽  
Carolina S.G. Pedrosa ◽  
Karina R. da Silva ◽  
Ronaldo J.F.C do Amaral ◽  
Michele C.L. Kochem ◽  
...  
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Silk Fibroin ◽  
Core Protein ◽  
Stem Cell Differentiation ◽  
Stem Cell Markers ◽  
Mesenchymal Progenitor Cells ◽  
Freeze Dried

Silks are naturally occurring polymers and fibroin, its filament core protein, has been shown to support stem cell differentiation in vitro, and promote tissue repair in vivo. The aim of this study is to develop a biomaterial based on silk-fibroin fibers that can be associated with mesenchymal progenitor cells from human perichondrium in vitro, in order to promote auricular reconstruction in vivo. Silk-fibroin concentrate was dissolved with formic acid solution and freeze-dried in auricular moulds. Fibroin-based material was characterized by scanning electron microscopy and by cytotoxic assays. Perichondrium mesenchymal progenitor cells were characterized by flow cytometry. They expressed the standard mesenchymal stem cell markers, and were able to differentiate into several mesenchymal lineages in vitro. This fibroin-based material is a three-dimensional fibrillar scaffold, non-woven and biocompatible, which was also well integrated with alginate and mesenchymal cells.

scholarly journals Non-Ionizing Radiation for Cardiac Human Amniotic Mesenchymal Stromal Cell Commitment: A Physical Strategy in Regenerative Medicine

2018 ◽  
Vol 19 (8) ◽  
pp. 2324 ◽  
Author(s):  
Mario Ledda ◽  
Enrico D’Emilia ◽  
Maria Lolli ◽  
Rodolfo Marchese ◽  
Claudio De Lazzari ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Therapy ◽  
Adult Stem Cells ◽  
Myocardial Damage ◽  
Stem Cell Differentiation ◽  
Differentiation Markers ◽  
Innovative Strategy ◽  
Cell Commitment

Cell therapy is an innovative strategy for tissue repair, since adult stem cells could have limited regenerative ability as in the case of myocardial damage. This leads to a local contractile dysfunction due to scar formation. For these reasons, refining strategy approaches for “in vitro” stem cell commitment, preparatory to the “in vivo” stem cell differentiation, is imperative. In this work, we isolated and characterized at molecular and cellular level, human Amniotic Mesenchymal Stromal Cells (hAMSCs) and exposed them to a physical Extremely Low Frequency Electromagnetic Field (ELF-EMF) stimulus and to a chemical Nitric Oxide treatment. Physically exposed cells showed a decrease of cell proliferation and no change in metabolic activity, cell vitality and apoptotic rate. An increase in the mRNA expression of cardiac and angiogenic differentiation markers, confirmed at the translational level, was also highlighted in exposed cells. Our data, for the first time, provide evidence that physical ELF-EMF stimulus (7 Hz, 2.5 µT), similarly to the chemical treatment, is able to trigger hAMSC cardiac commitment. More importantly, we also observed that only the physical stimulus is able to induce both types of commitments contemporarily (cardiac and angiogenic), suggesting its potential use to obtain a better regenerative response in cell-therapy protocols.

scholarly journals Human adipose stem cell differentiation is highly affected by cancer cells both in vitro and in vivo: implication for autologous fat grafting

2017 ◽  
Vol 8 (1) ◽  
pp. e2568-e2568 ◽  
Author(s):  
Francesca Paino ◽  
Marcella La Noce ◽  
Diego Di Nucci ◽  
Giovanni Francesco Nicoletti ◽  
Rosa Salzillo ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Stem Cell Differentiation ◽  
Fat Grafting ◽  
Adipose Stem Cell ◽  
Autologous Fat Grafting ◽  
Autologous Fat ◽  
Human Adipose Stem Cell

Involvement of the Integrin Alpha 6 Receptor in the Homing and Engraftment of Hematopoietic Stem and Progenitor Cells to Bone Marrow.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1293-1293
Author(s):  
Hong Qian ◽  
Sten Eirik W. Jacobsen ◽  
Marja Ekblom
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Bone Marrow Cells ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells ◽  
Functional Blocking

Abstract Within the bone marrow environment, adhesive interactions between stromal cells and extracellular matrix molecules are required for stem and progenitor cell survival, proliferation and differentiation as well as their transmigration between bone marrow (BM) and the circulation. This regulation is mediated by cell surface adhesion receptors. In experimental mouse stem cell transplantation models, several classes of cell adhesion receptors have been shown to be involved in the homing and engraftment of stem and progenitor cells in BM. We have previously found that integrin a6 mediates human hematopoietic stem and progenitor cell adhesion to and migration on its specific ligands, laminin-8 and laminin-10/11 in vitro (Gu et al, Blood, 2003; 101:877). Using FACS analysis, the integrin a6 chain was now found to be ubiquitously (>95%) expressed in mouse hematopoietic stem and progenitor cells (lin−Sca-1+c-Kit+, lin−Sca-1+c-Kit+CD34+) both in adult bone marrow and in fetal liver. In vitro, about 70% of mouse BM lin−Sca-1+c-Kit+ cells adhered to laminin-10/11 and 40% adhered to laminin-8. This adhesion was mediated by integrin a6b1 receptor, as shown by functional blocking monoclonal antibodies. We also used a functional blocking monoclonal antibody (GoH3) against integrin a6 to analyse the role of the integrin a6 receptor for the in vivo homing of hematopoietic stem and progenitor cells. We found that the integrin a6 antibody inhibited the homing of bone marrow progenitors (CFU-C) into BM of lethally irradiated recipients. The number of homed CFU-C was reduced by about 40% as compared to cells incubated with an isotype matched control antibody. To study homing of long-term repopulating stem cells (LTR), antibody treated bone marrow cells were first injected intravenously into lethally irradiated primary recipients. After three hours, bone marrow cells of the primary recipients were analysed by competitive repopulation assay in secondary recipients. Blood analysis 16 weeks after transplantation revealed an 80% reduction of stem cell activity of integrin a6 antibody treated cells as compared to cells treated with control antibody. These results suggest that integrin a6 plays an important role for hematopoietic stem and progenitor cell homing in vivo.

Donor Origin of Multipotent Adult Progenitor Cells in Radiation Chimeras.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1395-1395
Author(s):  
Morayma Reyes ◽  
Jeffrey S. Chamberlain
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Y Chromosome ◽  
Stromal Cells ◽  
Mononuclear Cells ◽  
Multipotent Adult Progenitor Cells

Abstract Multipotent Adult Progenitor Cells (MAPC) are bone marrow derived stem cells that can be extensively expanded in vitro and can differentiate in vivo and in vitro into cells of all three germinal layers: ectoderm, mesoderm, endoderm. The origin of MAPC within bone marrow (BM) is unknown. MAPC are believed to be derived from the BM stroma compartment as they are isolated within the adherent cell component. Numerous studies of bone marrow chimeras in human and mouse point to a host origin of bone marrow stromal cells, including mesenchymal stem cells. We report here that following syngeneic bone marrow transplants into lethally irradiated C57Bl/6 mice, MAPC are of donor origin. When MAPC were isolated from BM chimeras (n=12, 4–12 weeks post-syngeneic BM transplant from a transgenic mouse ubiquitously expressing GFP), a mixture of large and small GFP-positive and GFP-negative cells were seen early in culture. While the large cells stained positive for stroma cell markers (smooth muscle actin), mesenchymal stem cell makers (CD73, CD105, CD44) or macrophages (CD45, CD14), the small cells were negative for all these markers and after 30 cell doublings, these cells displayed the classical phenotype of MAPC (CD45−,CD105−, CD44−, CD73−, FLK-1+(vascular endothelial growth factor receptor 2, VEGFR2), Sca-1+,CD13+). In a second experiment, BM obtained one month post BM transplant (n=3) was harvested and mononuclear cells were sorted as GFP-positive and GFP-negative cells and were cultured in MAPC expansion medium. MAPC grew from the GFP-positive fraction. These GFP positive cells displayed the typical MAPC-like immunophenotypes, displayed a normal diploid karyotype and were expanded for more than 50 cell doublings and differentiated into endothelial cells, hepatocytes and neurons. To rule out the possibility that MAPC are the product of cell fusion between a host and a donor cell either in vivo or in our in vitro culture conditions, we performed sex mismatched transplants of female GFP donor BM cells into a male host. BM from 5 chimeras were harvested 4 weeks after transplant and MAPC cultures were established. MAPC colonies were then sorted as GFP-positive and GFP- negative and analyzed for the presence of Y-chromosome by FISH analysis. As expected all GFP-negative (host cells) contained the Y-chromosome whereas all GFP-positive cells (donor cells) were negative for the Y-chromosome by FISH. This proves that MAPC are not derived from an in vitro or in vivo fusion event. In a third study, BM mononuclear cells from mice that had been previously BM-transplanted with syngeneic GFP-positive donors (n=3) were transplanted into a second set of syngeneic recipients (n=9). Two months after the second transplant, BM was harvested and mononuclear cells were cultured in MAPC medium. The secondary recipients also contained GFP-positive MAPC. This is the first demonstration that BM transplantation leads to the transfer of cells that upon isolation in vitro generate MAPCs and, whatever the identity of this cell may be, is eliminated by irradiation. We believe this is an important observation as MAPC hold great clinical potential for stem cell and/or gene therapy and, thus, BM transplant may serve as a way to deliver and reconstitute the MAPC population. In addition, this study provides insight into the nature of MAPC. The capacity to be transplantable within unfractionated BM transplant renders a functional and physiological distinction between MAPC and BM stromal cells. This study validates the use of unfractionated BM transplants to study the nature and possible in vivo role of MAPC in the BM.

Integrin alpha 6 Is Essential for Fetal Hematopoietic Progenitor, but Not Fetal Stem Cell Homing to Bone Marrow.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1387-1387
Author(s):  
Hong Qian ◽  
Sten Eirik W. Jacobsen ◽  
Marja Ekblom
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Fetal Liver ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells ◽  
Integrin Alpha 6

Abstract Homing of transplanted hematopoietic stem cells (HSC) in the bone marrow (BM) is a prerequisite for establishment of hematopoiesis following transplantation. However, although multiple adhesive interactions of HSCs with BM microenviroment are thought to critically influence their homing and subsequently their engraftment, the molecular pathways that control the homing of transplanted HSCs, in particular, of fetal HSCs are still not well understood. In experimental mouse stem cell transplantation models, several integrins have been shown to be involved in the homing and engraftment of both adult and fetal stem and progenitor cells in BM. We have previously found that integrin a6 mediates human hematopoietic stem and progenitor cell adhesion to and migration on its specific ligands, laminin-8 and laminin-10/11 in vitro (Gu et al, Blood, 2003; 101:877). Furthermore, integrin a6 is required for adult mouse HSC homing to BM in vivo (Qian et al., Abstract American Society of Hematology, Blood 2004 ). We have now found that the integrin a6 chain like in adult HSC is ubiquitously (>99%) expressed also in fetal liver hematopoietic stem and progenitor cells (lin−Sca-1+c-Kit+, LSK ). In vitro, fetal liver LSK cells adhere to laminin-10/11 and laminin-8 in an integrin a6b1 receptor-dependent manner, as shown by function blocking monoclonal antibodies. We have now used a function blocking monoclonal antibody (GoH3) against integrin a6 to analyse the role of the integrin a6 receptor for the in vivo homing of fetal liver hematopoietic stem and progenitor cells to BM. The integrin a6 antibody inhibited homing of fetal liver progenitors (CFU-C) into BM of lethally irradiated recipients. The number of homed CFU-C in BM was reduced by about 40% as compared to the cells incubated with an isotype matched control antibody. To study homing of long-term repopulating stem cells, BM cells were first incubated with anti-integrin alpha 6 or anti-integrin alpha 4 or control antibody, and then injected intravenously into lethally irradiated primary recipients. After three hours, BM cells of the primary recipients were analysed by competitive repopulation assay in secondary recipients. Blood analysis up to 16 weeks after transplantation showed that no reduction of stem cell reconstitution from integrin a6 antibody treated cells as compared to cells treated with control antibody. In accordance with this, fetal liver HSC from integrin a6 gene deleted embryos did not show any impairment of homing and engraftment in BM as compared to normal littermates. These results suggest that integrin a6 plays an important developmentally regulated role for homing of distinct hematopoietic stem and progenitor cell populations in vivo.

Novel In Vivo Evidence That Not Only Androgens But Also Pituitary Gonadotropins and Prolactin Directly Stimulate Murine Bone Marrow Stem Cells – Implications For Potential Treatment Strategies In Aplastic Anemias

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2476-2476
Author(s):  
Kasia Mierzejewska ◽  
Ewa Suszynska ◽  
Sylwia Borkowska ◽  
Malwina Suszynska ◽  
Maja Maj ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Sex Hormones ◽  
Peripheral Blood ◽  
Hematopoietic Stem ◽  
Clonogenic Potential

Abstract Background Hematopoietic stem/progenitor cells (HSPCs) are exposed in vivo to several growth factors, cytokines, chemokines, and bioactive lipids in bone marrow (BM) in addition to various sex hormones circulating in peripheral blood (PB). It is known that androgen hormones (e.g., danazol) is employed in the clinic to treat aplastic anemia patients. However, the exact mechanism of action of sex hormones secreted by the pituitary gland or gonads is not well understood. Therefore, we performed a complex series of experiments to address the influence of pregnant mare serum gonadotropin (PMSG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), androgen (danazol) and prolactin (PRL) on murine hematopoiesis. In particular, from a mechanistic view we were interested in whether this effect depends on stimulation of BM-residing stem cells or is mediated through the BM microenvironment. Materials and Methods To address this issue, normal 2-month-old C57Bl6 mice were exposed or not to daily injections of PMSG (10 IU/mice/10 days), LH (5 IU/mice/10 days), FSH (5 IU/mice/10 days), danazol (4 mg/kg/10 days) and PRL (1 mg/day/5days). Subsequently, we evaluated changes in the BM number of Sca-1+Lin–CD45– that are precursors of long term repopulating hematopoietic stem cells (LT-HSCs) (Leukemia 2011;25:1278–1285) and bone forming mesenchymal stem cells (Stem Cell & Dev. 2013;22:622-30) and Sca-1+Lin–CD45+ hematopoietic stem/progenitor cells (HSPC) cells by FACS, the number of clonogenic progenitors from all hematopoietic lineages, and changes in peripheral blood (PB) counts. In some of the experiments, mice were exposed to bromodeoxyuridine (BrdU) to evaluate whether sex hormones affect stem cell cycling. By employing RT-PCR, we also evaluated the expression of cell-surface and intracellular receptors for hormones in purified populations of murine BM stem cells. In parallel, we studied whether stimulation by sex hormones activates major signaling pathways (MAPKp42/44 and AKT) in HSPCs and evaluated the effect of sex hormones on the clonogenic potential of murine CFU-Mix, BFU-E, CFU-GM, and CFU-Meg in vitro. We also sublethally irradiated mice and studied whether administration of sex hormones accelerates recovery of peripheral blood parameters. Finally, we determined the influence of sex hormones on the motility of stem cells in direct chemotaxis assays as well as in direct in vivo stem cell mobilization studies. Results We found that 10-day administration of each of the sex hormones evaluated in this study directly stimulated expansion of HSPCs in BM, as measured by an increase in the number of these cells in BM (∼2–3x), and enhanced BrdU incorporation (the percentage of quiescent BrdU+Sca-1+Lin–CD45– cells increased from ∼2% to ∼15–35% and the percentage of BrdU+Sca-1+Lin–CD45+ cells increased from 24% to 43–58%, Figure 1). These increases paralleled an increase in the number of clonogenic progenitors in BM (∼2–3x). We also observed that murine Sca-1+Lin–CD45– and Sca-1+Lin–CD45+ cells express sex hormone receptors and respond by phosphorylation of MAPKp42/44 and AKT in response to exposure to PSMG, LH, FSH, danazol and PRL. We also observed that administration of sex hormones accelerated the recovery of PB cell counts in sublethally irradiated mice and slightly mobilized HSPCs into PB. Finally, in direct in vitro clonogenic experiments on purified murine SKL cells, we observed a stimulatory effect of sex hormones on clonogenic potential in the order: CFU-Mix > BFU-E > CFU-Meg > CFU-GM. Conclusions Our data indicate for the first time that not only danazol but also several pituitary-secreted sex hormones directly stimulate the expansion of stem cells in BM. This effect seems to be direct, as precursors of LT-HSCs and HSPCs express all the receptors for these hormones and respond to stimulation by phosphorylation of intracellular pathways involved in cell proliferation. These hormones also directly stimulated in vitro proliferation of purified HSPCs. In conclusion, our studies support the possibility that not only danazol but also several other upstream pituitary sex hormones could be employed to treat aplastic disorders and irradiation syndromes. Further dose- and time-optimizing mouse studies and studies with human cells are in progress in our laboratories. Disclosures: No relevant conflicts of interest to declare.

Modeling Bone Marrow Failure and MDS in Shwachman Diamond Syndrome Using Induced Pluripotent Stem Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1496-1496 ◽  
Author(s):  
Melisa Ruiz-Gutierrez ◽  
Ozge Vargel Bolukbasi ◽  
Linda Vo ◽  
Ryohichi Sugimura ◽  
Marilyn Sanchez Bonilla ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Progenitor Cells ◽  
Bone Marrow Failure ◽  
Clonal Evolution ◽  
Chromosome 7 ◽  
Stem Cell Markers ◽  
Hematopoietic Stem ◽  
Monosomy 7

Abstract Myelodysplastic syndrome (MDS) caused by monosomy 7 or del(7q) is a frequent clonal abnormality that arises in the context of inherited bone marrow failure syndromes, such as Shwachman Diamond Syndrome (SDS). Monosomy 7/del(7q) also develops in a subset of patients with acquired aplastic anemia or de novo MDS in the general population. Monosomy 7/del(7q) is associated with high grade MDS and a high risk of malignant transformation, most frequently to acute myelogenous leukemia (AML). Bone marrow failure and clonal evolution to MDS and AML remain major causes of morbidity and mortality for individuals with SDS. Currently, the only curative therapy for these hematological complications is a hematopoietic stem cell transplant. Prognosis is extremely poor once SDS patients develop leukemia. The basis for this propensity to develop monosomy 7 clones remains unclear. The longterm aim of this study is to understand the molecular mechanisms underlying leukemia predisposition and develop more effective treatments. Whether monosomy 7/del(7q) functions as a driver of MDS, or is merely an associated marker of clonal progression in bone marrow failure remains a critical question. The lack of synteny between murine versus human chromosome 7 has posed a major barrier to the development of mouse models of monosomy 7/del(7q). To study the biological and molecular consequences of monosomy 7/del(7q) in SDS, induced pluripotent stem cells (iPSCs) were generated from bone marrow mononuclear cells of two patients with SDS. Each patient harbored homozygous c.258+2 T>C mutations in the canonical splice donor site of intron 2 in the SBDS gene. The SDS-iPSCs retained the pathogenic homozygous IVS2+2 T>C SBDS mutations, expressed stem cell markers, formed teratomas, and expressed reduced levels of SBDS protein similar to levels noted in the primary patient samples. Proliferation of 4 distinct SDS-iPSC clones derived from two different patients was reduced relative to wild type controls without an increase in cell death. SDS-iPSC formed smaller embryoid bodies with reduced production of CD34+ hematopoietic stem/progenitor cells. Hematopoietic differentiation from CD34+ to CD45+ cells was also impaired. Preliminary data suggest that SDS-iPSCs retain the capacity to give rise to hematopoietic stem/progenitor cells and early myeloid progenitor cells in vitro. These populations were also observed in primary SDS patient-derived bone marrow samples. Because the number of CD34+ cells derived from SDS-iPSCs are limiting, a previously reported 5 transcrition factor re-specification system was used to expand multilineage hematopietic progenitors for further characterization. SDS iPSCs were able to differentiate into an expandable CD34+ population in vitro. Further studies to characterize the hematopoietic impairment in SDS iPSC and primary marrow samples are ongoing. To model del(7q) in SDS iPSCs, a deletion of the MDS-associated long arm of chromosome 7 was genomically engineered using a previously published modified Cre-Lox approach. The deletion of 7q at locus (11.2) was confirmed by karyotyping and by qPCR across chromosome 7. The SDS (del7q) iPSCs retained the SBDS pathogenic mutations, expressed stem cell markers, and formed teratomas. Proliferation of the SDS del(7q) iPSC was markedly impaired compared to isogenic SDS iPSCs. No increase in cell death was observed in the SDS del7q iPSCs. Studies are in progress to determine the effects of del7q on hematopoiesis. Investigation is ongoing to determine the molecular consequences of deleting 7q. These isogenic SDS+/- del(7q) iPS models provide a platform to study the role of 7q loss in clonal evolution from bone marrow failure and to screen for novel therapeutic compounds or pathways to treat bone marrow failure and MDS. Disclosures No relevant conflicts of interest to declare.

Enforced expression of cyclin D2 enhances the proliferative potential of myeloid progenitors, accelerates in vivo myeloid reconstitution, and promotes rescue of mice from lethal myeloablation

Blood ◽  
2004 ◽  
Vol 104 (4) ◽  
pp. 986-992 ◽  
Author(s):  
Yutaka Sasaki ◽  
Christina T. Jensen ◽  
Stefan Karlsson ◽  
Sten Eirik W. Jacobsen
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Ex Vivo ◽  
Proliferative Potential ◽  
Cyclin D2 ◽  
Hematopoietic Stem ◽  
Murine Bone Marrow ◽  
Myeloid Progenitors

AbstractSevere and prolonged cytopenias represent a considerable problem in clinical stem cell transplantations. Cytokine-induced ex vivo expansion of hematopoietic stem and progenitor cells has been intensively explored as a means of accelerating hematopoietic recovery following transplantation but have so far had limited success. Herein, overexpression of D-type cyclins, promoting G0/G1 to S transition, was investigated as an alternative approach to accelerate myeloid reconstitution following stem cell transplantation. With the use of retroviral-mediated gene transfer, cyclin D2 was overexpressed in murine bone marrow progenitor cells, which at limited doses showed enhanced ability to rescue lethally ablated recipients. Competitive repopulation studies demonstrated that overexpression of cyclin D2 accelerated myeloid reconstitution following transplantation, and, in agreement with this, cyclin D2–transduced myeloid progenitors showed an enhanced proliferative response to cytokines in vitro. Furthermore, cyclin D2–overexpressing myeloid progenitors and their progeny were sustained for longer periods in culture, resulting in enhanced and prolonged granulocyte production in vitro. Thus, overexpression of cyclin D2 confers myeloid progenitors with an enhanced proliferative and granulocyte potential, facilitating rapid myeloid engraftment and rescue of lethally ablated recipients.

scholarly journals OTUB2 Facilitates Tumorigenesis of Gastric Cancer Through Promoting KDM1A-Mediated Stem Cell-Like Properties

2021 ◽  
Vol 11 ◽  
Author(s):  
Guangming Liu ◽  
Wei Guo ◽  
Junjie Qin ◽  
Zhiliang Lin
Keyword(s):  
Gastric Cancer ◽  
Stem Cell ◽  
Survival Rates ◽  
Histone Demethylase ◽  
Deubiquitinating Enzyme ◽  
Stem Cell Markers ◽  
Loss Of Function ◽  
Sphere Formation

Otubain 2 (OTUB2), a deubiquitinating enzyme, overexpression is considered to predict poor outcome in various cancers. However, the function and potential regulatory mechanisms of OTUB2 in gastric cancer (GC) progression remains unclear. To determine how OTUB2 participate in GC progression, the gain and loss of-function experiments were conducted in vivo and in vitro. We found that OTUB2 was upregulated in GC samples (n=140) and cells. Moreover, the overall, first progression and post progression survival rates of GC patients with high OTUB2 expression showed a poorer prognosis than that in those patients with low OTUB2 expression. Down-regulation of OTUB2 suppressed sphere formation and reduced expression of stem cell markers in GC cells. Furthermore, OTUB2-silenced GC cells also showed a decreased proliferation, invasion, migration, and in vivo tumorigenic ability. However, OTUB2 overexpression showed the opposite effects. Notably, we demonstrated that OTUB2 increased lysine-specific histone demethylase 1A (KDM1A) expression through deubiquitination. KDM1A, a demethylase known to promote demethylation of downstream genes, was identified to promote the maintenance of cancer stem cell characteristics. Moreover, the alterations caused by OTUB2 overexpression were partly inversed by KDM1A knockdown and in turn KDM1A overexpression reversed the changes induced by OTUB2 shRNA. Taken together, we demonstrate that OTUB2 may serve as a vital driver in GC tumorigenesis by enhancing KDM1A-mediated stem cell-like properties.

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