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Yongbaek Kim - One of the best experts on this subject based on the ideXlab platform.
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A subset of microRNAs defining the Side Population of a human malignant mesothelioma cell line.
Oncotarget, 2017Co-Authors: Myung-chul Kim, Na-yon Kim, Yu-ri Seo, Yongbaek KimAbstract:// Myung-Chul Kim 1, 2 , Na-Yon Kim 1, 2 , Yu-Ri Seo 1 and Yongbaek Kim 1, 3 1 Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Gwanak-Gu, Seoul 151-742, The Republic of Korea 2 BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Gwanak-Gu, Seoul 151-742, The Republic of Korea 3 Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Gwanak-Gu, Seoul 151-742, The Republic of Korea Correspondence to: Yongbaek Kim, email: yongbaek@snu.ac.kr Keywords: mesothelioma, Side Population, microRNA, intratumoral heterogeneity, microarray Received: December 08, 2016 Accepted: March 22, 2017 Published: April 13, 2017 ABSTRACT This study was performed to investigate the global expression profile of microRNAs in distinct subPopulations of a human malignant mesothelioma cell line. Total RNAs were isolated from the sorted Side Population and non-Side Population of MS1. The RNAs were subjected to analysis using Affymetrix GeneChip microRNA Arrays. After data extraction and normalization, a subset of microRNAs defining cell subPopulations was identified using bioinformatics softwares. Based on the criteria of 2-fold difference and the p-value of < 0.05, a total of 95 microRNAs were differentially expressed in the Side Population compared to the non-Side Population. Functional ontology revealed that target genes of the miRNAs were categorized into various gene ontology terms, such as stem cell maintenance, cell proliferation, programmed cell death, cell migration, and cellular response to stress. The Kyoto Encyclopedia of Genes and Genomes analysis showed that ErbB-2 receptor tyrosine kinases signaling pathway was the most represented. Integrated analysis of MiRTarBase and RNA-seq identified 12 target genes of microRNAs defining Side Population, including DDIT4 and ROCK2 . The present study indicates that a distinct set of microRNAs may be critically involved in the generation and maintenance of heterogeneous subPopulations of cancer cells. They could be a plausible target for the eradication of more aggressive cancer cell subPopulations.
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evaluation of a Side Population of canine lymphoma cells using hoechst 33342 dye
Journal of Veterinary Science, 2013Co-Authors: Myung-chul Kim, Susan Dcosta, Steven E Suter, Yongbaek KimAbstract:Cancer stem cell (CSC) research has increased exponentially to gain further insight into the mechanisms underlying both carcinogenesis and chemotherapy resistance. The present study was performed to explore the potential value of a Side Population (SP) assay for identifying and characterizing putative CSCs among canine lymphoma cells. Canine lymphoma cells from cell lines and clinical samples were subjected to the SP assay consisting of Hoechst 33342 staining and subsequent flow cytometric analysis. The SP assay revealed various amounts of a SP fraction among the canine lymphoma cells. The percentages of SP were not affected by inhibitors of membrane transporters, verapamil hydrochloride, or fumitremorgin C. Most of the canine lymphoma cells expressed high levels of Bmi-1 and membrane transporter proteins such as ABCG2 and phosphorylated (p)-glycoprotein. This investigation lays the groundwork for further studies of the biological behaviors and molecular characteristics of CSCs in cases of canine lymphoma.
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characterization of Side Population cells in human malignant mesothelioma cell lines
Lung Cancer, 2010Co-Authors: Kiyonori Kai, Susan Dcosta, Byungil Yoon, Arnold R Brody, Robert C Sills, Yongbaek KimAbstract:Side Population (SP) assay composed of Hoechst 33342 staining and subsequent flow cytometric analysis has been widely utilized for characterizing putative cancer stem cells (CSCs) in various human malignancies. The present study was designed to evaluate the SP assay as a research tool for mesothelial CSCs. A distinct fraction of SP cells was identified in various human malignant mesothelioma (HMM) cell lines, ranging from 0.05 to 1.32%. The sorted mesothelial SP cells exhibited enhanced proliferation potentials and higher expression of stem-cell genes, compared to non-SP (NSP) cells. Cisplatin treatment increased percentage of SP cells in the HMM cell lines. However, tumorigenic potential of SP cells in immunodeficient mice was similar to that of the NSP cells. These data indicated that SP assay may not be appropriate for enriching putative CSCs in HMM cell lines, and thus warrants the development of a novel tool for mesothelial CSC study.
Teruo Okano - One of the best experts on this subject based on the ideXlab platform.
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nectin 3 expression is elevated in limbal epithelial Side Population cells with strongly expressed stem cell markers
Biochemical and Biophysical Research Communications, 2009Co-Authors: Risa Kusanagi, Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Yu Matsuzaki, Yoshiro Kobayashi, Fumio Fukai, Teruo OkanoAbstract:Corneal epithelial stem cells (CESCs) are essential for maintaining the ocular surface. However, the lack of surface markers for CESCs remains a serious obstacle in the identification of CESCs. Previously, we showed that rabbit limbal epithelial Side Population (rLE-SP) cells exhibited stem cell phenotypes including increased expression of CD61, a marker for mouse hematopoietic stem cells. Here, we demonstrate that nectin-3, an immunoglobulin-like cell-cell adhesion molecule, is highly expressed in rLE-SP cells. Additionally, nectin-3(+) cells were significantly enriched among CD61(+)rLE-SP cells as compared to CD61(-)rLE-SP cells. In mouse bone marrow Side Population cells, a correlation between expression of nectin-3 and CD61 was also observed. These data strongly suggest that nectin-3 may contribute to the identification of CESCs.
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rat limbal epithelial Side Population cells exhibit a distinct expression of stem cell markers that are lacking in Side Population cells from the central cornea
FEBS Letters, 2005Co-Authors: Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Joseph Yang, Yasuo Tano, Chinatsu Kohno, Teruo OkanoAbstract:The Side Population (SP) phenotype is shared by stem cells in various tissues and species. Here we demonstrate SP cells with Hoechst dye efflux were surprisingly collected from the epithelia of both the rat limbus and central cornea, unlike in human and rabbit eyes. Our results show that rat limbal SP cells have a significantly higher expression of the stem cell markers ABCG2, nestin, and notch 1, compared to central corneal SP cells. Immunohistochemistry also revealed that ABCG2 and the epithelial stem/progenitor cell marker p63 were expressed only in basal limbal epithelial cells. These results demonstrate that ABCG2 expression is closely linked to the stem cell phenotype of SP cells.
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Limbal epithelial Side-Population cells have stem cell-like properties, including quiescent state.
Stem cells (Dayton Ohio), 2005Co-Authors: Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Joseph Yang, Yasuo Tano, Teruo OkanoAbstract:Corneal epithelial (CE) stem cells are believed to reSide in the basal layer of the limbal epithelium but remain poorly understood due to the lack of an accepted in vivo reconstitution assay as well as definitive markers for epithelial stem cells. It has been reported that Side-Population (SP) cells with the ability to efflux the DNA-binding dye Hoechst 33342 have stem cell-like properties and that the SP phenotype accurately represents a quiescent and immature stem cell Population in the adult bone marrow. In the present study, we investigated whether SP cells isolated from the limbal epithelium have stem cell-like properties. SP cells, separated by fluorescence-activated cell sorting, comprise approximately 0.4% of all limbal epithelial cells and have markedly higher expression of the stem cell markers ABCG2, Bmi-1, and nestin but no expression of markers for differentiated CE cells compared with non-SP cells. Cell-cycle and telomerase activity analyses revealed that SP cells are growth arrested and reSide in the quiescent state. Moreover, limbal epithelial SP cells did not demonstrate proliferative capabilities under typical in vitro epithelial cell culture conditions using 3T3 feeder layers. These findings present the possibility that quiescent limbal epithelial SP cells may represent an extremely immature stem cell Population compared with currently defined epithelial stem or progenitor cells.
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human limbal epithelium contains Side Population cells expressing the atp binding cassette transporter abcg2
FEBS Letters, 2004Co-Authors: K Watanabe, Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Teruo Okano, T Sumide, Kazuaki Yamamoto, Naoyuki Maeda, Hitoshi Watanabe, Yasuo TanoAbstract:Many types of organ-specific stem cells have been recently shown to exhibit a Side Population (SP) phenotype based on their ability to efflux Hoechst 33342 dye. Because stem cells from corneal epithelium reSide in the basal layer of the limbal epithelium, the purpose of this study was to examine whether the limbal epithelium contains SP cells. The ATP-binding cassette transporter Bcrp1/ABCG2 is reported to contribute to the SP phenotype in cells from several diverse sources. Here we show data from fluorescence-activated cell sorting and real-time quantitative RT-PCR analysis showing that harvested limbal epithelial cells contain SP cells expressing ABCG2. Immunofluorescence revealed that a portion of limbal epithelial basal cells expressed ABCG2. Data indicate that ABCG2 positive limbal epithelial cells are putative corneal epithelial stem cells.
Annette Meeson - One of the best experts on this subject based on the ideXlab platform.
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hypoxia increases thyroid cancer stem cell enriched Side Population
World Journal of Surgery, 2018Co-Authors: Kamilla Mahkamova, Nani Harlina Md Latar, Sebastian Aspinall, Annette MeesonAbstract:Hypoxic stress is a feature of rapidly growing thyroid tumours. Cancer progression is thought to be driven by a small Population of tumour cells possessing stem cell properties. Hypoxia-inducible factors (HIFs) are important mediators of hypoxia. Both HIF-1alpha and HIF-2alpha have been reported to be expressed in thyroid cancers. There is growing evidence that the HIF pathway plays a significant role in the maintenance of thyroid cancer stem cells (CSC). We have isolated thyroid CSC from a papillary thyroid cancer-derived cell line (BCPAP) and an anaplastic thyroid cancer-derived cell line (SW1736) as Side Population (SP) cells (a putative stem cell Population) and treated them with cobalt chloride (II) to induce hypoxia. We observed an increase in the SP of cells within the thyroid cancer cell lines following induction of hypoxia.
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optimised protocols for the identification of the murine cardiac Side Population
Stem Cell Reviews and Reports, 2013Co-Authors: Annette Meeson, Andrew Fuller, David T Breault, Andrew W Owens, Gavin D RichardsonAbstract:Cardiac Side Population (CSP) cells, defined by their ability to efflux the vital dye Hoechst 33342, have been identified as putative cardiac stem cells based on their potential to give rise to both cardiomyocytes and endothelial cells. The CSP phenotype relies on an active metabolic pathway and cell viability to identify a rare Population of cells and therefore technical differences in the CSP staining protocol can lead to inconsistent results and discrepancies between studies. Here we describe an established protocol for CSP identification and have optimised a protocol for CSP analysis utilizing an automated cardiac digestion procedure using gentleMACs dissociation and Hoechst 33342 staining followed by dual wavelength flow cytometric analysis.
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Breast cancer, Side Population cells and ABCG2 expression
Cancer letters, 2012Co-Authors: K.m. Britton, Rachel Eyre, I. J. Harvey, K. Stemke-hale, Da Browell, Thomas W. J. Lennard, Annette MeesonAbstract:Recurrent metastatic breast cancer may arise in part due to the presence of drug resistant adult stem cells such as Side Population (SP) cells, whose phenotype has been demonstrated to be due to the expression of ABCG2. We hypothesised that SP may be identified in Fine Needle Aspirates (FNAs) and their presence may be determined by expression of ABCG2 in breast tumours. SP and non-Side Population cells (NSP) were isolated using dual wavelength flow cytometry combined with Hoechst 33342 dye efflux and analysed for expression of ABCG2 and chemoresistance. FNA samples used in SP analysis were matched with paraffin-embedded tissue which was used in immunohistochemical analysis to assess ABCG2 expression. Results were correlated to the pathobiology of the tumour. MCF7 and MDA-MB-231 cell lines contain SP cells. MCF7 SP have increased expression of ABCG2 and increased resistance to mitoxantrone compared to NSP cells. The presence of SP in FNAs were significantly associated with ER-negative (p=0.008) and with triple negative breast cancers (p=0.011) which were also found to have a significant increase in ABCG2 protein expression. ABCG2 transcript was detected in some but not all SP cell Populations isolated from FNA samples.
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cellular and molecular regulation of skeletal muscle Side Population cells
Stem Cells, 2004Co-Authors: Annette Meeson, Thomas J Hawke, Sarabeth Graham, Nan Jiang, Joel Elterman, Kelley A Hutcheson, Michael J Dimaio, Teresa D Gallardo, Daniel J GarryAbstract:Muscle progenitor cells (satellite cells) function in the maintenance and repair of adult skeletal muscle. Side Population (SP) cells are enriched in repopulating activity and also reSide in adult skeletal muscle. In this study, we observed that Abcg2 is a determinant of the SP cell phenotype. Using reverse transcription polymerase chain reaction and immunohistochemical techniques, we localized Abcg2-expressing cells in the interstitium and in close approximation to the vasculature of adult skeletal muscle. Muscle SP cells are able to differentiate into myotubes and increase in number after cardiotoxin-induced muscle injury. Similar to myogenic progenitor cells, muscle SP cells express Foxk1 and are decreased in number in Foxk1 mutant skeletal muscle. Using emerging technologies, we examine the molecular signature of muscle SP cells from normal, injured, and Foxk1 mutant skeletal muscle to define common and distinct molecular programs. We propose that muscle SP cells are progenitor cells that participate in repair and regeneration of adult skeletal muscle.
Ronglih Liao - One of the best experts on this subject based on the ideXlab platform.
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A role for matrix stiffness in the regulation of cardiac Side Population cell function
American journal of physiology. Heart and circulatory physiology, 2015Co-Authors: Yiling Qiu, Ahmad F. Bayomy, Marcus V. Gomez, Michael Bauer, Yanfei Yang, Xin Zhang, Ronglih LiaoAbstract:The mechanical properties of the local microenvironment may have important influence on the fate and function of adult tissue progenitor cells, altering the regenerative process. This is particularly critical following a myocardial infarction, in which the normal, compliant myocardial tissue is replaced with fibrotic, stiff scar tissue. In this study, we examined the effects of matrix stiffness on adult cardiac Side Population (CSP) progenitor cell behavior. Ovine and murine CSP cells were isolated and cultured on polydimethylsiloxane substrates, replicating the elastic moduli of normal and fibrotic myocardium. Proliferation capacity and cell cycling were increased in CSP cells cultured on the stiff substrate with an associated reduction in cardiomyogeneic differentiation and accelerated cell ageing. In addition, culture on stiff substrate stimulated upregulation of extracellular matrix and adhesion proteins gene expression in CSP cells. Collectively, we demonstrate that microenvironment properties, including matrix stiffness, play a critical role in regulating progenitor cell functions of endogenous reSident CSP cells. Understanding the effects of the tissue microenvironment on reSident cardiac progenitor cells is a critical step toward achieving functional cardiac regeneration.
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cd31 but not cd31 cardiac Side Population cells exhibit functional cardiomyogenic differentiation
Circulation Research, 2005Co-Authors: Otmar Pfister, Ross Summer, Alan Fine, Frederic Mouquet, Mohit Jain, Michiel Helmes, Wilson S Colucci, Ronglih LiaoAbstract:Heart failure remains a leading cause of morbidity and mortality. The cellular mechanism underlying the development of cardiac dysfunction is a decrease in the number of viable cardiomyocytes. Recent observations have suggested that the adult heart may contain a progenitor cell Population. Side Population (SP) cells, characterized by a distinct Hoechst dye efflux pattern, have been shown to exist in multiple tissues and are capable of tissue-specific differentiation. In this report, we confirm the existence of a cardiac SP cell Population, immunophenotypically distinct from bone marrow SP cells. Moreover, we demonstrate that among cardiac SP cells, the greatest potential for cardiomyogenic differentiation is restricted to cells negative for CD31 expression and positive for stem cell antigen 1 (Sca1) expression (CD31−/Sca1+). Furthermore, we determine that CD31−/Sca1+ cardiac SP cells are capable of both biochemical and functional cardiomyogenic differentiation into mature cardiomyocytes, with expression o...
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CD31− but Not CD31+ Cardiac Side Population Cells Exhibit Functional Cardiomyogenic Differentiation
Circulation research, 2005Co-Authors: Otmar Pfister, Ross Summer, Alan Fine, Frederic Mouquet, Mohit Jain, Michiel Helmes, Wilson S Colucci, Ronglih LiaoAbstract:Heart failure remains a leading cause of morbidity and mortality. The cellular mechanism underlying the development of cardiac dysfunction is a decrease in the number of viable cardiomyocytes. Recent observations have suggested that the adult heart may contain a progenitor cell Population. Side Population (SP) cells, characterized by a distinct Hoechst dye efflux pattern, have been shown to exist in multiple tissues and are capable of tissue-specific differentiation. In this report, we confirm the existence of a cardiac SP cell Population, immunophenotypically distinct from bone marrow SP cells. Moreover, we demonstrate that among cardiac SP cells, the greatest potential for cardiomyogenic differentiation is restricted to cells negative for CD31 expression and positive for stem cell antigen 1 (Sca1) expression (CD31-/Sca1+). Furthermore, we determine that CD31-/Sca1+ cardiac SP cells are capable of both biochemical and functional cardiomyogenic differentiation into mature cardiomyocytes, with expression of cardiomyocyte-specific transcription factors and contractile proteins, as well as stimulated cellular contraction and intracellular calcium transients indistinguishable from adult cardiomyocytes. We also determine the necessity of cell-extrinsic signaling through coupling, although not fusion, with adult cardiomyocytes in regulating cardiomyogenic differentiation of cardiac SP cells. We, therefore, conclude that CD31-/Sca1+ cardiac SP cells represent a distinct cardiac progenitor cell Population, capable of cardiomyogenic differentiation into mature cardiomyocytes through a process mediated by cellular coupling with adult cardiomyocytes.
Terumasa Umemoto - One of the best experts on this subject based on the ideXlab platform.
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nectin 3 expression is elevated in limbal epithelial Side Population cells with strongly expressed stem cell markers
Biochemical and Biophysical Research Communications, 2009Co-Authors: Risa Kusanagi, Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Yu Matsuzaki, Yoshiro Kobayashi, Fumio Fukai, Teruo OkanoAbstract:Corneal epithelial stem cells (CESCs) are essential for maintaining the ocular surface. However, the lack of surface markers for CESCs remains a serious obstacle in the identification of CESCs. Previously, we showed that rabbit limbal epithelial Side Population (rLE-SP) cells exhibited stem cell phenotypes including increased expression of CD61, a marker for mouse hematopoietic stem cells. Here, we demonstrate that nectin-3, an immunoglobulin-like cell-cell adhesion molecule, is highly expressed in rLE-SP cells. Additionally, nectin-3(+) cells were significantly enriched among CD61(+)rLE-SP cells as compared to CD61(-)rLE-SP cells. In mouse bone marrow Side Population cells, a correlation between expression of nectin-3 and CD61 was also observed. These data strongly suggest that nectin-3 may contribute to the identification of CESCs.
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rat limbal epithelial Side Population cells exhibit a distinct expression of stem cell markers that are lacking in Side Population cells from the central cornea
FEBS Letters, 2005Co-Authors: Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Joseph Yang, Yasuo Tano, Chinatsu Kohno, Teruo OkanoAbstract:The Side Population (SP) phenotype is shared by stem cells in various tissues and species. Here we demonstrate SP cells with Hoechst dye efflux were surprisingly collected from the epithelia of both the rat limbus and central cornea, unlike in human and rabbit eyes. Our results show that rat limbal SP cells have a significantly higher expression of the stem cell markers ABCG2, nestin, and notch 1, compared to central corneal SP cells. Immunohistochemistry also revealed that ABCG2 and the epithelial stem/progenitor cell marker p63 were expressed only in basal limbal epithelial cells. These results demonstrate that ABCG2 expression is closely linked to the stem cell phenotype of SP cells.
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Limbal epithelial Side-Population cells have stem cell-like properties, including quiescent state.
Stem cells (Dayton Ohio), 2005Co-Authors: Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Joseph Yang, Yasuo Tano, Teruo OkanoAbstract:Corneal epithelial (CE) stem cells are believed to reSide in the basal layer of the limbal epithelium but remain poorly understood due to the lack of an accepted in vivo reconstitution assay as well as definitive markers for epithelial stem cells. It has been reported that Side-Population (SP) cells with the ability to efflux the DNA-binding dye Hoechst 33342 have stem cell-like properties and that the SP phenotype accurately represents a quiescent and immature stem cell Population in the adult bone marrow. In the present study, we investigated whether SP cells isolated from the limbal epithelium have stem cell-like properties. SP cells, separated by fluorescence-activated cell sorting, comprise approximately 0.4% of all limbal epithelial cells and have markedly higher expression of the stem cell markers ABCG2, Bmi-1, and nestin but no expression of markers for differentiated CE cells compared with non-SP cells. Cell-cycle and telomerase activity analyses revealed that SP cells are growth arrested and reSide in the quiescent state. Moreover, limbal epithelial SP cells did not demonstrate proliferative capabilities under typical in vitro epithelial cell culture conditions using 3T3 feeder layers. These findings present the possibility that quiescent limbal epithelial SP cells may represent an extremely immature stem cell Population compared with currently defined epithelial stem or progenitor cells.
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human limbal epithelium contains Side Population cells expressing the atp binding cassette transporter abcg2
FEBS Letters, 2004Co-Authors: K Watanabe, Terumasa Umemoto, Masayuki Yamato, Kohji Nishida, Teruo Okano, T Sumide, Kazuaki Yamamoto, Naoyuki Maeda, Hitoshi Watanabe, Yasuo TanoAbstract:Many types of organ-specific stem cells have been recently shown to exhibit a Side Population (SP) phenotype based on their ability to efflux Hoechst 33342 dye. Because stem cells from corneal epithelium reSide in the basal layer of the limbal epithelium, the purpose of this study was to examine whether the limbal epithelium contains SP cells. The ATP-binding cassette transporter Bcrp1/ABCG2 is reported to contribute to the SP phenotype in cells from several diverse sources. Here we show data from fluorescence-activated cell sorting and real-time quantitative RT-PCR analysis showing that harvested limbal epithelial cells contain SP cells expressing ABCG2. Immunofluorescence revealed that a portion of limbal epithelial basal cells expressed ABCG2. Data indicate that ABCG2 positive limbal epithelial cells are putative corneal epithelial stem cells.