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Lynette E Wilson - One of the best experts on this subject based on the ideXlab platform.
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basic fibroblast growth factor modulates the expression of glycophorin a and c kit and inhibits erythroid differentiation in K562 Cells
Journal of Cellular Physiology, 2002Co-Authors: Patricia E Burger, Pauline T Lukey, Sandra Coetzee, Lynette E WilsonAbstract:Basic fibroblast growth factor (bFGF) is produced by bone marrow stromal Cells as well as by normal and leukemic hematopoietic Cells. In this study, we examine the direct effects of bFGF on erythroid differentiation in K562 Cells in order to determine whether bFGF can promote the expression of a primitive phenotype. Low levels of bFGF inhibited erythroid differentiation as evidenced by decreased expression of glycophorin A and increased expression of c-kit. bFGF also increased both the numbers and the sizes of colonies of K562 Cells in soft agar assays. The addition of TGF-β to these Cells induced erythroid differentiation which resulted in an increase in glycophorin A and a decrease in c-kit. The simultaneous addition of bFGF and TGF-β to K562 Cells prevented both the TGF-β-mediated increase in glycophorin A expression and the decrease in c-kit expression associated with erythroid differentiation. bFGF antagonised the TGF-β-mediated promotion of erythroid differentiation in K562 Cells in a dose dependent manner and these two cytokines counteracted each other on an approximately molar basis. These results indicate that bFGF alone increases expression of c-kit and promotes a primitive phenotype in K562 Cells. In addition, bFGF counteracts the effects of differentiation-inducing cytokines, such as TGF-β, on hematopoietic Cells. It is therefore possible that enhanced production of bFGF by leukemic Cells could contribute to their neoplastic phenotype by opposing the effects of negative regulators or cytokines that induce differentiation. J. Cell. Physiol. 190: 83–91, 2002. © 2002 Wiley-Liss, Inc.
Roberto Gambari - One of the best experts on this subject based on the ideXlab platform.
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erythroid induction of K562 Cells treated with mithramycin is associated with inhibition of raptor gene transcription and mammalian target of rapamycin complex 1 mtorc1 functions
Pharmacological Research, 2015Co-Authors: Alessia Finotti, Nicoletta Bianchi, Enrica Fabbri, Monica Borgatti, Giulia Breveglieri, Jessica Gasparello, Roberto GambariAbstract:Rapamycin, an inhibitor of mTOR activity, is a potent inducer of erythroid differentiation and fetal hemoglobin production in β-thalassemic patients. Mithramycin (MTH) was studied to see if this inducer of K562 differentiation also operates through inhibition of mTOR. We can conclude from the study that the mTOR pathway is among the major transcript classes affected by mithramycin-treatment in K562 Cells and a sharp decrease of raptor protein production and p70S6 kinase is detectable in mithramycin treated K562 Cells. The promoter sequence of the raptor gene contains several Sp1 binding sites which may explain its mechanism of action. We hypothesize that the G + C-selective DNA-binding drug mithramycin is able to interact with these sequences and to inhibit the binding of Sp1 to the raptor promoter due to the following results: (a) MTH strongly inhibits the interactions between Sp1 and Sp1-binding sites of the raptor promoter (studied by electrophoretic mobility shift assays, EMSA); (b) MTH strongly reduces the recruitment of Sp1 transcription factor to the raptor promoter in intact K562 Cells (studied by chromatin immunoprecipitation experiments, ChIP); (c) Sp1 decoy oligonucleotides are able to specifically inhibit raptor mRNA accumulation in K562 Cells. In conclusion, raptor gene expression is involved in mithramycin-mediated induction of erythroid differentiation of K562 Cells and one of its mechanism of action is the inhibition of Sp1 binding to the raptor promoter.
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the dna binding drugs mithramycin and chromomycin are powerful inducers of erythroid differentiation of human K562 Cells
British Journal of Haematology, 1999Co-Authors: Nicoletta Bianchi, F Osti, Federica Ginanni Corradini, Cristina Rutigliano, Elena Borsetti, Marina Tomassetti, Carlo Mischiati, Giordana Feriotto, Roberto GambariAbstract:Summary. The human leukaemic K562 cell line can be induced in vitro to undergo erythroid differentiation by a variety of chemical compounds, including haemin, butyric acid, 5-azacytidine and cytosine arabinoside. Differentiation of K562 Cells is associated with an increased expression of embryo-fetal globin genes, such as the z, e and g globin genes. Therefore the K562 cell line has been proposed as a useful in vitro model system to determine the therapeutic potential of new differentiating compounds as well as to study the molecular mechanism(s) regulating changes in the expression of embryonic and fetal human globin genes. Inducers of erythroid differentiation which stimulate gglobin synthesis could be considered for possible use in the experimental therapy of those haematological diseases associated with a failure in the expression of adult b-globin genes. In this paper we demonstrated that the G ˛ C selective DNA-binding drugs chromomycin and mithramycin were powerful inducers of erythroid differentiation of K562 Cells. Erythroid differentiation was associated with an increase in the accumulation of (a) Hb Gower 1 and Hb Portland and (b) g-globin mRNA.
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human leukemia K562 Cells induction to erythroid differentiation by guanine guanosine and guanine nucleotides
Haematologica, 1997Co-Authors: F Osti, Federica Ginanni Corradini, Stefania Hanau, Maurizio Matteuzzi, Roberto GambariAbstract:BACKGROUND AND OBJECTIVE: Human leukemic K562 Cells are able to undergo erythroid differentiation in vitro when cultured with a variety of inducers, leading to increased expression of embryo-fetal globin genes such as the zita, epsilon and gamma-globin genes. Therefore the K562 cell line has been proposed as a very useful in vitro model system for determining the therapeutical potential of new differentiating compounds as well as for studying the molecular mechanism(s) that regulate changes in the expression of embryonic and fetal human globin genes. In this study we explored whether nucleoside triphosphates and related compounds are able to induce differentiation of K562 Cells. METHODS: K562 cell differentiation was studied using the benzidine test; hemoglobins were characterized by cellulose acetate gel electrophoresis and mRNA accumulation was investigated by Northern blot analysis. RESULTS: The main conclusion of this paper is that guanine, guanosine and guanine ribonucleotides are effective inducers of K562 cell differentiation. Expression of both Hb Portland and Hb Gower 1 is increased in GTP-induced K562 Cells. This increase is associated with greater gamma-globin mRNA accumulation. By contrast, ATP, CTP and UTP are not able to induce erythroid differentiation. INTERPRETATION AND CONCLUSIONS: These findings suggest that guanine, guanosine and guanine ribonucleotides are inducers of erythroid differentiation of K562 Cells. This is of some relevance since differentiating compounds have been proposed as antitumor agents. In addition, inducers of erythroid differentiation that stimulate gamma-globin synthesis might be considered in the experimental therapy of hematological diseases associated with a failure in the expression of adult beta-globin genes.
Junsang Doh - One of the best experts on this subject based on the ideXlab platform.
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expansion of human nk Cells using K562 Cells expressing ox40 ligand and short exposure to il 21
Frontiers in Immunology, 2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki Kim, Junsang DohAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction. Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4-5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells. Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation. Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
Soonho Kweon - One of the best experts on this subject based on the ideXlab platform.
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expansion of human nk Cells using K562 Cells expressing ox40 ligand and short exposure to il 21
Frontiers in Immunology, 2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki Kim, Junsang DohAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction. Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4-5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells. Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation. Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
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Table_1_Expansion of Human NK Cells Using K562 Cells Expressing OX40 Ligand and Short Exposure to IL-21.docx
2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki KimAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction.Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4–5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells.Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation.Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
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Image_2_Expansion of Human NK Cells Using K562 Cells Expressing OX40 Ligand and Short Exposure to IL-21.jpeg
2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki KimAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction.Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4–5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells.Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation.Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
Sangki Kim - One of the best experts on this subject based on the ideXlab platform.
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expansion of human nk Cells using K562 Cells expressing ox40 ligand and short exposure to il 21
Frontiers in Immunology, 2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki Kim, Junsang DohAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction. Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4-5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells. Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation. Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
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Table_1_Expansion of Human NK Cells Using K562 Cells Expressing OX40 Ligand and Short Exposure to IL-21.docx
2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki KimAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction.Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4–5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells.Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation.Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
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Image_2_Expansion of Human NK Cells Using K562 Cells Expressing OX40 Ligand and Short Exposure to IL-21.jpeg
2019Co-Authors: Soonho Kweon, Minhtrang Thi Phan, Sejong Chun, Jinho Kim, Seokho Kim, Jaemin Lee, Alaa Kassim Ali, Seunghwan Lee, Sangki KimAbstract:Background: Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK Cells. Here, we report a new effective method to expand human NK Cells ex vivo using K562 Cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction.Methods: K562-OX40L Cells were generated by lentiviral transduction and were used as feeder Cells to expand and activate NK Cells from PBMCs in the presence of IL-2/IL-15. Soluble IL-21 was also added in various concentrations only once at the beginning of the culture. NK Cells were expanded for 4–5 weeks, and the purity, expansion rate, phenotype and function (cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC), cytokine production, CD107a degranulation) of these expanded NK Cells were compared to those generated by using K562 feeder Cells.Results: The culture of NK Cells with K562-OX40L Cells in combination with the transient exposure to IL-21 highly enhanced NK cell expansion to approximately 2,000-fold after 4 weeks of culture, compared to a 303-fold expansion using the conventional K562 Cells. Mechanistically, the OX40-OX40L axis between the feeder Cells and NK Cells as well as the homotypic interaction between NK Cells through the OX40-OX40L axis were both necessary for NK cell expansion. The short exposure of NK Cells to IL-21 had a synergistic effect with OX40 signaling for NK cell expansion. Apart from their enhanced expansion, NK Cells grown with K562-OX40L feeder Cells were similar to those grown with conventional K562 Cells in regard to the surface expression of various receptors, cytotoxicity, ADCC, cytokine secretion, and CD107 degranulation.Conclusion: Our data suggest that OX40 ligand is a potent co-stimulant for the robust expansion of human NK Cells and the homotypic NK cell interactions through the OX40-OX40L axis is a mechanism of NK cell expansion.
