The Experts below are selected from a list of 147 Experts worldwide ranked by ideXlab platform
Takashi Muramatsu - One of the best experts on this subject based on the ideXlab platform.
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Embryoglycan: a highly branched poly-N-acetyllactosamine in pluripotent stem cells and early embryonic cells
Glycoconjugate Journal, 2017Co-Authors: Takashi MuramatsuAbstract:Embryonal carcinoma cells, stem cells of Teratocarcinomas, are pluripotent stem cells and also prototypes of embryonic stem cells. Embryonal carcinoma cells contain large amounts of a highly branched poly- N -acetyllactosamine called embryoglycan, which has a molecular weight of approximately 10,000 or greater, and is asparagine-linked. This glycan was found by analyses of fucose-labeled glycopeptides, and its characteristics were established by biochemical analyses. The content of embryoglycan progressively decreases during the in vitro differentiation of embryonal carcinoma cells. Embryoglycan is also abundant in mouse embryonic stem cells and preimplantation mouse embryos, and decreases during embryogenesis. Embryoglycan carries a number of carbohydrate markers of murine pluripotent stem cells. Lewis x markers, such as SSEA-1, 4C9 antigen, and binding sites for Lotus tetragonolobus agglutinin are of particular importance. 4C9 antigenicity requires clustering of Lewis x, best accomplished by poly- N -acetyllactosamine branching, whereas SSEA-1 does not. Although in vivo evidence is lacking, these epitopes have been suggested to participate in cell-to-cell and cell-to-substratum adhesion. Other markers on embryoglycan include α-galactosyl antigens such as ECMA-2, and binding sites for Dolichos biflorus agglutinin, the epitope of which is considered to be identical to Sd^a antigen, namely, GalNAcβ1–4(NeuAcα2–3)Galβ1–4GlcNAc. While embryoglycan is also present in human teratocarcinoma cells, the carbohydrate markers characterized in human pluripotent stem cells to date are largely carried by glycolipids and keratan sulfate. Information on embryoglycan and markers carried by it may assist in the development of new markers of human pluripotent stem cells and their progenies.
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Reactivity of a Monoclonal Antibody Raised against Human Leukemic Cells to Embryonic and Adult Tissues of
2016Co-Authors: The Mouse, Takashi MuramatsuAbstract:C-9-1, a monoclonal IgM antibody raised against human null cell acute lymphocytic leukemia cells reacted with restricted regions of embryonic and adult tissues of the mouse. The antigen positive sites in the embryos included embryonic ectoderm, visceral endoderm, trophoblastic cells invading the maternal decidua of 5-7-day embryos, primordial germ cells of 10-12-day embryos, epithelium of nasal chamber, the bronchus, Mullerian duct, epididymis and bladder of 12-17-day embryos. In the adult mice, C-9-1 antigen was detected in renal tubules, a part of stomach, bladder, endometrium and epididymal sperm. Embryonal carcinoma cells, but not endodermal cells of teratocarcinoma expressed the antigen. Thus, C-9-1 antigen showed distribution similar to SSEA-1. However, C-9-1 antigen was not detected in preimplantation embryos, nor in oviduct, both of which are positive for SSEA-I. Cell surface markers are useful in analysis of the proctss of cell differentiation. A notable example is early mouse embryos and Teratocarcinomas. Among a variety of cell surface markers found in the system, one of the most valuable ones is SSEA-1 (stage-specific embryonic antigen-I) which is defined by a monoclonal antibody and is determined by Fucd+3GlcNAc linkage ( I, 2, 3). In this communication, we describe another cell surface marker, which show
Reinhard Kurth - One of the best experts on this subject based on the ideXlab platform.
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expression of human endogenous retrovirus k in melanomas and melanoma cell lines
Cancer Research, 2005Co-Authors: Kristina Buscher, Maja A Hofmann, Wolfram Sterry, Reinhard Kurth, Uwe Trefzer, Joachim DennerAbstract:The human endogenous retrovirus K family (HERV-K) comprises 30 to 50 closely related proviruses, most of which are defective. In contrast to all other human endogenous retroviruses, some HERV-K proviruses have maintained open reading frames for all viral proteins. In addition to the structural proteins Gag and Env and the reverse transcriptase, two regulatory proteins (Rec and Np9) have been described. Malignant melanoma has the highest mortality among skin cancers and is particularly aggressive. To study the expression of HERV-K, a set of seven primers was developed that allows discrimination between full-length and spliced mRNA and mRNA from deleted and undeleted proviruses. Expression of full-length mRNA from deleted and undeleted proviruses was detected in all human cells investigated. Expression of spliced env and rec was detected in a teratocarcinoma cell line, in 45% of the metastatic melanoma biopsies, and in 44% of the melanoma cell lines. In normal neonatal melanocytes, spliced rec was detected but not spliced env. Viral proteins were shown to be expressed in primary melanomas, metastases, and melanoma cell lines by immunohistochemistry, immunofluorescence, and Western blot analyses using specific antisera. For the first time, antibodies against HERV-K were found in melanoma patients. Melanomas are, in addition to Teratocarcinomas and human breast cancer, the third tumor type with enhanced expression of HERV-K.
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Evidence That HERV-K Is the Endogenous Retrovirus Sequence That Codes for the Human Teratocarcinoma-Derived Retrovirus HTDV
Virology, 1993Co-Authors: Klaus Boller, Johannes Löwer, Roswitha Lower, Herbert König, Marlies Sauter, Nikolaus Mueller-lantzsch, Reinhard KurthAbstract:Abstract Human teratocarcinoma-derived viruses (HTDV) are retrovirus-like particles that are regularly observed by electron microscopy at low frequency in cell lines established from human Teratocarcinomas. Over the last years, one of our teratocarcinoma cell lines spontaneously began to produce high amounts of HTDV. This cell line is stained in immunofluorescence tests by an antiserum raised against recombinant gag protein of HERV-K, an expressed human endogenous retrovirus sequence. In immunoelectron microscopy of ultrathin frozen sections, this anti HERV-Kgag-specific antiserum reacts specifically with HTDV particles. In Western blots, the antiserum recognizes predominantly a protein with an apparent molecular weight of 30 kDa, presumably the major core protein of HTDV particles. Taken together, these results provide evidence that HERVK codes for HTDV.
Qijun Qian - One of the best experts on this subject based on the ideXlab platform.
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Establishment of Mouse Teratocarcinomas Stem Cells Line and Screening Genes Responsible for Malignancy
PloS one, 2012Co-Authors: Tao Liu, Ying Wang, Xinrong Peng, Liqing Zhang, Cheng Jingbo, Jin Huajun, Qijun QianAbstract:The sequential transplantation of embryonal carcinoma cells in vivo can accelerate the growth and malignancy of Teratocarcinomas. However, the possible molecular mechanisms in this process that reflect cancer formation in the early stage are largely unknown and. To identify which genes are associated with the changes of malignancy of Teratocarcinomas, we established a tumorigenesis model in which teratocarcinoma were induced via injecting embryonic stem cells into immuno-deficiency mice, isolating teratocarcinoma stem cell from a teratocarcinoma in serum-free culture medium and injecting teratocarcinoma stem cells into immune-deficient mice continuously. By using high-throughput deep sequence technology, we identified 26 differentially expressed genes related to the changes of characteristics of teratocarcinoma stem cell in which 18 out of 26 genes were down-regulated and 8 genes were up-regulated. Among these genes, several tumor-related genes such as Gata3, Arnt and Tdgf1, epigenetic associated genes such as PHC1 and Uty were identified. Pathway enrichment analysis result revealed that Wnt signaling pathway, primary immunodeficiency pathway, antigen processing and presentation pathway and allograft rejection pathway were involved in the teratocarcinoma tumorigenesis (corrected p value
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establishment of mouse Teratocarcinomas stem cells line and screening genes responsible for malignancy
PLOS ONE, 2012Co-Authors: Tao Liu, Ying Wang, Xinrong Peng, Liqing Zhang, Qijun Qian, Jingbo Cheng, Huajun JinAbstract:The sequential transplantation of embryonal carcinoma cells in vivo can accelerate the growth and malignancy of Teratocarcinomas. However, the possible molecular mechanisms in this process that reflect cancer formation in the early stage are largely unknown and. To identify which genes are associated with the changes of malignancy of Teratocarcinomas, we established a tumorigenesis model in which teratocarcinoma were induced via injecting embryonic stem cells into immuno-deficiency mice, isolating teratocarcinoma stem cell from a teratocarcinoma in serum-free culture medium and injecting teratocarcinoma stem cells into immune-deficient mice continuously. By using high-throughput deep sequence technology, we identified 26 differentially expressed genes related to the changes of characteristics of teratocarcinoma stem cell in which 18 out of 26 genes were down-regulated and 8 genes were up-regulated. Among these genes, several tumor-related genes such as Gata3, Arnt and Tdgf1, epigenetic associated genes such as PHC1 and Uty were identified. Pathway enrichment analysis result revealed that Wnt signaling pathway, primary immunodeficiency pathway, antigen processing and presentation pathway and allograft rejection pathway were involved in the teratocarcinoma tumorigenesis (corrected p value<0.05). In summary, our study established a tumorigenesis model and proposed some candidate genes and signaling pathways that may play a key role in the early stage of cancer occurrence.
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Establishment of Mouse Teratocarcinomas Stem Cells Line and Screening Genes Responsible for Malignancy
2012Co-Authors: Tao Liu, Ying Wang, Xinrong Peng, Liqing Zhang, Jingbo Cheng, Huajun Jin, Qijun QianAbstract:The sequential transplantation of embryonal carcinoma cells in vivo can accelerate the growth and malignancy of Teratocarcinomas. However, the possible molecular mechanisms in this process that reflect cancer formation in the early stage are largely unknown and. To identify which genes are associated with the changes of malignancy of Teratocarcinomas, we established a tumorigenesis model in which teratocarcinoma were induced via injecting embryonic stem cells into immuno-deficiency mice, isolating teratocarcinoma stem cell from a teratocarcinoma in serum-free culture medium and injecting teratocarcinoma stem cells into immune-deficient mice continuously. By using high-throughput deep sequence technology, we identified 26 differentially expressed genes related to the changes of characteristics of teratocarcinoma stem cell in which 18 out of 26 genes were down-regulated and 8 genes were up-regulated. Among these genes, several tumor-related genes such as Gata3, Arnt and Tdgf1, epigenetic associated genes such as PHC1 and Uty were identified. Pathway enrichment analysis result revealed that Wnt signaling pathway, primary immunodeficiency pathway, antigen processing and presentation pathway and allograft rejection pathway were involved in the teratocarcinoma tumorigenesis (corrected p value,0.05). In summary, our study established a tumorigenesis model and proposed some candidate gene
Mario Chevrette - One of the best experts on this subject based on the ideXlab platform.
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Suppression of tumorigenicity in human teratocarcinoma cell line PA-1 by introduction of chromosome 4.
Cancer Research, 1994Co-Authors: I.j. Mcgowan-jordan, Marsha D. Speevak, David Blakey, Mario ChevretteAbstract:Teratocarcinomas are tumors that develop spontaneously in the gonads and usually contain a rapidly dividing, undifferentiated stem cell population. Immature ovarian Teratocarcinomas are highly malignant with only 30–60% of patients surviving for 2 years after diagnosis. We have used microcell fusion to introduce individually tagged normal human chromosomes into the PA-1 human teratocarcinoma cell line. Introduction of human chromosome 4 caused a change of cell morphology in culture and suppressed PA-1 tumorigenicity in nude mice, whereas addition of portions of either chromosome 7 or 12 had no effect on the cell phenotype. The PA-1 cell line regained its tumorigenicity when the tagged chromosome 4 was lost under negative selection. We conclude that there is a putative tumor suppressor gene on human chromosome 4 whose expression interferes with the tumorigenicity of PA-1 cells.
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suppression of tumorigenicity in human teratocarcinoma cell line pa 1 by introduction of chromosome 4
Cancer Research, 1994Co-Authors: I J Mcgowanjordan, Marsha D. Speevak, David Blakey, Mario ChevretteAbstract:Teratocarcinomas are tumors that develop spontaneously in the gonads and usually contain a rapidly dividing, undifferentiated stem cell population. Immature ovarian Teratocarcinomas are highly malignant with only 30-60% of patients surviving for 2 years after diagnosis. We have used microcell fusion to introduce individually tagged normal human chromosomes into the PA-1 human teratocarcinoma cell line. Introduction of human chromosome 4 caused a cell morphology in culture and suppressed PA-1 tumorigenicity in nude mice, whereas addition of portions of either chromosome 7 or 12 had no effect on the cell phenotype. The PA-1 cell line regained its tumorigenicity when the tagged chromosome 4 was lost under negative selection. We conclude that there is a putative tumor suppressor gene on human chromosome 4 whose expression interferes with the tumorigenicity of PA-1 cells.
Joachim Denner - One of the best experts on this subject based on the ideXlab platform.
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expression of human endogenous retrovirus k in melanomas and melanoma cell lines
Cancer Research, 2005Co-Authors: Kristina Buscher, Maja A Hofmann, Wolfram Sterry, Reinhard Kurth, Uwe Trefzer, Joachim DennerAbstract:The human endogenous retrovirus K family (HERV-K) comprises 30 to 50 closely related proviruses, most of which are defective. In contrast to all other human endogenous retroviruses, some HERV-K proviruses have maintained open reading frames for all viral proteins. In addition to the structural proteins Gag and Env and the reverse transcriptase, two regulatory proteins (Rec and Np9) have been described. Malignant melanoma has the highest mortality among skin cancers and is particularly aggressive. To study the expression of HERV-K, a set of seven primers was developed that allows discrimination between full-length and spliced mRNA and mRNA from deleted and undeleted proviruses. Expression of full-length mRNA from deleted and undeleted proviruses was detected in all human cells investigated. Expression of spliced env and rec was detected in a teratocarcinoma cell line, in 45% of the metastatic melanoma biopsies, and in 44% of the melanoma cell lines. In normal neonatal melanocytes, spliced rec was detected but not spliced env. Viral proteins were shown to be expressed in primary melanomas, metastases, and melanoma cell lines by immunohistochemistry, immunofluorescence, and Western blot analyses using specific antisera. For the first time, antibodies against HERV-K were found in melanoma patients. Melanomas are, in addition to Teratocarcinomas and human breast cancer, the third tumor type with enhanced expression of HERV-K.