The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Kazumori Funatsu - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human Hepatoblastoma Cell Line hep g2 a possible Cell source for hybrid artificial liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Kazuhisa Ishihara, Hiroshi Mizumoto, Toshihisa Kajiwara, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human Hepatoblastoma Cell Line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a Cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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efficacy of a polyurethane foam spheroid artificial liver by using human Hepatoblastoma Cell Line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, K Sugimachi, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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Efficacy of a polyurethane foam/spheroid artificial liver by using human Hepatoblastoma Cell Line (Hep G2)
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, Sugimachi K, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
Junji Fukuda - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human Hepatoblastoma Cell Line hep g2 a possible Cell source for hybrid artificial liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Kazuhisa Ishihara, Hiroshi Mizumoto, Toshihisa Kajiwara, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human Hepatoblastoma Cell Line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a Cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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efficacy of a polyurethane foam spheroid artificial liver by using human Hepatoblastoma Cell Line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, K Sugimachi, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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Efficacy of a polyurethane foam/spheroid artificial liver by using human Hepatoblastoma Cell Line (Hep G2)
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, Sugimachi K, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
Hiroyuki Ijima - One of the best experts on this subject based on the ideXlab platform.
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expression of a liver specific function by a Hepatoblastoma Cell Line cocultured with three dimensional endothelialized tubes in collagen gels
Journal of Bioscience and Bioengineering, 2007Co-Authors: Takayuki Takei, Hiroyuki Ijima, Shinji Sakai, Koei KawakamiAbstract:A human Hepatoblastoma Cell Line, Hep G2, showed albumin production activity, a hepatic function, when cocultured with three-dimensional endothelialized tubes in collagen gels. The albumin production rate of the collagen-based liver-like constructs increased with increasing length of the endothelialized tube in the construct.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human Hepatoblastoma Cell Line hep g2 a possible Cell source for hybrid artificial liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Kazuhisa Ishihara, Hiroshi Mizumoto, Toshihisa Kajiwara, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human Hepatoblastoma Cell Line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a Cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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efficacy of a polyurethane foam spheroid artificial liver by using human Hepatoblastoma Cell Line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, K Sugimachi, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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Efficacy of a polyurethane foam/spheroid artificial liver by using human Hepatoblastoma Cell Line (Hep G2)
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, Sugimachi K, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
Jurgen Grote - One of the best experts on this subject based on the ideXlab platform.
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the tamoxifen induced suppression of telomerase activity in the human Hepatoblastoma Cell Line hepg2 a result of post translational regulation
Journal of Cancer Research and Clinical Oncology, 2005Co-Authors: Sebastian Brandt, H Heller, K D Schuster, Jurgen GroteAbstract:Purpose Patients with advanced hepatoCellular carcinoma (HCC) have shown to benefit from tamoxifen treatment. The mechanisms of tamoxifen action in HCC, however, are not yet clearly understood. Results from studies on the human Hepatoblastoma Cell Line HepG2 provide evidence that estrogen-receptor-α-independent antiproliferative actions of tamoxifen in HCC are mediated by the suppression of telomerase activity [5].
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The tamoxifen-induced suppression of telomerase activity in the human Hepatoblastoma Cell Line HepG2: a result of post-translational regulation
Journal of Cancer Research and Clinical Oncology, 2005Co-Authors: Sebastian Brandt, H Heller, K D Schuster, Jurgen GroteAbstract:Purpose Patients with advanced hepatoCellular carcinoma (HCC) have shown to benefit from tamoxifen treatment. The mechanisms of tamoxifen action in HCC, however, are not yet clearly understood. Results from studies on the human Hepatoblastoma Cell Line HepG2 provide evidence that estrogen-receptor-α-independent antiproliferative actions of tamoxifen in HCC are mediated by the suppression of telomerase activity [ 5 ]. Materials and methods We investigate the pathway of the tamoxifen-induced down-regulation of telomerase activity, using HepG2 Cells incubated over 24 h or 48 h in the presence of 20 μM tamoxifen. Results The transcriptional levels of the three telomerase core components—human telomerase RNA (hTR), human telomerase reverse transcriptase (hTERT) (all variants), and telomerase-associated protein (TP1)—did not change during tamoxifen treatment, as revealed by RT-PCR analysis. Furthermore, the hTERT splice pattern was not shifted from the active full-length variant (+α/+β) to the inactive deletion variants (−α; −β; −α/−β) and the level of the 120 kDa hTERT full-length protein remained constant, as shown by Western blot analysis. Protein kinase C (PKC) activity has been suggested to be crucial for post-translational up-regulation of telomerase activity. In HepG2 Cells, we observed a tamoxifen-induced suppression of the total protein kinase C (PKC) activity (cytosolic and membrane-bound). Inhibition of PKC with bisindolylmaleimide I resulted in a reduction of telomerase activity, as revealed by TRAP-assay. α-tocopherol (vitamin E) diminished the effects of tamoxifen on PKC-acivity as well as on telomerase activity. Conclusions We conclude that the tamoxifen-induced decrease of telomerase activity in HepG2 Cells is mediated post-translationally via suppression of PKC-activity.
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tamoxifen induces suppression of Cell viability and apoptosis in the human Hepatoblastoma Cell Line hepg2 via down regulation of telomerase activity
Liver International, 2004Co-Authors: Sebastian Brandt, H Heller, K D Schuster, Jurgen GroteAbstract:: Background/Aims: Antiproliferative action of tamoxifen in the estrogen receptor-α-negative human Hepatoblastoma Cell Line HepG2 was investigated. Methods: HepG2 Cells, seeded at different densities (4000–36 000 Cells/cm2), were incubated with tamoxifen (1, 10, or 20 μM) or the telomerase inhibitor 3′-azido-3′-deoxythymidine (AZT) (0.6–3.0 mM) up to 72 h. Cell viability was assessed (MTT-test), flow cytometric analysis was performed, and telomerase activity was measured (telomeric repeat amplification protocol assay). Results: Ten or 20 μM tamoxifen induced a reduction of Cell viability. Basically reduction of viability was related to an increase in the fraction of G0/1-phase. When tamoxifen was present at higher concentration (20 μM) or at low Cell density (4000/cm2) an additional increase of the rate of apoptotic Cells occurred with a delay, aggravating the effect of tamoxifen on Cell viability substantially. When apoptosis was induced a significant suppression of telomerase activity preceded regularly. Direct inhibition of telomerase activity with AZT resulted in a decrease of Cell viability and apoptotis. Conclusion: The tamoxifen-induced reduction of Cell viability in HepG2 Cells depends on drug concentration and Cell density and is due to cytostatic and cytocide effects. The latter may be mediated by a down-regulation of telomerase activity.
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Tamoxifen induces suppression of Cell viability and apoptosis in the human Hepatoblastoma Cell Line HepG2 via down‐regulation of telomerase activity
Liver International, 2004Co-Authors: Sebastian Brandt, H Heller, K D Schuster, Jurgen GroteAbstract:: Background/Aims: Antiproliferative action of tamoxifen in the estrogen receptor-α-negative human Hepatoblastoma Cell Line HepG2 was investigated. Methods: HepG2 Cells, seeded at different densities (4000–36 000 Cells/cm2), were incubated with tamoxifen (1, 10, or 20 μM) or the telomerase inhibitor 3′-azido-3′-deoxythymidine (AZT) (0.6–3.0 mM) up to 72 h. Cell viability was assessed (MTT-test), flow cytometric analysis was performed, and telomerase activity was measured (telomeric repeat amplification protocol assay). Results: Ten or 20 μM tamoxifen induced a reduction of Cell viability. Basically reduction of viability was related to an increase in the fraction of G0/1-phase. When tamoxifen was present at higher concentration (20 μM) or at low Cell density (4000/cm2) an additional increase of the rate of apoptotic Cells occurred with a delay, aggravating the effect of tamoxifen on Cell viability substantially. When apoptosis was induced a significant suppression of telomerase activity preceded regularly. Direct inhibition of telomerase activity with AZT resulted in a decrease of Cell viability and apoptotis. Conclusion: The tamoxifen-induced reduction of Cell viability in HepG2 Cells depends on drug concentration and Cell density and is due to cytostatic and cytocide effects. The latter may be mediated by a down-regulation of telomerase activity.
K Okamura - One of the best experts on this subject based on the ideXlab platform.
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differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human Hepatoblastoma Cell Line hep g2 a possible Cell source for hybrid artificial liver
Cell Transplantation, 2005Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Kazuhisa Ishihara, Hiroshi Mizumoto, Toshihisa Kajiwara, Kazumori FunatsuAbstract:The aim of this study was to investigate the feasibility of human Hepatoblastoma Cell Line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a Cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase—a urea cycle enzyme—was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volum...
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efficacy of a polyurethane foam spheroid artificial liver by using human Hepatoblastoma Cell Line hep g2
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, K Sugimachi, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...
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Efficacy of a polyurethane foam/spheroid artificial liver by using human Hepatoblastoma Cell Line (Hep G2)
Cell Transplantation, 2003Co-Authors: Junji Fukuda, K Okamura, Kohji Nakazawa, Hiroyuki Ijima, Y Yamashita, Mitsuo Shimada, Ken Shirabe, Eiji Tsujita, Sugimachi K, Kazumori FunatsuAbstract:We investigated the availability of human Hepatoblastoma Cell Line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a Cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multiCellular aggregates (spheroids) of 100–200 μm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit Cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit Cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, ...