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Berlin Brandenburg

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  • Cell Differentiation
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  • 1
    Language: English
    In: Experimental & Applied Acarology, 2002, Vol.28(1), pp.203-208
    Description: As already shown, some inducers of the differentiation of promyelocytic cells along the granulocytic pathway, such as dimethylsulphoxide (DMSO) or all- trans retinoic acid, can enhance propagation of granulocytic ehrlichiae in HL-60 cell cultures. This study was conducted to prove whether sodium valproate, a salt of di- n -propylacetic acid (VPA) known to trigger cellular differentiation in several solid and hematopoietic malignancies is similarly efficient in ehrlichial cultures. Two cell lines derived from HL-60, that is, low-passage undifferentiated HL-60 (HL-60F) and high-passage HL-60 spontaneously differentiated towards monocytic phenotype (HL-60J) were grown in RPMI 1640 medium supplemented with 10% FBS. The respective HL-60F and HL-60J IC 50 -values for NaVPA were estimated to be 0.8 and 2.2 mM under these culture conditions; to stimulate the differentiation, the respective doses of 0.3 and 1.2 mM were then applied. When the NaVPA-treated cells of both lines were challenged with an ehrlichial laboratory strain (HGE), maintained in splenectomized NMRI mice, the respective 1–2 and ≤0.1% primary infection rates in HL-60F and HL-60J cultures were observed 3 days post-inoculation. In comparison, only rare (≤0.1%) infected HL-60F and no infected HL-60J cells were recorded under the same experimental conditions in untreated control cultures. HGE continuously propagated in NaVPA-supplemented HL-60F cultures remained infectious to mice at least up to the 95th passage (12 months). NaVPA can thus facilitated continuous propagation of granulocytic ehrlichiae in cell cultures without a substantial loss of infectiveness.
    Keywords: Anaplasma phagocytophilum ; ehrlichiosis ; cell culture ; HL-60 ; sodium valproate
    ISSN: 0168-8162
    E-ISSN: 1572-9702
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  • 2
    Language: English
    In: International Journal of Cancer, 01/03/1996, Vol.65(1), pp.90-96
    Description: Human neuroblastoma cell line UKF-NB-4 persistently infected with human cytomegalovirus (HCMV) strain AD169 was established to study the effects of long-term HCMV infection on virus production and phenotypic characteristics of tumour cells. The cells designated UKF-NB-4 super(AD169) were subcultured (80 subcultures) over a period of more than 2 years after initiation of infection. UKF-NB-4 super(AD169) cells continued to produce infectious virus in successive passages, with a titre ranging from 9 x 10 super(3) to 1 x 10 super(5) and from 2 x 10 super(1) to 2 x 10 super(2) plaque-forming units per 10 super(6) cells and 1 ml culture medium, respectively; 10-20% of the cells produced HCMV-specific antigens, while 6-13% produced infectious virus progeny. The number of HCMV-specific DNA copies ranged from 9 x 10 super(4) to 9 x 10 super(6) per 10 super(6) cells. Transmission electron microscopy confirmed the productive nature of HCMV infection. UKF-NB-4 super(AD169) cultures proliferated, with population doubling time ranging from 24.5 to 26.6 hr (19.5 to 20.3 hr for UKF-NB-4) and cell viability from 79% to 85% (91-96% for UKF-NB-4). Significantly lower amounts of tyrosine hydroxylase and decreased activity for dopamine- beta -hydroxylase than in uninfected cells were observed in UKF-NB-4 super(AD169) cells. However, the expression of N-myc oncoprotein was significantly increased in persistently infected cultures. Our results show that long-term productive HCMV infection of UKF-NB-4 cell line is associated with the modulation of phenotypic properties, which may be related to the biological behaviour of neuroblastoma cells.
    Keywords: Cytomegalovirus ; Cytomegalovirus ; Neuroblastoma Cells ; Man ; Tumor Cells ; Phenotyping ; Neuroblastoma Cells ; Man ; Tumor Cells ; Phenotyping ; Neurovirology ; Virus Behavior in Cell Culture ; Tyrosine 3-Monooxygenase ; Dopamine Beta -Monooxygenase ; N-Myc Protein ; Tyrosine 3-Monooxygenase ; Dopamine Beta -Monooxygenase ; N-Myc Protein ; N-Myc Protein ; Dopamine Beta -Monooxygenase ; Tyrosine 3-Monooxygenase;
    ISSN: 00207136
    E-ISSN: 10970215
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  • 3
    Language: English
    In: International Journal of Oncology, January 2002, Vol.20(1), pp.97-106
    Description: Valproic acid (VPA) has been shown to induce growth-arrest and differentiation of human neuroectodermal tumors similarly to several other fatty acids. In the present study, we show that continuous VPA treatment together with Interferon-α (INF-α) synergistically inhibited cell growth of a well-established model of neuroblastoma (NB) differentiation using the human N-myc amplified cell line BE(2)-C. Suppression of tumor growth was accompanied by morphological features of neuronal differentiation and inhibition of histone deacetylase activity. Furthermore, induction of differentiation was concomitant with altered expression of genes related to malignant phenotype such as down-regulation of N-myc, induction of bcl-2 and neural cell adhesion molecule. Production of inhibitors of angiogenesis like thrombospondin-1 and activin A was up-regulated in differentiated NB cells. Treatment with VPA alone decreased the ability of BE(2)-C cells to adhere to and penetrate human endothelium. All these effects of VPA were significantly enhanced when combined with INF-α which on its own had little or no effect. These results suggest that combination of VPA and INF-α may provide a novel therapeutic strategy for NB due to enhanced inhibition of tumor cell growth, induction of tumor differentiation and suppression of malignant biology by reduced angiogenic and decreased metastatic potentials.
    Keywords: Antineoplastic Agents -- Therapeutic Use ; Brain Neoplasms -- Drug Therapy ; Cell Differentiation -- Drug Effects ; Enzyme Inhibitors -- Therapeutic Use ; Interferon-Alpha -- Therapeutic Use ; Neuroblastoma -- Drug Therapy ; Valproic Acid -- Therapeutic Use;
    ISSN: 1019-6439
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  • 4
    In: Anti-Cancer Drugs, 1997, Vol.8(10), pp.958-963
    Description: Sodium valproate (VPA) belongs to the group of simple branched-chain fatty acids and due its anticonvulsive activity is broadly applied in the treatment of epilepsy. We previously showed that VPA is able to induce cellular differentiation, to enhance immunogenicity and to inhibit proliferation of human neuroblastoma (NB) cells in vitro. Furthermore, we demonstrated that VPA inhibits proliferation, enhances neural cell adhesion molecule expression and decreases CD44 expression of human and rat glioma cells in vitro. In the present study we investigated the anttitumoral effects of VPA on established human NB xenografts from UKF-NB-3 human NB cells in athymic (nude) mice. When the animals developed s.c. tumors of about 100 mm volume they were treated with 400 or 200 mg/kg/day VPA i.p. At the end of the treatment period (40 days) tumor volumes in animals treated with 400 and 200 mg/kg VPA were about 4− (p〈 0.0001) and 2-fold (p〈 0.0005) smaller than in the saline-treated control group, respectively. Histological examination of the remnant tumors of treated animals revealed induction of differentiation by induction of stroma-rich tumors and nodules that contained elongated NB cells. Pyknotic nuclei and apoptotic bodies indicated induction of apoptosis. We conclude that VPA is able to abrogate NB growth in vivo and may therefore be useful in the treatment of NB patients.
    Keywords: Antineoplastic Agents -- Pharmacology ; Neuroblastoma -- Drug Therapy ; Valproic Acid -- Pharmacology;
    ISSN: 0959-4973
    E-ISSN: 14735741
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  • 5
    Language: English
    In: Cancer Letters, 1993, Vol.70(1), pp.15-24
    Description: Sodium phenylacetate (NaPA) at concentrations ranging from 2 to 6 mM stimulated morphological differentiation of two human neuroblastoma cell lines IMR-32 and UKF-NB-3. These concentrations inhibited growth and DNA synthesis of the cells in a dose dependent manner without significant effect on cell viability. The differentiated cells showed pseudoganglia formation and extension of cellular processes. The morphological differentiation in both cell lines was accompanied by decreased expression of N- myc oncoprotein. These results suggest that NaPA at concentrations, which have been achieved in humans with no significant adverse effects, promotes differentiation of cultured human neuroblastoma cells in association with the reduced expression of the malignant phenotype.
    Keywords: Neuroblastoma ; Differentiation ; Phenylacetate ; Retinoic Acid ; N- Myc ; Medicine
    ISSN: 0304-3835
    E-ISSN: 1872-7980
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  • 6
    Language: English
    In: Cell Biology International, April 1994, Vol.18(4), pp.271-278
    Description: The effects of aphidicolin, a specific inhibitor of DNA polymerase alpha, on cell growth, DNA synthesis and myogenic differentiation in the human alveolar rhabdomyosarcoma cell line KFR were studied. The treatment with aphidicolin at 5 x 10(-6) M concentration, which completely inhibited DNA synthesis and cell growth, induced morphological differentiation of small mononuclear cells to elongated, multinucleated (myotube-like) structures. The morphological differentiation was accompanied by the expression of skeletal muscle myosin; about 30% myosin-positive cells were observed after 14 days of treatment, compared to 2.3% in untreated cultures. The results showed that aphidicolin induces differentiation of human rhabdomyosarcoma cells and that multinucleated myotube-like elements may develop simply by cell fusion without cell division and DNA synthesis.
    Keywords: Biology
    ISSN: 1065-6995
    E-ISSN: 1095-8355
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  • 7
    In: Anti-Cancer Drugs, 1996, Vol.7(7), pp.766-773
    Description: Valproic acid (VPA) is a simple branched-chain fatty acid that has anticonvulsant activity and is widely used in the treatment of epilepsy. VPA was found to effect growth and differentiation of human neuroblastoma (NB) cells in vitro at concentrations that have been achieved in humans with no significant adverse effects. Treatment of UKF-NB-2 and UKF-NB-3 NB cell lines with VPA at concentrations ranging from 0.5 to 2 mM resulted in neuronal morphological differentiation characterized by extension of cellular processes without significant effects on cell viability. Ultra-structural features of VPA-treated cells were consistent with the neuronal type of differentiation. VPA treatment of NB cells was associated with decreased expression of N-myc oncoprotein and increased expression of neural cell adhesion molecule in their membrane. Treatment of NB cells with 0.5 mM VPA increased their sensitivity to lymphokine-activated killer lysis. The results indicate that VPA, at non-toxic pharmacological concentrations, arrests the growth, induces differentiation and increases immunogenicity of NB cells through non-toxic mechanisms.
    Keywords: Antibiotics ; Miscellaneous, Reviews ; Sodium Valproate ; Neuroblastoma ; Neuroblastoma ; Sodium Valproate;
    ISSN: 0959-4973
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  • 8
    Language: English
    In: Cancer Letters, 1994, Vol.78(1), pp.41-48
    Description: Sodium phenylacetate (NaPA) at concentrations ranging from 2 to 10 mM promoted myogenic differentiation of the human alveolar rhabdomyosarcoma cell line KFR. These concentrations inhibited DNA synthesis of the cells in a dose-dependent manner without significant effect on cell viability. The morphological differentiation of small mononuclear elements to terminal, elongated multinuclear structures resembling myotubes was accompanied by the expression of skeletal muscle myosin. The proportion of differentiated myosin-positive cells which was around 0.8-1.7% in control cultures 12 days after seeding was increased by NaPA treatment up to 47%. In the cytoplasm of differentiated cells, features of sarcomerogenesis were observed. These results suggest that NaPA is an effective inducer of rhabdomyosarcoma cell differentiation at concentrations that have been achieved in humans with no significant adverse effects.
    Keywords: Rhabdomyosarcoma ; Phenylacetate ; Glutamine ; Myogenic Differentiation ; Sarcomerogenesis ; Medicine
    ISSN: 0304-3835
    E-ISSN: 1872-7980
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