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Berlin Brandenburg

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  • 1
    Language: English
    In: Oncology Letters, 11/2017, Vol.14(5), pp.5513-5518
    Description: Treatment failure in metastatic bladder cancer is commonly caused by acquisition of resistance to chemotherapy in association with tumor progression. Since alterations of integrins can influence the adhesive and invasive behaviors of urothelial bladder cancer cell lines, the present study aimed to evaluate the role of integrins in bladder cancer cells with acquired resistance to standard first-line chemotherapy with gemcitabine, and cisplatin. Therefore, four gemcitabine- and four cisplatin-resistant sublines out of a panel of four parental urothelial bladder cancer cell lines (TCC-SUP, HT1376, T24, and 5637) were used. Expression of integrin subunits α3, α5, α6, β1, β3, and β4 was detected using flow cytometry. Adhesion and chemotaxis were analyzed. For functional assays, integrin β1 was attenuated with a blocking antibody. In untreated cells, chemotaxis was upregulated in 3/4 gemcitabine-resistant sublines. In cisplatin-resistant cells, chemotaxis was enhanced in 2/4 cell lines. Acquired chemoresistance induced the upregulation of integrin β1 in all four tested gemcitabine-resistant sublines, as well as an upregulation in 3/4 cisplatin-resistant sublines compared with parental cell lines. Following the inhibition of integrin β1, adhesion to extracellular matrix components was downregulated in 3/4 gemcitabine-resistant sublines and in all four tested cisplatin-resistant sublines. Since integrin β1 is frequently upregulated in chemoresistant urothelial cancer cell lines and inhibition of integrin β1 may influence adhesion, further studies are warranted to evaluate integrin β1 as a potential therapeutic target for bladder cancer in vivo .
    Keywords: Adhesion ; Acquired Resistance ; Cancer Cell Line Collection ; Chemotaxis ; Cisplatin ; Gemcitabine ; Integrin Β1 ; Urothelial Cancer
    ISSN: 1792-1074
    E-ISSN: 1792-1082
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  • 2
    Language: English
    In: Oncology Letters, 06/2017, Vol.13(6), pp.4085-4092
    Description: Nanoparticle albumin-bound (nab)-paclitaxel appears to exhibit better response rates in patients with metastatic urothelial cancer of the bladder whom are pretreated with nab-paclitaxel compared with conventional paclitaxel. Paclitaxel may induce multidrug resistance in patients with cancer, while the mechanisms of resistance against paclitaxel are manifold. These include reduced function of pro-apoptotic proteins, mutations of tubulin and overexpression of the drug transporter adenosine 5′-triphosphate-binding cassette transporter subfamily B, member 1 (ABCB1). To evaluate the role of ABCB1 in nab-paclitaxel resistance in urothelial cancer cells, the bladder cancer cell lines T24 and TCC-SUP, as well as sub-lines with acquired resistance against gemcitabine (T24 r GEMCI 20 and TCC-SUP r GEMCI 20 ) and vinblastine (T24 r VBL 20 and TCC-SUP r VBL 20 ) were examined. For the functional inhibition of ABCB1, multi-tyrosine kinase inhibitors with ABCB1-inhibiting properties, including cabozantinib and crizotinib, were used. Additional functional assessment was performed with cell lines stably transduced with a lentiviral vector encoding for ABCB1, and protein expression was determined by western blotting. It was indicated that cell lines overexpressing ABCB1 exhibited similar resistance profiles to nab-paclitaxel and paclitaxel. Cabozantinib and crizotinib sensitized tumor cells to nab-paclitaxel and paclitaxel in the same dose-dependent manner in cell lines overexpressing ABCB1, without altering the downstream signaling of tyrosine kinases. These results suggest that the overexpression of ABCB1 confers resistance to nab-paclitaxel in urothelial cancer cells. Additionally, small molecules may overcome resistance to anticancer drugs that are substrates of ABCB1.
    Keywords: Abcb1 ; Acquired Resistance ; Bladder Cancer ; Cabozantinib ; Cancer Cell Line Collection ; Crizotinib ; Nanoparticle Albumin-Bound Paclitaxel
    ISSN: 1792-1074
    E-ISSN: 1792-1082
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  • 3
    Language: English
    In: International Journal of Molecular Medicine, February 2005, Vol.15(2), pp.323-327
    Description: Clinical observations and our high-density oligonucleotide microarray results demonstrated increased expression of proinflammatory chemokines after SARS-CoV infection. Here, we investigated the influence of SARS-CoV infection on CXCL8 (interleukin 8) and CXCL10 (interferon-γ-inducible protein 10) in human intestinal epithelial (Caco2) cells. RT-PCR and ELISA showed time-dependent up-regulation of both chemokines after SARS-CoV infection. Electric mobility shift assay revealed increased DNA binding activity of the cellular transcription factors activator protein 1 (AP-1) and nuclear factor (B (NF-κB) in SARS-CoV infected cells. High hydrocortisone concentrations (≥50 µg/ml) completely prevented increased DNA binding activity of AP-1 and NF-κB and inhibited up-regulation of CXCL8 and CXCL10, but did not reduce chemokine expression to basal levels. Ribavirin that does not inhibit SARS-CoV replication in Vero cells inhibited SARS-CoV replication in Caco2 cells at therapeutical concentrations. Hydrocortisone neither influenced SARS-CoV titres alone nor in combination with ribavirin. Our results show that corticosteroids may be of limited benefit in the suppression of chemokine production by SARS-CoV-infected cells.
    Keywords: Gene Expression Regulation, Neoplastic ; Chemokines, Cxc -- Biosynthesis ; Colonic Neoplasms -- Metabolism ; Hydrocortisone -- Pharmacology ; Interleukin-8 -- Biosynthesis ; Intestines -- Cytology ; Sars Virus -- Metabolism ; Severe Acute Respiratory Syndrome -- Metabolism;
    ISSN: 1107-3756
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  • 4
    Language: English
    In: Oncology Reports, January 2005, Vol.13(1), pp.157-160
    Description: Aphidicolin, a tetracyclic diterpene antibiotic produced by Cephalosporium aphidicola, is under investigation as anti-cancer drug. Because of its poor solubility in water, it cannot be administered directly in vivo. Systemic application of aphidicolin glycinate or aphidicolin γ-cyclodextrin complexes resulted in tumour growth inhibition but not in cures. To improve the pharmacokinetics, a liposomal preparation of aphidicolin was developed and tested in neuroblastoma-bearing (UKF-NB-3) mice. The loading capacity of these liposomes was limited. Therefore, 4.5 mg aphidicolin/kg body weight was the maximum aphidicolin dose that could be applied as liposomal preparation in this approach. Comparison of effects on tumour growth exhibited by aphidicolin liposomes (4.5 mg aphidicolin/kg) given for 15 consecutive days to those of γ-cyclodextrin inclusion complexes (15 mg aphidicolin/kg) revealed comparable tumour growth inhibition, although aphidicolin concentrations were approximately 3-fold lower. This shows that liposomal encapsulation is a promising strategy for the improvement of systemic anti-cancer activity of aphidicolin.
    Keywords: Antibiotics, Antineoplastic -- Administration & Dosage ; Aphidicolin -- Administration & Dosage ; Neuroblastoma -- Drug Therapy;
    ISSN: 1021-335X
    E-ISSN: 17912431
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  • 5
    Language: English
    In: International Journal of Oncology, December 2004, Vol.25(6), pp.1795-1799
    Description: Valproic acid (VPA) as a differentiation inducing anti-neoplastic substance is currently tested in solid tumour and leukaemia patients. Previously, we were able to show that the anti-cancer activity of VPA was synergistically increased by interferon-α (IFN-α) in Be(2)-C neuroblastoma (NB) cells. Now, we studied the effects of VPA in combination with IFN-α on two other NB cell lines. UKF-NB-2 and UKF-NB-3 cell growth was synergistically inhibited by VPA and IFN-α. Cell cycle investigations revealed massive accumulation of cells in G0/G1-phase after a combined treatment with VPA and IFN-α. The VPA-induced accumulation of acetylated histones in NB cell nuclei that indicates inhibition of histone deacetylases was not further enhanced by the combination treatment with IFN-α. Most strikingly, VPA plus IFN-α synergistically inhibited growth of UKF-NB-3 xenograft tumours in nude mice and induced complete cures in two out of six animals, while single treatment merely inhibited tumour growth. The results of this study together with our previous report strongly encourage the clinical evaluation of VPA and IFN-α for NB patients.
    Keywords: Enzyme Inhibitors -- Pharmacology ; Interferon-Alpha -- Pharmacology ; Neuroblastoma -- Pathology ; Valproic Acid -- Pharmacology;
    ISSN: 1019-6439
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  • 6
    Language: English
    In: International Journal of Molecular Medicine, June 2003, Vol.11(6), pp.743-747
    Description: The human T-lymphoid cell line H9 resistant to 3'-azido-2',3'-dideoxythymidine (AZT) has a very low level of thymidine kinase (TK) expression which accounts for the failure of AZT to inhibit HIV-1 replication. In the present study DNA methylation and histone deacetylation as possible mechanisms of decreased TK gene expression in the resistant cells were investigated. The resistant cells expressed high levels of DNA methyltransferases (DNMTs) 3a and 3b. The DNA methylation inhibitor, 5-aza-cytidine (5-aza-C), increased TK gene expression and antiviral activity of AZT in the resistant cells, while histone deacetylase inhibitor trichostatin A (TSA) had no effect. The results suggest that hypermethylation of the TK gene but not histone deacetylation in AZT-resistant H9 cells accounts for decreased TK gene expression and failure of AZT to inhibit HIV-1 replication probably due to overexpression of DNMT 3a and 3b.
    ISSN: 1107-3756
    Source: Spandidios Publications (Spandidos Publications Ltd.)
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  • 7
    Language: English
    In: International Journal of Molecular Medicine, February 2004, Vol.13(2), pp.327-331
    Description: Recently, we reported that thrombin specifically stimulates protease-activated receptor-1 (PAR-1) signaling in RPE entailing inhibition of Sp1 dependent HCMV replication. We now studied whether thrombin modulates the expression of the proinflammatory cytokine/chemokines IL-6 and IL-8 in mock- and cytomegalovirus-infected human retinal pigment epithelial cells (RPE). Our data show that thrombin/PAR-1 stimulates IL-6 and IL-8 gene transcription and protein secretion in both mock- and HCMV-infected RPE. Thrombin/PAR-1-mediated signaling stimulated PKC and NF-κB-dependent IL-6 and IL-8 gene expression via phosphoinositide 3-kinase and further downstream via p42/44 and p38 MAPKs. Thus, thrombin/PAR-1-mediated IL-6/IL-8 gene expression is uncoupled from Sp1 inhibition and may support proinflammatory pathomechanisms probably involved in hemorrhage/HCMV retinitis progression.
    Keywords: Cytomegalovirus Infections -- Metabolism ; Interleukin-6 -- Genetics ; Interleukin-8 -- Genetics ; Pigment Epithelium of Eye -- Metabolism ; Thrombin -- Metabolism;
    ISSN: 1107-3756
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  • 8
    Language: English
    In: International Journal of Molecular Medicine, August 2004, Vol.14(2), pp.175-178
    Description: Recently, evidence has been obtained that the Na+/H+ exchange (NHE) inhibitor HOE642 may stabilize endothelial and epithelial barrier function in vivo. However, the underlying mechanisms are not known. Therefore, we studied the influence of HOE642 on the barrier function of the epithelial cell line CaCo2. The phorbolester phorbol 12-myristate 13-acetate (PMA) was used to induce hyperpermeability of the epithelial layer which was indirectly determined by measuring the transepithelial electrical resistance (TER). Confocal laser scan microscopy (LSM) served to analyze the intracellular localization of adherens and tight junction molecules. In five independent experiments we found that HOE642 increased TER in non-treated CaCo2 cells (control: 350±28 Ω/cm2; HOE642: 444±53 Ω/cm2) and prevented PMA-induced barrier dysfunction (PMA: 33±12 Ω/cm2; PMA plus HOE642: 496±47 Ω/cm2). LSM showed that HOE642 prevented the PMA-induced disassociation of the zonula adherens molecule β-catenin from the cell membrane and the decreased expression of the zonula occludens molecule ZO-1. From our data we conclude that HOE642 may prevent stress-induced epithelial dysfunction by stabilization of cell membrane-associated junction molecules.
    Keywords: Anti-Arrhythmia Agents -- Pharmacology ; Epithelium -- Metabolism ; Guanidines -- Pharmacology ; Sulfones -- Pharmacology;
    ISSN: 1107-3756
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  • 9
    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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  • 10
    Language: English
    In: International Journal of Oncology, October 2005, Vol.27(4), pp.1029-1037
    Description: Acquisition of P-gp-mediated multidrug-resistance does not always correlate with observed malignant behavior of NB. To characterize alterations accompanying development of multidrug-resistance in NB we established two neuroblastoma cell sublines resistant to vincristine (UKF-NB-3rVCR10) and doxorubicin (UKF-NB-3rDOX20). UKF-NB-3rVCR10 and UKF-NB-3rDOX20 overexpressed functional P-gp and developed an increased malignant phenotype: presented constitutive phosphorylation of AKT, resistance to γ-irradiation, and had increased survival in serum-free medium. Inhibition of P-gp restored chemosensitivity but did not affect increased survival in serum-free medium and sensitivity to γ-irradiation. Inhibition of AKT had no influence on chemoresistance but restored sensitivity to serum starvation. Both resistant cell lines acquired additional chromosomal changes. UKF-NB-3rVCR10 cells acquired a missense P53 mutation in exon 5, an increased MYCN amplification, an enhanced adhesion to endothelium, a decreased NCAM expression, a distinctly higher clonogenicity, and an increased in vivo tumorigenicity. We conclude that acquisition of increased malignant behavior in neuroblastoma occurs concomitantly with multidrug-resistance and is P-gp-independent.
    Keywords: Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; ATP Binding Cassette Transporter, Subfamily B, Member 1 -- Metabolism ; Neuroblastoma -- Pathology;
    ISSN: 1019-6439
    E-ISSN: 17912423
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