29 results on '"Paschke R"'
Search Results
2. Quantitative proteome analysis in benign thyroid nodular disease using the fluorescent ruthenium II tris(bathophenanthroline disulfonate) stain
- Author
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Berger, K., Wissmann, D., Ihling, C., Kalkhof, Stefan, Beck-Sickinger, A., Sinz, A., Paschke, R., Führer, D., Berger, K., Wissmann, D., Ihling, C., Kalkhof, Stefan, Beck-Sickinger, A., Sinz, A., Paschke, R., and Führer, D. more...
- Abstract
Thyroid tumorigenesis involves qualitative and quantitative changes in protein expression, which can be comprehensively studied by proteome analysis. However, one of the technical bottlenecks of proteomics remains a reliable, sensitive and inexpensive method for quantification of differentially expressed proteins. This is due to the limited linear range of most available protein stains, i.e. silver and Coomassie blue, and high costs of commercially available fluorescent stains. In this paper we describe our experience with a lab-made ruthenium based fluorescent stain (ruthenium II tris(bathophenanthroline disulfonate) (RuBPs)) to perform proteome analysis of nodular thyroid disease. We first compared the properties of RuBPs with two highly sensitive protein stains: (1) silver staining and (2) the commercially available fluorescent dye Sypro Ruby. We show that in addition to its highly sensitive staining capabilities similar to Sypro Ruby and silver (2 ng), RuBPs offers several advantages such as a broad dynamic range (similar to Sypro Ruby and 500 times broader than the dynamic range of silver stain), low costs (€ 0.03 per gel) and excellent compatibility with mass spectrometry. We then applied the inexpensive RuBPs stain to 2D gels (pH 4–7) of four benign thyroid nodules and normal thyroid tissue. We were able to detect 1800 protein spots/gel in our thyroid samples. Quantitative changes in protein expression levels of at least 20–42 proteins were noted in the benign nodules compared with the normal thyroid tissue of the same patient. Differentially expressed spots were further characterised by nano-LC-FTICR and MALDI-TOF mass spectrometry. In summary we demonstrate, that the novel fluorescent ruthenium II tris(bathophenanthroline disulfonate) stain is a highly sensitive, reliable and inexpensive tool for quantitative proteome analysis in thyroid nodular disease. more...
- Published
- 2004
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3. An Electrostatically-steered Conformational Selection Mechanism Promotes SARS-CoV-2 Spike Protein Variation.
- Author
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Sorokina M, Belapure J, Tüting C, Paschke R, Papasotiriou I, Rodrigues JPGLM, and Kastritis PL
- Subjects
- Angiotensin-Converting Enzyme 2, Humans, Pandemics prevention & control, Protein Binding, SARS-CoV-2 genetics, COVID-19 epidemiology, Spike Glycoprotein, Coronavirus chemistry, Spike Glycoprotein, Coronavirus genetics
- Abstract
After two years since the outbreak, the COVID-19 pandemic remains a global public health emergency. SARS-CoV-2 variants with substitutions on the spike (S) protein emerge increasing the risk of immune evasion and cross-species transmission. Here, we analyzed the evolution of the S protein as recorded in 276,712 samples collected before the start of vaccination efforts. Our analysis shows that most variants destabilize the S protein trimer, increase its conformational heterogeneity and improve the odds of the recognition by the host cell receptor. Most frequent substitutions promote overall hydrophobicity by replacing charged amino acids, reducing stabilizing local interactions in the unbound S protein trimer. Moreover, our results identify "forbidden" regions that rarely show any sequence variation, and which are related to conformational changes occurring upon fusion. These results are significant for understanding the structure and function of SARS-CoV-2 related proteins which is a critical step in vaccine development and epidemiological surveillance., Competing Interests: Competing Interest Statement I.P. is the founder and director of R.G.C.C. International GmbH. RP is the founder and director of BioSolutions Halle GmbH. MS is supported by both R.G.C.C. International GmbH and BioSolutions GmbH. The authors declare that they have no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.) more...
- Published
- 2022
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4. Combined 3-O-acetylbetulin treatment and carbonic anhydrase IX inhibition results in additive effects on human breast cancer cells.
- Author
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Petrenko M, Güttler A, Funtan A, Keßler J, Emmerich D, Paschke R, Vordermark D, and Bache M
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- Cell Movement drug effects, Cell Movement radiation effects, DNA Damage, Drug Synergism, Humans, MCF-7 Cells, Phenylurea Compounds pharmacology, Radiation Tolerance drug effects, Reactive Oxygen Species metabolism, Sulfonamides pharmacology, Tumor Hypoxia drug effects, Benzenesulfonamides, Antineoplastic Agents pharmacology, Breast Neoplasms pathology, Carbonic Anhydrase IX antagonists & inhibitors, Carbonic Anhydrase Inhibitors pharmacology
- Abstract
Hypoxia plays a key role in tumor progression and resistance to radiotherapy. Expression of the transmembrane-tethered enzyme carbonic anhydrase IX (CA IX) is strongly induced by hypoxia. High CA IX expression levels correlate with poor prognosis in cancer patients. Previously, we showed that the downregulation of CA IX expression by siRNA interference and the inhibition of CA IX activity results in increased cytotoxicity, inhibition of migration and radiosensitization of hypoxic cancer cells. Betulinic acid (BA) is a natural compound derived from birch bark. It has shown promising anti-tumor effects due to its cancer cell specific cytotoxic properties. We have shown that BA inhibits the HIF-1α pathway, resulting in apoptosis, inhibition of migration and enhanced cytotoxicity of breast cancer cells. In this study, we investigate the effects of the novel betulin derivative 3-O-acetylbetulin (3-AC) and carbonic anhydrase inhibitors (CAI) octyl disulfamate (OCT) or 4-(3-[4-fluorophenyl]ureido)benzenesulfonamide (SLC-0111), on cellular and radiobiological parameters in MDA-MB-231 and MCF-7 cells. Treatment with 3-AC or OCT alone only caused moderate cytotoxicity, reduction in cell migration, ROS production and DNA damage. However, the combined treatment with 3-AC and CAI strongly enhanced radiosensitivity, increased cytotoxicity, inhibited cell motility and enhanced DNA damage. Our findings suggest that the combination of two bioactive drugs 3-AC and a CAI, such as OCT or SLC-0111, could be a promising therapeutic approach for targeting hypoxic tumor cells., (Copyright © 2020 Elsevier B.V. All rights reserved.) more...
- Published
- 2021
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5. Evaluation of the Betulinic Acid-Cisplatin conjugate APC and its precursor DE9B for the treatment of human malignant glioma.
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Bache M, Hein A, Petrenko M, Güttler A, Keßler J, Wichmann H, Kappler M, Emmerich D, Paschke R, and Vordermark D
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- Antineoplastic Agents chemistry, Caspase 3 metabolism, Caspase 7 metabolism, Cell Hypoxia, Cell Line, Tumor, Cell Movement drug effects, Cell Survival drug effects, Coordination Complexes chemistry, Glioma metabolism, Glioma pathology, Humans, Pentacyclic Triterpenes, Betulinic Acid, Antineoplastic Agents pharmacology, Apoptosis drug effects, Cisplatin chemistry, Coordination Complexes pharmacology, Triterpenes chemistry
- Abstract
Despite the existence of multimodal therapy concepts, glioblastoma remains a tumor type with one of the worst prognoses. In particular, the poor prognosis is due to the lack of therapeutic efficacy of chemical agents and irradiation in hypoxic tumor areas. New therapeutic strategies could improve the treatment of glioblastoma. In this study, we investigated the therapeutic efficacy of a conjugate of cisplatin (DDP), a widely used chemotherapeutic agent, and betulinic acid (BA), a natural product from plane tree bark, in glioblastoma cells under different oxygen conditions. We investigated the effects of the BA-DDP conjugate κN',N''-{3-acetyloxy-BA-28-[2-(2-aminoethyl)aminoethyl]amide} dichlorido platinum(II) (APC) and its precursor 3-acetyloxy-BA-28-[2-(2-aminoethyl)aminoethyl]amide (DE9B) on cytotoxicity, cell growth, apoptosis, migration and radiosensitivity compared to BA or DDP alone under different oxygen conditions. Based on the EC
50 values, the precursor DE9B exhibited the strongest cytotoxic effects of the analyzed chemotherapeutic agents. The BA-DDP conjugate APC achieved a moderate cytotoxic effect in glioma cells. Both of the newly developed agents induced cell growth delay, apoptosis and inhibition of migration. Furthermore, additive effects could be achieved in combination with irradiation. In contrast to those of BA and DDP, the cell biological effects of APC and DE9B were not influenced by the oxygen concentration. In this study, the linking of BA and DDP did not produce a compound with additive therapeutic effects on glioblastoma cell lines in vitro. Nevertheless, the results of this study suggest that the precursor DE9B is an effective BA derivative for the treatment of glioblastoma in vitro., (Copyright © 2019 Elsevier B.V. All rights reserved.) more...- Published
- 2019
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6. Synthesis and biological investigation of new carbonic anhydrase IX (CAIX) inhibitors.
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Vanchanagiri K, Emmerich D, Bruschke M, Bache M, Seifert F, Csuk R, Vordermark D, and Paschke R
- Subjects
- A549 Cells, Apoptosis drug effects, Carbonic Anhydrase IX metabolism, Carbonic Anhydrase Inhibitors chemistry, Cell Cycle Checkpoints drug effects, Cell Line, Humans, MCF-7 Cells, Pentacyclic Triterpenes, Triterpenes chemical synthesis, Triterpenes chemistry, Triterpenes pharmacology, Betulinic Acid, Carbonic Anhydrase IX antagonists & inhibitors, Carbonic Anhydrase Inhibitors chemical synthesis, Carbonic Anhydrase Inhibitors pharmacology
- Abstract
In this report, we describe the synthesis, characterization, in vitro anticancer activity and Carbonic anhydrase IX (CAIX) inhibition of new sulfamate conjugates of Betulin and Betulinic acid (BA). The betulinyl sulfamates were subjected to inhibit carbonic anhydrases (CA), e.g. CAIX, an attractive target for tumor-selective therapy strategies in cancer cells. Data on combined in vitro antitumor activity with CAIX inhibition are very rare. The betulinyl sulfamates were tested against five tumor cell lines and normal human skin fibroblasts. The mode of cell death on MCF7 breast cancer cells induced by the most active compounds CAI1, CAI3 and CAI6 was investigated by Fluorescence Activated Cell Sorting (FACS) experiments. The compounds showed inhibitory activity towards CAIX, which was determined via in vitro enz-yme assay. Our preliminary investigations revealed that all compounds showed potent anticancer properties with IC
50 values below 20 μM against all tumor cells. Interestingly, among the panel of sulfamate conjugates, CAI3 found to be highly cytotoxic (average IC50 = 5-10 μM) and possess high inhibitory activity (Ki = 1.25 nM) towards CAIX. Our results suggest that betulinyl sulfamates seem to be attractive substances, due to their possibility of targeted drug delivery they deserve to be proceeded for further pre-clinical (kinetic studies) and in vivo investigations., (Copyright © 2018 Elsevier B.V. All rights reserved.) more...- Published
- 2018
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7. Inheritable and sporadic non-autoimmune hyperthyroidism.
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Ferraz C and Paschke R
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- Databases, Genetic, Genetic Counseling, Germ-Line Mutation, Humans, Hyperthyroidism diagnosis, Hyperthyroidism epidemiology, Inheritance Patterns, Mutation, Receptors, Thyrotropin genetics, Thyroid Diseases complications, Thyroid Diseases diagnosis, Thyroid Diseases epidemiology, Thyroid Diseases genetics, Hyperthyroidism genetics
- Abstract
Hyperthyroidism is a clinical state that results from high thyroid hormone levels which has multiple etiologies, manifestations, and potential therapies. Excluding the autoimmune Graves disease, autonomic adenomas account for the most import cause of non-autoimmune hyperthyroidism. Activating germline mutations of the TSH receptor are rare etiologies for hyperthyroidism. They can be inherited in an autosomal dominant manner (familial or hereditary, FNAH), or may occur sporadically as a de novo condition, also called: persistent sporadic congenital non-autoimmune hyperthyroidism (PSNAH). These three conditions: autonomic adenoma, FNAH and PSNAH constitute the inheritable and sporadic non-autoimmune hyperthyroidism. Particularities in epidemiology, etiology, molecular and clinical aspects of these three entities will be discussed in this review in order to guide to an accurate diagnosis allowing among others genetic counseling and presymptomatic diagnosis for the affected families. The optimal treatment based on the right diagnosis will avoid consequences of a persistent or relapsing hyperthyroidism., (Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.) more...
- Published
- 2017
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8. In vitro anticancer activity of Betulinic acid and derivatives thereof on equine melanoma cell lines from grey horses and in vivo safety assessment of the compound NVX-207 in two horses.
- Author
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Liebscher G, Vanchangiri K, Mueller T, Feige K, Cavalleri JM, and Paschke R
- Subjects
- Animals, Antineoplastic Agents adverse effects, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Apoptosis drug effects, Caspases metabolism, Cell Cycle drug effects, Cell Line, Tumor, Enzyme Activation drug effects, Female, Horses, Humans, Pentacyclic Triterpenes, Propanolamines chemistry, Triterpenes chemistry, Betulinic Acid, Melanoma pathology, Propanolamines adverse effects, Propanolamines pharmacology, Safety, Triterpenes adverse effects, Triterpenes pharmacology, Xenograft Model Antitumor Assays
- Abstract
Betulinic acid, a pentacyclic triterpene, and its derivatives are promising compounds for cancer treatment in humans. Melanoma is not only a problem for humans but also for grey horses as they have a high potential of developing melanoma lesions coupled to the mutation causing their phenotype. Current chemotherapeutic treatment carries the risk of adverse health effects for the horse owner or the treating veterinarian by exposure to antineoplastic compounds. Most treatments have low prospects for systemic tumor regression. Thus, a new therapy is needed. In this in vitro study, Betulinic acid and its two derivatives B10 and NVX-207, both with an improved water solubility compared to Betulinic acid, were tested on two equine melanoma cell lines (MelDuWi and MellJess/HoMelZh) and human melanoma (A375) cell line. We could demonstrate that all three compounds especially NVX-207 show high cytotoxicity on both equine melanoma cell lines. The treatment with these compounds lead to externalization of phosphatidylserines on the cell membrane (AnnexinV-staining), DNA-fragmentation (cell cycle analysis) and activation of initiator and effector caspases (Caspase assays). Our results indicate that the apoptosis is induced in the equine melanoma cells by all three compounds. Furthermore, we succeed in encapsulating the most active compound NVX-207 in 2-Hydroxyprolyl-β-cyclodextrine without a loss of its activity. This formulation can be used as a promising antitumor agent for treating grey horse melanoma. In a first tolerability evaluation in vivo the formulation was administered every one week for 19 consecutive weeks and well tolerated in two adult melanoma affected horses., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.) more...
- Published
- 2016
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9. Ruling in or ruling out thyroid malignancy by molecular diagnostics of thyroid nodules.
- Author
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Eszlinger M, Hegedüs L, and Paschke R
- Subjects
- Biopsy, Fine-Needle, Diagnosis, Differential, Goiter, Nodular genetics, Goiter, Nodular pathology, High-Throughput Nucleotide Sequencing, Humans, Mutation, Thyroid Nodule genetics, Thyroid Nodule pathology, Goiter, Nodular diagnosis, Molecular Diagnostic Techniques methods, Thyroid Nodule diagnosis
- Abstract
Routine morphologic cytology is the basis for any kind of (integrated) molecular FNA diagnostics. The rule out (gene expression classifier) approach requires confirmation by independent studies, whereas the rule in approach (detection of BRAF, NRAS, HRAS, and KRAS and PAX8/PPARG- and RET/PTC rearrangements) has been investigated by several groups with overall reproducible results. Moreover, molecular screening for point mutations and rearrangements is feasible in routine air-dried FNA smears, offering several advantages over obtaining additional fresh FNA material. The current panel of somatic mutations (rule in approach) for indeterminate FNAs clarifies only a subgroup of indeterminate FNAs. Therefore, further markers are urgently needed that can reliably identify the malignant, but mutation negative and especially the many benign nodules, among the indeterminate FNAs. miRNA markers and the targeted next generation sequencing (NGS) technology do have the potential to identify those nodules that are mutation negative by current approaches., (Copyright © 2014 Elsevier Ltd. All rights reserved.) more...
- Published
- 2014
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10. Sorafenib in radioactive iodine-refractory, locally advanced or metastatic differentiated thyroid cancer: a randomised, double-blind, phase 3 trial.
- Author
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Brose MS, Nutting CM, Jarzab B, Elisei R, Siena S, Bastholt L, de la Fouchardiere C, Pacini F, Paschke R, Shong YK, Sherman SI, Smit JW, Chung J, Kappeler C, Peña C, Molnár I, and Schlumberger MJ
- Subjects
- Adult, Aged, Aged, 80 and over, Antineoplastic Agents administration & dosage, Double-Blind Method, Female, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Niacinamide administration & dosage, Niacinamide therapeutic use, Phenylurea Compounds administration & dosage, Sorafenib, Survival Analysis, Treatment Outcome, Young Adult, Antineoplastic Agents therapeutic use, Niacinamide analogs & derivatives, Phenylurea Compounds therapeutic use, Thyroid Neoplasms drug therapy
- Abstract
Background: Patients with radioactive iodine ((131)I)-refractory locally advanced or metastatic differentiated thyroid cancer have a poor prognosis because of the absence of effective treatment options. In this study, we assessed the efficacy and safety of orally administered sorafenib in the treatment of patients with this type of cancer., Methods: In this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial (DECISION), we investigated sorafenib (400 mg orally twice daily) in patients with radioactive iodine-refractory locally advanced or metastatic differentiated thyroid cancer that had progressed within the past 14 months. Adult patients (≥18 years of age) with this type of cancer were enrolled from 77 centres in 18 countries. To be eligible for inclusion, participants had to have at least one measurable lesion by CT or MRI according to Response Evaluation Criteria In Solid Tumors (RECIST); Eastern Cooperative Oncology Group performance status 0-2; adequate bone marrow, liver, and renal function; and serum thyroid-stimulating hormone concentration lower than 0·5 mIU/L. An interactive voice response system was used to randomly allocate participants in a 1:1 ratio to either sorafenib or matching placebo. Patients, investigators, and the study sponsor were masked to treatment assignment. The primary endpoint was progression-free survival, assessed every 8 weeks by central independent review. Analysis was by intention to treat. Patients in the placebo group could cross over to open-label sorafenib upon disease progression. Archival tumour tissue was examined for BRAF and RAS mutations, and serum thyroglobulin was measured at baseline and at each visit. This study is registered with ClinicalTrials.gov, number NCT00984282, and with the EU Clinical Trials Register, number EudraCT 2009-012007-25., Findings: Patients were randomly allocated on a 1:1 basis to sorafenib or placebo. The intention-to-treat population comprised 417 patients (207 in the sorafenib group and 210 in the placebo group) and the safety population was 416 patients (207 in the sorafenib group and 209 in the placebo group). Median progression-free survival was significantly longer in the sorafenib group (10·8 months) than in the placebo group (5·8 months; hazard ratio [HR] 0·59, 95% CI 0·45-0·76; p<0·0001). Progression-free survival improved in all prespecified clinical and genetic biomarker subgroups, irrespective of mutation status. Adverse events occurred in 204 of 207 (98·6%) patients receiving sorafenib during the double-blind period and in 183 of 209 (87·6%) patients receiving placebo. Most adverse events were grade 1 or 2. The most frequent treatment-emergent adverse events in the sorafenib group were hand-foot skin reaction (76·3%), diarrhoea (68·6%), alopecia (67·1%), and rash or desquamation (50·2%)., Interpretation: Sorafenib significantly improved progression-free survival compared with placebo in patients with progressive radioactive iodine-refractory differentiated thyroid cancer. Adverse events were consistent with the known safety profile of sorafenib. These results suggest that sorafenib is a new treatment option for patients with progressive radioactive iodine-refractory differentiated thyroid cancer., Funding: Bayer HealthCare Pharmaceuticals and Onyx Pharmaceuticals (an Amgen subsidiary)., (Copyright © 2014 Elsevier Ltd. All rights reserved.) more...
- Published
- 2014
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11. Highly active neutral ruthenium(II) arene complexes: synthesis, characterization, and investigation of their anticancer properties.
- Author
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Ludwig G, Kaluđerović GN, Bette M, Block M, Paschke R, and Steinborn D
- Subjects
- Antineoplastic Agents pharmacology, Cell Line, Tumor, Cell Survival drug effects, Cisplatin pharmacology, Coordination Complexes pharmacology, Cymenes, Humans, Inhibitory Concentration 50, Magnetic Resonance Spectroscopy, Structure-Activity Relationship, X-Ray Diffraction, Antineoplastic Agents chemical synthesis, Coordination Complexes chemical synthesis, Monoterpenes chemistry, Ruthenium chemistry, Sulfides chemistry, Sulfones chemistry, Sulfoxides chemistry
- Abstract
Reactions of ω-diphenylphosphino-functionalized alkyl phenyl sulfides Ph(2)P(CH(2))(n)SPh (n=1, L1; 2, L2; 3, L3), sulfoxides Ph(2)P(CH(2))(n)S(O)Ph (n=1, L4; 2, L5; 3, L6) and sulfones Ph(2)P(CH(2))(n)S(O)(2)Ph (n=1, L7; 2, L8; 3, L9) with the dinuclear chlorido bridged ruthenium(II) complex [{Ru(η(6)-p-cymene)Cl(2)}(2)] afforded mononuclear ruthenium(II) complexes of the type [Ru(η(6)-p-cymene)Cl(2){Ph(2)P(CH(2))(n)S(O)(x)Ph-κP}] (n/x=1/0, 1; 2/0, 2; 3/0, 3; 1/1, 4; 2/1, 5; 3/1, 6; 1/2, 7; 2/2, 8; 3/2, 9) having the P(∩)S(O)(x) ligands κP coordinated. The complexes were characterized by (1)H, (13)C and (31)P NMR spectroscopy. The crystal structures of complexes 2, 7·CH(2)Cl(2) and 8 were determined by X-ray diffraction analysis. All complexes have been screened for cytostatic activity against cell lines 518A2, 8505C, A253, MCF-7, and SW480. In vitro biological experiments demonstrate that these compounds are active toward the used cell lines. The ruthenium(II) complex [Ru(η(6)-p-cymene)Cl(2){Ph(2)P(CH(2))(2)SPh-κP}] (2) is the most active compound in the human cancer cell line MCF-7 with the IC(50) value 1.4 μM lower than cisplatin (2.0 μM)., (Copyright © 2012 Elsevier Inc. All rights reserved.) more...
- Published
- 2012
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12. Study of the cytotoxicity and particle action in human cancer cells of titanocene-functionalized materials with potential application against tumors.
- Author
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García-Peñas A, Gómez-Ruiz S, Pérez-Quintanilla D, Paschke R, Sierra I, Prashar S, del Hierro I, and Kaluđerović GN
- Subjects
- Aluminum Oxide chemistry, Antineoplastic Agents pharmacology, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Drug Screening Assays, Antitumor, Durapatite chemistry, Humans, Inhibitory Concentration 50, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Molecular Structure, Organometallic Compounds pharmacology, Particle Size, Silicon Dioxide chemistry, Spectrophotometry, Thermogravimetry, X-Ray Diffraction, Antineoplastic Agents chemistry, Organometallic Compounds chemistry, Titanium chemistry
- Abstract
Titanocene dichloride [Ti(η(5)-C(5)H(5))(2)Cl(2)] (1), has been grafted onto dehydrated hydroxyapatite (HAP), Al(2)O(3) and two mesoporous silicas MSU-2 (Michigan State University Silica type 2) and HMS (Hexagonal Mesoporous Silica), to give the novel materials HAP/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S1) (1.01 wt.% Ti), Al(2)O(3)/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S2) (2.36 wt.% Ti), HMS/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S3) (0.75 wt.% Ti) and MSU-2/[Ti(η(5)-C(5)H(5))(2)Cl(2)] (S4) (0.74 wt.% Ti), which have been characterized by powder X-ray diffraction, X-ray fluorescence, nitrogen gas sorption, multinuclear magic angle spinning NMR spectroscopy, IR spectroscopy, thermogravimetry analysis, UV spectroscopy, scanning electronic microscopy and transmission electronic microscopy. The cytotoxicity of the titanocene-functionalized materials toward human cancer cell lines from five different histogenic origins: 8505C (anaplastic thyroid cancer), A253 (head and neck cancer), A549 (lung carcinoma), A2780 (ovarian cancer) and DLD-1 (colon cancer) has been determined. M(50) values (quantity of material needed to inhibit normal cell growth by 50%) and Ti-M(50) values (quantity of anchored titanium needed to inhibit normal cell growth by 50%) indicate that the activity of S1-S4 against studied human cancer cells depended on the surface type as well as on the cell line. In addition, studies on the titanocene release and the interaction of the materials S1-S4 with DNA show that the cytotoxic activity may be due to particle action, because no release of titanium complexes has been observed in physiological conditions, while electrostatic interactions of titanocene-functionalized particles with DNA have been observed., (Copyright © 2011 Elsevier Inc. All rights reserved.) more...
- Published
- 2012
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13. Lipophilic Pt(II) complexes with selective efficacy against cisplatin-resistant testicular cancer cells.
- Author
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Biersack B, Dietrich A, Zoldakova M, Kalinowski B, Paschke R, Schobert R, and Mueller T
- Subjects
- Acetylcysteine chemistry, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Apoptosis drug effects, Caspase 3 metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Coordination Complexes chemical synthesis, Coordination Complexes chemistry, DNA chemistry, DNA Fragmentation, Drug Screening Assays, Antitumor, Enzyme Activation, Ethidium chemistry, Humans, Hydrophobic and Hydrophilic Interactions, Intercalating Agents chemistry, Male, Membrane Potential, Mitochondrial drug effects, Testicular Neoplasms, Antineoplastic Agents pharmacology, Cisplatin pharmacology, Coordination Complexes pharmacology, Drug Resistance, Neoplasm, Platinum
- Abstract
A series of dichloridoplatinum(II) complexes with selective and high cytotoxicity [IC(90)(96h)≤3 μM] against cisplatin-resistant 1411HP testicular cancer cells were identified. They bear stationary 6-aminomethylnicotinate or 2,4-diaminobutyrate ligands esterified with lipophilic terpenyl residues, i.e., (-)/(+)-menthyl, (+)-cedrenyl, (-)-menthoxypropyl, or with a decyl-tethered 1,1,2-triphenylethene. They accumulated to a larger extent in 1411HP cells than in cells of the cisplatin-sensitive H12.1 germ cell tumour. Their mechanism of apoptosis induction differed from that of cisplatin by being independent of p53 and of caspase-3 activation and by an early loss of the mitochondrial membrane potential. The new complexes are promising candidates for the treatment of cisplatin-resistant testicular tumours., (Copyright © 2011 Elsevier Inc. All rights reserved.) more...
- Published
- 2011
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14. Nodulogenesis and goitrogenesis.
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Paschke R
- Subjects
- Female, Humans, Hydrogen Peroxide metabolism, Male, Mutagenesis, Genetic Predisposition to Disease, Goiter, Nodular genetics, Iodine deficiency, Thyroid Nodule genetics
- Abstract
Goitrogenisis is the consequence of a relative iodine deficiency interacting with a genetic predisposition for maladaptation to iodine deficiency. In the long run, the iodine deficiency induces increased H₂O₂ production that leads to an increased mutagenesis, resulting in somatic mutations with a proliferative advantage and thus the induction of thyroid nodules., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.) more...
- Published
- 2011
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15. Organogallium(III) complexes as apoptosis promoting anticancer agents for head and neck squamous cell carcinoma (HNSCC) cell lines.
- Author
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Kaluđerović MR, Kaluđerović GN, Gómez-Ruiz S, Paschke R, Hemprich A, Kühling J, and Remmerbach TW
- Subjects
- Antineoplastic Agents chemistry, Apoptosis, Carcinoma, Squamous Cell, Caspases metabolism, Cell Cycle drug effects, Cell Line, Tumor, Cell Survival drug effects, Coordination Complexes chemistry, DNA Fragmentation drug effects, Drug Screening Assays, Antitumor, Head and Neck Neoplasms, Humans, Inhibitory Concentration 50, Structure-Activity Relationship, Antineoplastic Agents pharmacology, Coordination Complexes pharmacology, Gallium
- Abstract
Organogallium(III) dinuclear (1-9) and tetranuclear (10) complexes present potential therapeutic agents for the treatment of various types of cancer. The antiproliferative activity of 1-10 was evaluated with cell lines of head and neck squamous cell carcinomas, e.g. HN (soft palate), Cal27, Cal33 (tongue) and FaDu (hypopharynx) cell lines. The activity of compound 8 is comparable with that of cisplatin on cell line Cal27 (IC(50) 4.6 μM for both compounds). The mode of cell death induced, caspase activity and cell cycle analysis were evaluated for potential hit compounds 3, 5 and 8 Potential hit compounds 3, 5 and 8 were further evaluated for the mode of cell death, caspase activity and cell cycle analysis. Apoptosis induced by compounds 3, 5 and 8 on Cal27 and FaDu cells was confirmed by DNA laddering , as well as acridine orange (AO) and ethidium bromide (EB) double staining. These compounds (3, 5 and 8) induced caspase-independent apoptosis (within 4 h of action) in cell line Cal27. Extrinsic-mediated apoptosis associated with caspase 8 and 3 activation is the main mode of cytotoxicity induced on FaDu cells by compounds 3, 5 and 8. Cell cycle perturbations caused by these compounds are also observed. Our data suggest that compounds 3, 5 and 8 should be studied further for the treatment of head and neck cancer., (Copyright © 2010 Elsevier Inc. All rights reserved.) more...
- Published
- 2011
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16. In vitro anticancer studies of alpha- and beta-D-glucopyranose betulin anomers.
- Author
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Kommera H, Kaluderović GN, Bette M, Kalbitz J, Fuchs P, Fulda S, Mier W, and Paschke R
- Subjects
- Antineoplastic Agents chemical synthesis, Apoptosis physiology, Caspase 3 metabolism, Cell Cycle drug effects, Cell Cycle physiology, Cell Line, Tumor, DNA Fragmentation drug effects, Drug Screening Assays, Antitumor, Glucose chemical synthesis, Glucose chemistry, HCT116 Cells, Humans, Isomerism, Magnetic Resonance Spectroscopy, Mass Spectrometry, Pentacyclic Triterpenes, Time Factors, Triterpenes chemical synthesis, Triterpenes pharmacology, X-Ray Diffraction, Betulinic Acid, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Apoptosis drug effects, Glucose analogs & derivatives, Glucose pharmacology, Triterpenes chemistry
- Abstract
Four derivatives of betulin containing a D-glucopyranosyl moiety at C3 position were synthesized and characterized by (1)H and (13)C NMR spectroscopy as well as mass spectrometry. The crystal structure of 28-O-acetylbetulin-3-yl-beta-D-(2',3',4',6'-tetra-O-acetyl)glucopyranoside was determined. The compounds were tested against fifteen tumor cell lines of different histogenic origins. The alpha- and beta-anomers of 28-O-acetylbetulin-3-yl-D-glucopyranoside, exerted a dose dependent antiproliferative action towards the tumor cell lines. Treatment of HCT-116 cells for 24h induced apoptosis, which was confirmed by the appearance of a typical ladder pattern in the DNA fragmentation assay and cell cycle analysis. The alpha- and beta-anomers of 28-O-acetylbetulin-3-yl-D-glucopyranoside seem to induce apoptosis by activation of different upstream caspases on colon cancer HCT-116 cell line., (2010 Elsevier Ireland Ltd. All rights reserved.) more...
- Published
- 2010
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17. Platinum(II) complexes with l-methionylglycine and l-methionyl-l-leucine ligands: synthesis, characterization and in vitro antitumoral activity.
- Author
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Kaluderović GN, Schmidt H, Paschke R, Kalinowski B, Dietrich A, Mueller T, and Steinborn D
- Subjects
- Animals, Dipeptides chemistry, Drug Screening Assays, Antitumor, Humans, Inhibitory Concentration 50, Leucine pharmacology, Ligands, Magnetic Resonance Spectroscopy, Organoplatinum Compounds chemical synthesis, Platinum pharmacology, Tumor Cells, Cultured, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Dipeptides pharmacology, Leucine chemistry, Organoplatinum Compounds pharmacology, Platinum chemistry
- Abstract
Four dipeptide complexes of the type [PtX(2)(dipeptide)] x H(2)O (X=Cl, I, dipeptide=l-methionylglycine, l-methionyl-l-leucine) were prepared. The complexes were characterized by (1)H, (13)C, (195)Pt NMR and infrared spectroscopy, DTG and elemental analysis. From the infrared, (1)H and (13)C NMR spectroscopy it was concluded that dipeptides coordinate bidentately via sulfur and amine nitrogen donor atoms. Confirmed with (13)C and (195)Pt NMR spectroscopy, each of the complexes exists in two diastereoisomeric forms, which are related by inversion of configuration at the sulfur atom. The (1)H NMR spectrum for the platinum(II) complex with l-methionylglycine and chloro ligands exhibited reversible, intramolecular inversion of configuration at the S atom; DeltaG( not equal)=72 kJ mol(-1) at coalescence temperature 349 K was calculated. In vitro cytotoxicity studies using the human tumor cell lines liposarcoma, lung carcinoma A549 and melanoma 518A2 revealed considerable activity of the platinum(II) complex with l-methionylglycine and chloro ligands. Further in vitro cytotoxic evaluation using human testicular germ cell tumor cell lines 1411HP and H12.1 and colon carcinoma cell line DLD-1 showed moderate cytotoxic activity for all platinum(II) complexes only in the cisplatin-sensitive cell line H12.1. Platinum uptake studies using atomic absorption spectroscopy indicated no relationship between uptake and activity. Potential antitumoral activity of this class of platinum(II) complexes is dependent on the kind of ligands as well as on tumor cell type. more...
- Published
- 2007
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18. Brassicaceae contain nortropane alkaloids.
- Author
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Brock A, Herzfeld T, Paschke R, Koch M, and Dräger B
- Subjects
- Alkaloids isolation & purification, Nortropanes isolation & purification, Solanaceous Alkaloids chemistry, Solanaceous Alkaloids isolation & purification, Tropanes chemistry, Tropanes isolation & purification, Alkaloids chemistry, Brassicaceae chemistry, Brassicaceae classification, Nortropanes chemistry
- Abstract
The report of cochlearine, the 3-hydroxybenzoate ester of tropine found in Cochlearia officinalis, Brassicaceae, initiated a screening for tropane alkaloids in Cochlearia species and for calystegines in further Brassicaceae. All ten Cochlearia species investigated contained cochlearine, tropine, and pseudotropine. Calystegines, nortropane alkaloids deriving from pseudotropine, were also identified in all Cochlearia species and accumulated up to 0.5% dry mass in leaves. Brassicaceae species of all major lineages of the family were analysed for calystegines. Of the 43 species included in the study, 18 accumulated calystegines of various structures. This is the first screening of Brassicaceae for products of the tropane alkaloid pathway, which is known as characteristic for plants of Solanaceae family. The identification of calystegines in all branches of the Brassicaceae family including Aethionema, a species at the basis of the family, suggests tropane alkaloids as secondary compound typical for Brassicaceae. more...
- Published
- 2006
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- View/download PDF
19. Regulation of adiponectin receptor R1 and R2 gene expression in adipocytes of C57BL/6 mice.
- Author
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Blüher M, Fasshauer M, Kralisch S, Schön MR, Krohn K, and Paschke R
- Subjects
- Adiponectin, Animals, Male, Mice, Mice, Inbred C57BL, Receptors, Adiponectin, Tissue Distribution, Adipocytes metabolism, Circadian Rhythm physiology, Fasting physiology, Gene Expression Regulation physiology, Intercellular Signaling Peptides and Proteins blood, Receptors, Cell Surface metabolism
- Abstract
Adiponectin has gained significant attention as a mediator of insulin sensitivity. Recently, two receptors of this adipocyte-secreted hormone, adiponectin receptor 1 (AdipoR1) and 2 (AdipoR2), have been cloned. To improve our understanding of the regulation of these receptors in adipocytes, AdipoR1 and AdipoR2 mRNA was measured by quantitative real-time reverse transcription-polymerase chain reaction in brown adipocytes and adipocytes from epigonadal and subcutaneous adipose tissue of C57BL/6 mice as a function of feeding and circadian clocks. AdipoR1 gene expression was higher in brown adipose tissue and epigonadal adipose tissue, but lower in subcutaneous fat in fasted as compared to random-fed mice. In parallel, AdipoR2 mRNA levels were also higher in epigonadal adipose tissue of fasted as compared to fed mice, however, there was no regulation of AdipoR2 mRNA in brown and subcutaneous fat depending on the feeding state. Furthermore, AdipoR2 gene expression was significantly higher in epigonadal as compared to subcutaneous fat. Interestingly, a parallel circadian gene expression pattern for both AdipoR1 and AdipoR2 with lower expression between 20:00 and 06:00 h in brown, epigonadal, and subcutaneous adipose tissue was also found. In conclusion, our results suggest a fat depot specific regulation of AdipoR1 and AdipoR2 gene expression in brown and white fat by fasting. In addition, we have identified a coordinated circadian pattern of AdipoR1 and AdipoR2 gene expression in these tissues. more...
- Published
- 2005
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- View/download PDF
20. Comparative analysis of conventional training and a computer-based interactive training program for celiac disease patients.
- Author
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Meyer KG, Fasshauer M, Nebel IT, and Paschke R
- Subjects
- Adult, Analysis of Variance, Educational Measurement, Germany, Humans, Multimedia, User-Computer Interface, Celiac Disease diet therapy, Computer-Assisted Instruction, Patient Education as Topic methods
- Abstract
Gluten-free diet (GFD) protects against the complications of celiac disease (CD). However, training in the dietetic field is rare in Germany. Thus, CD patients are likely to benefit from a computer-based interactive training program (CBITP) combined with interactive exercises. We compared a CBITP and a conventional training for CD patients regarding increased knowledge, transferability and sustainability. In that context we analyzed whether CD patients are more able to judge the risk of a food or a situation after practicing with the interactive training software. Sixty-four CD patients were included and randomized in two groups. While the first group used the CBITP, the control group received written instructions. Before and after taking part in the training program and 3 weeks later, the participants filled in a questionnaire for celiac knowledge. The results show that both intervention and control groups increased knowledge about CD. However, the intervention group showed significantly better outcome. A CBITP significantly increases knowledge and sustainability as compared to a conventional training for CD patients. CBITPs can enhance patients' training and treatment., (Copyright 2004 Elsevier Ireland Ltd.) more...
- Published
- 2004
- Full Text
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21. Comparative analysis of conventional and an adaptive computer-based hypoglycaemia education programs.
- Author
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Nebel IT, Klemm T, Fasshauer M, Müller U, Verlohren HJ, Klaiberg A, and Paschke R
- Subjects
- Attitude to Computers, Attitude to Health, Computer Literacy, Educational Measurement, Female, Humans, Male, Needs Assessment, Program Evaluation, Self Care methods, Self Care psychology, Surveys and Questionnaires, Time Factors, Computer-Assisted Instruction standards, Diabetes Mellitus, Type 1 complications, Diabetes Mellitus, Type 1 psychology, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 psychology, Hypoglycemia etiology, Hypoglycemia prevention & control, Patient Education as Topic standards, User-Computer Interface
- Abstract
Adaptive interactive computer-based education programs which can be personalized to patients' needs and skills might be more suitable for patients' training as compared to conventional ones. We tested whether there are differences between an adaptive and a conventional version of a computer-based hypoglycaemia education program concerning successful training and user friendliness. One hundred and twenty randomized diabetic patients were enrolled in this study. The two different programs were compared by using the following criteria: (1) the number of actions needed to get out of or prevent hypoglycaemia, (2) the need for external help, (3) the average time needed for completing one task and (4) user friendliness as determined by a questionnaire. Patients using the adaptive computer-based hypoglycaemia education program needed less actions to get out of or prevent hypoglycaemia, less external help and less time to finish tasks. Furthermore, the user friendliness of the adaptive computer program received a significantly better rating by the patients. The adaptive computer-based hypoglycaemia education program shows significantly better results as compared to a conventional one. Therefore, using adaptive computer-based programs might be helpful for education of patients. more...
- Published
- 2004
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- View/download PDF
22. Monocyte chemoattractant protein 1 expression is stimulated by growth hormone and interleukin-6 in 3T3-L1 adipocytes.
- Author
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Fasshauer M, Klein J, Kralisch S, Klier M, Lossner U, Bluher M, and Paschke R
- Subjects
- 3T3 Cells, Adipocytes cytology, Animals, Cell Differentiation drug effects, Cell Differentiation physiology, Dose-Response Relationship, Drug, Mice, Transcriptional Activation drug effects, Adipocytes drug effects, Adipocytes metabolism, Chemokine CCL2 metabolism, Dexamethasone pharmacology, Growth Hormone pharmacology, Insulin pharmacology, Interleukin-6 pharmacology, Tumor Necrosis Factor-alpha pharmacology
- Abstract
During the last 10 years, various adipocytokines have been described which influence insulin sensitivity profoundly and might, therefore, potentially link obesity and insulin resistance. Recently, monocyte chemoattractant protein (MCP)-1 was characterized as a novel adipose-secreted factor upregulated in obesity and insulin resistance that impairs insulin signaling in fat cells in vitro and can be found in atherosclerotic lesions. To clarify expression and regulation of this adipocytokine, MCP-1 mRNA was measured by quantitative real-time reverse transcription-polymerase chain reaction during differentiation of 3T3-L1 adipocytes and after treatment with various hormones known to induce insulin resistance. Interestingly, MCP-1 synthesis was significantly downregulated between 43% and 68% during differentiation of 3T3-L1 preadipocytes. Furthermore, 10 ng/ml tumor necrosis factor alpha, 100 nM insulin, 500 ng/ml growth hormone (GH), and 30 ng/ml interleukin (IL)-6-induced MCP-1 mRNA by up to 124-, 23-, 8-, and 2.5-fold, respectively, in a time-dependent fashion with significant stimulation seen at concentrations as low as 0.5 ng/ml GH and 30 ng/ml IL-6. In contrast, the glucocorticoid dexamethasone potently downregulated MCP-1 with significant suppression detectable at concentrations as low as 3 nM and as early as 2h after effector addition. Studies using pharmacological inhibitors suggested that the positive effects of GH and IL-6 on MCP-1 synthesis are at least in part mediated by janus kinase 2 and p44/42 mitogen-activated protein kinase. Taken together, our results show a differential regulation of MCP-1 mRNA by insulin resistance-inducing hormones and support the view that this adipocytokine might be an interesting novel candidate linking insulin resistance, obesity, and atherosclerosis. This adipocytokine could thus be a potential pharmacological target for the treatment of impaired insulin sensitivity. more...
- Published
- 2004
- Full Text
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23. Cholic acid-carboplatin compounds (CarboChAPt) as models for specific drug delivery: synthesis of novel carboplatin analogous derivatives and comparison of the cytotoxic properties with corresponding cisplatin compounds.
- Author
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Paschke R, Kalbitz J, Paetz C, Luckner M, Mueller T, Schmoll HJ, Mueller H, Sorkau E, and Sinn E
- Subjects
- Antineoplastic Agents pharmacokinetics, Carboplatin chemical synthesis, Carboplatin pharmacokinetics, Carboplatin pharmacology, Cell Death drug effects, Cholic Acid pharmacology, Cisplatin pharmacology, DNA, Neoplasm analysis, Dose-Response Relationship, Drug, Drug Carriers pharmacokinetics, Drug Resistance, Neoplasm, Drug Screening Assays, Antitumor, Electrophoresis methods, Humans, Organoplatinum Compounds chemistry, Organoplatinum Compounds pharmacokinetics, Organoplatinum Compounds pharmacology, Trypan Blue metabolism, Tumor Cells, Cultured, Antineoplastic Agents chemical synthesis, Antineoplastic Agents pharmacology, Carboplatin analogs & derivatives, Cholic Acid chemistry, Cisplatin analogs & derivatives, Drug Carriers chemical synthesis, Drug Carriers pharmacology
- Abstract
This report continues our work on new compounds which consist of three functional parts--a transport fragment, a spacer and a biologically active 'drug' component. Here cholic acid functions as the transport fragment, linked via an alkyl spacer to a carboplatin analog, representing the drug (carbo-ChAPt-Fig. 1). We describe the synthesis and characterization of the series of complexes [Pt(Cyclobutane-1,1-dicarboxylato)(diamine)], [diamine=CholCOO(CH(2))(n)CH(CH(2)NH(2))(2) and THP(CH(2))(n)CH-(CH(2)NH(2))(2), n=4, 6, 8, 11]. The compounds were characterized by elemental analysis and NMR-measurements. Cytostatic activity data are given. In general, the cytostatic activity is similar to that of the parent compound and is strongly influenced by the length of the alkyl chain spacer separating the drug and transport fragments, the ones with long chain spacers being more toxic than the parent complexes. Preliminary investigations indicate the ability of the ChAPt to break resistance of tumor cells against common platinum tumor drugs, e.g. cisplatin. They are effective even on cell lines that have developed resistance to other drugs such as cis- and carboplatin. They are more cytotoxic so they are potentially effective at lower dose concentrations. The mode of cell death was examined by trypan-blue exclusion test and DNA gelelectrophoresis. Typical fragmentation of DNA was observed and the cells were still able to exclude trypan-blue., (Copyright 2003 Elsevier Science Inc.) more...
- Published
- 2003
- Full Text
- View/download PDF
24. Functional significance of the thyrotropin receptor germline polymorphism D727E.
- Author
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Sykiotis GP, Neumann S, Georgopoulos NA, Sgourou A, Papachatzopoulou A, Markou KB, Kyriazopoulou V, Paschke R, Vagenakis AG, and Papavassiliou AG
- Subjects
- Adenoma genetics, Alleles, Animals, Base Sequence, COS Cells, Cyclic AMP biosynthesis, DNA, Neoplasm genetics, Germ-Line Mutation, Heterotrimeric GTP-Binding Proteins metabolism, Humans, In Vitro Techniques, Polymorphism, Genetic, Thyroid Neoplasms genetics, Thyrotropin pharmacology, Transfection, Receptors, Thyrotropin genetics, Receptors, Thyrotropin metabolism
- Abstract
In a toxic thyroid adenoma we identified a novel somatic mutation that constitutively activates the thyrotropin receptor (TSHR). Two heterozygous point mutations at adjacent nucleotides led to a substitution of alanine with asparagine at codon 593 (A593N) in the fifth transmembrane helix of TSHR. This somatic mutation resided on the same TSHR allele with the germline polymorphism D727E. The functional characteristics of the single TSHR mutants A593N and D727E and of the double mutant A593N/D727E were studied in transiently transfected COS-7 cells. The TSHR mutants A593N and A593N/D727E constitutively activated the cAMP cascade, whereas the D727E mutant did not differ from the wild-type TSHR. Surprisingly, the double mutant's specific constitutive activity was 2.3-fold lower than the A593N mutant. Thus, the polymorphism significantly ameliorates G(alphas) protein activation in the presence of the gain-of-function mutation A593N, although it is functionally inert in the context of the wild-type TSHR. more...
- Published
- 2003
- Full Text
- View/download PDF
25. Adiponectin gene expression and secretion is inhibited by interleukin-6 in 3T3-L1 adipocytes.
- Author
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Fasshauer M, Kralisch S, Klier M, Lossner U, Bluher M, Klein J, and Paschke R
- Subjects
- 3T3 Cells, Adiponectin, Animals, Colforsin pharmacology, Dexamethasone pharmacology, Down-Regulation drug effects, Gene Expression drug effects, Insulin Resistance physiology, Mice, Mitogen-Activated Protein Kinase 1 metabolism, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Tumor Necrosis Factor-alpha pharmacology, Adipocytes drug effects, Adipocytes metabolism, Intercellular Signaling Peptides and Proteins, Interleukin-6 pharmacology, Protein Biosynthesis, Proteins genetics
- Abstract
Recently, it has been shown that adiponectin is an important insulin-sensitizing fat-derived protein which is downregulated in insulin resistance and obesity, and replenishment of which improves insulin sensitivity. In contrast, interleukin (IL)-6 appears as an adipocytokine serum concentrations of which are elevated in these states. However, it has not been determined whether IL-6 might impact on expression and secretion of adiponectin. To clarify this, 3T3-L1 adipocytes were treated with different concentrations of IL-6 for various periods of time. Adiponectin mRNA was measured by quantitative real-time reverse transcription-polymerase chain reaction and secretion was determined by radioimmunoassays. Interestingly, treatment of 3T3-L1 cells with 30 ng/ml IL-6 significantly decreased adiponectin secretion to 75% of control levels. Adiponectin secretion was also inhibited between 25% and 45% by chronic treatment with forskolin (50 microM), tumor necrosis factor alpha (100 ng/ml), and dexamethasone (100 nM). Furthermore, adiponectin mRNA expression was downregulated by up to 50% in a time- and dose-dependent manner, with significant inhibition detectable at concentrations as low as 3 ng/ml IL-6 and as early as 8h after effector addition. The inhibitory effect of IL-6 was partially reversed by pretreatment of 3T3-L1 cells with pharmacological inhibitors of a p44/42 mitogen-activated protein (MAP) kinase. Moreover, the negative effect of IL-6 on adiponectin mRNA expression could be reversed by withdrawal of the hormone for 24h. Taken together, our results suggest that adiponectin gene expression is reversibly downregulated by IL-6 and support the concept of adiponectin being an important selectively controlled modulator of insulin sensitivity. more...
- Published
- 2003
- Full Text
- View/download PDF
26. Hormonal regulation of adiponectin gene expression in 3T3-L1 adipocytes.
- Author
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Fasshauer M, Klein J, Neumann S, Eszlinger M, and Paschke R
- Subjects
- 3T3 Cells, Adipocytes drug effects, Adiponectin, Animals, Dexamethasone pharmacology, Enzyme Inhibitors pharmacology, Gene Expression Regulation, Glucocorticoids pharmacology, Insulin pharmacology, Kinetics, Mice, Mitogen-Activated Protein Kinases antagonists & inhibitors, Phosphoinositide-3 Kinase Inhibitors, Proteins genetics, RNA, Messenger metabolism, Ribosomal Protein S6 Kinases antagonists & inhibitors, Transcription, Genetic drug effects, Tumor Necrosis Factor-alpha pharmacology, Adipocytes metabolism, Down-Regulation, Hormones pharmacology, Intercellular Signaling Peptides and Proteins, Proteins metabolism
- Abstract
Recently, it has been demonstrated that the fat-derived protein adiponectin is an important insulin-sensitizing adipocytokine which is downregulated in insulin resistance and obesity and replenishment of which in adiponectin-deficient states improves insulin sensitivity. To clarify the regulation of adiponectin gene expression, 3T3-L1 adipocytes were treated with various hormones known to induce insulin resistance in vivo and adiponectin mRNA was measured by quantitative real-time reverse transcription-polymerase chain reaction. Interestingly, treatment of 3T3-L1 cells with 100 nM insulin, 10 ng/ml tumor necrosis factor (TNF) alpha, or 100 nM dexamethasone for 16 h suppressed adiponectin gene expression by about 50 to 85% while angiotensin 2, growth hormone, and triiodothyronine did not have any effect. Furthermore, insulin reduced the level of adiponectin mRNA in a dose- and time-dependent fashion with inhibition detectable at concentrations as low as 10 nM insulin and as early as 4 h after effector addition. The inhibitory effect of insulin was partially reversed by pretreatment of 3T3-L1 cells with pharmacological inhibitors of p44/42 mitogen-activated protein (MAP) kinase, phosphatidylinositol (PI) 3-kinase, and p70S6 kinase. Moreover, the negative effects of insulin, TNFalpha, and dexamethasone on adiponectin gene expression could be completely reversed by withdrawal of the hormones for 24 h. Taken together, our results suggest that adiponectin gene expression is reversibly downregulated by insulin, TNFalpha, and dexamethasone. The data support the concept of adiponectin being an important selectively controlled modulator of insulin sensitivity. more...
- Published
- 2002
- Full Text
- View/download PDF
27. Evaluation of a computer based interactive diabetes education program designed to train the estimation of the energy or carbohydrate contents of foods.
- Author
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Nebel IT, Blüher M, Starcke U, Müller UA, Haak T, and Paschke R
- Subjects
- Germany, Humans, Computer-Assisted Instruction, Diabetes Mellitus, Type 1 diet therapy, Diabetes Mellitus, Type 2 diet therapy, Diet, Diabetic, Dietary Carbohydrates administration & dosage, Food Analysis, Patient Education as Topic methods, Software standards
- Abstract
The objective of this study was to evaluate a computer based interactive diabetes education program designed to train patients with diabetes to correctly estimate the energy or carbohydrate contents of foods. The acceptance and the operator convenience of the program were evaluated with an integrated program and written questionnaires. The training success was calculated for each user from the data sets after multiple repetitions of the same exercise. Age, weight, type of diabetes, previous training and computer experience of 126 patients with type 1 or 2 diabetes from three different German diabetes centres were documented. The evaluation of the computer program indicated a good acceptance and operator convenience. Moreover, there was a significant training success in patients who have never used a structured diabetes education program before. Therefore, the potential impact of the program is to support but not to replace structured diabetes education programs and to further motivate and attract patients to diabetes education programs. more...
- Published
- 2002
- Full Text
- View/download PDF
28. Tumor necrosis factor alpha is a negative regulator of resistin gene expression and secretion in 3T3-L1 adipocytes.
- Author
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Fasshauer M, Klein J, Neumann S, Eszlinger M, and Paschke R
- Subjects
- 3T3 Cells, Angiotensin II pharmacology, Animals, Culture Media, Serum-Free, Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors, Cyclic AMP-Dependent Protein Kinases metabolism, Dose-Response Relationship, Drug, Growth Hormone pharmacology, Intercellular Signaling Peptides and Proteins, Mice, Mitogen-Activated Protein Kinases antagonists & inhibitors, Mitogen-Activated Protein Kinases metabolism, Nerve Growth Factor, Obesity genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Resistin, Time Factors, Adipocytes drug effects, Adipocytes metabolism, Down-Regulation drug effects, Hormones, Ectopic genetics, Hormones, Ectopic metabolism, Proteins, Tumor Necrosis Factor-alpha pharmacology
- Abstract
Resistin has recently been implicated as an adipocytokine leading to insulin resistance and, therefore, potentially linking obesity and diabetes. To further characterize the regulation of this fat-secreted protein by insulin sensitivity-modulating hormones, 3T3-L1 adipocytes were treated with tumor necrosis factor (TNF) alpha, angiotensin (AT) 2, as well as growth hormone (GH), and resistin gene expression and protein secretion were determined by quantitative real-time reverse transcription-polymerase chain reaction and Western blotting. Interestingly, both, resistin mRNA expression and protein secretion, were inhibited by 70-90% after TNFalpha-treatment whereas AT2 and GH did not have any effect. The inhibitory effect of TNFalpha was time- and dose-dependent with significant inhibition occurring as early as 4 h after effector addition and at concentrations as low as 1 ng/ml TNFalpha. Pharmacological inhibition of protein kinase A (PKA), p44/42, and p38 mitogen-activated protein (MAP) kinase did not reverse the inhibitory effect of TNFalpha suggesting that neither of these signaling molecules is involved in suppression of resistin gene expression by TNFalpha. Furthermore, suppression of resistin mRNA levels could be completely reversed to control levels by withdrawal of TNFalpha for 24 h. Taken together, these results suggest that TNFalpha is a pivotal negative regulator of resistin gene expression. This may have important implications for the pathogenesis of insulin resistance and its link to obesity., (Copyright 2001 Academic Press.) more...
- Published
- 2001
- Full Text
- View/download PDF
29. Mutation detection in mosaic situations: RNA mismatch assay and denaturing gradient gel electrophoresis are more sensitive than conventional cycle sequencing.
- Author
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Dunger S, Neumann S, Zell R, Birch-Hirschfeld E, Stelzner A, Paschke R, Kinne RW, and Sickinger S
- Subjects
- Base Sequence, DNA Primers, Electrophoresis, Polyacrylamide Gel, Polymerase Chain Reaction, RNA chemistry, Base Pair Mismatch, Mosaicism, Mutation, RNA genetics
- Published
- 2001
- Full Text
- View/download PDF
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