TY - GEN A1 - Krüger-Genge, Anne A1 - Steinbrecht, Susanne A1 - Küpper, Jan-Heiner A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Evidence for cytostatic effect of cyclophosphamide on human vein endothelial cells in cancer therapy: preliminary in vitro results. T2 - Clinical Hemorheology and Microcirculation Y1 - 2018 U6 - https://doi.org/10.3233/CH-189125 SN - 1875-8622 SN - 1386-0291 VL - 69 IS - 1-2 SP - 267 EP - 276 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - König, Rosalie A1 - Schmidtke, Kai-Uwe A1 - Herzog, Natalie A1 - Scheibner, Katrin A1 - Krüger-Genge, Anne A1 - Jung, Friedrich A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - Metabolic activity testing can underestimate acute drug cytotoxicity as revealed by HepG2 cell clones overexpressing cytochrome P450 2C19 and 3A4 T2 - Toxicology Y1 - 2018 U6 - https://doi.org/10.1016/j.tox.2018.11.008 SN - 0300-483X VL - 412 SP - 37 EP - 47 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - HepG2 cells with recombinant cytochrome P450 enzyme overexpression: Their use and limitation as in vitro liver model T2 - Journal of Cellular Biotechnology Y1 - 2019 U6 - https://doi.org/10.3233/JCB-189013 SN - 2352-3697 SN - 2352-3689 VL - 5 IS - 1 SP - 55 EP - 64 ER - TY - GEN A1 - Haileka, Vanessa A1 - George, Sandra A1 - Steinbrecht, Susanne A1 - Jung, Friedrich A1 - Reinehr, R. A1 - Küpper, Jan-Heiner T1 - Colon cancer cells cultured under hyperosmotic conditions as in vitro model to investigate dehydration effects on cancer drug susceptibility T2 - Clinical Hemorheology and Microcirculation Y1 - 2019 U6 - https://doi.org/10.3233/CH-199210 SN - 1875-8622 VL - 73 IS - 1 SP - 169 EP - 176 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - Pfeifer, Nadine A1 - Herzog, Natalie A1 - Katzenberger, Nadine A1 - Schulz, Christian A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - HepG2-1A2 C2 and C7: Lentivirus vector-mediated stable and functional overexpression of cytochrome P450 1A2 in human hepatoblastoma cells T2 - Toxicology Letters N2 - Novel HepG2 cell clones 1A2 C2 and 1A2 C7 were independently generated by lentiviral transduction to functionally overexpress cytochrome P450 1A2 (CYP1A2). We found similar and stable CYP1A2 transcript and protein levels in both cell clones leading to specific enzyme activities of about 370 pmol paracetamol x min-1 x mg-1 protein analyzed by phenacetin conversion. Both clones showed dramatically increased sensitivity to the hepatotoxic compound aflatoxin B1 (EC50<100 nM) when compared to parental HepG2 cells (EC50 ∼5 μM). Thus, newly established cell lines are an appropriate tool to study metabolism and toxicity of substances depending on conversion by CYP1A2. KW - HepG2 KW - CYP1A2 KW - Cytochrome P450 KW - Liver metabolism Y1 - 2020 U6 - https://doi.org/10.1016/j.toxlet.2019.11.006 SN - 0378-4274 VL - 319 SP - 155 EP - 159 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - Kiebist, Jan A1 - König, Rosalie A1 - Thiessen, Markus A1 - Schmidtke, Kai-Uwe A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Scheibner, Katrin T1 - Synthesis of cyclophosphamide metabolites by a peroxygenase from Marasmius rotula for toxicological studies on human cancer cells T2 - AMB Express N2 - Cyclophosphamide (CPA) represents a widely used anti-cancer prodrug that is converted by liver cytochrome P450 (CYP) enzymes into the primary metabolite 4-hydroxycyclophosphamide (4-OH-CPA), followed by non-enzymatic generation of the bioactive metabolites phosphoramide mustard and acrolein. The use of human drug metabolites as authentic standards to evaluate their toxicity is essential for drug development. However, the chemical synthesis of 4-OH-CPA is complex and leads to only low yields and undesired side products. In past years, fungal unspecific peroxygenases (UPOs) have raised to powerful biocatalysts. They can exert the identical selective oxyfunctionalization of organic compounds and drugs as known for CYP enzymes with hydrogen peroxide being used as sole cosubstrate. Herein, we report the efficient enzymatic hydroxylation of CPA using the unspecific peroxygenase from Marasmius rotula (MroUPO) in a simple reaction design. Depending on the conditions used the primary liver metabolite 4-OH-CPA, its tautomer aldophosphamide (APA) and the overoxidized product 4-ketocyclophosphamide (4-keto-CPA) could be obtained. Using a kinetically controlled approach 4-OH-CPA was isolated with a yield of 32% (purity > 97.6%). Two human cancer cell lines (HepG2 and MCF-7) were treated with purified 4-OH-CPA produced by MroUPO (4-OH-CPAUPO). 4-OH-CPAUPO–induced cytotoxicity as measured by a luminescent cell viability assay and its genotoxicity as measured by γH2AX foci formation was not significantly different to the commercially available standard. The high yield of 4-OH-CPAUPO and its biological activity demonstrate that UPOs can be efficiently used to produce CYP-specific drug metabolites for pharmacological assessment. KW - Biocatalysis KW - Cyclophosphamide KW - Human drug metabolites KW - Peroxygenase KW - Toxicity Y1 - 2020 UR - https://amb-express.springeropen.com/articles/10.1186/s13568-020-01064-w U6 - https://doi.org/10.1186/s13568-020-01064-w SN - 2191-0855 VL - 10 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Steinbrecht, Susanne A1 - Jung, Conrad H. G. A1 - Westphal, Sophia A1 - Klöpzig, Stefanie A1 - Waldeck, Peter A1 - Küpper, Jan-Heiner A1 - Storsberg, J. A1 - Jung, Friedrich T1 - Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination T2 - Clinical Hemorheology and Microcirculation N2 - Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field. KW - Arthrospira platensis KW - endothelial cells KW - xCELLigence system Y1 - 2021 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch201096 U6 - https://doi.org/10.3233/CH-201096 SN - 1386-0291 VL - 78 IS - 2 SP - 151 EP - 161 ER -