TY  - JOUR
A1  - Schul, Daniela
A1  - Schmitt, Alexandra
A1  - Regneri, Janine
A1  - Schartl, Manfred
A1  - Wagner, Toni Ulrich
T1  - Bursted BMP Triggered Receptor Kinase Activity Drives Smad1 Mediated Long-Term Target Gene Oscillation in c2c12 Cells
JF  - PLoS ONE
N2  - Bone Morphogenetic Proteins (BMPs) are important growth factors that regulate many cellular processes. During embryogenesis they act as morphogens and play a critical role during organ development. They influence cell fates via concentration-gradients in the embryos where cells transduce this extracellular information into gene expression profiles and cell fate decisions. How receiving cells decode and quantify BMP2/4 signals is hardly understood. There is little data on the quantitative relationships between signal input, transducing molecules, their states and location, and ultimately their ability to integrate graded systemic inputs and generate qualitative responses. Understanding this signaling network on a quantitative level should be considered a prerequisite for efficient pathway modulation, as the BMP pathway is a prime target for therapeutic invention. Hence, we quantified the spatial distribution of the main signal transducer of the BMP2/4 pathway in response to different types and levels of stimuli in c2c12 cells. We found that the subcellular localization of Smad1 is independent of ligand concentration. In contrast, Smad1 phosphorylation levels relate proportionally to BMP2 ligand concentrations and they are entirely located in the nucleus. Interestingly, we found that BMP2 stimulates target gene expression in non-linear, wave-like forms. Amplitudes showed a clear concentration-dependency, for sustained and transient stimulation. We found that even burst-stimulation triggers gene-expression wave-like modulations that are detectable for at least 30 h. Finally, we show here that target gene expression oscillations depend on receptor kinase activity, as the kinase drives further expression pulses without receptor reactivation and the target gene expression breaks off after inhibitor treatment in c2c12 cells.
KW  - gene expression
KW  - BMP signaling
KW  - SMAD signaling
KW  - genetic oscillators
KW  - cell fusion
KW  - DNA-binding proteins
KW  - luciferase
KW  - kinase inhibitors
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130131
VL  - 8
IS  - 4
ER  - 
TY  - JOUR
A1  - Aghai, Fatemeh
A1  - Zimmermann, Sebastian
A1  - Kurlbaum, Max
A1  - Jung, Pius
A1  - Pelzer, Theo
A1  - Klinker, Hartwig
A1  - Isberner, Nora
A1  - Scherf-Clavel, Oliver
T1  - Development and validation of a sensitive liquid chromatography tandem mass spectrometry assay for the simultaneous determination of ten kinase inhibitors in human serum and plasma
JF  - Analytical and Bioanalytical Chemistry
N2  - A liquid chromatography tandem mass spectrometry method for the analysis of ten kinase inhibitors (afatinib, axitinib, bosutinib,cabozantinib, dabrafenib, lenvatinib, nilotinib, osimertinib, ruxolitinib, and trametinib) in human serum and plasma for theapplication in daily clinical routine has been developed and validated according to the US Food and Drug Administration andEuropean Medicines Agency validation guidelines for bioanalytical methods. After protein precipitation of plasma samples withacetonitrile, chromatographic separation was performed at ambient temperature using a Waters XBridge® Phenyl 3.5μm(2.1×50 mm) column. The mobile phases consisted of water-methanol (9:1, v/v) with 10 mM ammonium bicarbonate as phase A andmethanol-water (9:1, v/v) with 10 mM ammonium bicarbonate as phase B. Gradient elution was applied at a flow rate of 400μL/min. Analytes were detected and quantified using multiple reaction monitoring in electrospray ionization positive mode. Stableisotopically labeled compounds of each kinase inhibitor were used as internal standards. The acquisition time was 7.0 min perrun. All analytes and internal standards eluted within 3.0 min. The calibration curves were linear over the range of 2–500 ng/mLfor afatinib, axitinib, bosutinib, lenvatinib, ruxolitinib, and trametinib, and 6–1500 ng/mL for cabozantinib, dabrafenib, nilotinib,and osimertinib (coefficients of correlation≥0.99). Validation assays for accuracy and precision, matrix effect, recovery,carryover, and stability were appropriate according to regulatory agencies. The rapid and sensitive assay ensures high throughputand was successfully applied to monitor concentrations of kinase inhibitors in patients.
KW  - kinase inhibitors
KW  - therapeutic drug monitoring
KW  - liquid chromatography tandem mass spectrometry (LC-MS/MS
KW  - afatinib
KW  - osimertinib
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231925
SN  - 1618-2642
VL  - 413
ER  -