Cell experiment:

PANC-1 cells are seeded into six-well plates at a density of 5.0×103 cells/well in RPMI 1640 media containing 10% FBS. Cells are cotransfected with a pGL3-5x unfolded protein response element (UPRE)-luciferase reporter containing five repetitions of the XBP-1 DNA binding site and pRL-SV40 using the FuGENE6 transfection reagent. Forty-eight hours later, cells are treated with 2.5 mg/mL tunicamycin for 1 hour, followed by GSK2850163 treatment for 16 hours. Luciferase expression is measured using Dual-Glo Luciferase Assay kit and normalized to Renilla expression levels[1].

GSK2850163 is a novel inhibitor of inositol-requiring enzyme-1 alpha (IRE1α) which can inhibit IRE1α kinase activity and RNase activity with IC50s of 20 and 200 nM, respectively.

GSK2850163 is a novel inhibitor of inositol-requiring enzyme-1 alpha (IRE1α) which can inhibit IRE1α kinase activity and RNase activity with IC50s of 20 and 200 nM, respectively. The increased autophosphorylation of IRE1α could be reduced in a dose-dependent manner by GSK2850163. Increasing concentrations of GSK2850163 are capable of reducing the increased XBP 1 transcriptional activity. Two additional kinases are weakly inhibited by GSK2850163: Ron (IC50=4.4 μM) and FGFR1 V561M (IC50=17 μM)[1].

[1]. Nestor O. Concha, et al. Long-Range Inhibitor-Induced Conformational Regulation of Human IRE1α Endoribonuclease Activity. Molecular Pharmacology December 2015, 88 (6) 1011-1023.