EPZ015666

Kinase Assay [1]
EPZ015666 is serially diluted threefold from 1,000 to 0.051 nM and spotted into a 384-well polypropylene V-bottom microplate. 3H-SAM is serially diluted twofold in assay buffer for a seven-point dilution series with a top concentration of 700 nM (final assay concentration). Reactions are initiated by the addition of 4 nM enzyme and 40 nM peptide (final assay concentrations for both). Reactions are incubated for 60 min and quenched by the addition of 10 μL per well of 600 μM unlabeled SAM in assay buffer (final assay concentration). For the peptide competition, EPZ015666 is serially diluted threefold from 1,000 to 0.051 nM and spotted into a 384-well polypropylene V-bottom microplate. Peptide is serially diluted twofold in assay buffer for a seven-point dilution series with a top concentration of 480 nM (final assay concentration). Reactions are initiated by the addition of 4 nM enzyme and 75 nM 3H-SAM (final assay concentrations for both). Reactions are incubated for 60 min, and the reactions are quenched by the addition of 10 μL per well of 600 μM unlabeled SAM in assay buffer (final assay concentration)[1].

Cell Assay [1]
Cultured cells in linear/log-phase growth are split to a seeding density of 2×105 cells/mL in 2-20 mL of media, depending on the yield required at the end of the growth period. Compound is diluted in DMSO and added to each culture vessel with a final DMSO concentration of 0.2%. Cells are allowed to grow for 96 h undisturbed. At the conclusion of each treatment period, cells are harvested by centrifugation (5 min, 1,200 rpm), and cell pellets are rinsed once with PBS before being frozen on dry ice pending further processing. Long-term proliferation assays are performed on all MCL lines, with slight adjustments to initial seeding densities, depending on growth characteristics for each cell line. All assays are carried out for 12 d[1].

Animal Administration [1]
Mice[1] Male CD-1 mice (25-40 g; n=6, with 3 per time point) are treated with a single dose of EPZ015666 at 2 mg/kg by intravenous tail-vein injection and 10 mg/kg by oral gavage administration, with both doses formulated in 20% N-N-dimethylacetamide in water. Animals are fasted overnight and weighed before dose administration on the day of dosing. Approximately 30 μL of blood are taken from animals by submandibular or retro-orbital bleeding at pre-specified time intervals (seven time points). For the last time point (24 h), samples are collected via cardiac puncture while the animals are under anesthesia (70% CO2:30% O2). Blood samples are transferred into K2-EDTA tubes and placed on wet ice before centrifugation at 4°C (3,000g, 15 min) to obtain plasma within 30 min after sample collection. Plasma samples are stored at −70±10°C before protein precipitation and LC-MS/MS analysis. We constructed standard calibration curves by analyzing a series of control plasma aliquots containing 100 ng/mL labetalol as an internal standard and 1-3,000 ng/mL EPZ015666. Four levels of quality control are also included in the analysis (3-2,400 ng/mL EPZ015666). Data are analyzed using Phoenix WinNonlin 6.2.1.

References:
[1]. Chan-Penebre E, et al. A selective inhibitor of PRMT5 with in vivo and in vitro potency in MCL models. Nat Chem Biol. 2015 Jun;11(6):432-7. [2]. Kryukov GV, et al. MTAP deletion confers enhanced dependency on the PRMT5 arginine methyltransferase in cancer cells. Science. 2016 Mar 11;351(6278):1214-8.