K-756

Kinase experiment:

The activity of each enzyme is measured using a PARP1, PARP2, PARP3, PARP6, PARP7, and PARP11 Chemiluminescent Assay Kit, and a TNKS1 and TNKS2 Histone Ribosylation Assay Kit. Enzymatic reactions are conducted in duplicate at 30°C for 1 hour in a 50 μL mixture containing an assay buffer, an enzyme-coated plate, and a substrate. After the enzymatic reactions, 50 μL of Streptavidin-HRP is added to each well and the plate is incubated at room temperature for an additional 30 minutes. 100 μLs of developer reagents are added to the wells and luminescence is measured using a Synergy2 microplate reader. The luminescence data are analyzed using the GraphPad Prism software program[1].

Cell experiment:

For the cell viability assay, APC-mutant colorectal cancer cell line COLO 320DM and SW403 cells are seeded in 96-well white plates. siRNAs are reverse transfected by RNAiMax. After 144 hours, a cell viability assay is performed using a Cell Titer-Glo Luminescent Cell Viability Assay Kit. Luciferase activity is measured using a Top count NXT system. For the cell growth inhibition assay, cells are seeded in 96-well plates. The next day, the cells are treated with the compounds (e.g., K-756, 0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM and 10 μM). After 0, 72, or 144 hours of incubation, XTT reagent is added to the cells. After 3 hours of incubation, the formation of formazan dye from tetrazolium salt XTT is measured using a SpectraMax 340PC system[1].

Animal experiment:

Mice[1]SCID mice (CB17/Icr-Prkdcscid/CrlCrlj, male, 5 weeks old) are subcutaneously implanted with 5×106 cells of DLD-1/TCF-Luc cells. After 13 days, the mice with a tumor volume of 236.38 to 595.80 mm3 are divided into groups of 5 animals. On the day after grouping, 0.5% MC 400 or K-756 (100, 200, and 400 mg/kg) is orally administered to the mice once a day for 3 days. Twenty-four hours after the last administration of first and second day and 25 hours after the last administration of the third day, the tumor tissues are collected from the mice and frozen in liquid nitrogen. Tumor total RNA is extracted using an RNeasy mini Kit and reverse-transcribed using VILO reagent. An RT-PCR is performed.

References:

[1]. Okada-Iwasaki R, et al. The Discovery and Characterization of K-756, a Novel Wnt/β-Catenin Pathway Inhibitor Targeting Tankyrase. Mol Cancer Ther. 2016 Jul;15(7):1525-34.