SC-514

Kinase experiment:

IKK complexes are immunoprecipitated from IL-1β-treated RASF cell lysates (0.5-2 mg) using a NEMO antibody (3-10 μg) followed by the addition of protein A-agarose beads. Antibody complexes are pelleted by centrifugation and washed 3 times with 1 mL of cold whole-cell lysis buffer followed by 2 washes in kinase buffer (25 mM HEPES, pH 7.6, 2 mM MgCl2, 2 mM MnCl2, 10 mM NaF, 5 mM DTT, and 1 mM phenylmethylsulfonyl fluoride). 100-200 μg of immunoprecipitated IKK is analyzed for kinase activity in a reaction containing 10 μM biotinylated IκBα peptide as substrate and 1 μM [γ-33P]ATP (2500 Ci/mmol). After incubation at room temperature for 30 min, 25 μL of the reaction mixture is withdrawn and added to a SAM 96 biotin capture plate. After successive wash steps the plate was allowed to air-dry, and 25 μL of scintillation fluid is added to each well. Incorporation of [γ-33P]ATP is measured using a Top-Count NXT[1].

Cell experiment:

For crystal violet staining assay, melanoma cell lines (1×104) are seeded in 60 mm dishes, and then untreated or pretreated with SC-514 (50 µM) and/or Fotemustine. Then, cells are formalin-fixed and stained with crystal violet. Cell numbers are measured as the optical density at 595 nm (OD595) of solubilized crystal violet from formalin-fixed cells. Cytotoxicity are also determined by the MTT reduction assay[2].

Animal experiment:

Rats[1] SC-514 or vehicle (2% Me2SO in saline) is administered either by oral gavage (50 mg/kg) or intraperitoneally (10 and 50 mg/kg) to adult male Wistar rats that have been deprived of food overnight. Two hours after compound treatment, 1 mg/kg LPS (Escherichia coli) in saline is administered intraperitoneally 90 min after LPS administration; the animals are bled and serum TNFα levels analyzed by a rat-specific TNFα ELISA.Mice[2] Male nu/nu BALB/c mice (6 weeks old) are maintained in individual ventilated cages. A375 or G361 (5×106) cells are resuspended in 0.1 mL PBS and inoculated subcutaneously into the backs of nude mice and allowed to grow for 7 days. After that, mice are randomly assigned to 4 groups (n=6 for each group) and treated by intraperitoneal injection with 200 µL 30% PEG/5% Tween-80 solution as the vehicle control and 25 mg/kg SC-514 and/or 25 mg/kg Fotemustine daily for 13-15 consecutive days. Body weight and tumor volume are measured every 3 days. Tumor volumes are determined by a caliper and calculated. At the end of the experiment, mice are sacrificed and tumor xenografts are collected. Tumor tissues are stored at -80°C for Western blot analysis.

References:

[1]. Kishore N, et al. A selective IKK-2 inhibitor blocks NF-kappa B-dependent gene expression in interleukin-1 beta-stimulated synovial fibroblasts. J Biol Chem. 2003 Aug 29;278(35):32861-71.
[2]. Tse AK, et al. Sensitization of melanoma cells to alkylating agent-induced DNA damage and cell death via orchestrating oxidative stress and IKKβ inhibition. Redox Biol. 2017 Apr;11:562-576.