TAK-632

Kinase experiment:

Immunoprecipitated BRAF or CRAF is incubated with recombinant inactive MEK (K97R) at 30°C for 30 minutes in kinase reaction buffer containing ATP/Mg2+. RAS/RAF wild-type (A431, CsFb, and HeLa), KRAS-mutant (A549, HCT-116, and MIA PaCa-2), and NRAS-mutant melanoma (GAK, HMV-II, and SK-MEL-2) cells are treated with TAK-632 (0, 0.32, 1.6, 8, 40, 200, 1000 and 5000 nM) at the indicated concentrations for 2 hours. Cell lysates are analyzed by Western blot analysis[2].

Cell experiment:

Cell viability is assessed (3 replicates) using the Sulforhodamine B assay or by the CellTiter-Glo luminescent cell viability assay. The concentrations of TAK-632 that produced 50% growth inhibition (GI50) are calculated using PCP software. The combination index (CI) is calculated using CalcuSyn software. To investigate the antiproliferative activity of TAK-632, we performed proliferation assays in various cell lines harboring mutated BRAF, NRAS, or KRAS. HMV-II, SK-MEL-2, or A375 cells are cotreated with TAK-632 and TAK-733 at the indicated concentrations for 72 hours. Cell viability is measured. The CI value at EC50 is calculated. A375 cells stably expressing NRASQ61K or ΔN-BRAF are cotreated with TAK-632 and TAK-733 at the indicated concentrations for 72 hours. Cell viability is measured. The CI value at EC50 is calculated[2].

Animal experiment:

Mice[2] The xenograft-implanted nude mice are used. Mice bearing SK-MEL-2 xenografts are treated once daily for 21 consecutive days with vehicle or TAK-632 at the indicated concentrations (10 mice per each treatment group). Day 0 indicates the beginning of treatment. Tumors are measured twice a week. Mice bearing SK-MEL-2 xenografts are treated once daily (QD) for 3 days with vehicle, TAK-632 at 60 mg/kg (60 mpk), or TAK-632 at 120 mg/kg (120 mpk). Tumor xenografts are obtained at indicated time points after the final treatment and analyzed by Western blot analysis. Individual blots with dividing lines are combined from a single electrophoresis gel. Bars represent densitometric analysis of phospho-ERK, normalized to vehicle-treated control (mean±SD).

References:

[1]. Okaniwa M, et al. Discovery of a selective kinase inhibitor (TAK-632) targeting pan-RAF inhibition: design, synthesis, and biological evaluation of C-7-substituted 1,3-benzothiazole derivatives. J Med Chem. 2013 Aug 22;56(16):6478-94.
[2]. Nakamura A, et al. Antitumor activity of the selective pan-RAF inhibitor TAK-632 in BRAF inhibitor-resistant melanoma. Cancer Res. 2013 Oct 11.