Trametinib是一种口服有效的MEK抑制剂，抑制 MEK1 和 MEK2 的IC50分别为 2 nM。它可激活自噬，诱导凋亡。

Trametinib is an ATP-noncompetitive inhibitor of MEK 1/2 (IC50s: 0.7/0.9 nM). It shows low inhibition for more than 180 kinases, including B-Raf, c-Raf, and MEK5.

Trametinib (JTP-74057) inhibited the phosphorylation of MBP regardless of the isotype of Raf and MEK (IC50s: 0.92 to 3.4 nM). JTP-74057 demonstrated no inhibition of the kinase activities of c-Raf, B-Raf, ERK1 and ERK2. HT-29 and COLO205 cells, which are known to have a constitutively active B-Raf mutant, were most sensitive to JTP-74057, showing subnanomolar IC50 values. The cell lines bearing a K-Ras mutation showed a wide range of sensitivity to JTP-74057 [1]. Among KRAS mutant cell lines, cell lines with an expression pattern suggestive of epithelial-to-mesenchymal transition were less sensitive to GSK1120212. A proportion of cell lines from certain tissue types not known to carry frequent RAF/RAS mutations also seemed to be sensitive to GSK1120212 [2].

Both 0.3 mg/kg and 1 mg/kg of JTP-74057 were effective in inhibiting the HT-29 xenograft growth, and 1 mg/kg of JTP-74057 blocked the tumor increase almost completely. Neither significant changes in body weight nor gross lesions at autopsy were observed in the mice treated with 1 mg/kg of JTP-74057. The phosphorylation of ERK1/2 was completely inhibited in the established tumor tissues by a single oral dose of 1 mg/kg JTP-74057, and both p15INK4b and p27KIP1 protein levels were upregulated after 14 days of treatment with JTP-74057 [1]. JTP-74057 blocked tumor necrosis factor-α and interleukin-6 production from PBMCs. AIA and CIA development were suppressed almost completely by 0.1 mg/kg of JTP-74057. In the CIA, JTP-74057 suppressed collagen-reactive T-cell proliferation ex vivo [3].

A Raf-MEK-ERK cascade kinase assay was carried out as previously described. Briefly, nonphosphorylated myelin basic protein (MBP) was coated onto an ELISA plate, and the active form of B-Raf/c-Raf was mixed with unphosphorylated MEK1/MEK2 and ERK2 in 10 μM ATP and 12.5 mM MgCl2 containing MOPS buffer in the presence of various concentrations of JTP-74057. The phosphorylation of MBP was detected by the anti-phosphoMBP antibody. Kinase inhibitory activities against a total of 99 kinases were tested by kinase profiler at 10 μM ATP [1].

These cells were maintained in media recommended by the providers. Exponentially growing cells were precultured in 96-well tissue culture plates for 24 h and then exposed to JTP-74057. Cell growth was determined by an in vitro toxicology assay kit, sulforhodamine B based. For combination studies, two compounds were simultaneously added to the HT-29 cells and incubated for 72 h. In the presence of various concentrations of compound A, the 50% inhibitory concentration (IC50) values of compound B were determined. Then, the fixed concentration of compound A versus the IC50 value of compound B was plotted. Conversely, the IC50 values of compound A were determined in the presence of various concentrations of compound B and plotted [1].

Female BALB/c-nu/nu mice were used. On day 0, HT-29 cells or COLO205 cells suspended in ice-cold HBSS (-) were inoculated subcutaneously into the right flank of the mice at 5x10^6 cells/100 μl/site or 1x10^6 cells/100 μl/site, respectively. The acetic acid-solvated form of JTP-74057 was dissolved in 10% Cremophor EL-10% PEG400 and was administered orally once daily for 14 days from the day when the mean tumor volume reached 100 mm^3. The tumor length [L (mm)] and width [W (mm)] were measured using a micro gauge twice a week after the commencement of dosing, and the tumor volume was calculated using the following formula: tumor volume (mm^3) = L x W x W/2. All procedures relating to the use of animals in this study were reviewed and approved by the Institutional Animal Care and Use Committee of Japan Tobacco [1].

871700-17-3

C26H23FIN5O4

615.39

曲美替尼;GSK1120212;JTP-74057

DMSO:21 mg/mL (34.1 mM)
Ethanol:<1 mgml
Powder: -20°C for 3 years
In solvent: -80°C for 2 years