Trametinib (GSK1120212) is a MEK inhibitor that inhibits MEK1 and MEK2 (IC50=0.7/0.9 nM) with ATP non-competitive and oral activity. Trametinib activates autophagy and induces apoptosis.

MEK2:0.92 nM (cell free), MEK1:1.8 nM (cell free)

方法：小鼠肝内胆管癌细胞 SB1、LD-1 和人肝内胆管癌细胞 EGI-1 用 Trametinib (0-10000 nM) 处理 48 h，使用 MTT 方法检测细胞生长抑制情况。
结果：Trametinib 剂量依赖抑制 SB1、LD-1 和 EGI-1 细胞生长，IC50 分别为 41.48 nM、56.10 nM 和 27.89 nM。[1]
方法：人结肠癌细胞 RKO 用 Trametinib (200 nmol/L) 处理 30 h，使用 Western Blot 方法检测靶点蛋白表达水平。
结果：Trametinib 显著降低 p-ERK 和 p-AKT 水平。[2]
方法：人胶质瘤细胞 U87 和 U251 用 Trametinib (50 nM) 孵育 6-72 h，使用 Flow Cytometry 方法检测细胞凋亡情况。
结果：Trametinib 诱导 U87 和 U251 细胞的凋亡率明显增加。Trametinib 可以诱导神经胶质瘤细胞的晚期凋亡，而不会发生早期凋亡。[3]

方法：为检测体内抗肿瘤活性，将 Trametinib (0.3-1 mg/kg) 口服给药给携带人结直肠癌肿瘤 HT-29 和 COLO205 的 BALB/c-nu/nu 小鼠，每天一次，持续十四天。
结果：Trametinib 治疗显著抑制人结直肠癌肿瘤的生长，表明在体内具有抗肿瘤活性。[4]
方法：为检测体内抗肿瘤活性，将 Trametinib (5 mg/kg) 腹腔注射给携带人B淋巴细胞白血病肿瘤 KOPN8 和 COLO205 的 NSG 小鼠，每周三次，持续十四天。
结果：Trametinib 单药治疗延缓了白血病的进展，但不足以防止白血病的生长。[5]

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].