Trametinib (GSK1120212)

2 years -80 in solvent

Orally

HT-29, HCT-15, HCT116, COLO205, LS-174T, SW480, SW620, T84, LoVo and COLO320

Dissolved in DMSO, final concentrations ca.10 uM

Dissolved in 10% Cremophor EL-10% PEG400

GSK1120212 inhibits the phosphorylation of MBP regardless of the isotype of Raf and MEK, with IC50 ranging from 0.92 nM to 3.4 nM. GSK1120212 demonstrates no inhibition of the kinase activities of c-Raf, B-Raf, ERK1 and ERK2. In addition, GSK1120212 does not show drastic inhibitory activity against the other 98 kinases. GSK1120212 displays potent inhibitory activity against human colorectal cancer cell lines. HT-29 and COLO205 cells, which are known to have a constitutively active B-Raf mutant, are most sensitive to GSK1120212 with IC50 0.48 nM and 0.52 nM, respectively. The cell lines bearing a K-Ras mutation show a wide range of sensitivity to GSK1120212 with IC50 of 2.2-174 nM. In contrast, COLO320 DM cells, bearing the wild-type gene in both B-Raf and K-Ras, are found to be resistant to GSK1120212 even at 10 uM. GSK1120212 treatment for 24 hours induces cell-cycle arrest at the G1 phase in all sensitive cell lines. Consistently, GSK1120212 treatment leads to upregulation of p15INK4b and/or p27KIP1 in most of the colorectal cancer cell lines. GSK1120212 inhibits constitutive ERK phosphorylation in all sensitive cell lines. GSK1120212 induces apoptosis both in HT-29 and COLO205 cells, but that COLO205 cells are more sensitive to GSK1120212 than HT-29 cells in terms of apoptosis induction. [1] GSK1120212 blocks tumor necrosis factor-alpha and interleukin-6 production from peripheral blood mononuclear cells (PBMCs). [2]

3 or 4 days

Exponentially growing cells are precultured in 96-well tissue culture plates for 24 hours and then exposed to GSK1120212. Cell growth is determined by an in vitro toxicology assay kit, sulforhodamine B based. For apoptosis assay, both floating and adherent cells are collected and fixed with 70% ethanol. After washing with PBS, the cells are suspended in 100 ug/mL RNase and 25 ug/mL propidium iodide (PI) and incubated at 37 C for 30 minutes in the dark. The DNA content of each single cell is determined using the flow cytometer Cytomics FC500 or Guava EasyCyte plus.

Trametinib (GSK1120212, JTP-74057) is a highly specific and potent MEK1/2 inhibitor with IC50 of 0.92 nM/1.8 nM in cell-free assays, no inhibition of the kinase activities of c-Raf, B-Raf, ERK1/2. Trametinib activates autophagy and induces apoptosis.

More potent than PD0325901 or AZD6244