LJH685 is an effective pan-RSK inhibitor for RSK1/2/3 (IC50: 6/5/4 nM).

RSK3:4 nM, RSK1:6 nM, RSK2:5 nM

LJH685 通过有力且选择性地抑制细胞中的RSK，调节YB1磷酸化。在依赖MAPK通路的癌细胞系中，LJH685展现出抗增殖作用，并引起细胞周期调控及凋亡诱导。[1]

Inhibition of RSK1, RSK2, and RSK3 activity: Enzymatic activity of RSK isoforms 1, 2, and 3 (PV4049, PV4051, and PV3846) is assessed using recombinant full-length RSK protein. RSK1 (1 nmol/L), RSK2 (0.1 nmol/L), or RSK3 (1 nmol/L) is allowed to phosphorylate 200 nmol/L peptide substrate (biotin-AGAGRSRHSSYPAGT-OH) in the presence of ATP at concentration equal to the Km for ATP for each enzyme (RSK1, 5 μmol/L; RSK2, 20 μmol/L; and RSK3, 10 μmol/L) and appropriate dilutions of RSK inhibitors.

Cell growth under attached conditions is assessed by plating 1000 cells per well on 96-well tissue culture-treated plates in cell growth medium. Appropriate dilutions of compound are added medium above cells and cell growth is assessed after 72 hrs by addition of CellTiter Glo reagent according to manufacturer's directions.(Only for Reference)