This selective MEK/ERK pathway inhibitor (FW = 440.54 g/mol; CAS 1265916-41-3; Solubility: 100 mM in DMSO; 100 mM for monohydrochloride salt), also named (3Z)-3-[[[3-[(dimethylamino) methyl]phenyl]amino]phenylmethylene]-2,3-dihydro-N,N-dimethyl-2-oxo- 1H-indole-6-carboxamide, targets Mitogen/Extracellular signal-regulated Kinase-5, or MEK5 (IC50 = 1.5 nM), and Extracellular-signal-Regulated Kinase, or ERK5 (IC50 = 59 nM), showing far weaker effects on MEK1 (IC50 = 6200 nM), MEK2 (IC50 = >6200 nM), ERK1 (IC50 >6200 nM), JNK2 (IC50 >6200 nM), TGFβR1 (IC50 = 580 nM), EGFR (IC50 >6300 nM), and STK16 (IC50 >6300 nM). Pharmacology: ERK5 is an atypical MAPK that is activated in the heart by pressure overload. ERK5 regulates cardiac hypertrophy and hypertrophy-induced apoptosis, and silencing ERK5 expression or inhibiting its kinase activity with BIX02189 reduces Myocyte Enhancer Factor-2 (MEF2) transcriptional activity and blunted hypertrophic responses in neonatal rat cardiomyocytes, or NRCMs. By applying BIX02189 to NRCMs, ERK5 phosphorylation is blocked without affecting other MAP kinases. BIX02189 induces apoptosis in acute myeloid leukemia tumor cells without affecting T cells from healthy donors
