0000000000704238
AUTHOR
Linda S. Hoffmann
The JAK2 Kinase Inhibitor LS104 Induces Growth-Arrest and Apoptosis in JAK2V617F Positive Cells.
Abstract The JAK2V617F-mutation (V617F) is a novel, highly prevalent molecular marker in Ph-negative myeloproliferative disease (MPD). In vitro, the V617F mutation confers cytokine independent growth of Ba/F3 cells expressing erythropoietin receptor (EpoR) and constitutive activation of the JAK2 kinase and of the JAK-STAT pathway. In a murine bone-marrow transplant model the V617F-mutation alone is sufficient to induce a polycythemia vera-like phenotype. Therefore, mutant JAK2 kinase is a promising target for kinase inhibitor development. In this report, we characterize the small molecule LS104 (previously CR4; Grunberger et al., Blood 2003) as a novel non-ATP-competitive JAK2V617F kinase i…
LS104, a non-ATP-competitive small-molecule inhibitor of JAK2, is potently inducing apoptosis in JAK2V617F-positive cells
Abstract The activating JAK2V617F mutation has been described in the majority of patients with BCR-ABL-negative myeloproliferative disorders (MPD). In this report, we characterize the small-molecule LS104 as a novel non-ATP-competitive JAK2 inhibitor: Treatment of JAK2V617F-positive cells with LS104 resulted in dose-dependent induction of apoptosis and inhibition of JAK2 autophosphorylation and of downstream targets. Activation of these targets by JAK2 was confirmed in experiments using small interfering RNA. LS104 inhibited JAK2 kinase activity in vitro. This effect was not reversible using elevated ATP concentrations, whereas variation of the kinase substrate peptide led to modulation of …