Background:

NVP-BSK805 is a potent and selective inhibitor of JAK2 with IC50 value of 0.58 nM [1].
Janus kinase 2 (JAK2) is a member of the JAK family and is a non-receptor tyrosine kinase. JAK2 regulates signal transduction in the cell nucleus via activation of signal transducers and activators of transcription proteins (STATs), which form dimers upon phosphorylation and migrate into the nucleus to regulate the activation of target genes [2].
In JAK radiometric filter binding kinase assays, NVP-BSK805 inhibited full-length JAK2 wild-type and JAK2V617F enzymes with IC50 values of 0.58 nM and 0.56 nM, respectively [1]. In CHRF-288-11, SET-2 and HEL cells which expressed JAK2, NVP-BSK805 inhibited STAT5a phosphorylation [2].
In SCID beige mice injected with JAK2V617F-dependent Ba/F3 cells, NVP-BSK805 (150 mg/kg) suppressed STAT5 phosphorylation in spleen extracts by nearly 50% relative to vehicle-treated controls at the 6- and 12-hour time. In rats injected with recombinant human erythropoietin (rhEpo), which induced transient polycythemia and splenomegaly, NVP-BSK805 suppressed rhEpo-induced STAT5 phosphorylation in spleen in a dose-dependent way [1].
参考文献:
[1]. Baffert F, Régnier CH, De Pover A, et al. Potent and selective inhibition of polycythemia by the quinoxaline JAK2 inhibitor NVP-BSK805. Mol Cancer Ther, 2010, 9(7): 1945-1955.
[2]. Ringel F, Kaeda J, Schwarz M, et al. Effects of Jak2 type 1 inhibitors NVP-BSK805 and NVP-BVB808 on Jak2 mutation-positive and Bcr-Abl-positive cell lines. Acta Haematol, 2014, 132(1): 75-86.