LDN-192960 is a potent Haspin (Haploid Germ Cell-Specific Nuclear Protein Kinase) inhibitor with an IC50 of 0.010 µM.
A comparison of the profiles of LDN-192960 (compound 3) and 42 suggests that only six kinases, including haspin, are inhibited by both compounds ≥90% at 10 µM[1]. LDN-192960 alone does not cause detectable mitotic exit in the mitotic (phospho)-protein monoclonal-2 (MPM-2) assay in HeLa cells. In the presence of 1 µM ZM447439, even concentrations as low as 0.1 µM LDN-192960 cause substantial loss of MPM-2 epitopes, and similar results are obtained in the presence of Hesperadin. However, 10 µM LDN-192960 does not cause mitotic exit in combination with Aurora B inhibition, which is consistent with off-target effects at this higher dose[2].
[1]. Cuny GD, et al. Structure-activity relationship study of beta-carboline derivatives as haspin kinase inhibitors. Bioorg Med Chem Lett. 2012 Mar 1;22(5):2015-9. [2]. Fangwei Wang, et al. Haspin inhibitors reveal centromeric functions of Aurora B in chromosome segregation. J Cell Biol. 2012 Oct 15; 199(2): 251-268.