K858 is a potent, selective inhibitor of mitotic kinesin Eg5 ATPase activity with IC50 of 1.3 uM.
K858 displays >150-fold more selective for Eg5 than other members of the kinesin superfamily.
K858 induces mitotic arrest, apoptosis, and cell growth inhibition through the activation of the Mad2-mediated spindle checkpoint, and has no effect on microtubule polymerization.
K858 exhibits potent antitumor activity in xenograft models of cancer, and induces the accumulation of mitotic cells with monopolar spindles in tumor tissues.
