The microtubule-dependent motor protein Eg5 plays a critical role in spindle assembly and
maintenance in mitosis. Herein we show that the suppression of Eg5 by a specific inhibitor
arrested mitosis, induced apoptosis, and up-regulated Hsp70 in human multiple myeloma
cells. Mechanistically, Hsp70 induction occurred at the transcriptional level via a cis-
regulatory DNA element in Hsp70 promoter and was mediated by the phosphatidylinositol 3-
kinase/Akt pathway. Eg5 inhibitor-mediated Hsp70 up-regulation is cytoprotective because …