Estramustine induces disorganization of microtubules, perinuclear retraction of vimentin and endoplasmatic reticulum, and inhibits cell migration.

The effects of the mitotic inhibitor estramustine on the cytoskeleton of DU 145 and AG 1518 cells were studied. Estramustine caused a partial disassembly of microtubules and withdrawal of microtubules from the cell periphery, disorganized microtubules and delayed regrowth of disassembled microtubules. It also induced a spheroid cellular morphology and affected cellular adhesion and survival. Sometimes microtubules seemed to be organized from several microtubule-organizing centers. The cytoskeleton-dependent cell migration was inhibited in the presence of estramustine and the microtubule-interacting vimentin and endoplasmatic reticulum retracted to the perinuclear area. Our results show that not only a complete disassembly of microtubules, but also disturbances of the microtubule network can have dramatic effects on microtubule-dependent processes and localization of cellular organelles. These effects could be of importance in the treatment of prostatic carcinoma with estramustine.