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 partia l disassembly of microtubules and withdrawal of microtubules from the cell periphery, disorganized microtubules and delayed regrowth of disa ssembled microtubules. It also induced a spheroid cellular morphology and affected cellular adhesion and survival. Sometimes microtubules se emed 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 endoplasmat ic 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-d ependent processes and localization of cellular organelles. These effe cts could be of importance in the treatment of prostatic carcinoma wit h estramustine.