Question

Two natural plant products, vinblastine from the rosy periwinkle and paclitaxel (taxol) from the pacific yew, have been used successfully in the treatment of a wide range of cancers. these chemicals work by interfering with mitosis but by different methods. vinblastine inhibits mitosis by preventing the assembly of the spindle. paclitaxel promotes microtubule synthesis and binds to the microtubules preventing the depolymerization (disassembly) of the spindle during mitosis. based on your knowledge of mitosis, at what phase do you expect cell division to be interrupted by each of these cancer fighting compounds? explain your answer based on the activities occurring at mitotic stages.

Answer 1

If vinblastine prevents assembly of the spindle, then it interrupts cell division in Profase 1, when the assembly of the spindle begins. Paclitaxel prevents the depolymeritation of the spindle, so it will interrupt cell cycle in Anaphasis, when the dissasembly of spindle takes place.