Final answer:
Microtubule inhibitors such as vincristine and colchicines disrupt cell division in cancer cells by interfering with microtubule assembly and function, leading to arrested cell cycle and cell death.
Step-by-step explanation:
Microtubule inhibitors such as vincristine and colchicines are essential drugs used in chemotherapy to treat cancer. These drugs work by targeting microtubules, specifically the tubulin subunit, which is vital for the formation and function of the spindle apparatus during cell division. Microtubule inhibitors bind to tubulin and disrupt the assembly and disassembly of microtubules, which can arrest the cell cycle by preventing the spindle fibers from attaching to chromosomes or by inhibiting microtubule dynamics necessary for chromosome separation. Ultimately, this stops cell division, especially in rapidly dividing cancer cells, where mitosis is frequent and uncontrolled. Some of these drugs, like paclitaxel (taxol), exert their effect by stabilizing microtubules, whereas others, like vincristine, prevent their proper formation, both leading to disrupted mitosis and cell death.