Nocodazole

From Wikipedia, the free encyclopedia

Nocodazole is an anti-neoplastic agent which exerts its effect in cells by depolymerizing microtubules. Microtubules are one type of fibre which constitutes the cytoskeleton, and the dynamic microtubule network has several important roles in the cell, including vesicular transport, forming the mitotic spindle and in cytokinesis. Several drugs including vincristine and colcemid are similar to nocodazole in that they interfere with microtubule polymerisation.

As nocodazole affects the cytoskeleton, it is often used in cell biology experiments as a control: for example, some dominant negative Rho small GTPases cause a similar effect as nocodazole, and constitutively activated mutants often reverse or negate the effect.

Nocodazole is frequently used in cell biology laboratories to synchronize the cell division cycle. Cells treated with nocodazole arrest with a G2- or M-phase DNA content when analysed by flow cytometry. Microscopy of nocodazole-treated cells shows that they do enter mitosis but cannot form metaphase spindles because microtubules (of which the spindles are made) cannot polymerise. The absence of microtubule attachment to kinetochores activates the spindle assembly checkpoint, causing the cell to arrest in prometaphase. For cell synchronization experiments, nocodazole is usually used at a concentration of 100ng/mL of culture medium for a duration of 12-18 hrs. Prolonged arrest of cells in mitosis due to nocodazole treatment typically results in cell death by apoptosis.