| Tubulin Polymerization — Assembly of α/β-tubulin heterodimers into microtubules. Microtubule polymerization and depolymerization are highly dynamic processes required for mitotic spindle formation, chromosome segregation, intracellular transport, maintenance of cell shape, and cellular migration.
Typical modulation in cancer: Both excessive stabilization and inhibition of tubulin polymerization can be anticancer because disruption of normal microtubule dynamics interferes with mitosis. Tubulin-polymerization inhibitors such as vinca alkaloids, colchicine-site binders, and benzimidazoles cause microtubule loss and mitotic arrest, whereas taxanes stabilize polymerized microtubules and prevent normal depolymerization. Therefore, direction must be interpreted according to the drug mechanism rather than assuming that ↑ or ↓ polymerization is universally favorable.
Typical modulation in Alzheimer’s disease: Microtubule destabilization contributes to impaired axonal transport and neuronal dysfunction. Tau normally stabilizes microtubules, and pathological tau disrupts microtubule organization. Thus, preservation of appropriate microtubule polymerization/dynamics may be neuroprotective, although excessive stabilization can also impair normal microtubule function.
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