Microtubule (Tubulin beta chain)

Microtubules are dynamic cytoskeletal polymers composed of alpha- and beta-tubulin heterodimers that are essential for maintaining cell shape, facilitating intracellular transport, and forming the mitotic spindle during cell division (Jordan & Wilson, 2004). In oncology, microtubules are the direct target of the taxane component within chemotherapy regimens such as TPC (Taxane, Platinum, and Cyclophosphamide or Cetuximab), which is frequently utilized in the treatment of ovarian, breast, and lung cancers (National Cancer Institute). Taxanes, including paclitaxel and docetaxel, bind specifically to the beta-tubulin subunit on the inner surface of the microtubule, promoting assembly and suppressing the dynamic instability required for chromosome segregation (PubChem). This stabilization results in the formation of non-functional microtubule bundles, leading to cell cycle arrest at the G2/M phase and the induction of apoptosis (StatPearls). While highly effective, targeting microtubules with taxanes is often associated with dose-limiting toxicities such as peripheral neuropathy and neutropenia (FDA).

Other names

TubulinBeta-tubulinMitotic spindleMicrotubule polymerTubulin beta-1 chain

Taxanes bind to the interior surface of the microtubule specifically at the beta-tubulin subunit, which stabilizes the microtubule polymer and protects it from disassembly. This inhibition of depolymerization disrupts the dynamic instability required for mitotic spindle function, leading to cell cycle arrest at the G2/M phase and subsequent apoptosis.