Comparison of microtubules stabilized with the anticancer drugs cevipabulin and paclitaxel

Microtubules, one of the major components of the cytoskeleton, play important roles as pathways for neuronal transport of cellular traffic. The loss of structural stability of microtubules causes detrimental effects on neurons and may contribute to several neurodegenerative diseases, such as Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, etc. The triazolopyrimidine class compound cevipabulin is a synthetic microtubule-stabilizing agent that has recently emerged as a drug for the treatment of Alzheimer’s disease. However, the mechanism of microtubule stabilization by cevipabulin has not yet been revealed. Here, we explored the effect of cevipabulin on stabilizing microtubules polymerized from purified tubulins in vitro. We observed the effects of the concentration of microtubule-stabilizing drugs, incubation time, and modification of the cevipabulin structure on the stabilization of microtubules in comparison to those of the most commonly used anticancer drug, paclitaxel. This study will provide insight into the action of cevipabulin in the treatment of neurodegenerative diseases. Stabilization of microtubules occurs by paclitaxel bound to the taxoid site and cevipabulin (and its derivative) bound to the taxoid site and/or vinca alkaloid domain of the β-tubulin in tubulin heterodimer.