Dysregulation of microtubules and tubulin homeostasis has been linked to developmental disorders, neurodegenerative diseases, and cancer. In general, both microtubule-stabilizing and destabilizing agents have been powerful tools for studies of microtubule cytoskeleton and as clinical agents in oncology. However, many cancers develop resistance to these agents, limiting their utility. We sought to address this by developing a different kind of agent: tubulin-targeted small molecule degraders. Degraders (also known as proteolysis-targeting chimeras (PROTACs)) are compounds that recruit endogenous E3 ligases to a target of interest, resulting in the target’s degradation. We developed and examined several series of α- and β-tubulin degraders, based on microtubule-destabilizing agents. Our results indicate, that although previously reported covalent tubulin binders led to tubulin degradation, in our hands, cereblon-recruiting PROTACs were not efficient. In summary, while we consider tubulin degraders to be valuable tools for studying the biology of tubulin homeostasis, it remains to be seen whether the PROTAC strategy can be applied to this target of high clinical relevance.
微管和微管蛋白稳态失调与发育障碍、神经退行性疾病和癌症有关。总的来说,微管稳定和不稳定剂都是微管细胞骨架研究和临床用药的有力工具。然而,许多癌症对这些剂产生了抗药性,限制了它们的效用。我们试图通过开发一种不同类型的药剂来解决这个问题:以微管为靶点的小分子降解剂。降解剂(也称为蛋白降解靶向嵌合物(PROTACs))是一种将内源性E3连接酶招募到感兴趣的靶标上,导致靶标降解的化合物。我们开发并检查了几个α-和β-微管降解剂系列,基于微管不稳定剂。我们的结果表明,尽管先前报道的共价微管结合剂导致了微管降解,但在我们手中,招募cereblon的PROTACs并不高效。总之,虽然我们认为微管降解剂是研究微管稳态生物学的有价值工具,但还有待看到PROTAC策略是否可以应用于这个具有高临床相关性的靶标。