Abstract A novel class of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-b]pyrazine derivatives was designed and synthesized as tubulin polymerization disruptors. Among them, compound 10t emerged as the most potent agent, exhibiting IC₅。 values of 0.13-0.18 µM against HeLa, SGC‑7901, and MCF‑7 cancer cell lines. Functional studies revealed that 10t effectively inhibits tubulin assembly in vitro, destabilizes cellular microtubule networks, induces G₂/M cell‑cycle arrest, and triggers apoptosis. Molecular docking indicated that 10t binds to the colchicine site on tubulin, forming a unique hydrogen bond with β‑Asn349 that is not observed with the reference compound CA‑4. Importantly, 10t showed significantly lower cytotoxicity toward normal HUVECs than CA‑4, suggesting an improved safety profile. Collectively, these findings establish the pyrazolo[3,4‑b]pyrazine scaffold as a promising platform for microtubule‑targeting anticancer agents and identify 10t as a compelling lead for further development.
Zhu Guo, Yujing Zhang, Ping Zou et al.· Journal of Enzyme Inhibition...· 0 citations
Abstract Microtubules assembled from α/β-tubulin heterodimers are critical for cell division and well-established anticancer drug targets, making tubulin polymerization inhibitors a viable route for new chemotherapeutics. Guided by structural analysis of colchicine-site binders and tubulin-ligand computational simulations, we rationally designed and synthesized a series of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-d]pyrimidines as novel colchicine-binding site tubulin inhibitors. Derivative 9t displayed the strongest antiproliferative potency, with IC₅。 values of 0.065-0.096 μM across tested cancer lines. It exerted minimal toxicity to normal L929 fibroblasts, yielding a selectivity index over 300. Mechanistic assays confirmed 9t suppresses cell-free tubulin polymerization, destroys cellular microtubule architecture, induces persistent G₂/M cell cycle arrest, and activates cancer cell apoptosis. Overall, 9t serves as a promising dual-function tubulin inhibitor with both cytostatic and cytotoxic anticancer effects, meriting further preclinical investigation.
Jiake Gao, Yujing Zhang, Rui Qu et al.· Journal of Enzyme Inhibition...· 0 citations
