Design, synthesis and bioevaluation of 2,7-diaryl-pyrazolo[1,5-a]pyrimidines as tubulin polymerization inhibitors

Design, synthesis, and bioevaluation of 1h-pyrrolo[3,2-c]pyridine derivatives as colchicine-binding site inhibitors with potent anticancer activities

A new series of 1H-pyrrolo[3,2-c]pyridine derivatives were designed and synthesised as colchicine-binding site inhibitors. Preliminary biological evaluations showed that most of the target compounds displayed moderate to excellent antitumor activities against three cancer cell lines (HeLa, SGC-7901, and MCF-7) in vitro. Among them, 10t exhibited the most potent activities against three cancer cell lines with IC50 values ranging from 0.12 to 0.21 μM. Tubulin polymerisation experiments indicated that 10t potently inhibited tubulin polymerisation at concentrations of 3 μM and 5 μM, and immunostaining assays revealed that 10t remarkably disrupted tubulin microtubule dynamics at a concentration of 0.12 μM. Furthermore, cell cycle studies and cell apoptosis analyses demonstrated that 10t at concentrations of 0.12 μM, 0.24 μM, and 0.36 μM significantly caused G2/M phase cell cycle arrest and apoptosis. The results of molecular modelling studies suggested that 10t interacts with tubulin by forming hydrogen bonds with colchicine sites Thrα179 and Asnβ349. In addition, the prediction of physicochemical properties disclosed that 10t conformed well to the Lipinski's rule of five.

Structure-based approaches for the design of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-benzo[d][1,2,3]triazoles as tubulin polymerization inhibitors

The colchicine binding site on tubulin has been widely acknowledged as an attractive target for anticancer drug exploitation. Here, we reported the structural optimization of the lead compound 4, which was proved in our previous work as a colchicine binding site inhibitor (CBSI). Based on docking researches for the active binding conformation of compound 4, a series of novel 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-benzo[d][1,2,3]triazole derivatives (9a-9x) were developed by replacing a CH group in the 1H-benzo[d]imidazole skeleton of compound 4 with a nitrogen atom as a hydrogen bond acceptor. Among them, compound 9a showed the strongest antiproliferative activity with IC50 values ranging from 14 to 45 nM against three human cancer cell lines (MCF-7, SGC-7901 and A549), lower than that of compound 4. Mechanistic studies indicated that compound 9a could inhibit tubulin polymerization, destroy the microtubule skeleton, block the cell cycle in G2/M phase, induce cancer cell apoptosis, prevent cancer cell migration and colony formation. Moreover, compound 9a significantly inhibited tumor growth in vivo without observable toxicity in the mice 4T1 xenograft tumor model. In conclusion, this report shows a successful case of the structure-based design approach of a potent tubulin polymerization inhibitor for cancer treatment.

Design, synthesis and biological evaluation of 1,2,3-triazole benzothiazole derivatives as tubulin polymerization inhibitors with potent anti-esophageal cancer activities

In this work, we utilized the molecular hybridization strategy to design and synthesize novel 1,2,3-triazole benzothiazole derivatives K1-26. The antiproliferative activities against MGC-803, Kyse30 and HCT-116 cells were explored, and their structure-activity relationship were preliminarily conducted and summarized. Among them, compound K18, exhibited the strongest proliferation inhibitory activity, with esophageal cancer cells Kyse30 and EC-109 being the most sensitive to its effects (IC50 values were 0.042 and 0.038 μM, respectively). Compound K18 effectively inhibited tubulin polymerization (IC50 = 0.446 μM), thereby hindering tubulin polymerize into filamentous microtubules in Kyse30 and EC-109 cells. Additionally, compound K18 induced the degradation of oncogenic protein YAP via the UPS pathway. Based on these dual molecular-level effects, compound K18 could induce G2/M phase arrest and cell apoptosis in Kyse30 and EC-109 cells, as well as regulate the expression levels of cell cycle and apoptosis-related proteins. In summary, our findings highlight a novel 1,2,3-triazole benzothiazole derivative K18, which possesses significant potential for treating esophageal cancers.

Discovery of novel arylamide derivatives containing piperazine moiety as inhibitors of tubulin polymerisation with potent liver cancer inhibitory activity

In this work, a series of novel arylamide derivatives containing piperazine moiety were designed and synthesised as tubulin polymerisation inhibitors. Among 25 target compounds, compound 16f (MY-1121) exhibited low nanomolar IC50 values ranging from 0.089 to 0.238 μM against nine human cancer cells. Its inhibitory effects on liver cancer cells were particularly evident with IC50 values of 89.42 and 91.62 nM for SMMC-7721 and HuH-7 cells, respectively. Further mechanism studies demonstrated that compound 16f (MY-1121) could bind to the colchicine binding site of β-tubulin and directly act on β-tubulin, thus inhibiting tubulin polymerisation. Additionally, compound 16f (MY-1121) could inhibit colony forming ability, cause morphological changes, block cell cycle arrest at the G2 phase, induce cell apoptosis, and regulate the expression of cell cycle and cell apoptosis related proteins in liver cancer cells. Overall, the promising bioactivities of compound 16f (MY-1121) make the novel arylamide derivatives have the value for further development as tubulin polymerisation inhibitors with potent anticancer activities.

Discovery of a novel Coumarin-Dihydroquinoxalone derivative MY-673 as a tubulin polymerization inhibitor capable of inhibiting the ERK pathway with potent anti-gastric cancer activities

As a class of microtubule targeting agents, colchicine binding site inhibitors (CBSIs) are considered as promising drug candidates for cancer therapy. However, due to adverse reactions, there are currently no CBSIs approved by FDA for cancer treatment. Therefore, extensive efforts are still encouraged to find novel CBSIs with different chemical structures and better anticancer efficacies. In this work, we designed and synthesized a new coumarin-dihydroquinoxalone derivative, MY-673, and evaluated its anticancer potency in vitro and in vivo. We confirmed that MY-673 was a potent CBSI that it not only inhibited tubulin polymerization, but also exhibited significant inhibitory potency on the growth of 13 cancer cells with IC₅₀ values from 11.7 nM to 395.9 nM. Based on the results of kinase panel screening, MY-673 could inhibit ERK (extracellular regulated protein kinases) pathways-related kinases. We further confirmed that MY-673 could inhibit ERK signaling pathway in MGC-803 and HGC-27 cells, and then affected the expression level of SMAD4 protein in TGF-β (transforming growth factor β) /SMAD (small mother against decapentaplegic) signaling pathway using the western blotting assay. In addition, compound MY-673 could effectively inhibit cell proliferation, migration and induce cell apoptosis. We also further confirmed the in vivo efficacy of MY-673 in inhibiting tumor growth using the MGC-803 xenograft tumor model. At 20 mg/kg, the TGI rate was 85.9%, and it did not cause obvious toxicity to the main organs of mice. Together, the results we report here indicated that MY-673 was a promising CBSI for cancer treatment, which was capable of inhibiting the ERK pathway with potent antiproliferative activities in vitro and in vivo.

An update on the recent advances and discovery of novel tubulin colchicine binding inhibitors

Microtubules, formed by α- and β-tubulin heterodimer, are considered as a major target to prevent the proliferation of tumor cells. Microtubule-targeted agents have become increasingly effective anticancer drugs. However, due to the relatively sophisticated chemical structure of taxane and vinblastine, their application has faced numerous obstacles. Conversely, the structure of colchicine binding site inhibitors (CBSIs) is much easier to be modified. Moreover, CBSIs have strong antiproliferative effect on multidrug-resistant tumor cells and have become the mainstream research orientation of microtubule-targeted agents. This review focuses mainly on the recent advances of CBSIs during 2017-2022, attempts to depict their biological activities to analyze the structure-activity relationships and offers new perspectives for designing next generation of novel CBSIs.

Design, synthesis and biological evaluation of 9-aryl-5H-pyrido[4,3-b]indole derivatives as potential tubulin polymerization inhibitors

A series of new 9-aryl-5H-pyrido[4,3-b]indole derivatives as tubulin polymerization inhibitors were designed, synthesized, and evaluated for antitumor activity. All newly prepared compounds were tested for their anti-proliferative activity in vitro against three different cancer cells (SGC-7901, HeLa, and MCF-7). Among the designed compounds, compound 7k displayed the strongest anti-proliferative activity against HeLa cells with IC₅₀ values of 8.7 ± 1.3 μM. In addition, 7k could inhibit the polymerization of tubulin and disrupt the microtubule network of cells. Further mechanism studies revealed that 7k arrested cell cycle at the G2/M phase and induced apoptosis in a dose-dependent manner. Molecular docking analysis confirmed that 7k may bind to colchicine binding sites on microtubules. Our study aims to provide a new strategy for the development of antitumor drugs targeting tubulin.