Design, synthesis and biological evaluation of (E)-3-(3,4-dihydroxyphenyl)acrylylpiperazine derivatives as a new class of tubulin polymerization inhibitors

Design, synthesis of combretastatin A-4 piperazine derivatives as potential antitumor agents by inhibiting tubulin polymerization and inducing autophagy in HCT116 cells

A series of combretastatin A-4 (CA-4) derivatives were designed and synthesized, which contain stilbene core structure with different linker, predominantly piperazine derivatives. These compounds were evaluated for their cytotoxic activities against four cancer cell lines, HCT116, A549, AGS, and SK-MES-1. Among them, compound 13 displayed the best effectiveness with IC50 values of 0.227 μM and 0.253 μM against HCT116 and A549 cells, respectively, showing low toxicity to normal cells. Mechanistic studies showed that 13 inhibited HCT116 proliferation via arresting cell cycle at the G2/M phase through disrupting the microtubule network and inducing autophagy in HCT116 cells by regulating the expression levels of autophagy-related proteins. In addition, 13 displayed antiproliferative activities against A549 cells through blocking the cell cycle and inducing A549 cells apoptosis. Because of the poor water solubility of 13, four carbohydrate conjugates were synthesized which exhibited better water solubility. Further investigations revealed that 13 showed positive effects in vivo anticancer study with HCT116 xenograft models. These data suggest that 13 could be served as a promising lead compound for further development of anti-colon carcinoma agent.

Design, synthesis and evaluation of novel bis-substituted aromatic amide dithiocarbamate derivatives as colchicine site tubulin polymerization inhibitors with potent anticancer activities

As the continuation of our work on the development of tubulin inhibitors with potential anticancer activities, novel bis-substituted aromatic amide dithiocarbamate derivatives were designed by contacting bis-substituted aryl scaffolds (potential anti-tubulin fragments) with N-containing heterocycles (potential anti-tubulin fragments) in one hybrid using the anticancer dithioformate unit as the linker. The antiproliferative activity against three digestive tract tumor cells was evaluated and preliminary structure activity relationships were summarized. Among these compounds, compound 20q exhibited most potent antiproliferative activity against MGC-803, HCT-116, Kyse30 and Kyse450 cells with IC₅₀ values of 0.084, 0.227, 0.069 and 0.078 μM, respectively. In further studies, compound 20q was identified as a novel tubulin inhibitor targeting the colchicine binding site. Compound 20q could inhibit the microtubule assembly and disrupt cytoskeleton in Kyse30 and Kyse450 cells. The results of molecular docking suggested that compound 20q could tightly bind into the colchicine binding site of tubulin by hydrogen bonds and hydrophobic interactions. Compound 20q dose-dependently inhibited the cell growth and colony formation, effectively arrested cells at the G2/M phase and induce mitochondrial apoptosis in Kyse30 and Kyse450 cells. In addition, Compound 20q could regulate the expression of G2/M phase and mitochondrial apoptosis related proteins. Collectively, compound 20q was here reported as a novel tubulin inhibitor with potential anticancer activities.

Design, synthesis, and biological evaluation of 2,3-diphenyl-cycloalkyl pyrazole derivatives as potential tubulin polymerization inhibitors

Several novel cycloalkyl-fused 2,3-diaryl pyrazole derivatives were designed, synthesized, and evaluated as potential anti-tubulin agents. Compound A10 exhibited the most potent antiproliferative activity against a panel of cancer lines (IC₅₀  = 0.78-2.42 μM) and low cytotoxicity against 293T & L02 (CC₅₀ values of 131.74 and 174.89 μM, respectively). Moreover, A10 displayed inhibition of tubulin polymerization in vitro, arrested the G2/M phase of the cell cycle, changed morphology of tubulin, increased intracellular reactive oxygen species, and induced apoptosis of HeLa cells. Docking simulation and 3D-QSAR models were performed to elaborate on the anti-tubulin mechanism of the derivatives. The inhibition of monoclonal colony formation provided more intuitional data to verify the possibility of A10 as a novel tubulin assembling inhibitor.

Novel Peptide-Based Inhibitors for Microtubule Polymerization in Phytophthora capsici

The plant disease Phytophthora blight, caused by the oomycete pathogen Phytophthora capsici, is responsible for major economic losses in pepper production. Microtubules have been an attractive target for many antifungal agents as they are involved in key cellular events such as cell proliferation, signaling, and migration in eukaryotic cells. In order to design a novel biocompatible inhibitor, we screened and identified inhibitory peptides against alpha- and beta-tubulin of P. capsici using a phage display method. The identified peptides displayed a higher binding affinity (nanomolar range) and improved specificity toward P. capsici alpha- and beta-tubulin in comparison to Homo sapiens tubulin as evaluated by fluorometric analysis. One peptide demonstrated the high inhibitory effect on microtubule formation with a nanomolar range of IC₅₀ values, which were much lower than a well-known chemical inhibitor—benomyl (IC₅₀ = 500 µM). Based on these results, this peptide can be employed to further develop promising candidates for novel antifungal agents against Phytophthora blight.

Design, Synthesis and Anticancer Evaluation of Novel Series of Indibulin Analogues

Background:

Cancer is an important cause of human death worldwide. During the last decades, many anticancer agents with anti-tubulin mechanism have been synthesized or extracted from nature and some of them also entered clinical use. Indibulin is one of the most potent tubulin polymerization inhibitors with minimal peripheral neuropathy, which is a big problem by some of the antimitotic agents such as taxanes and vinka alkaloids. With respect to this giant benefit, herein we decided to design and synthesize novel indibulin related compounds and investigate their anticancer activity against HT-29, Caco-2 and T47-D cancerous cell lines as well as NIH-T3T as normal cell line.

Objective:

The aim of this study was to synthesize new anti-cancer agents and evaluates their cytotoxic activity on diverse cancerous and normal cell lines.

Method:

Target compounds were synthesized in multistep reaction and cytotoxic activity was investigated by MTT cell viability assay.

Results:

Herein, nine novel target compounds were synthesized in moderate to good yield. Some of the compounds exerted good cytotoxic activity against cancerous cell lines. Annexin V/PI staining showed that compound 4g could induce apoptosis and necrosis in HT-29 cell line.

Conclusion:

It is valuable to do further investigation on compound 4g which showed the highest activity against HT-29 and Caco-2 (IC50 values are 6.9 and 7 &µM respectively). Also, synthesis of new derivatives of current synthesized compounds is suggested.

N-Heterocyclic (4-Phenylpiperazin-1-yl)methanones Derived from Phenoxazine and Phenothiazine as Highly Potent Inhibitors of Tubulin Polymerization

We report here a series of 27 10-(4-phenylpiperazin-1-yl)methanones derived from tricyclic heterocycles which were screened for effects on tumor cell growth, inhibition of tubulin polymerization, and induction of cell cycle arrest. Several analogues, among them the 10-(4-(3-methoxyphenyl)piperazine-1-carbonyl)-10H-phenoxazine-3-carbonitrile (16o), showed excellent antiproliferative properties, with low nanomolar GI₅₀ values (16o, mean GI₅₀ of 3.3 nM) against a large number (93) of cancer cell lines. Fifteen compounds potently inhibited tubulin polymerization. Analysis of cell cycle by flow cytometry revealed that inhibition of tumor cell growth was related to an induction of G2/M phase cell cycle blockade. Western blotting and molecular docking studies suggested that these compounds bind efficiently to β-tubulin at the colchicine binding site. Our studies demonstrate the suitability of the phenoxazine and phenothiazine core and also of the phenylpiperazine moiety for the development of novel and potent tubulin polymerization inhibitors.

Design and Antiproliferative Activity of N-Heterocycle-Chalcone Derivatives

Nine chalcone derivatives containing an N-heterocyclic compound attached by its nitrogen atom to one of the benzene rings were prepared and evaluated for their antiproliferative activity against liver, gastric and neuroendocrine cancer cell lines. Most of the synthesised compounds exhibited moderate to good activity against all three cancer cell lines, but in particular, a chalcone containing a 4-(imidazol-1-yl)phenyl group and a 3,4,5-trimethoxyphenyl group showed the highest antiproliferative activity with an IC50 value of 5.39 μM against liver cancer cells.

Recent advances of cytotoxic chalconoids targeting tubulin polymerization: Synthesis and biological activity

Since microtubules have an important role in mitosis and other vital cellular functions, tubulin-targeting chemotherapy has been received growing attention in anticancer drug design and development. It was found that a number of naturally occurring compounds including distinct chalcones exert their effect by inhibition of tubulin polymerization. After the identification of tubulin polymerization as potential target for chalcone-type compounds, extensive researches have been made to design and synthesis of new anti-tubulin chalconoids. Although diverse chalcones have found to be potent anticancer agents but in the present review, we focused on the recently reported tubulin polymerization inhibitors from chalcone origin and related synthetic compounds, and their detailed synthetic methods and biological activities.

Design and synthesis of pyrazole/isoxazole linked arylcinnamides as tubulin polymerization inhibitors and potential antiproliferative agents

A series of pyrazole/isoxazole linked arylcinnamide conjugates were synthesized and investigated for their cytotoxic activity against a panel of four human cancer cell lines. Most of them have shown significant cytotoxicity apart from potential tubulin depolymerization activity.