Tubulin Polymerization Inhibitors Research Articles

Design, Synthesis and Biological Evaluation of 2-Phenylquinazolin-4-yl 4-Methylbenzenesulfonate Derivatives as Anticancer Agents via Tubulin Inhibition

AbstractMalignant behavior and multiple abnormal cellular functions have rendered cancer a great challenge for scientists to treat. The rising death toll presents an alarming situation, and the side effects associated with marketed drugs has further increased the quest to develop new anticancer drug molecules. We herein report a rationally designed 2,4-disubstituted quinazoline-based bioactive pharmacophore possessing different substitution patterns to obtain potent anticancer active agents targeting tubulin polymerization. In this series, two compounds showed potent cytotoxicity against all four cancer cell lines (MCF-7, MD-MBA-231, A549, and HCT-116) comparable to that of colchicine. The compounds showed cell cycle arrest in the G2/M phase and induced apoptosis, which showed these compounds might act via binding to the colchicine binding site. These results were further confirmed via tubulin polymerization inhibition, which showed a similar profile to colchicine. Compounds with a propargyl moiety showed very low cytotoxicity as compared to colchicines, even in the presence of a trimethoxy substituent at the quinazoline ring, except for compound case. Two compounds are obtained as potential lead compounds for the development of active anticancer agents, with one having a similar profile to colchicine activity on tubulin polymerization inhibition. These compounds represent promising leads that deserve further investigation and optimization.

Advances in antitumor research of CA-4 analogs carrying quinoline scaffold

Combretastatin A-4 (CA-4) is a potent inhibitor of tubulin polymerization and a colchicine binding site inhibitor (CBSI). The structure-activity relationship study of CA-4 showed that the cis double bond configuration and the 3,4,5-trimethoxy group on the A ring were important factors to maintain the activity of CA-4. Therefore, starting from this condition, chemists modified the double bond and also substituted 3,4,5-trimethoxyphenyl with various heterocycles, resulting in a new generation of CA-4 analogs such as chalcone, Flavonoid derivatives, indole, imidazole, etc. Quinoline derivatives have strong biological activity and have been sought after by major researchers for their antitumor activity in recent years. This article reviews the research progress of novel CA-4 containing quinoline analogs in anti-tumor from 1992 to 2022 and expounds on the pharmacological mechanisms of these effective compounds, including but not limited to apoptosis, cell cycle, tubulin polymerization inhibition, immune Fluorescence experiments, etc., which lay the foundation for the subsequent development of CA-4 containing quinoline analogs for clinical use.

Topical Tirbanibulin, a Dual Src Kinase and Tubulin Polymerization Inhibitor, for the Treatment of Plaque-Type Psoriasis: Phase I Results.

Plaque-type psoriasis is a common skin disorder. Tirbanibulin (KX01) is a new Src kinase inhibitor with potent antiproliferative activity against keratinocytes and has been approved for treatment of actinic keratosis. This Phase I study investigates the safety and activity of KX01 ointment in patients with plaque-type psoriasis. We recruited 28 patients from two medical centers in Taiwan. This study was performed in four stages. Double-blind treatments were randomized in stages I (KX01 0.01% + placebo, two rounds of two-week treatment) and II (KX01 0.1% + placebo, four weeks) and open-labelled in stages III (KX01 1%, five days) and IV (KX01 1%, five days weekly for four weeks). The safety, tolerability, KX01 concentration, target area score, physician global assessment, and disease relapse were determined. Most treatment-emergent adverse events were mild-to-moderate application site reactions. Three (50.0%) subjects from the stage IV group showed ≥50% reduction in the target area score (TAS50), while two subjects (33.3%) showed a clinically meaningful improvement in the physician global assessment score. KX01 0.01%, 0.1%, and 1% were safe and well-tolerated. KX01 1% at four weeks showed a promising activity for the treatment of plaque-type psoriasis.

Design, synthesis and biological evaluation of novel diarylpyridine derivatives as tubulin polymerisation inhibitors

A set of novel diarylpyridines as anti-tubulin agents were designed, synthesised using a rigid pyridine as a linker to fix the cis-orientation of ring-A and ring-B. All of the target compounds were evaluated for their in vitro antiproliferative activities. Among them, 10t showed remarkable antiproliferative activities against three cancer cell lines (HeLa, MCF-7 and SGC-7901) in sub-micromolar concentrations. Consistent with its potent antiproliferative activity, 10t also displayed potent anti-tubulin activity. Cellular mechanism investigation elucidated 10t disrupted the cellular microtubule structure, arrested cell cycle at G2/M phase and induces apoptosis. Molecular modelling studies showed that 10t could bind to the colchicine binding site on microtubules. These results provide motivation and further guidance for the development of new CA-4 analogues.

Novel combretastatin A-4 derivative containing aminophosphonates as dual inhibitors of tubulin and matrix metalloproteinases for lung cancer treatment

Here, sixteen novel conjugates containing tubulin inhibitor and matrix metalloproteinase inhibitor was synthesized together with their activity evaluated. Among them, 9e exhibited the most potent activity against various human cancer cells (IC50 values was 0.19–0.42 μM) as well as multidrug-resistant tumor cells (A549/CDDP and MCF-7/DOX) and also showed significantly lower cytotoxic activity toward human normal liver cells LO2 in comparison with that of CA-4. Interestingly, 9e not only strongly inhibited tubulin polymerization, and induced cell apoptosis and cell cycle arrest in G2/M stage, but also remarkably displayed inhibition of cell migration against A549 cells in vitro, and exhibited a moderate activity toward MMP-2, MMP-3 and MMP-9, respectively. Moreover, the significant down-regulation in the levels of Bcl-2 protein and up-regulated levels of proteins, such as Bax, p53 and caspase-3, indicated that 9e can induce apoptosis via mitochondria-dependent apoptosis pathway. Additionally, 9e can also cause ER stress demonstrating as up-regulation express of proteins (CHOP, p-eIF2a, and p-PERK). Importantly, 9e displayed significant in vivo antitumor efficacy in A549 xenograft models without inducing apparent systemic toxicity. Collectively, this work indicated that compound 9e, a dual MMPs and tubulin inhibitor, is a novel and promising agent for cancer therapy.

Synthesis and antimitotic evaluation of Schiff bases derivatives based on 2-amino-combretastatin

Combretastatins A, B, and D are a group of stilbenes, dihydrostilbenes, phenanthrenes, and macrocyclic lactones that may be found in the bark of the Combretum caffrum tree. Preclinical studies have shown that the lead chemical, combretastatin A-4, is highly cytotoxic and inhibits tubulin polymerisation by interacting with the microtubule's colchicine binding site. The anti-cancer activity of a new series of Schiff bases derived from 2-amino-combretastatin as analogues of combretastatin A-4 (CA-4) was investigated. The structures of the synthesised derivatives were proved using 1 H and 13 C NMR, I.R. spectroscopy and elemental analysis. As tubulin polymerisation inhibitors, several drugs demonstrated excellent anti-proliferative activity. IC 50 values for compounds 8a, 8d, 8c and 8i were 1.6, 1.9, 1.9 and 1.3 µM, respectively. In addition, prepared Schiff bases exhibited anti-proliferative action in several human cell lines derived from various organs, namely, HT-29, MCF-7, and A-549, as well as the non-tumor cell line HEK-273. The Schiff bases substituent at the 2-position of ring A in the combretastatin chemical skeleton may play a significant role in the bioactivity of this group of drugs.

PH-sensitive nanomedicine of novel tubulin polymerization inhibitor for lung metastatic melanoma.

Microtubule binding agents such as paclitaxel and vincristine have activity in metastatic melanoma. However, even responsive tumors develop resistance, highlighting the need to investigate new drug molecules. Here, we showed that a new compound, CH-2-102, developed by our group, has high anti-tumor efficacy in human and murine melanoma cells. We confirmed that CH-2-102 robustly suppresses the microtubule polymerization process by directly interacting with the colchicine binding site. Our results unveil that CH-2-102 suppresses microtubule polymerization and subsequently induces G2 phase cell arrest as one of the possible mechanisms. Notably, CH-2-102 maintains its efficacy even in the paclitaxel resistance melanoma cells due to different binding sites and a non-Pgp substrate. We developed a pH-responsive drug-polymer Schiff bases linker for high drug loading into nanoparticles (NPs). Our CH-2-102 conjugated NPs induced tumor regression more effectively than Abraxane® (Nab-paclitaxel, N-PTX), free drug, and non-sensitive NPs in B16-F10 cell-derived lung metastasis mouse model. Furthermore, our results suggest that the formulation has a high impact on the in vivo efficacy of the drug and warrants further investigation in other cancers, particularly taxane resistant. In conclusion, the microtubule polymerization inhibitor CH-2-102 conjugated pH-responsive NPs induce tumor regression in lung metastasis melanoma mice, suggesting it may be an effective strategy for treating metastatic melanoma.

Evaluation of 3,5-Diphenyl-2-Pyrazolines for Antimitotic Activity by Inhibition of Tubulin Polymerization

Chalcones have a skeleton of diphenyls connected via an α,β-unsaturated carbonyl group. Many chalcone derivatives have been shown to interact with tubulin. Based on previous reports, chalcones derived by substitution of a carbonyl group with 2-pyrazoline can be expected to inhibit tubulin polymerization. Therefore, 3,5-diphenyl-2-pyrazolines were prepared to investigate their ability to inhibit tubulin polymerization. The clonogenic long-term survival assay showed that derivative 4, 5-(3,5-dimethoxyphenyl)-3-(2-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide, was the most effective at inhibiting the clonogenicity of HCT116 human colon cancer cells. Derivative 4 induced G2/M cell cycle arrest. In addition, derivative 4 caused dispersed microtubules, a disorganized spherical arrangement of chromosomes, and inhibition of mitotic spindle formation. The binding mode between tubulin and derivative 4 was elucidated by in silico molecular docking. Derivative 4 was superimposed with colchicine and entered the colchicine-binding site well. These results suggest that derivative 4 inhibits tubulin polymerization by binding to the colchicine binding site of tubulin, thus preventing mitotic spindle formation during mitosis in HCT116 colon cancer cells. We propose that derivative 4 could be used as a promising antimitotic chemotherapeutic agent.

Design, synthesis and molecular docking study of thiophenyl hydrazone derivatives as tubulin polymerization inhibitors

A series of thiophene derivatives substituted at 2, 3 and 5 positions were designed and synthesized using 2,3-disubstituted thiophene aldehyde and alcohol as key building blocks. Invitro cytotoxicity assessed against PC-3, DU145 (prostate), A549 (lung), HT29, HCT116 (colon), MCF7, MDAMB231 (breast), B16F10 (melanoma) NCI (Colorectal) cancer cell lines by conducting (MTT) assay of thiophene derivatives. Most of these synthesized compounds showed anti-cancer activity, compound 5b showed good cytotoxicity with IC50 = 2.61 ± 0.34 µM on HT29 cell line. Also, the key property of cell migration was observed while treating cells with 5b. The Cell cycle arrest at G2/M phase was observed by 5b on HT29 cell line which inhibited tubulin polymerization with IC50 value of 8.21 ± 0.30 μM. Moreover, binding pose with co-crystal ligand and interaction with colchicine binding site of 5b was established by molecular docking studies. Hence this scaffold can be developed as anti-cancer agents that target tubulin polymerization.

Design, synthesis, and molecular docking of novel pyrazole-chalcone analogs of lonazolac as 5-LOX, iNOS and tubulin polymerization inhibitors with potential anticancer and anti-inflammatory activities

Uncontrolled inflammation predisposes to pleiotropic effects leading to cancer development thanks to promoting all stages of tumorigenesis. Therefore, cancer-associated inflammation has been delegated as the seventh hallmark of cancer. Thus, raging the war against both inflammation and cancer via the innovation of bioactive agents with dual anti-inflammatory and anticancer activities is a necessity. Herein, a novel series of pyrazole-chalcone analogs of Lonazolac (7a-g and 8a-g) have been synthesized and investigated for their in vitro anticancer activity against four cancer cell lines using the MTT assay method. Among all, hybrid 8g was the most potent against three cancer cell lines, HeLa, HCT-116, and RPMI-822 with IC50 values of 2.41, 2.41, and 3.34 µM, respectively. In contrast, hybrid 8g showed moderate inhibitory activity against MCF-7 with IC50 28.93 μM and with a selectivity profile against MCF-10A (non-cancer cells). Mechanistically, hybrid 8g was the most potent inhibitor against tubulin polymerization (IC50 = 4.77 µM), suggesting tubulin as a molecular target and explaining the observed cytotoxicity of hybrid 8g. This was mirrored by the detected potent pre-G1 apoptosis induction and G2/M cell cycle arrest. Moreover, hybrid8gexhibited selectivity against COX-2 (IC50 = 5.13 µM) more than COX-1 (IC50 = 33.46 µM), indicating that 8g may have lower cardiovascular side effects, but is still not potent as celecoxib (COX-2 IC50 = 0.204 µM, COX-1 = 35.8 µM). Notably, hybrid 8g showed promising inhibitory activity towards 5-LOX (IC50 = 5.88 µM). Finally, the anti-inflammatory activity of hybrid8 g was confirmed by high iNOS and PGE2 inhibitory activities in LPS-stimulated RAW cells with IC50 values of4.93 µM and 10.98 µM, respectively, that accompanied by showingthe most potent inhibition of NO release (70.61 % inhibition rate). Molecular docking studies of hybrid 8g confirmed good correlations with the executed biological results. Furthermore, hybrid 8g had good drug-likeness and suitable physicochemical properties. Taken together, the combined results suggested hybrid8gas a promising orally administered candidate in the journey of repurposing NSAIDs for cancer chemopreventionand treatment.

Anticancer Dual Molecule Targeting Inhibition of Tubulin Polymerization and HDAC

Anticancer Dual Molecule Targeting Inhibition of Tubulin Polymerization and HDAC

Bioactive Aurones, Indanones, and Other Hemiindigoid Scaffolds: Medicinal Chemistry and Photopharmacology Perspectives.

Hemiindigoids comprise a range of natural and synthetic scaffolds that share the same aromatic hydrocarbon backbone as well as promising biological and optical properties. The encouraging therapeutic potential of these scaffolds has been unraveled by many studies over the past years and uncovered representants with inspiring pharmacophoric features such as the acetylcholinesterase inhibitor donezepil and the tubulin polymerization inhibitor indanocine. In this review, we summarize the last advances in the medicinal potential of hemiindigoids, with a special attention to molecular design, structure-activity relationship, ligand-target interactions, and mechanistic explanations covering their effects. As their strong fluorogenic potential and photoswitch behavior recently started to be highlighted and explored in biology, giving rise to the development of novel fluorescent probes and photopharmacological agents, we also discuss these properties in a medicinal chemistry perspective.

Novel indole–chalcone platinum(IV) complexes as tubulin polymerization inhibitors to overcome oxaliplatin resistance in colorectal cancer

In order to reverse drug resistance and reduce side effects of oxaliplatin (OXA) in colon cancer (CRC) treatment, six platinum(IV) complexes modified with indole–chalcone derivatives were synthesized and evaluated for their antiproliferative activities against various CRC cell lines. Among them, indole–chalcone oxaliplatin(IV)-propanoate (ICplatin-18), which obtained a two-methylene linker and was derived from oxaliplatin(IV), exhibited the most parental anticancer activity compared with either monotherapy or combination against parent and OXA-resistant HCT-116 (HCT-116/OXA) cells, obtained good selectivity toward normal cell line (L02 and HUEVC), and significantly inhibited migration of HCT-116 cells. This performance may be associated to the dramatic increase in intracellular accumulation and enhancement of DNA damage. Further mechanistic studies indicated that ICplatin-18 significantly inhibited tubulin polymerization, elevated accumulation of intracellular reactive oxygen molecule, and activated mitochondrial apoptotic.

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.

Development of [1,2]oxazoloisoindoles tubulin polymerization inhibitors: Further chemical modifications and potential therapeutic effects against lymphomas

Lymphomas are among the ten most common cancers, and, although progress has been achieved in increasing survival, there is still an unmet need for more effective therapeutic approaches, including better options for patients with refractory tumors that initially respond but then relapse. The lack of effective alternative treatment options highlights the need to develop new therapeutic strategies capable of improving survival prospects for lymphoma patients. Herein, we describe the identification and exploration of the SAR of a series of [1,2]oxazolo[5,4-e]isoindoles as potent small molecules that bind to the colchicine site of tubulin and that have promise for the treatment of refractory lymphomas. Exploration of the chemical space of this class of compounds at the pyrrole moiety and at the [1,2]oxazole ring highlighted two compounds bearing a 3,5-dimethoxybenzyl and a 3,4,5-trimethoxybenzyl group as potent candidates and showed that structural modifications at the isoxazole moiety are generally not favorable for activity. The two best candidates showed efficacy against different lymphoma histotypes and displayed 88 and 80% inhibition of colchicine binding fitting well into the colchicine pocket, as demonstrated by X-ray crystallography T2R-TTL–complexes, docking and thermodynamic analysis of the tubulin-colchicine complex structure. These results were confirmed by transcriptome data, thus indicating [1,2]oxazolo[5,4-e]isoindoles are promising candidates as antitubulin agents for the treatment of refractory lymphomas.

Synthesis and Molecular Docking Study of New Thiazole Derivatives as Potential Tubulin Polymerization Inhibitors.

A new series of 2,4-disubstituted thiazole derivatives containing 4-(3,4,5-trimethoxyphenyl) moiety was synthesized and evaluated for their potential anticancer activity as tubulin polymerization inhibitors. All designed compounds were screened for cytotoxic activity against four human cancer cell lines, namely, HepG2, MCF-7, HCT116, and HeLa, using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, with combretastatin A-4 as a reference drug. Compounds 5c, 6d, 7c, 8, and 9a,b showed superior activity against the tested cell lines, with IC50 values ranging from 3.35 ± 0.2 to 18.69 ± 0.9 μM. Further investigation for the most active cytotoxic agents as tubulin polymerization inhibitors was also performed in order to explore the mechanism of their antiproliferative activity. The obtained results suggested that compounds 5c, 7c, and 9a remarkably inhibit tubulin polymerization, with IC50 values of 2.95 ± 0.18, 2.00 ± 0.12, and 2.38 ± 0.14 μM, respectively, which exceeded that of the reference drug combretastatin A-4 (IC50 2.96 ± 0.18 μM). Molecular docking studies were also conducted to investigate the possible binding interactions between the targeted compounds and the tubulin active site. The interpretation of the results showed clearly that compounds 7c and 9a were identified as the most potent tubulin polymerization inhibitors with promising cytotoxic activity and excellent binding mode in the docking study.

Benzimidazole based bis-carboxamide derivatives as promising cytotoxic agents: Design, synthesis, in silico and tubulin polymerization inhibition

A new series of carboxamide-bearing benzimidazole derivatives have been reported for their cytotoxicity profile (in vitro) on selected human tumour cells like A549, HCT116, SK-Mel-28, and MCF-7. Among the derivatives, the utmost cytotoxicity was shown by compounds 10g and 10m, with specificity toward SK-Mel-28 skin cancer cells displaying potent IC50 values (0.41–51.21 μM). The compounds 10g and 10m unveiled to be safe on testing them against human non-cancerous lung epithelial cells (BEAS: IC50: >100 μM). The annexin V binding assay and JC-1 were implemented to evaluate the scope of apoptosis and loss of mitochondrial transmembrane potential in SK-Mel-28 cell lines. The G2/M phase arrest in the cell cycle examination was observed by active molecule 10m dose-dependently. Target-based findings suggested tubulin polymerization inhibition by 10m (IC50 of 2.36 ± 0.20 μM) and its efficacious binding with DNA. The detailed binding interactions of compounds 10g and 10m with tubulin and DNA was examined by docking studies on PDB ID: 3E22 and DNA hexamer (PDB ID: 1NAB) respectively.

Potentiation of Drug Toxicity through Virus Latency Reversal Promotes Preferential Elimination of HIV Infected Cells

AbstractEliminating latently infected cells is a highly challenging, indispensable step toward the cure for HIV/AIDS. Hypothesis put forward herein is that the unique HIV protease cut site (Phe‐Pro) can be reconstructed using a potent inhibitor of tubulin polymerization, monomethyl auristatin F (MMAF), which features Phe at its C‐terminus. This presents opportunities to design prodrugs that are specifically activated by the HIV protease. To this end, a series of MMAF derivatives is synthesized and evaluated in cell culture using latently HIV‐infected cells. The cytotoxicity of compounds is indeed enhanced upon latency reversal by up to 11‐fold. As a result, in a mixed cell population, nanomolar concentrations of the lead compounds depletes predominantly the HIV‐infected cells and in doing so markedly enriches the pool of the uninfected cells. Affinity of the lead compounds to the viral protease is validated computationally and experimentally but despite expectations, the mechanism of action of the synthesized toxins is shown to be independent from the enzymatic activity of the HIV protease.

KC-180-2 Exerts Anti-SCLC Effects via Dual Inhibition of Tubulin Polymerization and Src Signaling.

In this study, a series of N-benzyl-2-(5-phenylpyridin-2-yl) acetamide-based derivatives were successfully designed and synthesized as anti-cancer agents. KC-180-2 was screened as a potentially leading compound with dual mechanisms of action: Src signaling and tubulin polymerization inhibition. It efficiently suppressed the proliferation of five cancer cell lines (MDA-MB-231, H446, SKOV-3, HepG2, and HT29), with IC50 values ranging from 5 to 188 nM, especially small-cell lung cancer (SCLC) cells (IC50, 5 nM). Correspondingly, it exerted a significant therapeutic effect on the H446 small-cell lung cancer xenograft model, significantly reducing the volume of tumors without obvious toxicity. Mechanistically, this compound significantly inhibited the polymerization of purified tubulin in vitro, inducing G2/M cell cycle arrest and binding to the kinase catalytic domain of the Src protein, which reduced the phosphorylation of Src. Thus, KC-180-2 is a potential lead compound for the further development of a new anti-tumor drug against SCLC.

Synthesis of new 1,3,4-oxadiazole-1,4-benzoxazinone hybrids as tubulin polymerization inhibiting anticancer agents and their in silico studies

Herein, we synthesized some new 1,3,4-oxadiazole-1,4-benzoxazinone hybrids (7a-7n) and evaluated for their in vitro anticancer potency towards A549 (lung), MCF-7 (breast) and HeLa (cervicl) cancer cell lines. Amongst series (7a-7n), compound 7d had greater potency against all cell lines than the standard nocodazole with IC50 ranging from 0.3 ± 0.07 to 0.9 ± 0.16 μM. Compounds 7j and 7l have also shown superior potency against A549 (lung) and most promising potency against MCF-7 (breast) as compared to positive control. Further, compounds 7d and 7j were found to be 2 to 3 times more potent in in vitro tubulin polymerization inhibition than the standard CA-4. Finally, the results of in silico studies were also supporting the corresponding in vitro anticancer activity and tubulin polymerization inhibition data of compounds 7d, 7j and 7l.