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1.
Toxicol Appl Pharmacol ; 421: 115534, 2021 06 15.
Article in English | MEDLINE | ID: mdl-33852878

ABSTRACT

Monomethyl auristatin E (MMAE) is a potent anti-cancer microtubule-targeting agent (MTA) used as a payload in three approved MMAE-containing antibody drug conjugates (ADCs) and multiple ADCs in clinical development to treat different types of cancers. Unfortunately, MMAE-ADCs can induce peripheral neuropathy, a frequent adverse event leading to treatment dose reduction or discontinuation and subsequent clinical termination of many MMAE-ADCs. MMAE-ADC-induced peripheral neuropathy is attributed to non-specific uptake of the ADC in peripheral nerves and release of MMAE, disrupting microtubules (MTs) and causing neurodegeneration. However, molecular mechanisms underlying MMAE and MMAE-ADC effects on MTs remain unclear. Here, we characterized MMAE-tubulin/MT interactions in reconstituted in vitro soluble tubulin or MT systems and evaluated MMAE and vcMMAE-ADCs in cultured human MCF7 cells. MMAE bound to soluble tubulin heterodimers with a maximum stoichiometry of ~1:1, bound abundantly along the length of pre-assembled MTs and with high affinity at MT ends, introduced structural defects, suppressed MT dynamics, and reduced the kinetics and extent of MT assembly while promoting tubulin ring formation. In cells, MMAE and MMAE-ADC (via nonspecific uptake) suppressed proliferation, mitosis and MT dynamics, and disrupted the MT network. Comparing MMAE action to other MTAs supports the hypothesis that peripheral neuropathy severity is determined by the precise mechanism(s) of each individual drug-MT interaction (location of binding, affinity, effects on morphology and dynamics). This work demonstrates that MMAE binds extensively to tubulin and MTs and causes severe MT dysregulation, providing convincing evidence that MMAE-mediated inhibition of MT-dependent axonal transport leads to severe peripheral neuropathy.


Subject(s)
Breast Neoplasms/drug therapy , Microtubules/drug effects , Oligopeptides/toxicity , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System/drug effects , Tubulin Modulators/toxicity , Tubulin/metabolism , Axonal Transport/drug effects , Binding Sites , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Cycle/drug effects , Cell Proliferation/drug effects , Female , Humans , MCF-7 Cells , Microtubules/metabolism , Microtubules/pathology , Mitosis/drug effects , Oligopeptides/metabolism , Peripheral Nervous System/metabolism , Peripheral Nervous System/pathology , Peripheral Nervous System Diseases/metabolism , Peripheral Nervous System Diseases/pathology , Protein Binding , Risk Assessment , Spindle Apparatus/drug effects , Spindle Apparatus/metabolism , Spindle Apparatus/pathology , Tubulin Modulators/metabolism
2.
Int J Mol Sci ; 22(8)2021 Apr 16.
Article in English | MEDLINE | ID: mdl-33923421

ABSTRACT

Vincristine-induced peripheral neurotoxicity (VIPN) is a very common side effect of vincristine chemotherapy among pediatric patients with cancer. Neuropathy may be sensory, motor and/or autonomic, with consequent reduction, delay or discontinuation of vincristine-chemotherapy, but also pain, disability, reduced quality of life of patients and an increase in medical costs. Vincristine acts out its antineoplastic function by altering the normal assembly and disassembly of microtubules, with their consequent mitosis block and death. Vincristine leads to VIPN through a complex mechanism of damage, which occurs not only on the microtubules, but also on the endothelium and the mitochondria of nerve cells. Furthermore, both patient-related risk factors (age, race, ethnicity and genetic polymorphisms) and treatment-related risk factors (dose, time of infusion and drug-drug interactions) are involved in the pathogenesis of VIPN. There is a lack of consensus about the prophylaxis and treatment of VIPN among pediatric oncologic patients, despite several molecules (such as gabapentin, pyridoxine and pyridostigmine, glutamic acid and glutamine) having been already investigated in clinical trials. This review describes the molecular mechanisms of VIPN and analyzes the risk factors and the principal drugs adopted for the prophylaxis and treatment of VIPN in pediatric patients with cancer.


Subject(s)
Antineoplastic Agents/toxicity , Neurotoxicity Syndromes/etiology , Peripheral Nervous System Diseases/etiology , Tubulin Modulators/toxicity , Vincristine/toxicity , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacokinetics , Child , Humans , Neurotoxicity Syndromes/drug therapy , Neurotoxicity Syndromes/prevention & control , Peripheral Nervous System Diseases/drug therapy , Peripheral Nervous System Diseases/prevention & control , Tubulin Modulators/administration & dosage , Tubulin Modulators/pharmacokinetics , Vincristine/pharmacokinetics
3.
Methods Mol Biol ; 2267: 207-215, 2021.
Article in English | MEDLINE | ID: mdl-33786794

ABSTRACT

Mitotic catastrophe is a modality of cell death (or occasionally senescence) that occurs after cells enter, and fail to resolve, abnormal mitosis, for instance after DNA damage or perturbations of the cell cycle. Mitotic catastrophe can avoid the generation of neoplastic cells from premalignant precursors, yet may also occur in cancer cells as a result of radiotherapy or chemotherapy. Of note, vinca alkaloids and taxanes, which are both known for affecting the stability of microtubules, can trigger mitotic catastrophe. Such agents can also cause cancer cells to undergo immunogenic cell death (ICD), which allows therapeutic responses to last beyond treatment discontinuation due to the induction of an antitumor immune response. ICD is commonly characterized by the exposure of the endoplasmic reticulum protein calreticulin on the cell surface. Here we describe an immunofluorescence-based cytofluorometric technique to detect calreticulin exposure on tumor cells exposed to drugs that induce mitotic catastrophe.


Subject(s)
Calreticulin/metabolism , Flow Cytometry/methods , Immunogenic Cell Death , Mitosis , Animals , Cell Line, Tumor , Humans , Tubulin Modulators/toxicity
4.
Bioorg Med Chem Lett ; 30(23): 127608, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33038545

ABSTRACT

The ability of monomethoxy-substituted o-diphenylisoxazoles 2a-d to interact with the colchicine site of tubulin was predicted using computational modeling, docking studies, and calculation of binding affinity. The respective molecules were synthesized in high yields by three steps reaction using easily available benzaldehydes, acetophenones, and arylnitromethanes as starting material. The calculated antitubulin effect was confirmed in vivo in a sea urchin embryo model. Compounds 2a and 2c showed high antimitotic microtubule destabilizing activity compared to that of CA4. Isoxazole 2a also exhibited significant cytotoxicity against human cancer cells in NCI60 screen. For the first time, isoxazole-linked CA4 derivatives 2a and 2c with only one methoxy substituent were identified as potent antimitotic microtubule destabilizing agents. These molecules could be considered as promising structures for further optimization.


Subject(s)
Isoxazoles/pharmacology , Tubulin Modulators/pharmacology , Animals , Binding Sites , Cell Line, Tumor , Embryo, Nonmammalian/drug effects , Humans , Isoxazoles/chemical synthesis , Isoxazoles/metabolism , Isoxazoles/toxicity , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , Protein Binding , Sea Urchins/drug effects , Structure-Activity Relationship , Tubulin/metabolism , Tubulin Modulators/chemical synthesis , Tubulin Modulators/metabolism , Tubulin Modulators/toxicity
5.
Eur J Med Chem ; 207: 112724, 2020 Dec 01.
Article in English | MEDLINE | ID: mdl-32827941

ABSTRACT

Two series of heterocyclic colchicinoids bearing ß-methylenedihydrofuran or 2H-pyran-2-one fragments were synthesized by the intramolecular Heck reaction. Methylenedihydrofuran compounds 9a and 9h were found to be the most cytotoxic among currently known colchicinoids, exhibiting outstanding antiproliferative activity on tumor cell lines in picomolar (0.01-2.1 nM) range of concentrations. Compound 9a potently and substoichiometrically inhibits microtubule formation in vitro, being an order of magnitude more active in this assay than colchicine. Derivatives 9a and 9h revealed relatively low acute toxicity in mice (LD50 ≥ 10 mg/kg i.v.). The X-Ray structure of colchicinoid 9a bound to tubulin confirmed interaction of this compound with the colchicine binding site of tubulin.


Subject(s)
Antimitotic Agents/chemistry , Antimitotic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Colchicine/analogs & derivatives , Colchicine/pharmacology , Animals , Antimitotic Agents/toxicity , Antineoplastic Agents/toxicity , Cell Line, Tumor , Cell Proliferation/drug effects , Colchicine/toxicity , Crystallography, X-Ray , Drug Screening Assays, Antitumor , Furans/chemistry , Furans/pharmacology , Furans/toxicity , Humans , Mice, Inbred BALB C , Mice, Inbred C57BL , Molecular Docking Simulation , Neoplasms/drug therapy , Neoplasms/metabolism , Tubulin/metabolism , Tubulin Modulators/chemistry , Tubulin Modulators/pharmacology , Tubulin Modulators/toxicity
6.
Environ Toxicol Pharmacol ; 78: 103405, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32446185

ABSTRACT

Commercial benzamide fungicides are applied to crops to control damage caused by oomycete fungi and are used as veterinary pharmaceuticals in aquaculture. The mechanism of action of these fungicides is to induce mitotic arrest via binding to beta-tubulin, thus inhibiting tubulin polymerization. However, there are little toxicity data available for benzimidazole fungicides in fish. To address this knowledge gap, we conducted zebrafish embryo toxicity tests to assess deformities, survival, and sub-lethal responses following exposure to zoxamide (0, 0.5, 1.0, 2.5, 5.0 and 10 µM zoxamide). We hypothesized that skeletal deformities would be prevalent in zebrafish due to its mechanism of inhibiting beta-tubulin polymerization. Zoxamide was relatively toxic to zebrafish embryos and larvae, and survival was reduced ∼50 % at 2 days post fertilization (dpf) with 10 µM exposure and over time at 6 dpf, 2.5 µM exposure reduced survival by ∼20 %. Frequency of hatch was also reduced/delayed in zebrafish at 3 dpf with >2.5 µM zoxamide. Pericardial edema, body length shortening, and spine curvature were observed in larvae exposed to >5 µM. Mitochondrial bioenergetics were assessed in ∼30 hpf embryos (24-hour exposure) using an XFe24 Flux Analyzer and regression analysis revealed a negative relationship between basal respiration and zoxamide concentration. Superoxide dismutase 1 and caspase 3 mRNA levels were both decreased in 6 dpf larvae exposed to 2.5 µM zoxamide, but were not changed in expression at 0.5 nor 1 µM zoxamide. Continuous 6-day exposure to zoxamide reduced larval activity at 2.5 µM; conversely a 24-hour exposure (at 5-6 dpf) induced hyperactivity at 5 µM suggesting dose and time dependent effects on fish behavior. Based on sub-lethal endpoints, we conceptualize an adverse outcome pathway for chemicals that inhibit tubulin polymerization.


Subject(s)
Amides/toxicity , Fungicides, Industrial/toxicity , Tubulin Modulators/toxicity , Zebrafish , Adverse Outcome Pathways , Animals , Embryo, Nonmammalian , Energy Metabolism , Larva , Mitochondria/drug effects , Tubulin , Zebrafish/abnormalities
7.
Eur J Med Chem ; 197: 112323, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32339854

ABSTRACT

Inhibition of tubulin polymerisation with small molecules has been clinically validated as a promising therapy for multiple solid tumours. Herein, a series of chiral azetidin-2-ones were asymmetrically synthesised and biologically evaluated for antitumour activities. Among them, a chiral fluorinated azetidin-2-one, 18, was found to exhibit the most potent activities against five cancer cell lines, including a drug-resistant cell line, with IC50 values ranging from 1.0 to 3.6 nM. Further mechanistic studies revealed that the compound 18 worked by disrupting tubulin polymerisation, blocking the cell cycle in the G2/M phase, inducing cellular apoptosis, and suppressing angiogenesis. Additionally, 18 exhibited higher human-microsomal metabolic stability and aqueous solubility compared to those of combretastatin A-4. Finally, 18 was also found to effectively inhibit tumour growth in a xenograft mice model with low toxicity and thus might be a promising lead for further clinical development.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Azetidines/therapeutic use , Neoplasms/drug therapy , Tubulin Modulators/therapeutic use , Tubulin/metabolism , Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/metabolism , Angiogenesis Inhibitors/toxicity , Animals , Apoptosis/drug effects , Azetidines/chemical synthesis , Azetidines/metabolism , Azetidines/toxicity , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Resistance, Multiple/drug effects , Drug Resistance, Neoplasm/drug effects , Drug Stability , G2 Phase Cell Cycle Checkpoints/drug effects , Humans , Mice , Microsomes, Liver/metabolism , Molecular Docking Simulation , Molecular Structure , Structure-Activity Relationship , Tubulin/chemistry , Tubulin Modulators/chemical synthesis , Tubulin Modulators/metabolism , Tubulin Modulators/toxicity , Xenograft Model Antitumor Assays
8.
Eur J Med Chem ; 190: 112105, 2020 Mar 15.
Article in English | MEDLINE | ID: mdl-32035399

ABSTRACT

A novel series of shikonin-benzo[b]furan derivatives were designed and synthesized as tubulin polymerization inhibitors, and their biological activities were evaluated. Most compounds revealed the comparable anti-proliferation activities against the cancer cell lines to that of shikonin and simultaneously low cytotoxicity to non-cancer cells. Among them, compound 6c displayed powerful anti-cancer activity with the IC50 value of 0.18 µM against HT29 cells, which was significantly better than that of the reference drugs shikonin and CA-4. What's more, 6c could inhibit tubulin polymerization and compete with [3H] colchicine in binding to tubulin. Further biological studies depicted that 6c can induce cell apoptosis and cell mitochondria depolarize, regulate the expression of apoptosis related proteins in HT29 cells. Besides, 6c actuated the HT29 cell cycle arrest at G2/M phase, and influenced the expression of the cell-cycle related protein. Moreover, 6c displayed potent inhibition on cell migration and tube formation that contributes to the antiangiogenesis. These results prompt us to consider 6c as a potential tubulin polymerization inhibitor and is worthy for further study.


Subject(s)
Benzofurans/pharmacology , Naphthoquinones/pharmacology , Tubulin Modulators/pharmacology , Tubulin/metabolism , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Benzofurans/chemical synthesis , Benzofurans/metabolism , Benzofurans/toxicity , Binding Sites , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , G2 Phase Cell Cycle Checkpoints/drug effects , Human Umbilical Vein Endothelial Cells , Humans , Molecular Docking Simulation , Naphthoquinones/chemical synthesis , Naphthoquinones/metabolism , Naphthoquinones/toxicity , Protein Binding , Tubulin Modulators/chemical synthesis , Tubulin Modulators/metabolism , Tubulin Modulators/toxicity
9.
Eur J Med Chem ; 188: 111986, 2020 Feb 15.
Article in English | MEDLINE | ID: mdl-31884407

ABSTRACT

Breast cancer is the second leading cause of deaths in women globally. Present communication deals with design and synthesis of a few diarylnaphthyls as possible anti-breast cancer agents. Among the thirty three representatives with significant antiproliferative activity compounds 23 and 50 were quite efficacious against human breast cancer cells. Compound 50 induced apoptosis in both MCF-7 and MDA-MB-231 cells and exerted S phase and G2/M phase arrest respectively via distinct mechanistic pathways. It showed moderate microtubule destabilization. Further, it exhibited DNA topoisomerase-II inhibition effect in MCF-7 cells. It was well tolerable and found safe up to 300 mg/kg dose in Swiss albino mice. The dual action antiproliferative effect of compound 50 is quite interesting and warrants for future development.


Subject(s)
Antineoplastic Agents/pharmacology , Naphthalenes/pharmacology , Pyrrolidines/pharmacology , Topoisomerase II Inhibitors/pharmacology , Tubulin Modulators/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Breast Neoplasms/drug therapy , Cell Line, Tumor , Drug Screening Assays, Antitumor , Female , G2 Phase Cell Cycle Checkpoints/drug effects , Humans , Male , Mice , Molecular Docking Simulation , Naphthalenes/chemical synthesis , Naphthalenes/toxicity , Pyrrolidines/chemical synthesis , Pyrrolidines/toxicity , Topoisomerase II Inhibitors/chemical synthesis , Topoisomerase II Inhibitors/toxicity , Tubulin Modulators/chemical synthesis , Tubulin Modulators/toxicity
10.
Continuum (Minneap Minn) ; 25(6): 1712-1731, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31794468

ABSTRACT

PURPOSE OF REVIEW: This article reviews the pathogenesis, clinical features, and management of toxic myopathy related to common medications, critical illness, and illicit substances. RECENT FINDINGS: Muscle symptoms are common among statin users and are usually reversible after discontinuation of the statin; rarely, however, statins trigger an immune-mediated necrotizing myopathy that persists and requires immunomodulatory therapy. Autoantibodies targeting 3-hydroxy-3-methylglutaryl coenzyme A reductase can distinguish the toxic and immune-mediated forms. Immune checkpoint inhibitors, increasingly used in the treatment of advanced cancer, have recently been associated with the development of inflammatory myositis. A reversible mitochondrial myopathy has long been associated with zidovudine, but recent reports elucidate the risk of myopathy with newer antivirals, such as telbivudine and raltegravir. SUMMARY: The medications most commonly associated with myopathy include statins, amiodarone, chloroquine, hydroxychloroquine, colchicine, certain antivirals, and corticosteroids, and myopathy can occur with chronic alcoholism. Certain clinical, electrodiagnostic, and histologic features can aid in early recognition. Stopping the use of the offending agent reverses symptoms in most cases, but specific and timely treatment may be required in cases related to agents that trigger immune-mediated muscle injury.


Subject(s)
Adrenal Cortex Hormones/toxicity , Anti-Retroviral Agents/toxicity , Enzyme Inhibitors/toxicity , Fibric Acids/toxicity , Hydroxymethylglutaryl-CoA Reductase Inhibitors/toxicity , Immunologic Factors/toxicity , Myotoxicity , Tubulin Modulators/toxicity , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Myotoxicity/etiology , Myotoxicity/genetics , Myotoxicity/physiopathology
11.
Article in English | MEDLINE | ID: mdl-31699346

ABSTRACT

An aneuploidy workgroup was established as part of the 7th International Workshops on Genotoxicity Testing. The workgroup conducted a review of the scientific literature on the biological mechanisms of aneuploidy in mammalian cells and methods used to detect chemical aneugens. In addition, the current regulatory framework was discussed, with the objective to arrive at consensus statements on the ramifications of exposure to chemical aneugens for human health risk assessment. As part of these efforts, the workgroup explored the use of adverse outcome pathways (AOPs) to document mechanisms of chemically induced aneuploidy in mammalian somatic cells. The group worked on two molecular initiating events (MIEs), tubulin binding and binding to the catalytic domain of aurora kinase B, which result in several adverse outcomes, including aneuploidy. The workgroup agreed that the AOP framework provides a useful approach to link evidence for MIEs with aneuploidy on a cellular level. The evidence linking chemically induced aneuploidy with carcinogenicity and hereditary disease was also reviewed and is presented in two companion papers. In addition, the group came to the consensus that the current regulatory test batteries, while not ideal, are sufficient for the identification of aneugens and human risk assessment. While it is obvious that there are many different MIEs that could lead to the induction of aneuploidy, the most commonly observed mechanisms involving chemical aneugens are related to tubulin binding and, to a lesser extent, inhibition of mitotic kinases. The comprehensive review presented here should help with the identification and risk management of aneugenic agents.


Subject(s)
Adverse Outcome Pathways , Aneuploidy , Genetic Diseases, Inborn/chemically induced , Mitosis/drug effects , Mutagenicity Tests/methods , Mutagens/toxicity , Neoplasms/chemically induced , Animals , Aurora Kinase B/antagonists & inhibitors , Aurora Kinase B/physiology , Carcinogens/toxicity , Chromosome Aberrations/chemically induced , Chromosome Segregation/drug effects , Chromosomes/drug effects , Genes, Reporter , Genetic Diseases, Inborn/genetics , Germ Cells/drug effects , Germ Cells/ultrastructure , Humans , Mice , Micronucleus Tests , Microtubules/drug effects , Mitosis/physiology , Mutagenicity Tests/standards , Mutagens/analysis , Neoplasms/genetics , Nondisjunction, Genetic/drug effects , Risk Management/legislation & jurisprudence , Tubulin Modulators/toxicity
12.
Article in English | MEDLINE | ID: mdl-31699349

ABSTRACT

Aneuploidy is regarded as a hallmark of cancer, however, its role is complex with both pro- and anti-carcinogenic effects evident. In this IWGT review, we consider the role of aneuploidy in cancer biology; cancer risk associated with constitutive aneuploidy; rodent carcinogenesis with known chemical aneugens; and chemotherapy-related malignant neoplasms. Aneuploidy is seen at various stages in carcinogenesis. However, the relationship between induced aneuploidy occurring after exposure and clonal aneuploidy present in tumours is not clear. Recent evidence indicates that the induction of chromosomal instability (CIN), may be more important than aneuploidy per se, in the carcinogenic process. Down Syndrome, trisomy 21, is associated with altered hematopoiesis in utero which, in combination with subsequent mutations, results in an increased risk for acute megakaryoblastic and lymphoblastic leukemias. In contrast, there is reduced cancer risk for most solid tumours in Down Syndrome. Mouse models with high levels of aneuploidy are also associated with increased cancer risk for particular tumours with long latencies, but paradoxically other types of tumour often show decreased incidence. The aneugens reviewed that induce cancer in humans and animals all possess other carcinogenic properties, such as mutagenicity, clastogenicity, cytotoxicity, organ toxicities, hormonal and epigenetic changes which likely account for, or interact with aneuploidy, to cause carcinogenesis. Although the role that aneuploidy plays in carcinogenesis has not been fully established, in many cases, it may not play a primary causative role. Tubulin-disrupting aneugens that do not possess other properties linked to carcinogenesis, were not carcinogenic in rodents. Similarly, in humans, for the tubulin-disrupting aneugens colchicine and albendazole, there is no reported association with increased cancer risk. There is a need for further mechanistic studies on agents that induce aneuploidy, particularly by mechanisms other than tubulin disruption and to determine the role of aneuploidy in pre-neoplastic events and in early and late stage neoplasia.


Subject(s)
Aneuploidy , Carcinogenesis/genetics , Carcinogens/toxicity , Chromosomal Instability , Mutagenicity Tests/methods , Neoplasms/chemically induced , Animals , Centrosome , Chromosome Disorders/genetics , Chromosomes/drug effects , Down Syndrome/complications , Down Syndrome/genetics , Genetic Predisposition to Disease , Humans , Mice , Models, Animal , Mutagenicity Tests/standards , Mutagens/toxicity , Neoplasms/genetics , Neoplasms, Second Primary/chemically induced , Neoplasms, Second Primary/genetics , Spindle Apparatus/drug effects , Tubulin Modulators/toxicity
13.
Int J Mol Sci ; 20(9)2019 Apr 30.
Article in English | MEDLINE | ID: mdl-31052191

ABSTRACT

Tubulins and microtubules (MTs) represent targets for taxane-based chemotherapy. To date, several lines of evidence suggest that effectiveness of compounds binding tubulin often relies on different post-translational modifications on tubulins. Among them, methylation was recently associated to drug resistance mechanisms impairing taxanes binding. The sea urchin is recognized as a research model in several fields including fertilization, embryo development and toxicology. To date, some α- and ß-tubulin genes have been identified in P. lividus, while no data are available in echinoderms for arginine methyl transferases (PRMT). To evaluate the exploiting of the sea urchin embryo in the field of antiproliferative drug development, we carried out a survey of the expressed α- and ß-tubulin gene sets, together with a comprehensive analysis of the PRMT gene family and of the methylable arginine residues in P. lividus tubulins. Because of their specificities, the sea urchin embryo may represent an interesting tool for dissecting mechanisms of tubulin targeting drug action. Therefore, results herein reported provide evidences supporting the P. lividus embryo as animal system for testing antiproliferative drugs.


Subject(s)
Cytostatic Agents/toxicity , Intracellular Signaling Peptides and Proteins/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Sea Urchins/drug effects , Toxicity Tests/methods , Tubulin Modulators/toxicity , Tubulin/metabolism , Animals , Embryo, Nonmammalian/drug effects , Methylation , Protein Processing, Post-Translational , Sea Urchins/embryology
14.
Acta Pharmacol Sin ; 40(7): 971-979, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30643210

ABSTRACT

Emerging evidence demonstrates that a c-Met antibody-drug conjugate (ADC) has superior efficacy and safety profiles compared with those of currently available small molecules or antibody inhibitors for the treatment of c-Met-overexpressing cancers. Here we described both the in vitro and in vivo efficacies of SHR-A1403, a novel c-Met ADC composed of a humanized IgG2 monoclonal antibody against c-Met conjugated to a novel cytotoxic microtubule inhibitor. SHR-A1403 showed high affinity to c-Met proteins derived from human or monkey and potent inhibitory effects in cancer cell lines with high c-Met protein expression. In mice bearing tumors derived from cancer cell lines or patient HCC tissues with confirmed c-Met overexpression, SHR-A1403 showed excellent anti-tumor efficacy. Antibody binding with c-Met contributed to SHR-A1403 endocytosis; the subsequent translocation to lysosomes and cytotoxicity of the released toxin are speculated to be predominant mechanisms underlying the anti-tumor activity of SHR-A1403. In conclusion, SHR-A1403 showed significant anti-tumor activity in cancer cell lines, xenograft mouse models and an HCC PDX model, which all have high c-Met levels. These data provide references for SHR-A1403 as a potential therapy for the treatment of cancers with c-Met overexpression.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Immunoconjugates/therapeutic use , Liver Neoplasms/drug therapy , Proto-Oncogene Proteins c-met/antagonists & inhibitors , Tubulin Modulators/therapeutic use , Animals , Antibodies, Monoclonal, Humanized/immunology , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal, Humanized/toxicity , Antineoplastic Agents/immunology , Antineoplastic Agents/toxicity , Cell Line, Tumor , Cell Proliferation/drug effects , G2 Phase Cell Cycle Checkpoints/drug effects , Humans , Immunoconjugates/immunology , Immunoconjugates/toxicity , Macaca fascicularis , Male , Mice, Inbred BALB C , Microtubules/drug effects , Proto-Oncogene Proteins c-met/immunology , Tubulin Modulators/immunology , Tubulin Modulators/toxicity , Xenograft Model Antitumor Assays
15.
Genetics ; 211(1): 105-119, 2019 01.
Article in English | MEDLINE | ID: mdl-30442759

ABSTRACT

Pif1 family helicases are found in virtually all eukaryotes. Saccharomyces cerevisiae (Sc) encodes two Pif1 family helicases, ScPif1 and Rrm3 ScPif1 is multifunctional, required not only for maintenance of mitochondrial DNA but also for multiple distinct nuclear functions. Rrm3 moves with the replication fork and promotes movement of the fork through ∼1400 hard-to-replicate sites, including centromeres. Here we show that ScPif1, like Rrm3, bound robustly to yeast centromeres but only if the centromere was active. While Rrm3 binding to centromeres occurred in early to mid S phase, about the same time as centromere replication, ScPif1 binding occurred later in the cell cycle when replication of most centromeres is complete. However, the timing of Rrm3 and ScPif1 centromere binding was altered by the absence of the other helicase, such that Rrm3 centromere binding occurred later in pif1-m2 cells and ScPif1 centromere binding occurred earlier in rrm3Δ cells. As shown previously, the modest pausing of replication forks at centromeres seen in wild-type cells was increased in the absence of Rrm3 While a lack of ScPif1 did not result in increased fork pausing at centromeres, pausing was even higher in rrm3Δ pif1Δ cells than in rrm3Δ cells. Likewise, centromere function as monitored by the loss rate of a centromere plasmid was increased in rrm3Δ but not pif1Δ cells, and was even higher in rrm3Δ pif1Δ cells than in rrm3Δ cells. Thus, ScPif1 promotes centromere replication and segregation, but only in the absence of Rrm3 These data also hint at a potential post-S phase function for ScPif1 at centromeres. These studies add to the growing list of ScPif1 functions that promote chromosome stability.


Subject(s)
Chromosome Segregation , DNA Helicases/metabolism , DNA Replication , Saccharomyces cerevisiae Proteins/metabolism , Centromere/genetics , DNA Helicases/genetics , Drug Resistance, Fungal/genetics , Saccharomyces cerevisiae , Saccharomyces cerevisiae Proteins/genetics , Tubulin Modulators/toxicity
16.
Biochem Pharmacol ; 162: 154-168, 2019 04.
Article in English | MEDLINE | ID: mdl-30414389

ABSTRACT

Albendazole (ABZ) is a microtubule-targeting anthelmintic that acts against a variety of human cancer cells, but the dependence of its cytotoxicity on non-mitotic effect remains elusive. Thus, we aimed to explore the mechanistic pathway underlying the cytotoxicity of ABZ in human leukemia U937 cells. ABZ-induced apoptosis of U937 cells was characterized by mitochondrial ROS generation, p38 MAPK activation, TNF-α upregulation and activation of the death receptor-mediated pathway. Meanwhile, ABZ induced tubulin depolymerization and G2/M cell cycle arrest. ABZ-induced SIRT3 degradation elicited ROS-mediated p38 MAPK activation, leading to pyruvate kinase M2-mediated tristetraprolin (TTP) degradation. Inhibition of TTP-mediated TNF-α mRNA decay elicited TNF-α upregulation in ABZ-treated cells. Either the overexpression of SIRT3 or abolishment of ROS/p38 MAPK activation suppressed TNF-α upregulation and rescued the viability of ABZ-treated cells. In contrast to the inhibition of ROS/p38 MAPK pathway, SIRT3 overexpression attenuated tubulin depolymerization and G2/M arrest in ABZ-treated cells. Treatment with a SIRT3 inhibitor induced TNF-α upregulation and cell death without the induction of G2/M arrest in U937 cells. Taken together, our data indicate that ABZ-induced SIRT3 downregulation promotes its microtubule-destabilizing effect, and that the non-mitotic effect of ABZ largely triggers apoptosis of U937 cells via SIRT3/ROS/p38 MAPK/TTP axis-mediated TNF-α upregulation. Notably, the same pathway is involved in the ABZ-induced death of HL-60 cells.


Subject(s)
Albendazole/toxicity , Reactive Oxygen Species/metabolism , Sirtuin 3/metabolism , Tristetraprolin/biosynthesis , Tumor Necrosis Factor-alpha/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Apoptosis/drug effects , Apoptosis/physiology , Dose-Response Relationship, Drug , HL-60 Cells , Humans , Leukemia/metabolism , Leukemia/pathology , Mitosis Modulators , Tubulin Modulators/toxicity , U937 Cells , Up-Regulation/drug effects , Up-Regulation/physiology
17.
Biol Pharm Bull ; 41(7): 1001-1005, 2018.
Article in English | MEDLINE | ID: mdl-29962396

ABSTRACT

Colchicine or vincristine depolymerize microtubules, an action which blocks neuron axonal transport. Thus, these chemicals showed selective neurotoxicity in hippocampal neurons. However, the mechanism of neurotoxicity by these antimicrotubule agents has remained unclear. Our previous studies have suggested that colchicine-induced hippocampal neuron death is caused by incremental increases in intraneuronal free zinc. We have demonstrated that zinc transporter 3 gene deletion (ZnT3-/-) reduces dentate granule cell death after colchicine injection. This ZnT3-/--mediated reduction of dentate granule cell death was accompanied by a decrease in the incidence of oxidative injury. Unexpectedly, we found that ZnT3-/- mice contain a higher glutathione (GSH) level in the hippocampal neurons than wild type mice. Thus, ZnT3-/- mice showed less neuronal GSH depletion by colchicine injection, and thus less neuronal death. These results suggest that the higher levels of neuronal GSH in ZnT3-/- mice result in less dentate granule cell death after colchicine injection. In addition to colchicine, our lab also demonstrated that a chemotherapeutic agent, pacritaxel (Taxol), which is a microtubule stabilizing agent, depleted vesicular zinc in the presynaptic terminals and induced a reduction of neurogenesis. Therefore, in the present review, we discussed how antimicrotubule agent-induced neurotoxicity and cognitive impairment is associated with zinc dyshomeostasis in the brain.


Subject(s)
Cell Death/drug effects , Hippocampus/drug effects , Microtubules/drug effects , Neurotoxicity Syndromes/pathology , Tubulin Modulators/toxicity , Animals , Cation Transport Proteins/genetics , Cation Transport Proteins/metabolism , Cognitive Dysfunction/chemically induced , Cognitive Dysfunction/genetics , Cognitive Dysfunction/pathology , Colchicine/toxicity , Disease Models, Animal , Hippocampus/cytology , Hippocampus/pathology , Humans , Mice , Neurogenesis/drug effects , Neurons/cytology , Neurons/drug effects , Neurons/pathology , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/genetics , Paclitaxel/pharmacology , Presynaptic Terminals/drug effects , Presynaptic Terminals/pathology , Vincristine/toxicity
18.
Mol Divers ; 22(3): 669-683, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29611020

ABSTRACT

A quantitative structure-activity (QSAR) model has been developed for enriched tubulin inhibitors, which were retrieved from sequence similarity searches and applicability domain analysis. Using partial least square (PLS) method and leave-one-out (LOO) validation approach, the model was generated with the correlation statistics of [Formula: see text] and [Formula: see text] of 0.68 and 0.69, respectively. The present study indicates that topological descriptors, viz. BIC, CH_3_C, IC, JX and Kappa_2 correlate well with biological activity. ADME and toxicity (or ADME/T) assessment showed that out of 260 molecules, 255 molecules successfully passed the ADME/T assessment test, wherein the drug-likeness attributes were exhibited. These results showed that topological indices and the colchicine binding domain directly influence the aetiology of helminthic infections. Further, we anticipate that our model can be applied for guiding and designing potential anthelmintic inhibitors.


Subject(s)
Anthelmintics , Models, Molecular , Tubulin Modulators , Animals , Anthelmintics/chemical synthesis , Anthelmintics/pharmacokinetics , Anthelmintics/toxicity , Haemonchus , Helminth Proteins/chemistry , Least-Squares Analysis , Protein Conformation , Quantitative Structure-Activity Relationship , Tubulin/chemistry , Tubulin Modulators/chemical synthesis , Tubulin Modulators/pharmacokinetics , Tubulin Modulators/toxicity
19.
J Neuroimmunol ; 317: 15-23, 2018 04 15.
Article in English | MEDLINE | ID: mdl-29501081

ABSTRACT

The present study was designed to investigate the effectiveness of etoricoxib induced inhibition of neuroinflammation by studying the peripheral inflammatory markers and select immune parameters in intracerebroventricular colchicine injected rats (ICIR). Results showed time dependent upregulation of the inflammatory markers in the serum along with alterations of peripheral immune parameters in ICIR and dose-dependent recovery was observed upon administration of etoricoxib to ICIR; most of these effects were greater with the longer duration of study. The present study indicates that colchicine induced neuroinflammation may cause systemic inflammation and alteration of immune responses which are mediated by increased cox- 2 activity.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cyclooxygenase 2/immunology , Etoricoxib/pharmacology , Inflammation/chemically induced , Inflammation/immunology , Animals , Colchicine/administration & dosage , Colchicine/toxicity , Injections, Intraventricular , Male , Rats , Tubulin Modulators/administration & dosage , Tubulin Modulators/toxicity
20.
Bioorg Chem ; 76: 314-325, 2018 02.
Article in English | MEDLINE | ID: mdl-29227915

ABSTRACT

A series of novel compounds carrying 1,2,4-triazole scaffold was synthesized and evaluated for their anticancer activity against a panel of cancer cell lines using MTT assay. Compounds 8a, 8b, 8c, 8d, 10b, 10e, and 10 g showed remarkable antiproliferative activity against the tested cell lines. Compounds 8a, 8b, 8c, 8d, 10b, 10e, and 10 g with the least IC50 values in MTT assay were tested against three known anticancer targets including EGFR, BRAF and Tubulin. The results revealed that compounds 8c and 8d showed almost same BRAF inhibitory activity and were discovered to be potent inhibitors of cancer cell proliferation and were also observed to be strong Tubulin inhibitors. Moreover, 8c also showed the best EGFR inhibition with IC50 = 3.6 µM. Finally molecular modeling studies were performed to explore the binding mode of the most active compounds to the target enzymes.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Triazoles/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/toxicity , Binding Sites , Cell Line, Tumor , Drug Screening Assays, Antitumor , ErbB Receptors/antagonists & inhibitors , Erlotinib Hydrochloride/pharmacology , Humans , Hydrogen Bonding , Ligands , Models, Chemical , Molecular Docking Simulation , Molecular Structure , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/chemistry , Triazoles/toxicity , Tubulin/metabolism , Tubulin Modulators/chemical synthesis , Tubulin Modulators/chemistry , Tubulin Modulators/pharmacology , Tubulin Modulators/toxicity
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