ABSTRACT
Recently a new di-gold(I) organometallic complex [1,3-(Ph(3)PAu)(2)-C(6)H(4)] (KF0101) has been synthesised and found to exhibit cytotoxic activity in vitro. Subsequently it has been demonstrated that KF0101 shows little or no cross-resistance against a number of the cisplatin resistant ovarian cancer cell lines in vitro suggesting a different mode of action for the drug. In this study, syncrotron radiation infrared microspectroscopy (SR-IRMS) has been used on drug treated single A2780 cells in order to determine if this different mode of action can be identified spectroscopically. The aim of the study was to establish: (i) if single cell SR-IRMS could be used to give insight into the cellular response on treatment with different cytotoxic agents relative to non-treated cells (control) and (ii) that if the cytotoxic drugs elicit a different biochemical response these responses could be distinguished from each other. The most striking features obtained after Principal Components Analysis (PCA) of Resonant Mie Scattering (RMieS) corrected single cell spectra of drug treated ovarian A2780 cells are: (i) The spectra obtained for the control are quite heterogeneous and several hundred spectra are required to adequately define the nature of the control; (ii) after drug treatment at the IC50 level for 24 h with cisplatin, KF0101, methotrexate, paclitaxel or 5-fluorouracil the cell spectra, as represented on a PCA scores plot, generally concentrate in certain well defined areas of the control, there are however a small number of spectra that fall outside of the area defined by the control; and (iii) a differentiation between cell spectra obtained on treatment with different drugs is observed which fits well with different in vitro cell culture behaviour and a flow cytometry cell cycle analysis of the control and drug treated cells. Inspection of the loading plots shows that PC1 is essentially the same for all plots and reflects changes in cell biochemistry related to the cell cycle. PC2, however, on comparison of the control versus cisplatin or cisplatin versus KF0101 is indicative of differences induced by drug treatment and has been termed as cell cycle-plus behaviour. These data are shown to be consistent with that obtained using bench-top IRMS by averaging a number of single cell spectra and carrying out a PCA, but SR-IRMS offers more insight into how the drug is affecting the cell population. More importantly, this approach enables the influence of the cell cycle on both the control and drug treated samples to be taken into consideration when evaluating the drug-cell interaction.
Subject(s)
Antineoplastic Agents/pharmacology , Single-Cell Analysis/methods , Spectroscopy, Fourier Transform Infrared/methods , Synchrotrons , Cell Cycle/drug effects , Cell Line, Tumor , Female , Flow Cytometry , Humans , Inhibitory Concentration 50 , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/pathology , Principal Component Analysis , Single-Cell Analysis/instrumentation , Spectroscopy, Fourier Transform Infrared/instrumentationABSTRACT
The alpha-methyl chalcone SD400 is a potent inhibitor of tubulin assembly and possesses potent anticancer activity. Various chalcone analogues were synthesized and evaluated for their cell growth inhibitory properties against the K562 human chronic myelogenous leukemia cell line (SD400, IC(50) 0.21nM; combretastatin A4 CA4, IC(50) 2.0nM). Cell cycle analysis by flow cytometry indicated that these agents are antimitotic (SD400, 83% of the cells are in G(2)/M phase; CA4 90%). They inhibit tubulin assembly at low concentration (SD400, IC(50) 0.46microM; CA4, 0.10microM) and compete with [(3)H]colchicine for binding to tubulin (8% [(3)H]colchicine remained bound to tubulin after competition with SD400 or CA4). Upon treatment with SD400, remarkable cell shape changes were elicited in HUVEC cells, consistent with vasculature damaging activity.
Subject(s)
Antineoplastic Agents/chemical synthesis , Bibenzyls/pharmacology , Cell Proliferation/drug effects , Chalcones/pharmacology , Microtubules/drug effects , Neovascularization, Physiologic/drug effects , Tubulin Modulators/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Bibenzyls/chemical synthesis , Bibenzyls/chemistry , Cell Line, Tumor , Chalcones/chemical synthesis , Chalcones/chemistry , Drug Evaluation, Preclinical , Drug Screening Assays, Antitumor , Humans , K562 Cells , Microtubules/metabolism , Structure-Activity Relationship , Tubulin Modulators/chemistry , Tubulin Modulators/pharmacologyABSTRACT
PURPOSE: The purpose of our study was to investigate the cellular accumulation, DNA cross-linking ability, and cellular toxicity of RH1 (2,5-diaziridinyl-3-[hydroxymethyl[-6-methyl-1,4-benzoquinone), a novel DNA alkylating agent currently in clinical trials. In addition, the in vivo efficacy of RH1 formulated in different vehicles was also compared. EXPERIMENTAL DESIGN: RH1 is activated by the two-electron reducing enzyme NQO1 [NADPH:quinone oxidoreductase] forming a potent cytotoxic agent that cross-links DNA. We have used whole blood, cell lines, and primary explanted tumor cultures to measure both the cellular accumulation, DNA cross-linking, and cytotoxicity of RH1. Furthermore, the pharmacokinetic and pharmacodynamic characteristics of RH1 formulated in different vehicles were measured in vivo using the validated comet-X assay in mice bearing human tumor xenografts. RESULTS: Accumulation of RH1 was shown to be both time and concentration dependent, reaching a maximum after 2 hours and correlated well with DNA cross-linking measurements. DNA cross-linking in vitro could be detected at low (1-10 nmol/L) concentrations after as little as 2 hours exposure. In primary tumor cultures, RH1 induces much higher levels of DNA cross-links at lower doses than either mitomycin C or cisplatin. In vivo efficacy testing using polyvinyl pyrrolidone, saline, or cyclodextrin as vehicles showed DNA cross-links readily detectable in all tissues examined and was enhanced when given in cyclodextrin compared with polyvinyl pyrrolidone or saline. CONCLUSIONS: RH1 represents a potent bioreductive anticancer drug, which may prove effective in the treatment of cancers, particularly those that overexpress NQO1. DNA cross-linking can be reliably measured in tissue using the validated comet-X assay.
Subject(s)
Aziridines/pharmacology , Benzoquinones/pharmacology , Xenograft Model Antitumor Assays/methods , Animals , Aziridines/blood , Aziridines/pharmacokinetics , Benzoquinones/blood , Benzoquinones/pharmacokinetics , Cell Line, Tumor , Cell Proliferation/drug effects , Comet Assay/methods , Cross-Linking Reagents/pharmacology , DNA/chemistry , DNA/genetics , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Female , Humans , Mice , Mice, Nude , Treatment Outcome , TritiumABSTRACT
Fibroblast growth factor-2 (FGF-2) is a potent angiogenic cytokine that is dependent on heparan sulfate for its biological activity. We have investigated the relationship among heparan sulfate, FGF-2, and the signal-transducing receptors in human, advanced-stage, serous ovarian adenocarcinoma. Using a unique molecular probe, FR1c-Ap, which consisted of a soluble FGF receptor 1 isoform IIIc covalently linked to an alkaline phosphatase moiety, the distribution of heparan sulfate that had the ability to support the formation of a heparan sulfate/FGF-2/FGFR1 isoform IIIc alkaline phosphatase heparan sulfate construct complex was determined. This may be taken as a surrogate marker for the distribution of biologically active heparan sulfate and was distributed predominantly in endothelial cells and stroma but was absent from adenocarcinoma cells. In situ hybridization revealed the expression of FGFR1 mRNA in the endothelium and reverse transcription-PCR confirmed the presence of FGFR1 isoform IIIc but not isoform IIIb. The presence of FGF-2 around tumor endothelium was detected through immunohistochemistry. Double-staining techniques showed that heparan sulfate was found predominantly at the basal aspect of the endothelium and suggested that syndecan-3 might function as one of the proteoglycans involved in FGF-2 signaling in the endothelium. The data suggest that the entire extracellular signaling apparatus, consisting of FGF-2, biologically active heparan sulfate, and FGFRs capable of responding to FGF-2, is present in ovarian cancer endothelium, thereby highlighting the cytokine and its cognate receptor as potential targets for the antiangiogenic treatment of this disease.
Subject(s)
Endothelium/pathology , Fibroblast Growth Factor 2/metabolism , Ovarian Neoplasms/pathology , Alkaline Phosphatase/metabolism , Endothelium/chemistry , Endothelium/metabolism , Female , Gene Expression Regulation, Neoplastic , Heparitin Sulfate/metabolism , Humans , Immunohistochemistry/methods , In Situ Hybridization , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, Fibroblast Growth Factor, Type 1 , Receptors, Fibroblast Growth Factor/genetics , Receptors, Fibroblast Growth Factor/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sulfates/metabolismABSTRACT
BACKGROUND: In previous experiments, we showed that heparin oligosaccharides inhibit the angiogenic cytokine fibroblast growth factor-2. Here, we present the first in vivo study of size-fractionated heparin oligosaccharides in four models of angiogenesis that are progressively less dependent on fibroblast growth factor-2. EXPERIMENTAL DESIGN: Heparin oligosaccharides were prepared using size-exclusion gel filtration chromatography and characterized through depolymerization and strong anion exchange high-performance liquid chromatography. Size-defined oligosaccharides (20 mg/kg/d) were given to mice bearing s.c. sponges that were injected with fibroblast growth factor-2 (100 ng/d). After 14 days, octasaccharides and decasaccharides reduced the microvessel density to levels below control. In a second experiment, HEC-FGF2 human endometrial cancer cells that overexpress fibroblast growth factor-2 were implanted in a hollow fiber placed s.c. in vivo. Oligosaccharides were given at 20 mg/kg/d for 2 weeks and the data again showed that octasaccharides significantly reduced microvessel density around the fiber (P = 0.03). In a more complex model, where angiogenesis was induced by a broad spectrum of growth factors, including vascular endothelial growth factor, we implanted H460 lung carcinoma cells in hollow fibers and treated the animals with oligosaccharides at 20 mg/kg/d over 3 weeks. Octasaccharides reduced the microvessel density to that of control. Preliminary investigation of 6-O-desulfated heparins showed that these also had antiangiogenic activity. RESULTS: Finally, we examined the inhibitory potential of hexasaccharides and octasaccharides given at 20 mg/kg/d and these inhibited the growth of H460 lung carcinoma in vivo. At clinically attainable concentrations, significant anticoagulation (activated partial thromboplastin time, anti-factor Xa, and anti-factor IIa) was not observed in vitro unless species containing > or =16 saccharide residues were investigated. CONCLUSIONS: Thus, our preclinical data show that heparin octasaccharides represent novel antiangiogenic compounds that can be given without the anticoagulant effects of low molecular weight heparin.
Subject(s)
Lung Neoplasms/prevention & control , Neovascularization, Pathologic/prevention & control , Neovascularization, Physiologic/drug effects , Oligosaccharides/pharmacology , Angiogenesis Inhibitors/pharmacology , Animals , Anticoagulants/pharmacology , Cell Line, Tumor , Female , Fibroblast Growth Factor 2/pharmacology , Heparin/chemistry , Heparin/pharmacology , Humans , Lung Neoplasms/blood supply , Lung Neoplasms/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Nude , Partial Thromboplastin Time , Xenograft Model Antitumor Assays/instrumentation , Xenograft Model Antitumor Assays/methodsABSTRACT
BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent angiogenic cytokine, and various inhibitory agents, including specific antibodies, have been developed to block VEGF-stimulated angiogenesis. We developed HuMV833, a humanized version of a mouse monoclonal anti-VEGF antibody (MV833) that has antitumor activity against a number of human tumor xenografts, and investigated the distribution and biologic effects of HuMV833 in patients in a phase I trial. METHODS: Twenty patients with progressive solid tumors were treated with various doses of HuMV833 (0.3, 1, 3, or 10 mg/kg). Positron emission tomography with (124)I-HuMV833 was used to measure the antibody distribution in and clearance from tissues. Magnetic resonance imaging was used to measure the vascular permeability surface area product with a first-pass pharmacokinetic model (k(fp)) to determine tumor vascular permeability. RESULTS: The antibody was generally well tolerated, although the incremental dose, phase I study design, and pharmacodynamic endpoints could not identify the optimum biologically active dose. Antibody distribution and clearance were markedly heterogeneous between and within patients and between and within individual tumors. HuMV833 distribution to normal tissues also varied among patients, but the antibody was cleared from these tissues in a homogeneous fashion. Permeability was strongly heterogeneous between and within patients and between and within individual tumors. All tumors showed a reduction in k(fp) 48 hours after the first treatment (median = 44%; range = 4%-91%). CONCLUSIONS: Because of the heterogeneity in tumor biology with respect to antibody uptake and clearance, we suggest that either intrapatient dose escalation approaches or larger, more precisely defined patient cohorts would be preferable to conventional strategies in the design of phase I studies with antiangiogenic compounds like HuMV833.
Subject(s)
Antibodies, Monoclonal/pharmacokinetics , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/therapeutic use , Endothelial Growth Factors/immunology , Lymphokines/immunology , Magnetic Resonance Imaging/methods , Neoplasms/diagnostic imaging , Neoplasms/therapy , Neovascularization, Pathologic/physiopathology , Animals , Antibodies, Monoclonal, Humanized , Antibody Formation , Capillary Permeability , Dose-Response Relationship, Immunologic , Drug Design , Drug Evaluation, Preclinical , Endothelial Growth Factors/metabolism , Humans , Iodine Radioisotopes , Lymphokines/metabolism , Macaca fascicularis/immunology , Maximum Tolerated Dose , Mice , Mice, Inbred BALB C , Middle Aged , Neoplasms/blood supply , Neoplasms/immunology , Tissue Distribution , Tomography, Emission-Computed , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth FactorsABSTRACT
The development of combretastatin as an antimitotic agent has led to an enormous effort to design other tubulin-targeting agents. The intriguing discovery that combretastatin A-4 phosphate causes selective damage to tumor vasculature has stimulated even more activity in this field. This attention to tubulin binding agents and their antivasculature activity is highly likely to lead to significant clinical advances for the treatment of cancer. This review focuses on the development of ketones as tubulin-binding agents such as chalcones and related enones as surrogates of combretastatin and colchicine.
Subject(s)
Antineoplastic Agents/chemistry , Chalcone/chemistry , Antineoplastic Agents/pharmacology , Benzophenones/chemistry , Chalcone/pharmacology , Colchicine/chemistry , Crystallization , Drug Design , Flavones/chemistry , Tubulin/metabolism , X-Ray DiffractionABSTRACT
PURPOSE: Heparan sulfate proteoglycans have been implicated in cancer cell growth, invasion, metastasis, and angiogenesis. This study was designed to compare their expression in normal ovary and ovarian tumors and then to examine their prognostic significance in ovarian cancer. EXPERIMENTAL DESIGN: The expression of syndecan-1, -2, -3, and -4, glypican-1, and perlecan was assessed by immunohistochemistry in 147 biopsies that included normal ovary and benign, borderline, and malignant ovarian tumors. Clinical data, including tumor stage, performance status, treatment, and survival, were collected. Univariate and multivariate analyses were performed to evaluate prognostic significance. RESULTS: The expression patterns of syndecan-1 and perlecan were altered in ovarian tumors compared with normal ovary. Syndecan-1 was not detected in normal ovary but was present in the epithelial and stromal cells of benign and borderline tumors and in ovarian adenocarcinomas. Perlecan expression was decreased in basement membranes that were disrupted by cancer cells but maintained in the basement membranes of blood vessels. Syndecan-2, -3, and -4, and glypican-1 were expressed in normal ovary and benign and malignant ovarian tumors. Stromal expression of syndecan-1 and glypican-1 were poor prognostic factors for survival in univariate analysis. CONCLUSION: We report for the first time distinct patterns of expression of cell surface and extracellular matrix heparan sulfate proteoglycans in normal ovary compared with ovarian tumors. These data reinforce the role of the tumor stroma in ovarian adenocarcinoma and suggest that stromal induction of syndecan-1 contributes to the pathogenesis of this malignancy.
Subject(s)
Heparan Sulfate Proteoglycans/metabolism , Ovarian Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Cell Proliferation , Disease-Free Survival , Extracellular Matrix/metabolism , Female , Heparan Sulfate Proteoglycans/biosynthesis , Humans , Immunohistochemistry , Membrane Glycoproteins/biosynthesis , Middle Aged , Multivariate Analysis , Neoplasm Invasiveness , Neoplasm Metastasis , Neovascularization, Pathologic , Ovarian Neoplasms/pathology , Ovary/metabolism , Ovary/pathology , Prognosis , Proteoglycans/biosynthesis , Syndecan-1 , Syndecan-2 , Syndecan-3 , Syndecan-4 , Syndecans , Time Factors , Treatment OutcomeABSTRACT
A series of combretastatins substituted with epoxides, amides and small alkyl groups has been synthesised and evaluated for cytotoxicity and their ability to inhibit the assembly of tubulin. The methyl and ethyl substituted phenols 36, 44 have shown potent antimitotic effects whilst exhibiting reduced cytotoxicity.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Bibenzyls/chemical synthesis , Bibenzyls/pharmacology , Stilbenes/chemical synthesis , Stilbenes/pharmacology , Amides/chemical synthesis , Amides/chemistry , Amides/pharmacology , Antineoplastic Agents/chemistry , Bibenzyls/chemistry , Cell Cycle/drug effects , Cell Survival/drug effects , Epoxy Compounds/chemical synthesis , Epoxy Compounds/chemistry , Epoxy Compounds/pharmacology , Formazans/chemistry , Humans , Inhibitory Concentration 50 , K562 Cells , Magnetic Resonance Spectroscopy , Molecular Structure , Spectrophotometry, Ultraviolet , Stilbenes/chemistry , Tetrazolium Salts/chemistry , Tubulin/metabolism , Tubulin ModulatorsABSTRACT
NAD(P)H:quinone oxidoreductase 1 (NQO1; DT-diaphorase; DTD) is a cytosolic two-electron reductase, and compounds of the quinone family such as mitomycin C are efficiently bioactivated by this enzyme. The observation that DT-diaphorase is highly expressed in many cancerous tissues compared to normal tissues has provided us with a potentially selective target that can be exploited in the design of novel anticancer agents. Because of the relative lack of information about the cell-specific expression of DT-diaphorase, the purpose of this study was to map the distribution of this enzyme in normal human tissues. Fifteen tissue samples from normal human kidney were analyzed for expression of DT-diaphorase by immunohistochemistry (two-step indirect method). We found a specific high expression of DT-diaphorase in glomerular visceral epithelial cells (podocytes). These results suggest that a high expression of DT-diaphorase in podocytes could play a major role in the pathogenesis of renal toxicity and mitomycin C-induced hemolytic uremic syndrome, in which injury to the glomerular filtration mechanism is the primary damage, leading to a cascade of deleterious events including microangiopathic hemolytic anemia and thrombocytopenia. This observation has potential therapeutic implications because the DT-diaphorase metabolic pathway is influenced by many agents, including drugs, diet, and environmental cell factors such as pH and oxygen tension.
Subject(s)
Kidney/enzymology , NAD(P)H Dehydrogenase (Quinone)/metabolism , Humans , Immunohistochemistry , Kidney/cytology , Kidney Glomerulus/cytology , Kidney Glomerulus/enzymology , Urothelium/cytology , Urothelium/enzymologyABSTRACT
To investigate within live mammalian cells the uptake and disposition of combretastatins, fluorescence lifetime imaging was used with two-photon excitation (2PE). Combretastatin A4 (CA4) and analogues are potential anticancer drugs due to their ability to inhibit angiogenesis. E(trans)-combretastatins are considerably less active than the Z(cis)-combretastatins proposed for clinical use. However the E-combretastatins exhibit stronger intrinsic fluorescence with quantum yields and lifetimes that depend markedly on solvent polarity and viscosity. It is proposed that 2PE in the red and near-infrared tissue window may allow in situ isomerization of E-combretastatins to the more active Z-isomer, offering spatial and temporal control of drug activation and constitute a novel form of photodynamic therapy. In the present work we have characterised 2PE of E-CA4 and have used fluorescence lifetime imaging with 2PE to study uptake and intracellular disposition of E-CA4 and an analogue. The results show that these molecules accumulate rapidly in cells and are located mainly in lipidic environments such as lipid droplets. Within the droplets the local concentrations may be up to two orders of magnitude higher than that of the drug in the surrounding medium.
Subject(s)
Bibenzyls/pharmacokinetics , Microscopy, Fluorescence, Multiphoton , Stilbenes/pharmacokinetics , Animals , Bibenzyls/chemistry , CHO Cells , Cricetinae , HeLa Cells , Humans , Stilbenes/chemistryABSTRACT
The tyrosine kinase inhibitor imatinib (STI 571; glivec) is a potent inhibitor of bcr-abl, c-kit and platelet-derived growth factor receptors. Imatinib was evaluated both alone and in combination with established chemotherapeutic agents in adenoid cystic carcinoma (ACC) primary cultures and established cell lines representing squamous cell carcinoma of the head and neck (HNSCC). Over 90% of ACC tumors are c-kit-positive, and these primary cultures proved to be of short-term usefulness in assessing chemosensitivity. Interaction was determined over a wide range of drug combinations using a statistical three-dimensional analysis model. Both ACC short-term cultures and HNSCC cell lines were demonstrated to have a response ranging from additive to synergistic when imatinib and cisplatin were combined. The interaction of imatinib on cisplatin-induced DNA cross-linking was further investigated using the comet-X assay. In contrast, significant antagonism was observed when imatinib and gemcitabine were combined. Since gemcitabine is activated by deoxycytidine kinase (dCK), the effect of imatinib on this enzyme was investigated. A dose-dependent inhibition of dCK was observed, highlighting this kinase as a possible additional secondary molecular target for imatinib. This work demonstrates a synergistic interaction between cisplatin and imatinib, which may prove to be clinically relevant in the future management of both ACC and HNSCC.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Carcinoma, Squamous Cell/pathology , Head and Neck Neoplasms/pathology , Piperazines/pharmacology , Pyrimidines/pharmacology , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Benzamides , Carcinoma, Adenoid Cystic/pathology , Cell Line, Tumor , Comet Assay , Drug Antagonism , Drug Synergism , Humans , Imatinib Mesylate , Inhibitory Concentration 50 , Piperazines/administration & dosage , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/administration & dosageABSTRACT
A series of combretastatins possessing both a trimethoxy unit and other substituents on ring A has been synthesised and tested for cytotoxicity and their ability to interact with the protein tubulin. All previous studies have indicated that the trimethoxy unit is essential for interaction with tubulin. The studies herein show that molecules possessing functionalities other than trimethoxy can also interact with tubulin. Importantly a trimethyl substituted agent 52a has shown reduced cytotoxicity, but increased potency in its ability to inhibit the assembly of tubulin.
Subject(s)
Antineoplastic Agents/chemistry , Bibenzyls/chemistry , Stilbenes/chemistry , Tubulin/drug effects , Animals , Antineoplastic Agents/pharmacology , Bibenzyls/pharmacology , Cell Line , Chlorocebus aethiops , Drug Screening Assays, Antitumor , Humans , Immunohistochemistry , Inhibitory Concentration 50 , K562 Cells , Molecular Structure , Stilbenes/analysis , Stilbenes/chemical synthesis , Stilbenes/pharmacology , Structure-Activity Relationship , Vero CellsABSTRACT
The naturally occurring aurone 1, isolated from Uvaria hamiltonii, and a series of aurones analogues based structurally on known tubulin binding agents were prepared and evaluated for anticancer activity. Aurone 20 was the most active (IC(50) K562 50 nM) and caused significant G2/M cell-cycle arrest.
Subject(s)
Antineoplastic Agents, Phytogenic/chemical synthesis , Antineoplastic Agents, Phytogenic/pharmacology , Benzofurans/chemical synthesis , Benzofurans/pharmacology , Flavonoids/chemical synthesis , Flavonoids/pharmacology , Uvaria/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Benzofurans/isolation & purification , Cell Cycle/drug effects , DNA, Neoplasm/drug effects , G2 Phase/drug effects , Humans , Indicators and Reagents , K562 Cells , Mitosis/drug effects , Models, Molecular , Molecular Conformation , Protein Binding , Structure-Activity Relationship , Tetrazolium Salts , Thiazoles , Tubulin/drug effects , Tubulin/metabolismABSTRACT
Microtubules are intracellular organelles formed from the protein tubulin. These organelles have a number of essential cellular functions including chromosome segregation, the maintenance of cell shape, transport, motility, and organelle distribution. Drugs that affect the tubulin-microtubule equilibrium (taxol, vinca alkaloids) are effective anticancer drugs. This review describes the molecular target, methods used in screening, the structures of compounds known to interact with tubulin, and the clinical use of these agents. In addition the ability of these agents to destroy tumour vasculature is described. This represents an exciting new molecular target in the design of anticancer drugs.
Subject(s)
Antineoplastic Agents/pharmacology , Microtubules/drug effects , Neoplasms/drug therapy , Tubulin Modulators , Animals , Binding Sites/drug effects , Binding Sites/physiology , Drug Screening Assays, Antitumor , Humans , Microtubules/metabolism , Molecular Conformation , Neoplasms/metabolism , Neoplasms/physiopathology , Taxoids/pharmacology , Tubulin/metabolism , Vinca Alkaloids/pharmacologyABSTRACT
The organomercurial compounds Hg[1-C(6)H(4)-2-C(H)=NC(6)H(5-n)R(n)](2) (R = 4-NMe(2), 6a; 4-Me, 6b; 4-I, 6c; 4-NO(2), 6d; 2-(i)Pr, 6e; 2-Me, 6f; 2,6-(i)Pr(2), 6g; 2,6-Me(2), 6h) have been prepared in good overall yield from 2-bromobenzaldehyde. All of the compounds have been characterized by elemental analysis, (1)H NMR, (13)C[(1)H] NMR, and infrared spectroscopy. In addition, compounds 6a [C(30)H(30)HgN(4), triclinic, P, a = 6.20000(10) A, b = 9.2315(2) A, c = 10.9069(3) A, alpha = 85.8510(10) degrees, beta = 89.3570(10) degrees, gamma = 87.206(2) degrees, Z = 1], 6b [C(28)H(24)HgN(2), monoclinic, P2(1)/c, a = 12.8260(5) A, b = 14.0675(4) A, c = 6.1032(2) A, beta = 90.0990(10) degrees, Z = 2], 6g [C(38)H(44)HgN(2), triclinic, P, a = 8.2626(2) A, b = 9.8317(2) A, c = 11.8873(3) A, alpha = 103.6650(10) degrees, beta = 109.3350(10) degrees, gamma = 104.627(2) degrees, Z = 1], and 6h [C(30)H(28)HgN(2), monoclinic, P2(1)/c, a = 12.5307(2) A, b = 10.9852(2) A, c = 18.2112(2) A, beta = 104.0190(10) degrees, gamma = 87.206(2) degrees, Z = 4] have been characterized by low-temperature single-crystal X-ray diffraction studies, and two different molecular geometries about the central mercury atom have been observed; intramolecular contacts suggest a van der Waals radius for Hg of 2.1-2.2 A.