701
|
McPhail LD, McIntyre DJO, Ludwig C, Kestell P, Griffiths JR, Kelland LR, Robinson SP. Rat tumor response to the vascular-disrupting agent 5,6-dimethylxanthenone-4-acetic acid as measured by dynamic contrast-enhanced magnetic resonance imaging, plasma 5-hydroxyindoleacetic acid levels, and tumor necrosis. Neoplasia 2006; 8:199-206. [PMID: 16611413 PMCID: PMC1578525 DOI: 10.1593/neo.05739] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dose-dependent effects of 5,6-dimethylxanthenone-4-acetic acid (DMXAA) on rat GH3 prolactinomas were investigated in vivo. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to assess tumor blood flow/permeability pretreatment and 24 hours posttreatment with 0, 100, 200, or 350 mg/kg DMXAA. DCE-MRI data were analyzed using K(trans) and the integrated area under the gadolinium time curve (IAUGC) as response biomarkers. High-performance liquid chromatography (HPLC) was used to determine the plasma concentration of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) following treatment to provide an index of increased vessel permeability and vascular damage. Finally, tumor necrosis was assessed by grading hematoxylin and eosin-stained sections cut from the same tumors investigated by MRI. Both tumor K(trans) and IAUGC were significantly reduced 24 hours posttreatment with 350 mg/kg DMXAA only, with no evidence of dose response. HPLC demonstrated a significant increase in plasma 5-HIAA 24 hours posttreatment with 200 and 350 mg/kg DMXAA. Histologic analysis revealed some evidence of tumor necrosis following treatment with 100 or 200 mg/kg DMXAA, reaching significance with 350 mg/kg DMXAA. The absence of any reduction in K(trans) or IAUGC following treatment with 200 mg/kg, despite a significant increase in 5-HIAA, raises concerns about the utility of established DCE-MRI biomarkers to assess tumor response to DMXAA.
Collapse
Affiliation(s)
- Lesley D McPhail
- Division of Basic Medical Sciences, St. George's, University of London, London, UK.
| | | | | | | | | | | | | |
Collapse
|
702
|
Abstract
The combination of chemotherapy and radiation has led to clinical breakthroughs in several disease sites, and current work continues to define optimum combinations of proven chemotherapy as well as more recently available, noncytotoxic agents. Administration of systemic therapies allows modulation of radiation response to improve tumor control (radiosensitization) or to prevent normal tissue toxicity (radioprotection). Substantial progress has been made in identifying the targets of standard chemotherapeutic radiation sensitizers and protectors as well as in the introduction of a new generation of molecularly targeted therapies in combination with radiation. We have reviewed the most recent, predominantly early phase clinical trials combining systemic agents with radiation. Although the proof of an improved schedule ultimately needs to come from well-run Phase III trials, the search among schedules could be shortened by the use of surrogate endpoints such as presence of active drug metabolites in the tumor. This has been accomplished only in a few cases and needs to become a more standard part of radiation sensitizer and protector trials.
Collapse
Affiliation(s)
- Aaron C Spalding
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0010, USA
| | | |
Collapse
|
703
|
Seshadri M, Mazurchuk R, Spernyak JA, Bhattacharya A, Rustum YM, Bellnier DA. Activity of the vascular-disrupting agent 5,6-dimethylxanthenone-4-acetic acid against human head and neck carcinoma xenografts. Neoplasia 2006; 8:534-42. [PMID: 16867215 PMCID: PMC1601938 DOI: 10.1593/neo.06295] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Head and neck squamous cell carcinomas (HNSCC) constitute a majority of the tumors of the upper aerodigestive tract and continue to present a significant therapeutic challenge. To explore the potential of vascular-targeted therapy in HNSCC, we investigated the antivascular, antitumor activity of the potent vascular-disrupting agent (VDA) 5,6-dimethylxanthenone-4-acetic acid (DMXAA) against two HNSCC xenografts with markedly different morphologic and vascular characteristics. Athymic nude mice bearing subcutaneous FaDu (human pharyngeal squamous cell carcinoma) and A253 (human submaxillary gland epidermoid carcinoma) tumors were administered a single dose of DMXAA (30 mg/kg, i.p). Changes in vascular function were evaluated 24 hours after treatment using contrast-enhanced magnetic resonance imaging (MRI) and immunohistochemistry (CD31). Signal enhancement (E) and change in longitudinal relaxation rates (deltaR1) were calculated to measure alterations in vascular perfusion. MRI showed a 78% and 49% reduction in vascular perfusion in FaDu and A253 xenografts, respectively. CD31-immunostaining of tumor sections revealed three-fold (FaDu) and two-fold (A253) reductions in microvessel density (MVD) 24 hours after treatment. DMXAA was equally effective against both xenografts, with significant tumor growth inhibition observed 30 days after treatment. These results indicate that DMXAA may be clinically beneficial in the management of head and neck cancers, alone or in combination with other treatments.
Collapse
Affiliation(s)
- Mukund Seshadri
- Department of Cell Stress Biology (Photodynamic Therapy Center), Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | | | | | |
Collapse
|
704
|
Madhu B, Waterton JC, Griffiths JR, Ryan AJ, Robinson SP. The response of RIF-1 fibrosarcomas to the vascular-disrupting agent ZD6126 assessed by in vivo and ex vivo 1H magnetic resonance spectroscopy. Neoplasia 2006; 8:560-7. [PMID: 16867218 PMCID: PMC1601935 DOI: 10.1593/neo.06319] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The response of radiation-induced fibrosarcoma 1 (RIF-1) tumors treated with the vascular-disrupting agent (VDA) ZD6126 was assessed by in vivo and ex vivo 1H magnetic resonance spectroscopy (MRS) methods. Tumors treated with 200 mg/kg ZD6126 showed a significant reduction in total choline (tCho) in vivo 24 hours after treatment, whereas control tumors showed a significant increase in tCho. This response was investigated further within both ex vivo unprocessed tumor tissues and tumor tissue metabolite extracts. Ex vivo high-resolution magic angle spinning (HRMAS) and 1H MRS of metabolite extracts revealed a significant reduction in phosphocholine and glycerophosphocholine in biopsies of ZD6126-treated tumors, confirming in vivo tCho response. ZD6126-induced reduction in choline compounds is consistent with a reduction in cell membrane turnover associated with necrosis and cell death following disruption of the tumor vasculature. In vivo tumor tissue water diffusion and lactate measurements showed no significant changes in response to ZD6126. Spin-spin relaxation times (T2) of water and metabolites also remained unchanged. Noninvasive 1H MRS measurement of tCho in vivo provides a potential biomarker of tumor response to VDAs in RIF-1 tumors.
Collapse
Affiliation(s)
- Basetti Madhu
- Cancer Research UK Biomedical Magnetic Resonance Research Group, Division of Basic Medical Sciences, St. George's, University of London, London SW17 ORE, UK.
| | | | | | | | | |
Collapse
|
705
|
Thomas CD, Walczak C, Kaffy J, Pontikis R, Jouanneau J, Volk A. Early effects of combretastatin A4 phosphate assessed by anatomic and carbogen-based functional magnetic resonance imaging on rat bladder tumors implanted in nude mice. Neoplasia 2006; 8:587-95. [PMID: 16867221 PMCID: PMC1601936 DOI: 10.1593/neo.06232] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Combretastatin A4 phosphate (CA4P) causes rapid disruption of the tumor vasculature and is currently being evaluated for antivascular therapy. We describe the initial results obtained with a noninvasive multiparametric magnetic resonance imaging (MRI) approach to assess the early effects of CA4P on rat bladder tumors implanted on nude mice. MRI (4.7 T) comprised a fast spin-echo sequence for growth curve assessment; a multislice multiecho sequence for T2 measurement before, 15 minutes after, and 24 hours after CA4P (100 mg/kg); and a fast T2w* gradient-echo sequence to assess MR signal modification under carbogen breathing before, 35 minutes after, and 24 hours after CA4P. The tumor fraction with increased T2w* signal intensity under carbogen (T+) was used to quantify CA4P effect on functional vasculature. CA4P slowed tumor growth over 24 hours and accelerated necrosis development. T+ decrease was observed already at 35 minutes post-CA4P. Early T2 increase was observed in regions becoming necrotic at 24 hours post-CA4P, as confirmed by high T2 and histology. These regions exhibited, under carbogen, a switch from T2w* signal increase before CA4P to a decrease postCA4P. The combination of carbogen-based functional MRI and T2 measurement may be useful for the early follow-up of antivascular therapy without the administration of contrast agents.
Collapse
|
706
|
Tron GC, Pirali T, Sorba G, Pagliai F, Busacca S, Genazzani AA. Medicinal chemistry of combretastatin A4: present and future directions. J Med Chem 2006; 49:3033-44. [PMID: 16722619 DOI: 10.1021/jm0512903] [Citation(s) in RCA: 512] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gian Cesare Tron
- Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche and Drug and Food Biotechnology Center, Università degli Studi del Piemonte Orientale A. Avogadro, Via Bovio 6, 28100 Novara, Italy.
| | | | | | | | | | | |
Collapse
|
707
|
Salmon HW, Siemann DW. Effect of the second-generation vascular disrupting agent OXi4503 on tumor vascularity. Clin Cancer Res 2006; 12:4090-4. [PMID: 16818709 DOI: 10.1158/1078-0432.ccr-06-0163] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE As first-generation small-molecule vascular disrupting agents (VDA) have begun to enter clinical trials, second-generation agents are under active development. One such agent is the combretastatin A4 disodium phosphate (CA4P) analogue OXi4503 (CA1P). EXPERIMENTAL DESIGN C3H/HeJ mice bearing KHT sarcomas were treated with CA4P and OXi4503 and the effect on tumor vasculature was determined by evaluating the extent of vascular shutdown (Hoechst-33342 vessel staining) and tumor perfusion inhibition (dynamic contrast-enhanced magnetic resonance imaging). Dynamic contrast-enhanced magnetic resonance imaging and tumor necrosis end points also were used to examine the pathophysiologic tumor effects following repeated exposures to these agents. RESULTS Single doses of either agent (CA4P, 100 mg/kg; OXi4503, 25 mg/kg) resulted in an 80% to 90% reduction in tumor perfusion 4 hours after treatment. Whereas recovery in tumor perfusion was observed 48 hours posttreatment, this recovery was significantly slower in mice treated with OXi4503. Tumors re-treated with either VDA 72 hours after the first drug exposure showed a similar reduction and recovery in tumor perfusion. Histologic evidence showed the presence of a smaller viable rim after exposure to OXi4503 than that observed after CA4P treatment. Furthermore, the extent of recovery of tumor necrosis 72 hours after drug treatment was less for OXi4053. CONCLUSIONS The present studies show that the second-generation VDA OXi4503 possesses significant antivascular effects in solid tumors. Importantly, the vasculature of tumors of mice that had received an initial dose this agent was as responsive to a subsequent treatment.
Collapse
MESH Headings
- Animals
- Cell Survival/drug effects
- Diphosphates/administration & dosage
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- Female
- Injections, Intraperitoneal
- Magnetic Resonance Imaging
- Mice
- Mice, Inbred C3H
- Neovascularization, Pathologic/diagnostic imaging
- Neovascularization, Pathologic/drug therapy
- Neovascularization, Pathologic/pathology
- Radiography
- Sarcoma, Experimental/blood supply
- Sarcoma, Experimental/diagnostic imaging
- Sarcoma, Experimental/drug therapy
- Stilbenes/administration & dosage
- Time Factors
- Transplantation, Heterologous
- Xenograft Model Antitumor Assays
Collapse
Affiliation(s)
- Howard W Salmon
- Department of Radiation Oncology, Shands Cancer Center, University of Florida, Gainesville, Florida 32610, USA.
| | | |
Collapse
|
708
|
Dupeyre G, Chabot GG, Thoret S, Cachet X, Seguin J, Guénard D, Tillequin F, Scherman D, Koch M, Michel S. Synthesis and biological evaluation of (3,4,5-trimethoxyphenyl)indol-3-ylmethane derivatives as potential antivascular agents. Bioorg Med Chem 2006; 14:4410-26. [PMID: 16529936 DOI: 10.1016/j.bmc.2006.02.037] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 02/16/2006] [Accepted: 02/21/2006] [Indexed: 11/20/2022]
Abstract
Combretastatin A-4 (CSA-4), a stilbene derivative, is a potent vascular disrupting agent (VDA) with the structural requirement of a cis-configuration to maintain a molecular geometry and a correct orientation of both phenyl groups. A series of indolic analogues of CSA-4 was synthesized by means of an efficient strategy. Six compounds (20b, 25b-27b, 32b, and 35b) were identified as potent inhibitors of tubulin polymerization and also displayed cytotoxic activities on B16 melanoma cells at a nanomolar level. Both activities were well correlated with the ability to induce morphological changes of EA.hy 926 endothelial cells. In conclusion, the cis-stilbene skeleton of CSA-4 could conveniently be replaced by the 3-aroylindolic moiety, thus avoiding any isomerization leading to inactive trans compounds.
Collapse
Affiliation(s)
- Grégory Dupeyre
- Université Paris 5, Faculté des Sciences Pharmaceutiques et Biologiques, UMR 8638 CNRS, Laboratoire de Pharmacognosie, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
709
|
Mitra A, Nan A, Papadimitriou JC, Ghandehari H, Line BR. Polymer-peptide conjugates for angiogenesis targeted tumor radiotherapy. Nucl Med Biol 2006; 33:43-52. [PMID: 16459258 DOI: 10.1016/j.nucmedbio.2005.09.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 09/07/2005] [Accepted: 09/12/2005] [Indexed: 11/24/2022]
Abstract
INTRODUCTION New methods of delivering radiotherapy to sites of occult or disseminated cancer are needed to control the disease and address the failure of conventional therapy. Because tumor cells rely on angiogenesis for survival, we assessed the effectiveness of beta-emitter radiotherapy delivered by polymer-peptide conjugates that target tumor neovasculature. This molecularly targeted radiation is intended to damage both the endothelial bed and surrounding neoplastic cells. METHODS N-(2-Hydroxypropyl) methacrylamide (HPMA), a biocompatible and water-soluble copolymer, was derivatized to incorporate side chains for (99m)Tc and (90)Y chelation and was further conjugated to a alpha(V)beta(3) integrin-targeting peptide (RGD4C). The HPMA copolymer-RGD4C conjugate was characterized by its side-chain contents, in vitro endothelial cell adhesion assay and its biodistribution and antitumor effectiveness in a SCID mouse xenograft model of human prostate carcinoma. RESULTS The conjugate contained about 16 RGD4C moieties per polymer backbone. Tumor accumulation significantly increased (P < .01) over time from 1.05 +/- 0.03 % injected dose (%ID)/g tissue at 1 h to 4.32 +/-0.32% at 72 h. The activity in major normal tissues significantly decreased (P < .05) during that period. At 21 days, the control tumors increased 442% in volume from baseline. In contrast, a 7% and a 63% decrease of tumor volume were observed for the 100- and 250-microCi (90)Y treatment groups, respectively. Histopathological examination revealed increased apoptosis in the treated tumors with no acute signs of radiation-induced toxicity to other organs. CONCLUSION This copolymer-peptide conjugate targets tumor angiogenic vessels and delivers sufficient radiotherapy to arrest tumor growth.
Collapse
Affiliation(s)
- Amitava Mitra
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, 21201, USA
| | | | | | | | | |
Collapse
|
710
|
Abstract
For more than 50 years, a major goal of research in cancer therapeutics has been to develop universally effective agents that render cancer cells more sensitive to cytotoxic chemotherapy without substantially increasing toxicity to normal cells. The results of recent clinical trials indicate that certain antiangiogenic drugs may produce this long-sought effect. Here, I describe three distinct mechanisms that may help to explain the chemosensitizing activity of these drugs: normalizing tumor vasculature, preventing rapid tumor cell repopulation, and augmenting the antivascular effects of chemotherapy. I then discuss how these potential mechanisms might be exploited to maximize therapeutic efficacy.
Collapse
Affiliation(s)
- Robert S Kerbel
- Sunnybrook Health Sciences Centre, Departments of Medical Biophysics and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M4N 3M5, Canada.
| |
Collapse
|
711
|
Kaffy J, Pontikis R, Carrez D, Croisy A, Monneret C, Florent JC. Isoxazole-type derivatives related to combretastatin A-4, synthesis and biological evaluation. Bioorg Med Chem 2006; 14:4067-77. [PMID: 16510288 DOI: 10.1016/j.bmc.2006.02.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 01/30/2006] [Accepted: 02/03/2006] [Indexed: 12/28/2022]
Abstract
Novel combretastatin analogues bearing various five-membered heterocycles with consecutive oxygen and nitrogen atoms, in place of the olefinic bridge of CA4, have been synthesized (isoxazole, isoxazoline, oxadiazole, etc). These compounds have been evaluated for cytotoxicity and their ability to inhibit the tubulin assembly. On the basis of the relative position of the aromatic A- and B-rings on the heterocyclic moiety, they could be split in two classes, the alpha,gamma- or alpha,beta-diaryl heterocyclic derivatives. In the first series, the 3,5-diaryloxadiazole 9a displayed comparable antitubulin activity to that of CA4, but was devoid of cytotoxic effects. Among the alpha,beta-diaryl heterocyclic derivatives, the 4,5-diarylisoxazole 35 exhibited greater antitubulin activity than that of CA4 (0.75 vs 1.2 microM), but modest antiproliferative activity. These data showed that minor alteration in the chemical structure of the heterocyclic ring and its relative orientation with regard to the two phenyl rings of CA4 could dramatically influence the tubulin binding properties.
Collapse
Affiliation(s)
- Julia Kaffy
- CNRS, UMR 176, Institut Curie, Centre de Recherche, 26 rue d'Ulm, 75248 Paris cedex 05, France
| | | | | | | | | | | |
Collapse
|
712
|
Liekens S, Bronckaers A, Hernández AI, Priego EM, Casanova E, Camarasa MJ, Pérez-Pérez MJ, Balzarini J. 5′-O-Tritylated Nucleoside Derivatives: Inhibition of Thymidine Phosphorylase and Angiogenesis. Mol Pharmacol 2006; 70:501-9. [PMID: 16675660 DOI: 10.1124/mol.105.021188] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Thymidine phosphorylase (TPase) is one of the key enzymes involved in the pyrimidine nucleoside salvage pathway. However, TPase also stimulates angiogenesis, and its expression correlates well with microvessel density and metastasis in a variety of human tumors. We have shown recently that 5'-O-trityl-inosine (KIN59) allosterically inhibits TPase enzymatic activity. KIN59 also inhibits TPase-induced angiogenesis in the chick chorioallantoic membrane (CAM) assay. The trityl group was found to be instrumental to preserve both the anti-TPase and antiangiogenic effect. We have now synthesized a variety of novel 5'-O-trityl nucleoside derivatives. Enzyme activity studies showed that the anti-TPase activity is significantly improved by replacement of the hypoxanthine base by thymine [3.5-fold; i.e., 5'-O-tritylthymidine (KIN6)] and the introduction of chloride on the trityl group [7-fold; i.e., 5'-O-(4-chlorotrityl)-inosine (TP136)], whereas removal of 2'-hydroxyl in the ribose did not significantly alter the anti-TPase activity. Enzyme kinetic studies also demonstrated that 1-(5'-O-trityl-beta-d-ribofuranosyl)-thymine (TP124), like KIN59, inhibits TPase in a noncompetitive fashion both with respect to phosphate and thymidine. Most KIN59 analogs markedly inhibited TPase-induced angiogenesis in the CAM assay. In vitro studies showed that the antiangiogenic effect of these compounds is not attributed to endothelial cell toxicity. For several compounds, there was no stringent correlation between their anti-TPase and antiangiogenic activity, indicating that these compounds may also act on other angiogenesis mediators. The antiangiogenic 5'-O-trityl nucleoside analogs also caused degradation of pre-existing, immature vessels at the site of drug exposure. Thus, 5'-O-trityl nucleoside derivatives combine antiangiogenic and vascular-targeting activities, which opens perspectives for their potential use as anticancer agents.
Collapse
Affiliation(s)
- Sandra Liekens
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
| | | | | | | | | | | | | | | |
Collapse
|
713
|
Monk KA, Siles R, Hadimani MB, Mugabe BE, Ackley JF, Studerus SW, Edvardsen K, Trawick ML, Garner CM, Rhodes MR, Pettit GR, Pinney KG. Design, synthesis, and biological evaluation of combretastatin nitrogen-containing derivatives as inhibitors of tubulin assembly and vascular disrupting agents. Bioorg Med Chem 2006; 14:3231-44. [PMID: 16442292 DOI: 10.1016/j.bmc.2005.12.033] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Revised: 12/16/2005] [Accepted: 12/20/2005] [Indexed: 11/26/2022]
Abstract
A series of analogs with nitro or serinamide substituents at the C-2'-, C-5'-, or C-6'-position of the combretastatin A-4 (CA4) B-ring was synthesized and evaluated for cytotoxic effects against heart endothelioma cells, blood flow reduction to tumors in SCID mice, and as inhibitors of tubulin polymerization. The synthesis of these analogs typically featured a Wittig reaction between a suitably functionalized arylaldehyde and an arylphosphonium salt followed by separation of the resultant E- and Z-isomers. Several of these nitrogen-modified CA4 derivatives (both amino and nitro) demonstrate significant inhibition of tubulin assembly as well as cytotoxicity and in vivo blood flow reduction. 2'-Aminostilbenoid 7 and 2'-amino-3'-hydroxystilbenoid 29 proved to be the most active in this series. Both compounds, 7 and 29, have the potential for further pro-drug modification and development as vascular disrupting agents for treatment of solid tumor cancers and certain ophthalmological diseases.
Collapse
Affiliation(s)
- Keith A Monk
- Baylor University, Department of Chemistry and Biochemistry and The Center for Drug Discovery, One Bear Place # 97348, Waco, TX 76798, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
714
|
Mahindroo N, Liou JP, Chang JY, Hsieh HP. Antitubulin agents for the treatment of cancer – a medicinal chemistry update. Expert Opin Ther Pat 2006. [DOI: 10.1517/13543776.16.5.647] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
715
|
Santel A, Aleku M, Keil O, Endruschat J, Esche V, Fisch G, Dames S, Löffler K, Fechtner M, Arnold W, Giese K, Klippel A, Kaufmann J. A novel siRNA-lipoplex technology for RNA interference in the mouse vascular endothelium. Gene Ther 2006; 13:1222-34. [PMID: 16625243 DOI: 10.1038/sj.gt.3302777] [Citation(s) in RCA: 277] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
For the application of RNA interference (RNAi) in vivo the functional delivery of short interfering RNAs (siRNAs) is still the major obstacle. Therefore, delivery technologies need to be established for the systemic application of RNAi in vivo. Here we report uptake, biodistribution and in vivo efficacy of siRNA molecules formulated into siRNA-lipoplexes. The applied formulation is based on complex formation of positively charged liposomes, a mixture of cationic and fusogenic lipids complexed with the negatively charged siRNA. We determined by fluorescence microscopy the temporal and spatial distribution of fluorescently labeled siRNA-lipoplexes, the body clearance and endothelial cell type specific uptake after single intravenous injection. Furthermore, by using siRNA molecules for targeting endothelia-specifically expressed genes, such as CD31 and Tie2, we were able to demonstrate downregulation of the corresponding mRNA and protein in vivo. Taken together, we show the applicability of this non-viral delivery technology for inducing RNAi in the vasculature of mice after systemic application.
Collapse
MESH Headings
- Animals
- Cell Line, Tumor
- Down-Regulation
- Endothelial Cells/metabolism
- Endothelium, Vascular/metabolism
- Genetic Therapy/methods
- Humans
- Immunohistochemistry/methods
- Injections, Intravenous
- Interleukin-12/blood
- Kidney/metabolism
- Liposomes
- Male
- Mice
- Mice, Nude
- Microscopy, Fluorescence
- Platelet Endothelial Cell Adhesion Molecule-1/blood
- Platelet Endothelial Cell Adhesion Molecule-1/genetics
- Polyethyleneimine
- RNA Interference
- RNA, Messenger/analysis
- RNA, Small Interfering/administration & dosage
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Receptor, TIE-2/blood
- Receptor, TIE-2/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Transfection/methods
Collapse
Affiliation(s)
- A Santel
- Atugen AG (SR Pharma plc subsidiary), Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
716
|
Zhang L, Zhang JY. Microwave-Assisted, Boron Trichloride Mediated Acylation of Phenols−Synthesis of (o-Hydroxyaryl)(Aryl)methanones and Xanthones. ACTA ACUST UNITED AC 2006; 8:361-7. [PMID: 16677006 DOI: 10.1021/cc0501007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel and efficient microwave-assisted, BCl(3) mediated coupling reaction to synthesize o-(hydroxyaryl)(aryl)methanone structures from phenols and acyl chlorides is described. This reaction was further incorporated into a two-step synthesis of biologically interesting xanthones.
Collapse
Affiliation(s)
- Lei Zhang
- CytRx laboratories, Inc., Worcester, Massachusetts 01605, USA
| | | |
Collapse
|
717
|
Cullis ER, Kalber TL, Ashton SE, Cartwright JE, Griffiths JR, Ryan AJ, Robinson SP. Tumour overexpression of inducible nitric oxide synthase (iNOS) increases angiogenesis and may modulate the anti-tumour effects of the vascular disrupting agent ZD6126. Microvasc Res 2006; 71:76-84. [PMID: 16530791 DOI: 10.1016/j.mvr.2006.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 01/20/2006] [Accepted: 01/24/2006] [Indexed: 11/20/2022]
Abstract
Tumours derived from DLD-1 colon adenocarcinoma cells, transfected to either overexpress inducible nitric oxide synthase (clone iNOS-19) or with empty vector (pBAN2R), were utilised to test the hypothesis that tumour expression of iNOS (a) increases tumour angiogenesis and (b) modulates the anti-tumour activity of the vascular disrupting agent ZD6126. Overexpression of iNOS by clone iNOS-19 cells and murine xenografts was confirmed by the Griess assay and western blot analysis respectively. Clone iNOS-19 tumours grew more rapidly than pBAN2R tumours. Tumour perfusion, assessed by Hoechst 33342 uptake, was significantly greater in the clone iNOS-19 tumours (P < 0.001). A significant reduction in the perfusion of only the pBAN2R tumours, compared with control, was obtained 24 h after treatment with an intermediate dose of 100 mg/kg ZD6126 (P < 0.001), whereas 200 mg/kg significantly reduced the perfusion of both tumour types (P < 0.001). Whilst pBAN2R tumour necrosis increased in a dose-dependent manner, significant at 100 and 200 mg/kg ZD6126 (P < 0.05), intermediate doses did not induce a similar degree of necrosis in clone iNOS-19 tumours. A significant reduction in splenic perfusion was found 24 h after treatment with 100 mg/kg ZD6126, primarily associated with the red pulp. Overexpression of iNOS increases tumour growth, the degree of functionally perfused vasculature and angiogenesis, and also confers resistance to the vascular disrupting agent ZD6126.
Collapse
Affiliation(s)
- Elizabeth R Cullis
- Division of Basic Medical Sciences, St. George's, University of London, Cranmer Terrace, London SW17 ORE, UK
| | | | | | | | | | | | | |
Collapse
|
718
|
Lawrence NJ, Armitage ESM, Greedy B, Cook D, Ducki S, McGown AT. The synthesis of indanones related to combretastatin A-4 via microwave-assisted Nazarov cyclization of chalcones. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2005.12.110] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
719
|
Thorne SH, Tam BYY, Kirn DH, Contag CH, Kuo CJ. Selective intratumoral amplification of an antiangiogenic vector by an oncolytic virus produces enhanced antivascular and anti-tumor efficacy. Mol Ther 2006; 13:938-46. [PMID: 16469543 DOI: 10.1016/j.ymthe.2005.12.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 12/02/2005] [Accepted: 12/06/2005] [Indexed: 11/20/2022] Open
Abstract
The development of effective cancer therapy will require the simultaneous targeting of multiple steps in tumor development. We have previously described an antiangiogenic gene therapy vector, Ad Flk1-Fc, which expresses a soluble VEGF receptor capable of inhibiting tumor angiogenesis and growth. We have also described an oncolytic virus, dl922/947, whose replication and subsequent cytotoxicity are restricted to cancer cells with a loss of the G1-S cell cycle checkpoint. Here we have optimized methods for combining these therapies, yielding significantly greater anti-tumor effects than the respective monotherapies. In cultured tumor lines, co-infection with both Ad Flk1-Fc and dl922/947 allowed replication and repackaging of the replication-deficient Ad Flk1-Fc and enhanced soluble VEGF receptor expression. Similar repackaging and increased gene expression were demonstrated in vivo using bioluminescence imaging studies. Finally, coadministration of these therapeutic viral therapies in vivo produced significantly enhanced anti-tumor effects in colon HCT 116 and prostate PC-3 xenografts in mice. This increased therapeutic benefit correlated with replication of Ad Flk1-Fc viral genomes, increased intratumoral levels of Flk1-Fc protein, and decreased microvessel density, consistent with enhanced antiangiogenic activity.
Collapse
Affiliation(s)
- Stephen H Thorne
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | | | | | | |
Collapse
|
720
|
Chen B, Pogue BW, Luna JM, Hardman RL, Hoopes PJ, Hasan T. Tumor Vascular Permeabilization by Vascular-Targeting Photosensitization: Effects, Mechanism, and Therapeutic Implications. Clin Cancer Res 2006; 12:917-23. [PMID: 16467106 DOI: 10.1158/1078-0432.ccr-05-1673] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Loss of vascular barrier function has been observed shortly following vascular-targeting photodynamic therapy. However, the mechanism involved in this event is still not clear, and the therapeutic implications associated with this pathophysiologic change have not been fully explored. EXPERIMENTAL DESIGN The effect of vascular-targeting photodynamic therapy on vascular barrier function was examined in both s.c. and orthotopic MatLyLu rat prostate tumor models and endothelial cells in vitro, using photosensitizer verteporfin. Vascular permeability to macromolecules (Evans blue-albumin and high molecular weight dextran) was assessed with dye extraction (ex vivo) and intravital microscopy (in vivo) methods. Intravital microscopy was also used to monitor tumor vascular functional changes after vascular-targeting photodynamic therapy. The effects of photosensitization on monolayer endothelial cell morphology and cytoskeleton structures were studied with immunofluorescence staining. RESULTS Vascular-targeting photodynamic therapy induced vascular barrier dysfunction in the MatLyLu tumors. Thus, tumor uptake of macromolecules was significantly increased following photodynamic therapy treatments. In addition to vascular permeability increase, blood cell adherence to vessel wall was observed shortly after treatment, further suggesting the loss of endothelial integrity. Blood cell adhesion led to the formation of thrombi that can occlude blood vessels, causing vascular shutdown. However, viable tumor cells were often detected at tumor periphery after vascular-targeting photodynamic therapy. Endothelial cell barrier dysfunction following photodynamic therapy treatment was also observed in vitro by culturing monolayer endothelial cells on Transwell inserts. Immunofluorescence study revealed microtubule depolymerization shortly after photosensitization treatment and stress actin fiber formation thereafter. Consequently, endothelial cells were found to retract, and this endothelial morphologic change led to the formation of intercellular gaps. CONCLUSIONS Vascular-targeting photodynamic therapy permeabilizes blood vessels through the formation of endothelial intercellular gaps, which are likely induced via endothelial cell microtubule depolymerization following vascular photosensitization. Loss of endothelial barrier function can ultimately lead to tumor vascular shutdown and has significant implications in drug transport and tumor cell metastasis.
Collapse
Affiliation(s)
- Bin Chen
- Department of Surgery, Dartmouth Medical School, Lebanon, New Hampshire, USA
| | | | | | | | | | | |
Collapse
|
721
|
Abstract
Angiogenesis refers to the process of remodeling the vascular tissue characterized by the branching out of a new blood vessel from a pre-existing vessel. Angiogenesis is particularly active during embryogenesis, while during adult life it is quiescent and limited to particular physiologic phenomena. Recently, the study of molecular mechanisms of angiogenesis has stirred renewed interest due to the recognition of the role played by angiogenesis in several pathologies of significant medical impact, such as cancer and cardiovascular disease, and due to the pharmacologic interest rising from the possibility of modulating these phenomena. Antibodies, peptides and small molecules targeting active endothelial cells represent an innovative tool in therapeutic and diagnostic fields. In this study, we reviewed the literature of peptide and peptidomimetics in angiogenesis and their potential applications. Two specific protein systems, namely the vascular endothelial growth factor and its receptor and integrins, will be discussed in detail.
Collapse
Affiliation(s)
- Luca Domenico D'Andrea
- Institute of Biostructure and Bioimaging, CNR and Department of Biological Sciences, CIRPEB, University of Napoli Federico II, via Mezzocannone 16, 80134 Napoli, Italy
| | | | | | | |
Collapse
|
722
|
|
723
|
Clapp C, Martínez de la Escalera G. Aquaporin-1: a novel promoter of tumor angiogenesis. Trends Endocrinol Metab 2006; 17:1-2. [PMID: 16309919 DOI: 10.1016/j.tem.2005.11.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 10/25/2005] [Accepted: 11/14/2005] [Indexed: 11/21/2022]
Abstract
Angiogenesis is critical to solid tumor growth; therefore, understanding how blood vessels form within a developing tumor has become a principal, yet challenging, objective. The recent discovery that deletion of the water channel protein, aquaporin-1, impairs tumor angiogenesis provides novel insights into the mechanisms governing the neovascularization and growth of tumors.
Collapse
Affiliation(s)
- Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Qro, México 76230.
| | | |
Collapse
|
724
|
Yang XX, Hu ZP, Chan SY, Zhou SF. Monitoring drug-protein interaction. Clin Chim Acta 2005; 365:9-29. [PMID: 16199025 DOI: 10.1016/j.cca.2005.08.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 08/16/2005] [Accepted: 08/23/2005] [Indexed: 11/25/2022]
Abstract
A variety of therapeutic drugs can undergo biotransformation via Phase I and Phase II enzymes to reactive metabolites that have intrinsic chemical reactivity toward proteins and cause potential organ toxicity. A drug-protein adduct is a protein complex that forms when electrophilic drugs or their reactive metabolite(s) covalently bind to a protein molecule. Formation of such drug-protein adducts eliciting cellular damages and immune responses has been a major hypothesis for the mechanism of toxicity caused by numerous drugs. The monitoring of protein-drug adducts is important in the kinetic and mechanistic studies of drug-protein adducts and establishment of dose-toxicity relationships. The determination of drug-protein adducts can also provide supportive evidence for diagnosis of drug-induced diseases associated with protein-drug adduct formation in patients. The plasma is the most commonly used matrix for monitoring drug-protein adducts due to its convenience and safety. Measurement of circulating antibodies against drug-protein adducts may be used as a useful surrogate marker in the monitoring of drug-protein adducts. The determination of plasma protein adducts and/or relevant antibodies following administration of several drugs including acetaminophen, dapsone, diclofenac and halothane has been conducted in clinical settings for characterizing drug toxicity associated with drug-protein adduct formation. The monitoring of drug-protein adducts often involves multi-step laboratory procedure including sample collection and preliminary preparation, separation to isolate or extract the target compound from a mixture, identification and determination. However, the monitoring of drug-protein adducts is often difficult because of short half-lives of the protein adducts, sampling problem and lack of sensitive analytical techniques for the protein adducts. Currently, chromatographic (e.g. high performance liquid chromatography) and immunological methods (e.g. enzyme-linked immunosorbent assay) are two major techniques used to determine protein adducts of drugs in patients. The present review highlights the importance for clinical monitoring of drug-protein adducts, with an emphasis on methodology and with a further discussion of the application of these techniques to individual drugs and their target proteins.
Collapse
Affiliation(s)
- Xiao-Xia Yang
- Department of Pharmacy, Faculty of Science, National University of Singapore, Science Drive 4, Singapore 117543, Singapore
| | | | | | | |
Collapse
|