ognizant Communication Corporation

ONCOLOGY RESEARCH
AN INTERNATIONAL JOURNAL
INCORPORATING ANTI-CANCER DRUG DESIGN

ABSTRACTS
VOLUME 14, NUMBERS 11/12

Oncology Research, Volume 14, pp. 529-539
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Copper Chelation as an Antiangiogenic Therapy

S. A. Lowndes and A. L. Harris

Cancer Research UK Medical Oncology Unit, The Churchill Hospital, Oxford OX3 7LJ, UK

Angiogenesis is now recognized as a crucial process in tumor development. Copper appears to act as an essential cofactor for several angiogenic growth factors, and both copper metabolism and ceruloplasmin expression are upregulated in many tumors. The role of copper chelators has been investigated in animal models with promising results. New therapies for Wilson's disease (a disease of copper accumulation) have enabled clinical trials of copper chelation to be undertaken. Here we discuss the evidence for a role of copper in angiogenesis and possible mechanisms of action of anticopper agents.

Key words: Copper; Chelation; Angiogenesis; Antiangiogenic therapy

Address correspondence to Professor A. L. Harris, Cancer Research UK Medical Oncology Unit, The Churchill Hospital, Oxford OX3 7LJ, UK. Tel: +441865 222457; Fax: +441865 222431; E-mail: harrisa@cancer.org.uk




Oncology Research, Volume 14, pp. 541-558
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Design and Construction of a Phosphorylatable Chimeric Monoclonal Antibody With a Highly Stable Phosphate

Wei Wu,1* John E. Kerrigan,2 Prem Yadav,1 Barbara Schwartz,1 Lara Izotova,1 Thomas B. Lavoie,4 and Sidney Pestka1,3,4

1Department of Molecular Genetics and Microbiology, and 2Academic Computing Services, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, 675 Hoes Lane
Piscataway, NJ 08854-5635
3Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901-1914
4PBL Biomedical Laboratories, 131 Ethel Road West, Suite 6, Piscataway, NJ 08854-5900

A recognition site for the cAMP-dependent protein kinase was introduced into the MAb-chCC49 by site-directed mutation of the coding sequence to make a variant of MAb-chCC49 containing a highly stable phosphate. To design this monoclonal antibody (MAb) without changing its immunoreactivity or biological properties, molecular modeling was used to locate appropriate regions for introduction of the cAMP-dependent phosphorylation site with desirable properties. We selected one position to mutate on the heavy chain based on molecular dynamics study of the solvated antibody. A vector expressing the mutant was constructed and transfected into mouse myeloma NS0 cells that expressed a high level of the resultant MAb-WW5. MAb-WW5 contained the cAMP-dependent phosphorylation site at the hinge region of the heavy chain, could be phosphorylated by the catalytic subunit of cAMP-dependent protein kinase with [g-32P]ATP to high specific activity, and retained the phosphate stably. Compared with MAb-chCC49K1, another phosphorylatable variant of MAb-chCC49, the phosphate attached to MAb-WW5 showed much improved stability: about a 10-fold increase in resistance to hydrolysis. MAb-WW5 exhibited the same binding specificity to the TAG-72 antigen on MCF-7 4C10 breast cancer cells as we observed with MAb-chCC49K1. The improved stability of the attached phosphate provides a MAb with potential to be used in diagnosis and therapy of adenocarcinomas.

Key words: Radiophosphate-labeled antibody; Phosphokinase recognition sites; Molecular modeling; Phosphorylated antibodies; Radio therapeutic; Phosphate stability

Address correspondence to Sidney Pestka, Department of Molecular Genetics and Microbiology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854-5635. Tel: (732) 235-4567; Fax: (732) 235-5223; E-mail: pestka@waksman.rutgers.edu

*Current address: Division of Pulmonary Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, 3459 5th Avenue NW 628 MUH, Pittsburgh, PA 15213




Oncology Research, Volume 14, pp. 559-566
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Radiation-Induced Sensitizing Effect of Folic Acid (Vitamin B11) and its Synergistic Action to Mitomycin C: In Vitro Experiments and Radiolysis

Alexandra Delipetar-Grudl and Nikola Getoff

Ludwig Boltzmann Institute for Radiation Chemistry and Radiation Biology, c/o The University of Vienna, UZA II, Althanstraße 14,A-1090 Wien, Austria

Folic acid (FA; vitamin B11) is found to exhibit very strong cytostatic effects upon g-irradiation in neutral media. This effect depends on the FA concentration, pH of the media, and on the presence of air. The largest cytostatic efficiency of FA was observed in an air-free environment (pH 7.4), where DD37 = -90 for 10-4 mol/dm3 FA and DD37 = -160 for 10-3 mol/dm3 FA was found. FA also acts as a very efficient electron donor and is therefore able, in air-free neutral media, to enhance the efficiency of 7.5 x 10-7 mol/dm3 mitomycin C (MMC) from DD37 = -80 up to DD37 = -200 in the presence of 5 x 10-5 mol/dm3 FA, respectively. This synergistic effect offers a new pathway for more efficient radiation therapy by joint implementation of MMC and FA. Additionally, FA radiolysis was studied in the absence and presence of air as well as in media saturated with N2O (conversion of e-aq into OH). As a result of these investigations, various products were detected: ammonia, aldehydes, and a mixture of carboxylic acids, in addition to some not yet identified compounds. Their individual yields could not be identified at present.

Key words: Folic acid (vitamin B11); Cytostatic efficiency; Radiolysis

Address correspondence to Prof. Dr. Nikola Getoff, Ludwig Boltzmann Institute for Radiation Chemistry and Radiation Biology, c/o The University of Vienna, UZA II, Althanstraße 14,A-1090 Wien, Austria. Tel: 43-1-4277-52710; Fax: 43-1-4277-52795; E-mail: nikola.getoff@univie.ac.at




Oncology Research, Volume 14, pp. 567-578
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Resistance of Ovarian Carcinoma Cells to Docetaxel Is XIAP Dependent and Reversible by Phenoxodiol

Eva Sapi,1,2 Ayesha B. Alvero,1 Wei Chen,3 David O'Malley,1 Xiao-Ying Hao,1 Bambang Dwipoyono,2 Manish Garg,2 Marijke Kamsteeg,1 Thomas Rutherford,1 and Gil Mor1

1Department of Obstetrics & Gynecology, Yale University School of Medicine, P.O. Box 208040, New Haven, CT 06520-8040
2Department of Biology and Environmental Sciences, University of New Haven, 300 Orange Ave., West Haven, CT 06516
3Department of Obstetrics & Gynecology, Nanfang Hospital, The First Military Medical University, Guangzhou 510515, China

Although several pathways have been proposed to explain chemoresistance, all lead to some specific defect in the mechanism of apoptosis. The objective of this study was to characterize the molecular mechanisms of drug resistance to docetaxel in epithelial ovarian cancer cells (EOC) and the use of phenoxodiol as a chemosensitizer. Four established and 12 primary cultures of ovarian carcinoma cell lines (EOC) were treated with docetaxel (5-500 ng/ml) for 24 and/or 48 h. In all the studied cell lines, the best response was seen using 500 ng/ml of docetaxel. Sensitive cell lines were identified as those with IC50 < 100 ng/ml for 48 h while resistant cell lines were identified as those with IC50 > 100 ng/ml. The morphological features of apoptosis and the activation of caspases were seen only in the sensitive cell lines determined by Hoechst staining and Caspase GloTM assay. Although X-linked inhibitor of apoptosis protein (XIAP) was expressed in all EOC cells, it was only inactivated in chemosensitive cells. We confirmed the role of XIAP in docetaxel resistance by downregulation of XIAP expression using RNA interference (RNAi) as well as by pretreatment with phenoxodiol. Our results indicate that 1) docetaxel induces its cytotoxic effect through the activation of apoptosis; 2) caspase activation relies on the removal of XIAP; and 3) phenoxodiol restores sensitivity in docetaxel-resistant EOC cells. We demonstrate that phenoxodiol, by interfering with XIAP activity, functions as a chemosensitizer to docetaxel and could provide a more effective treatment for refractory ovarian cancer.

Key words: X-linked inhibitor of apoptosis protein (XIAP); Chemotherapy; Chemosensitizer; Phenoxodiol; Ovarian cancer

Address correspondence to Dr. Gil Mor, Associate Professor, Department of Obstetrics and Gynecology, Reproductive Immunology Unit, Yale University, School of Medicine, P.O. Box 208063, 333 Cedar St., New Haven, CT 06520-8063. Tel: (203) 785-6294; Fax: (203) 785-4883; E-mail: gil.mor@yale.edu




Oncology Research, Volume 14, pp. 579-587
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

The Unique Biological Features of the Marine Product YondelisTM (ET-743, Trabectedin) Are Shared by its Analog ET-637, Which Lacks the C Ring

E. Erba,1 E. Cavallaro,1 G. Damia,1 R. Mantovani,2 A. Di Silvio,2 A. M. Di Francesco,3 R. Riccardi,3 C. Cuevas,4 G. T. Faircloth,5 and M. D'Incalci1

1Department of Oncology, Mario Negri Institute for Pharmacological Research, Via Eritrea 62, 20157 Milan, Italy
2Department of Genetics and Biology of Microorganisms, University of Milan, Italy
3Division of Pediatric Oncology, Catholic University A. Gemelli, Rome, Italy
4Pharma Mar, S.A., Colmenar Viejo, Madrid, Spain
5Pharma Mar USA, Inc., Cambridge, MA

It was previously suggested that the peculiar mechanism of action of the novel anticancer drug YondelisTM (ET-743, trabectedin) was due to part of the molecule, units A and B, binding to DNA in the minor groove, causing an alkylation at the N2 of guanine, while unit C protrudes out of DNA, possibly interacting with transcription factors or other DNA binding proteins. To test this hypothesis, we have compared the biological activity and the mode of action of YondelisTM with its analogue ET-637, which has the same chemical structure except for the lack of the C ring. YondelisTM and ET-637 showed similar cytotoxic potency and cell cycle perturbations. As already reported for YondelisTM, the UV-96 cell line, deficient in ERCC-1, was less sensitive to ET-637 than the parental cell line. The binding of YondelisTM or ET-637 to DNA-oligonucleotides was demonstrated by gel shift assay and SDS did not reverse the binding. Both compounds blocked the temperature-induced activation of the HSP40 promoter in the range of 1-10 nM. This study indicates that ET-637 acts similarly to YondelisTM and demonstrates that the C ring of YondelisTM may not be required for its biological activity.

Key words: ET-743 analog; Cell cycle; Nucleotide excision repair

Address correspondence to M. D'Incalci, Department of Oncology, Mario Negri Institute for Pharmacological Research, Via Eritrea 62, 20157 Milan, Italy. Tel: +39/02/39014473; Fax: +39/02/3546277; E-mail: dincalci@marionegri.it




Oncology Research, Volume 14, pp. 589-602
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

secErbB4-26/549 Antagonizes Ligand-Induced ErbB4 Tyrosine Phosphorylation

Jennifer L. Gilmore and David J. Riese, II

Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy, West Lafayette, IN 47907-1333

ErbB4 is a member of the ErbB family of receptor tyrosine kinases. Because of a paucity of appropriate pharmacologic tools, little is known about ErbB4 functions in vivo. In response to this need, we hypothesized that a recombinant form of the extracellular domain of ErbB4 would antagonize ligand-induced receptor tyrosine phosphorylation and subsequent downstream signaling and could be used to probe ErbB4 function. Indeed, we show here that one such ErbB4 protein, secErbB4-26/549, is a potent inhibitor of ligand-induced ErbB4 tyrosine phosphorylation and of ligand-induced ErbB4 coupling to biological responses. Furthermore, we demonstrate that secErbB4-26/549 antagonizes ligand-induced ErbB4 signaling by acting as a ligand sink. Thus, secErbB4-26/549 is suitable for elucidating the effects of ErbB4 ligand-induced ErbB signaling in a variety of biological contexts.

Key words: ErbB4; ErbB3; Neuregulin; Antagonist

Address correspondence to David J. Riese, II, HANS 114, 201 S. University Street, Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-2064. Tel: (765) 494-6091; Fax: (765) 496-3601; E-mail: driese@purdue.edu




Oncology Research, Volume 14, pp. 603-610
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Serum Levels of Soluble E-Selectin Are Associated With the Clinical Course of Metastatic Disease in Patients With Liver Metastases From Breast Cancer

Michael H. R. Eichbaum, Thomas M. de Rossi, Sepp Kaul, and Gunther Bastert

University of Heidelberg Medical School, Department of Gynecology and Obstetrics, Heidelberg, Germany

Increasing evidence indicates that the expression of the endothelial adhesion molecule E-selectin is associated with progression and metastasis of breast cancer. Patients with liver metastases also show increased serum levels of the soluble form of E-selectin. It was our aim to compare serum levels of soluble E-selectin (sES) in such patients with the biology of the primary tumor and the course of the metastatic disease under therapy. We examined 69 patients with liver metastases from breast cancer who were selected to receive systemic tumor therapy because of progressive disease (n = 44) or newly detected liver metastases (n = 25). Serum concentrations of sES were measured before each therapy cycle using a specific ELISA. Serum concentrations of sES before the start of therapy were compared to clinical parameters and histopathological findings referring to the primary tumor. Secondly, serum levels of sES were compared to serum concentrations of the corresponding tumor markers. We observed a possible trend for certain unfavorable prognostic parameters (e.g., young women, low-graded tumors, human epidermal growth factor receptor 2 overexpression) to be related to higher serum levels of sES. Serum levels of sES were correlated with tumor marker levels in a logarithmical relation (r = 0.44, P < 0.0005). In some cases it could be demonstrated that serum levels of sES changed similarly to the course of tumor marker levels. We conclude that serum levels of sES are associated with the clinical course of liver metastases from breast cancer. Further investigations are needed to clarify if serum levels of sES may serve as tumor marker in certain clinical situations. E-selectin should be evaluated as a possible target for antimetastatic therapy studies.

Key words: Adhesion molecules; E-selectin; Liver metastases; Metastatic breast cancer; Tumor markers

Address correspondence to Michael H. R. Eichbaum, M.D., University of Heidelberg Medical School, Department of Gynecology and Obstetrics, Voss-Strasse 9, D-69115 Heidelberg, Germany. Tel: ++49-6221-56-37345; Fax: ++49-6221-56-8599; E-mail: Michael_Eichbaum@med.uni-heidelberg.de




Oncology Research, Volume 14, pp. 611-615
0965-0407/04 $20.00 + .00
Copyright © 2004 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Concentrations of VEGF and VEGFR1 in Paired Tumor Arteries and Veins in Patients With Rectal Cancer

Mads N. Svendsen, Jakob Lykke, Kim Werther, Ib J. Christensen, and Hans J. Nielsen

Department of Surgical Gastroenterology 435, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark

Increased plasma concentrations of vascular endothelial growth factor (sVEGF) are associated with poor prognosis of colorectal cancer patients. The aim was to investigate the contribution of the tumor to plasma concentrations of VEGF and VEGF receptor 1 (VEGFR1). Preoperative blood samples from a peripheral vein and intraoperative blood samples from a tumor artery, a tumor vein, and from a peripheral vein were drawn from 28 patients undergoing elective surgical resection of primary rectal cancer. Plasma concentrations of VEGF and VEGFR1 were determined by ELISA. Counts of white blood cells and platelets were performed in all samples. No significant difference between plasma VEGF levels in the obtained blood samples was found (0.35 < P < 0.86). Plasma sVEGFR1 concentrations were significantly increased in tumor veins compared with tumor arteries. In addition, a significant reduction in plasma sVEGFR1 concentrations from preoperative to intraoperative samples was observed. There was a significant efflux of neutrophils to the tumor, but none of the observed changes in plasma VEGF or VEGFR1 levels correlated to changes in counts of white blood cells or platelets (sVEGF: 0.33 < P < 0.73 and sVEGFR1: 0.32 < P < 0.98). No changes in sVEGF plasma concentrations from tumor arteries to tumor veins were demonstrated, whereas there was a significant increase in sVEGFR1 from tumor arteries to tumor veins. Changes in sVEGF or sVEGFR1 from tumor arteries to tumor veins were not associated with changes in counts of white blood cells or platelets.

Key words: Vascular endothelial growth factor; Vascular endothelial growth factor receptor 1; Tumor vessels; Rectal cancer; Neutrophils

Address correspondence to Mads Nordahl Svendsen, Department of Surgical Gastroenterology 435, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark. Tel: +45 3632 2249; Fax: +45 3632 3760; E-mail: madsnsvendsen@hotmail.com