ognizant Communication Corporation

ONCOLOGY RESEARCH
AN INTERNATIONAL JOURNAL
INCORPORATING ANTI-CANCER DRUG DESIGN

ABSTRACTS
VOLUME 13, NUMBER 2

Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 61-70
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Stimulatory Effect of Topical Application of Caffeine on UVB-Induced Apoptosis in Mouse Skin

Yao-Ping Lu,1 You-Rong Lou,1 Xiang-Hong Li,1 Jian-Guo Xie,1 Yong Lin,2,3 Weichung Joe Shih,2,3 and Allan H. Conney1,3,4

1Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8020
2University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ 08901
3The Cancer Institute of New Jersey, New Brunswick, NJ 08901
4William M. and Myrle W. Garbe Professor of Cancer and Leukemia Research

In an earlier study, we showed that oral administration of green tea or caffeine to SKH-1 mice for 2 weeks prior to a single application of UVB enhanced UVB-induced increases in the number of p53-positive cells, p21(WAF1/CIP1)-positive cells, and apoptotic sunburn cells in the epidermis. In the present study, we found that topical application of caffeine, a major chemopreventive agent in tea, to the dorsal skin of SKH-1 mice immediately after irradiation with UVB (30 mJ/cm2) enhanced UVB-induced apoptosis as measured by the number of morphologically distinct epidermal apoptotic sunburn cells and the number of caspase 3-positive cells. Time course studies indicated that UVB-induced increases in apoptotic sunburn cells were correlated with elevated levels of caspase 3, a key protease that becomes activated during an early stage of apoptosis. Topical application of caffeine immediately after UVB enhanced UVB-induced increases in caspase 3 (active form)-immunoreactive-positive cells and in caspase 3 enzyme activity in the epidermis. Topical application of caffeine had only a small stimulatory effect on UVB-induced increases in the level of wild-type p53 protein and these changes were not related temporally to caffeine-induced increases in apoptotic cells. There was little or no effect of topical applications of caffeine on epidermal cell proliferation as determined by bromodeoxyuridine (BrdU) incorporation into DNA. Topical application of (-)-epigallocatechin gallate (EGCG) to the dorsal skin of mice immediately after irradiation with UVB had a small inhibitory effect on UVB-induced increases in BrdU-positive cells in the basal layer of the epidermis, but this treatment had no effect on UVB-induced increases in apoptotic sunburn cells. The results of this study indicate a proapoptotic effect of topical application of caffeine on UVB-irradiated mouse skin.

Key words: UV carcinogenesis; Apoptotic sunburn cells; Caspase 3; p53; Chemoprevention

Address correspondence to Dr. Allan H. Conney, Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854-8020. Tel: (732) 445-4940; Fax: (732) 445-0687; E-mail: aconney@rci.rutgers.edu




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 71-78
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Low Molecular Weight Hyaluronan Induces Malignant Mesothelioma Cell (MMC) Proliferation and Haptotaxis: Role of CD44 Receptor in MMC Proliferation and Haptotaxis

Najmunnisa Nasreen, Kamal A. Mohammed, Joyce Hardwick, Robert D. Van Horn, Kerry Sanders, Hasmeena Kathuria, Farzad Loghmani, and Veena B. Antony

Division of Pulmonary and Critical Care Medicine, Department of Medicine, Veterans Affairs Medical Center, Indiana University School of Medicine, Indianapolis, IN 46202

Hyaluronan (HA) is a nonsulfated glycosaminoglycan that is secreted in significant quantities by pleural mesothelial cells (PMC) and malignant mesothelioma cells (MMC). The functional significance of HA deposition in the pleural space has not been fully elucidated. In this study, we hypothesized that low molecular weight but not high molecular weight hyaluronan induces proliferation and migration of MMC, and that the hyaluronan receptor (CD44S) expressed on the mesothelioma cell surface is involved in this process. We evaluated the effect of low molecular weight hyaluronan (LMWHA) and high molecular weight hyaluronan (HMWHA) on four MMC lines (CRL-2081, CRL-5915, CRL-5830, CRL-5820) proliferation and haptotactic migration. We also studied the expression of HA receptor CD44S on MMC by Northern hybridization and flow cytometry. The binding of LMWHA and HMWHA to MMC surface was determined by FACS analysis using FITC-conjugated hyaluronan. Our results indicate that the MMC line that expressed the highest amount of CD44 receptor showed increased proliferation and haptotactic migration of MMC when stimulated with LMWHA but not HMWHA. Monoclonal antibody against CD44 inhibited proliferation by about 12-40% and migration by 10-35% in the MMC lines that were studied, and thus in part inhibited LMWHA-induced proliferation and migration in MMC. LMWHA binding to MM cell surface was significantly higher than HMWHA. This directly correlated with their CD44 receptor expression. Neutralization of CD44 receptor significantly reduced the LMMHA binding to MMC. These results provide evidence that the interaction between the adhesive protein receptor CD44 and extracellular matrix component (HA) transmits regulatory signals for mediating the locomotion and proliferation of MMC, and thus plays an important role in localized extension of tumor growth.

Key words: Malignant mesothelioma; Hyaluronan; CD44 receptor; Haptotaxis; Proliferation

Address correspondence to Veena B. Antony, M.D., Veterans' Affairs Medical Center, 1481 West 10th Street, 111-P, Indianapolis, IN 46202. Fax: (317) 554-0292; E-mail: vantony@iupui.edu




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 79-85
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Adherence of Ovarian Cancer Cells Induces Pleural Mesothelial Cell (PMC) Permeability

P. S. Sriram, Kamal A. Mohammed, Najmunnisa Nasreen, Joyce Hardwick, Robert Van Horn, Kerry Sanders, and Veena B. Antony

Division of Pulmonary and Critical Care Medicine, Department of Medicine, Veterans Affairs Medical Center, Indiana University School of Medicine, Indianapolis, IN 46202

Malignant pleural effusion (MPE) carries a grave prognosis with median survival after diagnosis being 5 months. The major causes of MPE are lung, breast, ovary, and gastric cancer. It is still unclear how cancer cells penetrate the pleural mesothelial monolayer and reach the pleural space. In this study we examined the effect of ovarian epithelial cancer cells on a confluent pleural mesothelial cell (PMC) monolayer. We demonstrate that ovarian cancer cells adhere to the mesothelial monolayer in a time-dependent manner and induce PMC barrier dysfunction as evidenced by a drop in electrical resistance on electrical cell substrate impedance-sensing system (ECIS) and increased protein permeability. Barrier dysfunction is attenuated by addition of vascular endothelial growth factor (VEGF) antibody. Significant release of VEGF was noted when ovarian cancer cells were cocultured with PMC. Electron microscopy demonstrated gap formation in PMC monolayer only at the site of cancer cell attachment with surrounding areas remaining confluent.

Key words: Ovarian cancer cells; Mesothelial cells; Vascular endothelial growth factor; Protein permeability

Address correspondence to Veena B. Antony, M.D., Veterans Affairs Medical Center, 1481 West 10th Street, 111P, Indianapolis, IN 46202. Fax: (317) 554-0262; E-mail: vantony@iupui.edu




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 87-94
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Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Glucocorticoids Induce Neuroendocrine Cell Differentiation and Increase Expression of N-myc in N-type Human Neuroblastoma Cells

Robert A. Ross,1 Anne M. Hein,1 John A. Braca, III,1 Barbara A. Spengler,1 June L. Biedler,1 and Jonathan G. Scammell2

1Department of Biological Sciences, Fordham University, Bronx, NY 10458
2Department of Pharmacology and Comparative Medicine, University of South Alabama College of Medicine, Mobile, AL 36688

Human neuroblastoma cell lines comprise cellular counterparts of normal differentiation phenotypes arising from the developing neural crest. Three distinct cell types have been isolated from cell lines: N-type cells with properties of embryonic sympathoadrenoblasts, S-type cells resembling nonneuronal Schwannian/glial/melanoblastic precursors, and I-type stem cells that can differentiate into either N- or S-type cells. Sympathoadrenoblasts from the normal neural crest further differentiate into neuronal or neuroendocrine cells. In this study, we show that malignant N-type neuroblasts likewise can differentiate further along these same pathways. Retinoic acid and forskolin induce a neuronal phenotype, denoted morphologically by cell aggregation and increased neurite formation and biochemically by increases in neurofilament proteins, tyrosine hydroxylase, and secretogranin II and decrease in chromogranin A. By contrast, dexamethasone, a synthetic glucocorticoid, induces a chromaffin cell phenotype characterized by increased cell flattening, loss of neuritic processes, increased chromogranin A and tyrosine hydroxylase proteins, and decreased amounts of secretogranin II and neurofilaments. N-myc gene expression is upregulated by glucocorticoids; dexamethasone-treated N-type cells show significant (2.3- to 7.8-fold) increases in N-myc mRNA and protein steady-state levels. This effect is specific for glucocorticosteroids, is blocked by addition of the steroid receptor antagonist RU486, and involves direct activation of the N-myc promoter. These findings are the first to show that glucocorticoids upregulate N-myc expression in human neuroblastoma cells.

Key words: Human neuroblastoma; Differentiation; Chromogranins; N-myc; Glucocorticoid; Dexamethasone

Address correspondence to Dr. Robert A. Ross, Head, Laboratory of Neurobiology, LH 200, Department of Biological Sciences, 441 East Fordham Road, Bronx, NY 10458. Tel: (718) 817-3654; Fax: (718) 817-3616; E-mail: rross@fordham.edu




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 95-101
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Uptake of the Antivascular Agent 5,6-Dimethylxanthenone-4-Acetic Acid (DMXAA) and Activation of NF-kB in Human Tumor Cell Lines

See-Tarn Woon,1 Bruce C. Baguley,1 Brian D. Palmer,1 John D. Fraser,2 and Lai-Ming Ching1

1Auckland Cancer Society Research Centre and 2Department of Molecular Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand

5,6-Dimethylxanthenone-4-acetic acid (DMXAA), a new anticancer drug synthesized in this laboratory and currently in clinical trial, induces tumor vascular damage in vivo that is mediated primarily by cytokine synthesis by host cells. Although its pharmacology and antitumor activity have been extensively studied, little is known of its action on tumor cell lines. We measured [3H]DMXAA uptake in the Raji, Daudi, Jurkat, ECV304, NZM12, HL60, and K562 human tumor lines using velocity centrifugation through silicon oil layers, and also measured NF-kB activation by electrophoretic mobility shift assays. All lines accumulated [3H]DMXAA, and uptake by ECV304 cells was rapid, pH dependent (greater uptake at pH 6.5), similar at 4°C and 37°C, and unaffected by the addition of 5 mM sodium azide. The uptake ratio was 4.5-fold at a low drug concentration (4 mM) and decreased significantly (P < 0.01) to 4.0 as the external drug concentration was increased to 0.7 mM, providing evidence of saturability. [3H]DMXAA interacted weakly with isolated cytoplasmic proteins, as measured by equilibrium dialysis, providing a basis for the observed cellular uptake. Uptake was slightly reduced by addition of a less potent analogue, flavone acetic acid, or of an inactive analogue, 8-methylxanthenone-4-acetic acid, suggesting competition for binding sites. The Raji, Daudi, Jurkat, and ECV304 lines showed evidence of activation of the NF-kB transcription factor in response to DMXAA, but the identity of the NF-kB subunits translocated to the nucleus varied according to the line. The results are consistent with the hypothesis that DMXAA is taken up rapidly into cells by passive diffusion and binds to cellular proteins. The observed activation of NF-kB in some lines suggests that the effects of DMXAA on tumor cells, as well as host cells, must be considered in understanding its antitumor action.

Key words: NF-kB; Drug uptake; Flavone acetic acid; Antivascular

Address correspondence to Dr. See-Tarn Woon, Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, Private Bag 92019, Auckland, New Zealand. Tel: 64 9 3737-599, ext. 6140; Fax: 64 9 3737-502; E-mail: st.woon@auckland.ac.nz




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 103-111
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Immunoglobulin Superfamily Expression in Primary Retinoblastoma and Retinoblastoma Cell Lines

Michele C. Madigan,1 Philip L. Penfold,1 Nicholas J. C. King,2 Francis A. Billson,1 and Robert M. Conway1

1Save Sight Institute, Department of Clinical Ophthalmology, and 2Department of Pathology, University of Sydney, NSW 2006, Australia

Retinoblastoma (Rb) is the most common intraocular tumor of childhood. In this study we examined primary Rb specimens and Rb cell lines for the expression of immunoglobulin superfamily (IgSF) antigens: MHC class I and II (MHC-I and MHC-II), neural cell adhesion molecule (NCAM), intercellular adhesion molecule-1 (ICAM-1), and Thy-1, which play an important role in immune system and tumor cell interactions. MHC-I and -II, ICAM-1 (CD54), NCAM (CD56), and Thy-1 (CDw90) immunoreactivity was studied in eight primary Rb biopsy specimens using immunohistochemistry, three using immunoelectron microscopy, and six Rb cell lines using flow cytometry (FCM). Parenchymal and vascular-associated cells, phenotypically similar to retinal microglia, strongly expressed MHC-II immunoreactivity and were distributed throughout primary Rb specimens. However, MHC-II expression on Rb cell lines was similar to nonspecific control levels. Tumor cells in primary Rb specimens displayed high NCAM, moderate Thy-1, and low MHC-I and ICAM-1 immunolabeling. Tumor vasculature expressed low to moderate MHC-I and ICAM-1 immunoreactivity and moderate Thy-1 immunoreactivity. NCAM was not detected on the vasculature of primary Rb specimens. Rb cell lines displayed variable expression of Thy-1, ICAM-1, and MHC-I. NCAM was highly expressed on five of six Rb cell lines. The high levels of constitutive NCAM immunoreactivity on Rb tumor cells confirm the neuroectodermal origins of this tumor. Additionally, the variable expression of Thy-1 may suggest separate neural lineages or differences in the maturational status of some Rb tumors. The presence of a population of infiltrating MHC-II-positive cells in primary Rb tumors has implications for immunomodulation of Rb growth.

Key words: Differentiation; Immunotherapy; MHC-II; Mast cells; Microglia; Retina; Vasculature

Address correspondence to M. C. Madigan, Save Sight Institute, Department of Clinical Ophthalmology, GPO Box 4337, Sydney, N.S.W. Australia, 2001. Tel: 61-2-9382 7283; Fax: 61-2-9382 7318; E-mail: michele@eye.usyd.edu.au




Oncology Research/Anti-Cancer Drug Design, Volume 13, pp. 113-122
0965-0407/02 $20.00 + .00
Copyright © 2002 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

The Possible Correlation Between Activation of NF-kB/IkB Pathway and the Susceptibility of Tumor Cells to Paclitaxel-Induced Apoptosis

Yi Huang,1* Yong Fang,1 Jennifer M. Dziadyk,1 James S. Norris,2 and Weimin Fan1

Departments of 1Pathology and Laboratory Medicine and 2Microbiology and Immunology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425

Paclitaxel (Taxol®) is a naturally occurring antimitotic agent that has been shown to induce apoptosis in both leukemic and solid tumor cells, but many tumor cells exhibit a high resistance to paclitaxel. The mechanism of different susceptibility among tumor cells to paclitaxel-induced apoptotic cell death is not entirely clear. In this study, we identified and characterized two solid tumor cell lines, human breast tumor MCF7 cells and rat prostate tumor R3227 cells, which were resistant to paclitaxel-induced apoptosis. The results indicated that these tumor cells were highly resistant to paclitaxel-induced nucleosomal DNA fragmentation, but still sensitive to paclitaxel-induced microtubule bundling and cell cycle arrest at G2-M. This selective resistance of MCF7 and R3227 to paclitaxel suggests that mitotic arrest and apoptotic cell death might be two separate events, and paclitaxel-induced mitotic arrest may not always be followed by apoptotic cell death. Further, through comparative studies and analyses of a number of genes whose expression or activation may be involved in the regulation of apoptotic cell death or drug resistance, we found that paclitaxel induced the degradation of IkBa protein, which in turn activated NF-kB in paclitaxel-sensitive tumor cells, but such a paclitaxel-induced activation of the NF-kB/IkBa cascade was not observed in either MCF7 or R3227 cells. These findings suggest that the activation of NF-kB/IkBa signaling pathway might play an important role in determining the susceptibility of tumor cells to paclitaxel-induced apoptosis.

Key words: Paclitaxel; Mitotic arrest; Apoptosis; NF-kB/IkB

Address correspondence to Weimin Fan, M.D., Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425. Tel: (843) 792-5108; Fax: (843) 792-0368;  E-mail: fanw@musc.edu

*Current address: The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD 21231.