Abstract
In human androgen-independent prostate cancer (PCa), epidermal growth factor receptor (EGFR) regulates angiogenesis, tumor growth, and progression. In this study, we evaluated whether the blockade of EGFR by the anti-EGFR antibody ImClone C225 (IMC-C225) inhibited tumor growth and metastasis by inhibiting angiogenesis, and whether paclitaxel enhanced the results of therapy in androgen-independent PCa. PC-3M-LN4 PCa cells were implanted orthotopically in athymic nude mice and treated with i.p. IMC-C225 (1 mg twice a week) and/or paclitaxel (200 microg once a week). In vitro treatment of PC-3M-LN4 with IMC-C225 inhibited EGFR autophosphorylation without any significant antiproliferative effect. In contrast, in vivo therapy with IMC-C225 alone (P < 0.05) or in combination with paclitaxel (P < 0.005) significantly inhibited PCa growth and metastasis. Serum levels of interleukin (IL) 8 were lower after therapy, and IL-8 mRNA expression was down-regulated within the tumors after therapy. The down-regulation of IL-8 correlated with reduced microvessel density. IMC-C225 reduced tumor cell proliferation, enhanced p27(kip1) expression, and induced tumor and endothelial cell apoptosis. These studies indicate that IMC-C225 has significant antitumor effect in this murine model, mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. The simultaneous administration of paclitaxel enhanced this effect.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Androgens / physiology
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Angiogenesis Inhibitors / pharmacology*
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Animals
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Antibodies, Monoclonal / pharmacology*
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Antibodies, Monoclonal, Humanized
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Apoptosis / drug effects
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Blood Vessels / drug effects
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Blood Vessels / pathology
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Cell Cycle Proteins / drug effects
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Cell Cycle Proteins / metabolism
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Cell Division / drug effects
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Cetuximab
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Cyclin-Dependent Kinase Inhibitor p27
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Dose-Response Relationship, Drug
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Epidermal Growth Factor / pharmacology
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ErbB Receptors / immunology*
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ErbB Receptors / metabolism
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Humans
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Interleukin-8 / blood
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Interleukin-8 / genetics
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Male
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Mice
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Mice, Inbred BALB C
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Mice, Nude
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Neoplasm Metastasis / prevention & control
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Neoplasm Transplantation
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Neovascularization, Pathologic / prevention & control*
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Paclitaxel / pharmacology
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Phosphorylation / drug effects
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Prostatic Neoplasms / blood supply
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Prostatic Neoplasms / drug therapy*
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Prostatic Neoplasms / pathology
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RNA, Messenger / drug effects
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Tumor Cells, Cultured
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Tumor Suppressor Proteins / drug effects
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Tumor Suppressor Proteins / metabolism
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Tyrosine / metabolism
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Up-Regulation
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Xenograft Model Antitumor Assays
Substances
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Androgens
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Angiogenesis Inhibitors
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Antibodies, Monoclonal
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Antibodies, Monoclonal, Humanized
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Cdkn1b protein, mouse
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Cell Cycle Proteins
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Interleukin-8
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RNA, Messenger
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Tumor Suppressor Proteins
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Cyclin-Dependent Kinase Inhibitor p27
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Tyrosine
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Epidermal Growth Factor
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ErbB Receptors
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Paclitaxel
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Cetuximab