In vivo evaluation of epidermal growth factor (EGF) receptor density on human tumor xenografts using radiolabeled EGF and anti-(EGF receptor) mAb 425

ABSTRACT Coronaviruses are positive-strand RNA viruses with features attractive for oncolytic therapy. To investigate this potential, we redirected the coronavirus murine hepatitis virus (MHV), which is normally unable to infect human cells, to human tumor cells by using a soluble receptor (soR)-based expression construct fused to an epidermal growth factor (EGF) receptor targeting moiety. Addition of this adapter protein to MHV allowed infection of otherwise nonsusceptible, EGF receptor (EGFR)-expressing cell cultures. We introduced the sequence encoding the adaptor protein soR-EGF into the MHV genome to generate a self-targeted virus capable of multiround infection. The resulting recombinant MHV was viable and had indeed acquired the ability to infect all glioblastoma cell lines tested in vitro. Infection of malignant human glioblastoma U87ΔEGFR cells gave rise to release of progeny virus and efficient cell killing in vitro. To investigate the oncolytic capacity of the virus in vivo, we used an orthotopic U87ΔEGFR xenograft mouse model. Treatment of mice bearing a lethal intracranial U87ΔEGFR tumor by injection with MHVsoR-EGF significantly prolonged survival compared to phosphate-buffered saline-treated (P = 0.001) and control virus-treated (P = 0.004) animals, and no recurrent tumor load was observed. However, some adverse effects were seen in normal mouse brain tissues that were likely caused by the natural murine tropism of MHV. This is the first demonstration of oncolytic activity of a coronavirus in vivo. It suggests that nonhuman coronaviruses may be attractive new therapeutic agents against human tumors.

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Identification of Epidermal Growth Factor Receptors (EGF-R) on Human Tumor Xenografts

Immunodeficient Mice in Oncology - Contributions to Oncology ◽

10.1159/000421280 ◽

1992 ◽

pp. 210-219

Author(s):

R. Senekowitsch ◽

R. Nissl ◽

H. W. Pabst

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Human Tumor ◽

Growth Factor Receptors ◽

Epidermal Growth Factor Receptors ◽

Human Tumor Xenografts ◽

Tumor Xenografts ◽

Epidermal Growth

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Rapid Visualization of Human Tumor Xenografts through Optical Imaging with a Near-Infrared Fluorescent Anti–Epidermal Growth Factor Receptor Nanobody

Molecular Imaging ◽

10.2310/7290.2011.00025 ◽

2012 ◽

Vol 11 (1) ◽

pp. 7290.2011.00025 ◽

Cited By ~ 89

Author(s):

Sabrina Oliveira ◽

Guus A.M.S. van Dongen ◽

Marijke Stigter-van Walsum ◽

Rob C. Roovers ◽

Jord C. Stam ◽

...

Keyword(s):

Epidermal Growth Factor Receptor ◽

Growth Factor ◽

Epidermal Growth Factor ◽

Optical Imaging ◽

Near Infrared ◽

Growth Factor Receptor ◽

Human Tumor ◽

Human Tumor Xenografts ◽

Tumor Xenografts ◽

Epidermal Growth

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Modulation of epidermal growth factor receptor proto-oncogene transcription by a promoter site sensitive to S1 nuclease

Molecular and Cellular Biology ◽

10.1128/mcb.8.10.4174-4184.1988 ◽

1988 ◽

Vol 8 (10) ◽

pp. 4174-4184

Author(s):

A C Johnson ◽

Y Jinno ◽

G T Merlino

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Egf Receptor ◽

Receptor Gene ◽

Gene Promoter ◽

Direct Repeat ◽

S1 Nuclease ◽

Epidermal Growth ◽

Specific Factors

The epidermal growth factor (EGF) receptor is the functional target of the mitogen EGF and the cellular homolog of the avian erythroblastosis virus erbB oncogene product. Regulation of expression of the proto-oncogene encoding the EGF receptor can be elucidated by studying the structure and function of the gene promoter outside the confines of the cell. Previously, we reported the isolation of the human EGF receptor gene promoter. The promoter is highly GC rich, contains no TATA or CAAT box, and has multiple transcription start sites. An S1 nuclease-sensitive site has now been found 80 to 110 base pairs (bp) upstream from the major in vivo transcription initiation site. Two sets of direct repeat sequences were found in this area; both conform to the motif TCCTCCTCC. When deletion mutations were made in this region of the promoter by using either Bal 31 exonuclease or S1 nuclease, we found that in vivo activity dropped three- to fivefold, on the basis of transient-transfection analysis. Examination of nuclear protein binding to normal and mutated promoter DNAs by gel retardation analysis and DNase I footprinting revealed that two specific factors bind to the direct repeat region but cannot bind to the S1 nuclease-mutated promoter. One of the specific factors is the transcription factor Sp1. The results suggest that these nuclear trans-acting factors interact with the S1 nuclease-sensitive region of the EGF receptor gene promoter and either directly or indirectly stimulate transcription.

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Five enzymes of the glycolytic pathway serve as substrates for purified epidermal-growth-factor-receptor kinase

Biochemical Journal ◽

10.1042/bj2390691 ◽

1986 ◽

Vol 239 (3) ◽

pp. 691-697 ◽

Cited By ~ 43

Author(s):

N Reiss ◽

H Kanety ◽

J Schlessinger

Keyword(s):

Epidermal Growth Factor Receptor ◽

Growth Factor ◽

Epidermal Growth Factor ◽

Egf Receptor ◽

Growth Factor Receptor ◽

Glycolytic Pathway ◽

Dependent Manner ◽

Receptor Kinase ◽

Epidermal Growth

Several enzymes of the glycolytic pathway are phosphorylated in vitro and in vivo by retroviral transforming protein kinases. These substrates include the enzymes phosphoglycerate mutase (PGM), enolase and lactate dehydrogenase (LDH). Here we show that purified EGF (epidermal growth factor)-receptor kinase phosphorylates the enzymes PGM and enolase and also the key regulatory enzymes of the glycolytic pathway, phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), in an EGF-dependent manner. Stoichiometry of phosphate incorporation into GAPDH (calculated from native Mr) is the highest, reaching approximately 1. LDH and other enzymes of the glycolytic pathway are not phosphorylated by the purified EGF-receptor kinase. These enzymes are phosphorylated under native conditions, and the Km values of EGF-receptor kinase for their phosphorylation are close to the physiological concentrations of these enzymes in the cell. EGF stimulates the reaction by 2-5-fold by increasing the Vmax. without affecting the Km of this process. Phosphorylation is rapid at 22 degrees C and at higher temperatures. However, unlike the self-phosphorylation of EGF-receptor, which occurs at 4 degrees C, the glycolytic enzymes are poorly phosphorylated at this temperature. Some enzymes, in particular enolase, increase the receptor Km for ATP in the autophosphorylation process and thus may act as competitive inhibitors of EGF-receptor self-phosphorylation. On the basis of the Km values of EGF receptor for the substrate enzymes and for ATP in the phosphorylation reaction, these enzymes may also be substrates in vivo for the EGF-receptor kinase.

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