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Query: UNIPROT:P04626 (
erbB-2
)
5,251
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Overexpression of the p185 product of the
c-erb B2
/neu gene is correlated with cell transformation and tumorigenesis. To study expression of this gene, a 1548-base pair fragment (-1571 to -24 bp relative to the ATG initiator codon) of the human
c-erb B2
/neu 5'-noncoding region was isolated, sequenced, and analyzed with respect to basal and inducible activity using the luciferase expression vector pSVOAL delta 5'. This fragment contained an Alu repetitive element which was confirmed in two independent clones. Basal activity of the 1548-base pair fragment was equivalent to the epidermal growth factor receptor promoter region and 32 and 16% as active as the
Herpes simplex
thymidine kinase and Rous sarcoma virus promoters, respectively. Induction of luciferase activity was observed in response to epidermal growth factor, 12-O-tetradecanoylphorbol-13-acetate, dibutyryl cAMP, and retinoic acid. Additive and synergistic responses with more than 30-fold increases were observed after treatment with combinations of inducing agents, indicating complex regulation of this gene. These results show that the promoter region of the
c-erb B2
/neu gene contains sequences that dictate regulatory responses to several environmental signals.
...
PMID:Structure and inducible regulation of the human c-erb B2/neu promoter. 196 58
We previously demonstrated that occupancy of the
epidermal growth factor (EGF) receptor
reduced the ability of vaccinia virus to infect L cells [Eppstein et al: Nature 318:663, 1985]. This result suggested that vaccinia virus was utilizing the EGF receptor as one pathway to infect cells. We have studied this system further, and now find that antibodies to the EGF receptor also reduce the ability of vaccinia virus to infect cells productively. Inclusion of both EGF and antibodies to the EGF receptor did not cause inhibition over that obtained by EGF alone, providing another line of evidence that the antiviral effects on vaccinia virus were at the level of the EGF receptor. The antiviral effects of EGF or synthetic peptides corresponding to the third disulfide loop of TGF-alpha or the vaccinia virus growth factor were specific to vaccinia virus and did not inhibit replication of
herpes simplex
virus type 2 or vesicular stomatitis virus. The inhibitory effects on replication of vaccinia virus were obtained when EGF (but not insulin or growth hormone) was present prior to, but not after, productive viral adsorption. These results provided further evidence that the antivaccinia viral effects of EGF were at the level of initial receptor occupancy. As interferon (IFN) treatment has been shown to interfere with the action of some growth factors, including EGF, we examined the effects of IFN treatment of cells on the antivaccinia viral activity of EGF. Our results show that the antivaccinia effect of IFN-beta either interfered with or partially coalesced with the inhibitory effects of EGF.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Vaccinia virus and the EGF receptor: a portal for infectivity? 349 35
The purpose of this study was to characterize the clinical and histological features of intraoral squamous cell carcinoma in men who were seropositive for the human immunodeficiency virus and to evaluate viral cofactors (human papillomavirus,
herpes simplex
virus, Epstein-Barr virus), proliferative index (proliferating cell nuclear antigen), a factor associated with invasion (cathepsin D), and mutated tumor suppressor gene and proto-oncogene products (mutated p53, c-
erbB-2
). Four men who were seropositive for the human immunodeficiency virus and had acquired immunodeficiency syndrome presented with painful oral lesions of variable duration. Oral cancer risk factors included heavy tobacco use (four of four), heavy alcohol use (three of four), and previous radiotherapy (one of four). The lesions consisted of ulcers (two of four), a fungating mass (one of four), and papillary erythroplakia (one of four). Incisional biopsy specimens were obtained. High-stringency in situ hybridization was performed with DNA probes to the human papillomavirus (types 6/11; 16/18; 31/33/35) and Epstein-Barr virus: Immunocytochemical studies for the
herpes simplex
virus, proliferating cell nuclear antigen, cathepsin D, mutated p53, and c-
erbB-2
were performed. Two lesions were moderately differentiated squamous cell carcinoma, one lesion was a basaloid squamous cell carcinoma, and one was carcinoma in situ. Stage of disease at diagnosis was II (one of four), III (two of four), and IV (one of four). Three cases were positive for the human papillomavirus, one case was positive for Epstein-Barr virus, and three cases were positive for the
herpes simplex
virus.
C-erbB-2
was focally positive in one case, and mutated p53 was positive in a separate case.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Intraoral squamous cell carcinoma in human immunodeficiency virus infection. A clinicopathologic study. 755 63
To constitute the site-specific expression of the
herpes simplex
virus thymidine-kinase (HSV-TK) gene in tumor cells, we have assessed the promoter function of the simian virus 40 (SV40) promoter and the 5'flanking region of c-
erbB-2
gene using a luciferase-expressing reporter plasmid. After the transfection of the luciferase plasmid directed by the promoter region of c-
erbB-2
gene, a large amount of luciferase activity was observed in c-
erbB-2
-expressing cells (Colo201, MCF-7, and HEC1-A), while none was detected in cells with no expression of c-
erbB-2
protein (HRA and KF cells). On the other hand, a high level of luciferase activity was detected in all tumor cell lines tested, when the transfection was performed with SV40 promoter. The repeated transfection of the liposome-conjugated HSV-TK gene regulated by the SV40 promoter or by the promoter region of c-
erbB-2
gene with cultivation in 100 micrograms/ml of aciclovir for 5 days in vitro resulted in growth inhibition for all four cell lines examined or for only c-
erbB-2
-expressing cells in the presence of SV40 promoter or c-
erbB-2
promoter, respectively. Finally, direct injection of the DNA-liposome complex into established tumors in the presence of 50 mg/kg of aciclovir led to significant tumor volume reduction in all three tumors tested when SV40 promoter was employed. However, this anti-tumor effect was noted only in c-
erbB-2
-positive cells (Colo201 cells) upon intratumoral injection of HSV-TK gene regulated by c-
erbB-2
promoter. In the case of intratumoral gene transfer, foreign DNA was detected in only one of seven mice by polymerase chain reaction (PCR) analysis performed 7 days following injection. When PCR analysis was carried out at 14 or 21 days following injection, no DNA signal was found at all. However, DNA was detected in several normal tissues at all three times tested in the case of intravenous injection. No abnormalities were seen in histologic examinations of normal tissues or in serum biochemical parameters following DNA liposome delivery. These results suggest that the direct gene transfer of HSV-TK gene regulated by tumor-specific transcriptional units may be one of the most clinically promising of the selective genetic strategies against cancer.
...
PMID:Direct intratumoral gene transfer of the herpes simplex virus thymidine kinase gene with DNA-liposome complexes: growth inhibition of tumors and lack of localization in normal tissues. 911 45
In recent years the idea of using gene therapy as a modality in the treatment of diseases other than genetically inherited, monogenic disorders has taken root. This is particularly obvious in the field of oncology where currently more than 100 clinical trials have been approved worldwide. This report will summarize some of the exciting progress that has recently been made with respect to both targeting the delivery of potentially therapeutic genes to tumor sites and regulating their expression within the tumor microenvironment. In order to specifically target malignant cells while at the same time sparing normal tissue, cancer gene therapy will need to combine highly selective gene delivery with highly specific gene expression, specific gene product activity, and, possibly, specific drug activation. Although the efficient delivery of DNA to tumor sites remains a formidable task, progress has been made in recent years using both viral (retrovirus, adenovirus, adeno-associated virus) and nonviral (liposomes, gene gun, injection) methods. In this report emphasis will be placed on targeted rather than high-efficiency delivery, although those would need to be combined in the future for effective therapy. To date delivery has been targeted to tumor-specific and tissue-specific antigens, such as epithelial growth factor receptor, c-kit receptor, and folate receptor, and these will be described in some detail. To increase specificity and safety of gene therapy further, the expression of the therapeutic gene needs to be tightly controlled within the target tissue. Targeted gene expression has been analyzed using tissue-specific promoters (breast-, prostate-, and melanoma-specific promoters) and disease-specific promoters (carcinoembryonic antigen,
HER-2/neu
, Myc-Max response elements, DF3/MUC). Alternatively, expression could be regulated externally with the use of radiation-induced promoters or tetracycline-responsive elements. Another novel possibility that will be discussed is the regulation of therapeutic gene products by tumor-specific gene splicing. Gene expression could also be targeted at conditions specific to the tumor microenvironment, such as glucose deprivation and hypoxia. We have concentrated on hypoxia-targeted gene expression and this report will discuss our progress in detail. Chronic hypoxia occurs in tissue that is more than 100-200 microns away from a functional blood supply. In solid tumors hypoxia is widespread both because cancer cells are more prolific than the invading endothelial cells that make up the blood vessels and because the newly formed blood supply is disorganized. Measurements of oxygen partial pressure in patients' tumors showed a high percentage of severe hypoxia readings (less than 2.5 mmHg), readings not seen in normal tissue. This is a major problem in the treatment of cancer, because hypoxic cells are resistant to radiotherapy and often to chemotherapy. However, severe hypoxia is also a physiological condition specific to tumors, which makes it a potentially exploitable target. We have utilized hypoxia response elements (HRE) derived from the oxygen-regulated phosphoglycerate kinase gene to control gene expression in human tumor cells in vitro and in experimental tumors. The list of genes that have been considered for use in the treatment of cancer is extensive. It includes cytokines and costimulatory cell surface molecules intended to induce an effective systemic immune response against tumor antigens that would not otherwise develop. Other inventive strategies include the use of internally expressed antibodies to target oncogenic proteins (intrabodies) and the use of antisense technology (antisense oligonucleotides, antigenes, and ribozymes). This report will concentrate more on novel genes encoding prodrug activating enzymes, so-called suicide genes (
Herpes simplex
virus thymidine kinase, Escherichia coli nitroreductase, E. (ABSTRACT TRUNCATED)
...
PMID:Targeting gene therapy to cancer: a review. 940 37
To create a universal system for the control of gene expression, we have studied methods for the construction of novel polydactyl zinc finger proteins that recognize extended DNA sequences. Elsewhere we have described the generation of zinc finger domains recognizing sequences of the 5'-GNN-3' subset of a 64-member zinc finger alphabet. Here we report on the use of these domains as modular building blocks for the construction of polydactyl proteins specifically recognizing 9- or 18-bp sequences. A rapid PCR assembly method was developed that, together with this predefined set of zinc finger domains, provides ready access to 17 million novel proteins that bind the 5'-(GNN)6-3' family of 18-bp DNA sites. To examine the efficacy of this strategy in gene control, the human
erbB-2
gene was chosen as a model. A polydactyl protein specifically recognizing an 18-bp sequence in the 5'-untranslated region of this gene was converted into a transcriptional repressor by fusion with Kr uppel-associated box (KRAB), ERD, or SID repressor domains. Transcriptional activators were generated by fusion with the
herpes simplex
VP16 activation domain or with a tetrameric repeat of VP16's minimal activation domain, termed VP64. We demonstrate that both gene repression and activation can be achieved by targeting designed proteins to a single site within the transcribed region of a gene. We anticipate that gene-specific transcriptional regulators of the type described here will find diverse applications in gene therapy, functional genomics, and the generation of transgenic organisms.
...
PMID:Toward controlling gene expression at will: specific regulation of the erbB-2/HER-2 promoter by using polydactyl zinc finger proteins constructed from modular building blocks. 984 40
The "Fab immunogene" is a novel gene transfer vehicle in which the Fab fragment of anti-human
epidermal growth factor (EGF) receptor
antibody B4G7 is conjugated with poly-L-lysine to form an affinity complex with DNA. It was developed to target delivery of therapeutic genes into EGF receptor-hyperproducing tumor cells. Various characteristic features of the immunogene have been documented (Chen et al., 1998). Here we add further evidence to prove that in vitro transfer of beta-galactosidase/Fab immunogene is exclusively to EGF receptor-positive cells and that the
herpes simplex
virus thymidine kinase (TK)/Fab immunogene induces substantial suicide effects on A431 tumor cells when treated together with ganciclovir. The in vivo specificity of the immunogene transfer was examined using A431 tumor-bearing nude mice. When these nude mice were injected intraperitoneally with the chloramphenicol acetyltransferase (CAT)/Fab immunogene, CAT DNA was detected in the tumors as well as in liver and kidney but not brain, whereas CAT mRNA and enzyme activity were detected only in the tumors. Local and intraperitoneal injection of the TK/Fab immunogene and subsequent administration of ganciclovir effectively suppressed the growth of A431 tumors transplanted on the backs of nude mice. These observations suggest a possible application of the Fab immunogene system in cancer gene therapy.
...
PMID:Targeted in vivo delivery of therapeutic gene into experimental squamous cell carcinomas using anti-epidermal growth factor receptor antibody: immunogene approach. 987 65
The Fab fragment of monoclonal antibody B4G7 against human
epidermal growth factor (EGF) receptor
was conjugated with cationic poly-L-lysine and the resulting conjugate was further complexed with reporter genes or therapeutic genes. This Fab/DNA complex was designated as "Fab immunogene." The Fab immunogene transfer in vitro was mediated through the EGF receptors in two melanoma cell lines. The frequency of cells expressing beta-galactosidase (beta-Gal) reporter gene was approximately 1%. The induction of suicide effects after Fab immunogene transfer of
herpes simplex
virus thymidine kinase (TK) or Escherichia coli cytosine deaminase (CD) gene was quite remarkable, and the growth of melanoma cells was inhibited for over 7 days in the presence of ganciclovir (GCV) or 5-fluorocytosine (5-FC). Similarly, when melanoma cells treated in vitro with the Fab immunogene carrying TK or CD were transplanted into the back of nude mouse, subsequent systemic administration of GCV or 5-FC effectively suppressed the growth of tumors, indicating the occurrence of in vivo suicide effects.
...
PMID:Ex vivo delivery of suicide genes into melanoma cells using epidermal growth factor receptor-specific Fab immunogene. 1036 86
The c-
erbB-2
gene is frequently overexpressed in human breast cancers as a result of gene amplification and/or elevated transcription. We therefore examined a possible usage of promoter regions of the c-
erbB-2
gene to express a suicide gene preferentially in breast cancer cells. Previous studies did not reveal the minimal promoter region that enabled transcriptional activation specific to breast cancer cells. The present reporter gene assays using deletion mutants of the c-
erbB-2
promoter region demonstrated that the 251-bp (-213/+38 from the transcriptional start site), but not the 125-bp, fragment (-87/+38) could direct transcription of the linked luciferase gene better than the SV40 immediate early promoter in breast cancer cells. In contrast, the 251-bp fragment-mediated promoter activity in nonbreast cancer cells and in normal fibroblasts was lower than the activity by the SV40 promoter. The 126-bp fragment (-213/-87) thereby contains a cis-acting element(s), which is responsible for the preferential transcriptional activity in breast cancer cells. An electrophoretic mobility shift assay suggested that a possible modification of a transcriptional factor was involved in the tumor specificity. Transfection with the plasmid DNA containing the
herpes simplex
virus thymidine kinase gene linked with the 251-bp promoter (p256-TK) resulted in increased sensitivity to ganciclovir in breast cancer, but not in nonbreast cancer cells. Administration of ganciclovir into nude mice bearing human breast tumors that were transfected with the p256-TK DNA suppressed subsequent growth of the transplanted tumors. These results suggest that delivery of a suicide gene linked with the 251-bp c-
erbB-2
promoter can be a feasible therapeutic strategy specific to breast cancer.
...
PMID:A minimum c-erbB-2 promoter-mediated expression of herpes simplex virus thymidine kinase gene confers selective cytotoxicity of human breast cancer cells to ganciclovir. 1177 79
We examined the expression level of the midkine (MK) and c-
erbB-2
genes in both tumorous and matched nontumorous specimens from 18 patients with breast cancer. Expression of the MK and c-
erbB-2
genes in nontumorous regions was relatively low, and the expression levels of both genes were not markedly different among the nontumorous samples. In contrast, the expression of the MK and c-
erbB-2
genes in tumorous specimens was upregulated in 18 and 6 specimens, respectively. Regulatory regions of the MK gene were able to activate a reporter gene to a similar degree as those of the c-
erbB-2
gene in the human breast cancer cell lines tested. Transfection of breast cancer cells with either the MK promoter- or the c-
erbB-2
promoter-linked
herpes simplex
virus thymidine kinase gene increased their sensitivity to the prodrug ganciclovir. These data showed that the MK promoter activated a therapeutic gene in a wider range of human breast cancer than the c-
erbB-2
promoter and suggest that MK promoter-mediated gene therapy is potentially more favorable in clinical settings.
...
PMID:Midkine promoter can mediate transcriptional activation of a fused suicide gene in a broader range of human breast cancer compared with c-erbB-2 promoter. 1513 67
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