Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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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

Increases in the average gene copy number (AGCN) of the erbB oncogenes, especially the erbB-2 gene, have been found in a variety of human cancers. Such information is useful with respect to prognosis of the disease. Poor reproducibility and DNA damage complicate quantitative polymerase chain reaction (PCR)-based methods. Therefore, we describe a quantitative PCR method for the estimation of AGCN in the oncogenes erbB-1 (egfr), erbB-2, and erbB-3. The method comprises a competitive and differential PCR in a one-tube reaction (competitive-differential PCR, or cdPCR). Genomic sequences of the oncogene and the human beta-globin (HBB) reference gene and two competitors for the oncogene and reference gene were amplified with two primer pairs simultaneously. The competitors were chosen to be amplified with the same efficiency as the genomic sequences. Using this method, we confirmed egfr and erbB-2 amplification in cancer cell lines and tumor tissue, and we also detected erbB-3 amplifications. Furthermore, gene dosage decreases were detectable, e.g., an erbB-2 hemizygosity in MCF-7 cells. Thus, cdPCR facilitates the detection of both increases and decreases in AGCN with high reproducibility, sensitivity, and accuracy. This method is therefore suitable for clinical studies on erbB oncogene dosage deviations.
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PMID:Competitive-differential polymerase chain reaction for gene dosage estimation of erbB-1 (egfr), erbB-2, and erbB-3 oncogenes. 915 Apr 31

We previously demonstrated that delivery of a gene encoding an anti-erbB-2 intracellular single-chain antibody (sFv) resulted in down-regulation of cell surface erbB-2 levels and induction of apoptosis in erbB-2 overexpressing ovarian cancer cells. Based upon these findings, we hypothesized that human breast carcinomas overexpressing erbB-2 would be similarly affected by this genetic intervention. We evaluated the phenotypic effects resulting from intracellular expression of the anti-erbB-2 sFv on the human breast cancer cell lines MDA-MB-361, SK-BR-3, BT-474, MCF-7 and MDA-MB-231. Recombinant adenoviruses encoding either a reporter gene (AdCMVLacZ) or the endoplasmic reticulum (ER) directed anti-erbB-2 sFv (Ad21) were delivered to various breast cancer cell lines. Cell viability was determined by a proliferation assay and fluorescent microscopy allowed visualization of apoptotic cells. An erbB-2 ELISA quantified the endogenous erbB-2 levels of each cell line. The anti-erbB-2 sFv-encoding-adenovirus, Ad21, but not the beta-galactosidase encoding adenovirus, AdCMVLacZ, was cytotoxic to > 95% of the tumor cells in the MDA-MB-361 and SK-BR-3 lines, and > 60% of the tumor cells in the BT-474 line. In marked contrast, the MCF-7 and MDA-MB-231 cell lines showed no change in the rate of cell proliferation following this treatment. The cytotoxic effects generated in the first three lines were a consequence of the induction of apoptosis by the anti-erbB-2 sFv. An ELISA specific for erbB-2 showed that the breast cancer cell lines most susceptible to the anti-erbB-2 sFv, MDA-MB-361, SK-BR-3 and BT-474, overexpressed the erbB-2 protein while the cell lines demonstrating no response to the anti-erbB-2 sFv, MCF-7 and MDA-MB-231, expressed the lowest levels of erbB-2. These results demonstrate that targeted killing of erbB-2 overexpressing cells via intracellular knockout can be accomplished in the context of breast carcinoma. Furthermore, erbB-2 levels in breast tumor cells may be predictive of their sensitivity to sFv-mediated killing. The ability to accomplish selective cytotoxicity of breast cancer cell lines overexpressing the erbB-2 tumor marker should allow for derivation of clinical gene therapy strategies for breast cancer utilizing this approach.
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PMID:An intracellular anti-erbB-2 single-chain antibody is specifically cytotoxic to human breast carcinoma cells overexpressing erbB-2. 917 17

Amplification and over-expression of the HER-2/neu proto-oncogene are associated with poor prognosis in women with both node-positive and node-negative breast cancer. Therefore, the encoded surface glycoprotein represents an attractive target for cancer immunotherapies. Furthermore, the extracellular domain of HER-2/neu is released from the cell surface by proteolytic cleavage. In the present experiments, we investigated the potential biologic effects of soluble HER-2/neu with particular emphasis on its interaction with anti-HER-2/neu antibodies. A monoclonal antibody specific for the extracellular domain of HER-2/neu dose dependently inhibited the proliferation of highly HER-2/neu-expressing SK-BR-3 and BT-474 breast cancer cells but had no effect on the proliferation of weakly to moderately HER-2/neu-expressing MCF-7, HBL-100 and ZR-75-1 breast cells. Addition of SK-BR-3 or BT-474 cell supernatants with high concentrations of soluble HER-2/neu led to a neutralization of anti-HER-2/neu antibody-mediated inhibition of proliferation due to a binding of soluble HER-2/neu by the antibody, which could be demonstrated by immunoprecipitation. Furthermore, the ability of anti-HER-2/neu antibodies to mediate antibody-dependent cellular cytotoxicity (ADCC) by lymphokine-activated killer cells was assessed. Cytolysis of SK-BR-3 tumor cells was increased significantly in the presence of anti-HER-2/neu antibodies. Similar to the proliferation inhibition, ADCC was neutralized by addition of soluble HER-2/neu-containing supernatants. Our data suggest that tumors rich in HER-2/neu might thus escape certain steps of immunologic control by neutralizing biologic activities of anti HER-2/neu antibodies due to the presence of soluble HER-2/neu.
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PMID:Soluble HER-2/neu neutralizes biologic effects of anti-HER-2/neu antibody on breast cancer cells in vitro. 939 69

HER2 (erbB-2) proto-oncogene amplification and/or overexpression correlate with poor prognosis in many malignancies. The precise biological role of this oncogenic signaling pathway (which also involves the HER4 gene) in breast cancer is unclear. One property conferred by this oncogene relates to response to drug therapy. Clinical studies support an association between HER2 overexpression and resistance to alkylating agents (cisplatinum and cyclophosphamide). Data from the Cancer and Leukemia Group B 8869/8541 study indicate enhanced dose responsiveness to doxorubicin (Adriamycin) in patients who overexpress the HER2 receptor. Heregulin beta-2, a naturally occurring ligand that activates the HER2 receptor by inducing its heterodimerization with the HER4 receptor, has recently been cloned. The ability of this ligand to phosphorylate the HER2 receptor exogenously allows us to study the effect of HER2 activation on cancer cell behavior. To study the relationship between chemotherapy response and activation of HER2, MCF-7 cells expressing biologically active heregulin were assessed for response to doxorubicin and etoposide, both of which are topoisomerase IIalpha (topo IIalpha) inhibitors. Several clones show markedly increased sensitivity to these drugs. In addition, the same wild-type MCF-7 cells transfected with heregulin beta-2 under the control of an inducible promoter also show this dose-response relationship to doxorubicin after the expression of heregulin beta-2 is activated by zinc. The modulation of topo IIalpha was studied in the cell lines transfected with heregulin. topo IIalpha mRNA and protein (total protein and enzymatic decatenating activity) were found to be up-regulated in heregulin beta-2-transfected cells. Moreover, topo IIalpha promoter activity was also modestly increased in heregulin beta-2-transfected cells. Because up-regulation of topo IIalpha in vitro and in clinical specimens is associated with increased response to doxorubicin (presumptively by an increase in drug substrate), this may be the mechanism of the increased sensitivity to doxorubicin seen in heregulin beta-2-transfected cells. This implies that activation of HER2 or one of the other members of the receptor family may increase sensitivity to doxorubicin by up-regulation of topo IIalpha. This finding suggests the use of receptor/ligand expression to direct patient-specific therapeutic choices (e.g., doxorubicin versus alkylator-based regimens) and the use of biological agents (such as heregulin) in combination with certain chemotherapeutic agents to enhance response to treatment in breast cancer patients.
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PMID:Induction of sensitivity to doxorubicin and etoposide by transfection of MCF-7 breast cancer cells with heregulin beta-2. 956 96

A cDNA clone covering part of the C-terminal domain of human EF-1 delta was isolated from mammary cancer cells by subtractive hybridisation. The higher expression of EF-1 delta in the tumours suggested that malignant transformation in vivo requires an increase in translation factor mRNA and protein synthesis for entry into and transition through the cell cycle. To explore the relation between cell division and EF-1 delta expression, MCF-7 cells were treated with dexamethasone, an inducer of differentiation. There was no change in the mRNA levels of EF-1 delta in the dexamethasone-treated cells. To explore the relation between oncogenes and EF-1 delta expression, a variety of oncogenes were introduced into human mammary epithelial cells (MCF-7) and human keratinocytes (HaCaT). Despite high oncogene mRNA expression, there was no significant change in the EF-1 delta mRNA level by v-src, c-erbB (EGF Receptor), c-erbB-2, v-myc and v-fos oncogenes. However, overexpression of v-Ha-ras in HaCaT cells resulted in a three to five-fold decrease in the steady-state mRNA level of EF-1 delta. Taken together, the data provides further support on the interaction of translation factors and oncogenic transformation.
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PMID:Modulation of elongation factor-1 delta (EF-1 delta) expression by oncogenes in human epithelial cells. 956 7

New therapeutic strategies are now being developed against adenocarcinoma associated with erbB-2 amplification, particularly by inhibiting p185erbB-2 expression. Antisense oligodeoxynucleotides seem promising for this purpose as long as they are efficiently protected against degradation and targeted into the cells. We present antisense oligonucleotide carriers, the supramolecular biovectors (SMBVs), for which we have already demonstrated the ability to improve both cellular uptake and protection of oligodeoxynucleotide. The present work demonstrates that SMBVs elicit a specific and non-toxic action of antisense compounds in a cell model, irrespective of their sensitivity to nucleases. This is a major point, considering the specificity problems associated with the use of nuclease-resistant phosphorothioate oligodeoxynucleotide. SMBVs improve antisense efficiency of oligodeoxynucleotide designed against p185erbB-2, with a complete growth arrest of SK-Br-3, human adenocarcinoma mammary cells that overexpress p185erbB-2 and no effect on MCF-7 cells that normally express p185erbB-2. The comparison of SMBVs with DOTAP reveals the statistically higher efficiency of SMBVs, which allows the antisense inhibition of p185erbB-2 expression in 65-75% of SK-Br-3 cells (P < 0.05). The efficiency and controlled synthesis of SMBVs underline their potentialities as oligodeoxynucleotide carriers for in vivo experiments.
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PMID:SupraMolecular BioVectors (SMBV) improve antisense inhibition of erbB-2 expression. 965 60

We investigated the effects of all-trans retinoic acid (ATRA) and fenretinide (4-HPR) on c-erbB-2 expression in SK-BR-3, BT-474 and MCF-7 breast cancer cells and on the growth, differentiation, apoptosis and cisplatin (CDDP) sensitivity of SK-BR-3 cells. It has been reported that oestrogen inhibits c-erbB-2 in oestrogen receptor-positive breast cancer cells. Using ELISA, Western and Northern analysis we have demonstrated that ATRA and 4-HPR exert similar effects down-regulating c-erbB-2 protein and mRNA in c-erbB-2-overexpressing SK-BR-3 and BT-474 and in normally expressing MCF-7 cells. Both retinoids inhibit SK-BR-3 cell growth. ATRA induces cellular enlargement and flattening, suggesting epithelial differentiation. 4-HPR causes nuclear and cytoplasmic condensation, DNA fragmentation and externalization of phosphatidylserine, indicating apoptosis. c-erbB-2 expression/activity has been linked to sensitivity against CDDP. Therefore, combinations of ATRA or 4-HPR with CDDP were tested for their anti-proliferative activity. Retinoid-conditioned cells were either exposed to retinoid and CDDP (schedule I, 'continuous retinoid treatment') or to CDDP alone (schedule II, 'retinoid pretreatment'). This retinoid-conditioning followed by CDDP +/- retinoid yields stronger growth inhibition compared with unconditioned cells, which were exposed to CDDP +/- retinoid (schedule III, 'no retinoid pretreatment'). The inefficacy of schedule III indicates that retinoid-conditioning is essential for the improvement of the antiproliferative effect. The interactions in schedules I and II are synergistic for ATRA and CDDP, but slightly antagonistic for 4-HPR and CDDR However, 4-HPR + CDDP is more effective in growth inhibition than each drug alone.
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PMID:Effects of retinoic acid and fenretinide on the c-erbB-2 expression, growth and cisplatin sensitivity of breast cancer cells. 966 55

Molecular changes associated with breast cancer progression were characterized using the MCF-10F cell series. MCF-10F was established from fibrous mastectomy tissue of a patient without detectable cancer. In vitro treatment of MCF-10F cells with benzo(a)pyrene resulted in a transformed subclone MCF-10F-BP1 (BP1). Transfection of clone BP1 with T24-Hras resulted in the tumorigenic line MCF-10F-BP1-Tras (BP1-Tras). Using flow cytometry, the expression of HLA I, ERBB-2 and MUC-1 was found to be comparable in 'normal' MCF-10F, transformed BP1 and tumorigenic BP1-Tras cells. Glycosylated mucin is elevated in BP1 but reduced in BP1-Tras cells. Using mRNA differential display analysis, cDNA profiles of the 'normal', transformed and tumorigenic cell lines were strikingly similar, yet distinct and elevated expression of several common cDNA fragments was detected in BP1 and BP1-Tras when compared with MCF-10F cells. These fragments were cloned and sequenced. The sequences of clones T1-360 and C4-310 are homologous to two reported EST cDNA clones from human fetal tissue and were further characterized. Elevated expression of the genes corresponding to clones T1-360 and C4-310 was verified using Northern blotting. High-level expression of these genes was also detected in the breast cancer cell line MCF-7 that was derived from the pleural effusion of a patient with advanced breast cancer. Therefore, specific molecular changes associated with breast cancer development were identified and may be indicators of neoplastic progression.
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PMID:Neoplastic progression of breast epithelial cells--a molecular analysis. 968 93

c-erbB-2, a member of the tyrosine kinase oncogene family, is overexpressed in about 30% of human breast tumors where it correlates with poor prognosis. In vitro studies have suggested that increased expression of the receptor plays an important role in malignant progression. To better understand the direct effects of p185HER2 overexpression, a human c-erbB-2 expression vector was transfected into the hormone-dependent MCF-7 human breast carcinoma cell line and cell growth was analysed. Unexpectedly, colony formation assay revealed a reduction in the number and size of colonies as compared with mock-transfected cells. In hormone-deprived medium, c-erbB-2 transfected cells acquired growth capability, consistent with previous reports. By contrast, two c-erbB-2-transfected clones grown in complete medium showed a reduced proliferation rate despite the activation of a fully functional oncoprotein capable of autophosphorylation and induction of the MAPK pathway. The number of c-erbB-2-overexpressing cells in the S phase of the cell cycle was about one-half the number of control and mock-transfected cells. Also, overexpression of c-erbB-2 induced overexpression of p21WAF1, pRB hypophosphorylation and a mature differentiated cell phenotype with production of lipid droplets. Functional inactivation of p185HER2 by means of a specific single chain antibody indicated the c-erbB-2-dependence of the observed alterations. These data show that the exogenous overexpression of the c-erbB-2 gene in hormone-dependent breast cancer cells inhibits proliferation and induces differentiation.
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PMID:Increased expression of c-erbB-2 in hormone-dependent breast cancer cells inhibits cell growth and induces differentiation. 969 35


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