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)

HER-2/neu is a 185 kDa glycoprotein related to the epidermal growth factor receptor. Overexpressed in 25-30% of primary breast carcinomas, HER-2/neu is associated with a poor clinical outcome. Recently the FDA approved an antibody to HER-2/neu, trastuzumab (Herceptin), for the treatment of HER-2/neu overexpressing metastatic breast cancers. Relatively little is known about HER-2/neu status and lung cancers. We reasoned that if HER-2/neu status could be ascertained in non-small cell lung carcinomas (NSCLCs), and a clinical correlation can be established, a rationale for the use of Herceptin in this tumor type could be established. Using a FDA-approved standardized diagnostic kit, HercepTest, for detection of HER-2/neu in clinical specimens, we examined the expression of HER-2/neu in NSCLCs in archival paraffin-embedded specimens (N = 81). In normal epithelium, HER-2/neu expression was not detected in a majority of samples (74/81). HER-2/neu overexpression was detected in 27% of the tumors of different histological types including adenocarcinomas, large cell carcinomas, and squamous cell carcinomas. Poor to moderately differentiated, but not well differentiated tumors showed overexpression of HER-2/neu. The specificity of HercepTest was further increased (from 27% to 21%) when the expression in the few normal tissues was subtracted from the tumor score. HER-2/neu may offer an attractive predictive and prognostic factor for NSCLC.
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PMID:HER-2/neu expression in archival non-small cell lung carcinomas using FDA-approved Hercep test. 1092 58

Since the development of novel immunotherapy using Herceptin as the first agent specifically indicated for HER-2/neu overexpression in metastatic breast cancer, there has been interest in using HercepTest as a predictor of response to such therapy. There is debate whether it is justifiable to perform HercepTest on every newly diagnosed breast cancer, since only approximately 43% of the cases will have related metastatic disease, and Herceptin is indicated only for breast cancer with metastatic disease. It may be more cost-effective to limit HercepTest to the related metastatic lesions. Therefore, it is important to assess whether the pattern of HER-21neu overexpression of metastatic breast cancer is also present in the primary lesion. HercepTest was performed on formalin-fixed, paraffin-embedded tissue sections of 56 primary breast cancers and their corresponding metastatic lesions. The protocol and scoring guidelines recommended by the manufacturer were followed. Tissue sections (5 microm) of a primary and the metastatic lesion from the same case were placed parallel on a single glass slide. The pattern and intensity of HER-2/neu overexpression (32%) in the primary and metastatic lesions were found to be nearly identical. Heterogeneity was observed in only one case. The score of primary cancer was 3+, and the metastatic lesion was 2+. Both were reported as positive. Intratumor heterogeneity (1+ to 3+) was also noted in two (4%) cases. However, the same pattern was found in both the primary and related metastatic lesions. The nearly identical HercepTest results in the primary and metastatic lesions suggest the potentiality of limiting the HercepTest to breast cancer-related metastases. Currently, any superficial and most deep-seated metastatic lesions can be easily sampled by fine needle aspiration biopsy or core biopsy, providing adequate samples for HercepTest. Eliminating unnecessary use of the HercepTest may provide a cost-effective alternative approach to the management of breast cancer patients.
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PMID:Assessment of Her-2/neu overexpression in primary breast cancers and their metastatic lesions: an immunohistochemical study. 1094 65

Pharmacogenomic analysis aspires to identify individuals with specific genetic characteristics in order to predict a positive response or reduce a negative response to a therapeutic modality. While the search continues for the many single nucleotide polymorphisms which will be used in such genetic analyses, other genetic alterations in specific cell types have proven useful in determining the potential for response to therapy. One such genetic alteration is amplification of entire gene sequences which results in overexpression of a gene product or protein. Amplification of the HER2 (neu, erbB-2) oncogene is found in up to 35% of human breast cancers and is associated with a poor prognosis. In addition, this genetic alteration may predict response to various therapeutic modalities. Assays are available to detect the HER2 protein receptor or copies of the HER2 gene sequence to determine eligibility for Herceptin treatment or adriamycin treatment in node positive patients, respectively. This model represents a somatic event used in the functional determination of a therapeutic strategy.
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PMID:Gene amplification as means for determining therapeutic strategies in human cancers. 1109 37

The human epidermal growth factor receptor HER2 or C-erbB-2/neu is a tyrosine kinase membrane receptor, which when activated, induces a phosphorylation cascade in cytoplasmic kinases leading to increased protein transcription and cellular growth. HER2 plays an important role in the biology of breast cancer, an observation that has led to the selection of HER2 as a potential target for breast cancer treatment. Trastuzumab (Herceptin) is the first anti-HER2 monoclonal antibody that has shown a survival benefit in metastatic breast cancer patients with HER2-positive tumours (Norton et al., Proc ASCO 2000 18, 127a (abstract 483)). Tumour HER2 status should no longer be ignored because of its direct implications for the optimal management of breast cancer patients. A high priority for future research is to refine and standardise HER2 testing in order to minimise false-negative results. Furthermore, this procedure would overcome current issues relating to test reproducibility between pathology laboratories and definitions of HER2 positivity. In the meantime, a HER2-positive status on testing using any approved technique has implications for clinical practice (Fig. 1). The treatment algorithm given in Fig. 1 considers the lack of level 1, evidence-based studies that demonstrate convincingly the value of HER2 as a predictive marker for resistance or sensitivity to classic forms of breast cancer therapy (Piccart et al., Eur J Cancer 2000, 36, 1755-1761). In addition, the algorithm incorporates the available data from 1999-2000, which were generated from prospective trials exploring the value of trastuzumab both as a single agent and in combination with chemotherapy.
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PMID:Closing remarks and treatment guidelines. 1116 89

Previous studies have shown a synergistic interaction between trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA) and the cytotoxic drug cisplatin in human breast cancer cells. To define the nature of the interaction between trastuzumab and other classes of cytotoxic drugs, we applied multiple drug effect/combination index isobologram analysis to a variety of chemotherapeutic drug/trastuzumab combinations in vitro. Synergistic interactions at clinically relevant drug concentrations were observed for trastuzumab in combination with cisplatin, docetaxel, thiotepa, 4-OH cyclophosphamide, vinorelbine, and etoposide. Additive cytotoxic effects were observed with trastuzumab plus doxorubicin, paclitaxel, methotrexate, and vinblastine. One drug, 5-fluorouracil was found to be antagonistic with trastuzumab in vitro. In vivo drug/trastuzumab studies were conducted with HER-2/neu-transfected MCF7 human breast cancer xenografts in athymic mice. Combinations of trastuzumab plus cisplatin, docetaxel, cyclophosphamide, doxorubicin, paclitaxel, methotrexate, etoposide, and vinblastine in vivo resulted in a significant reduction in xenograft volume compared to chemotherapy-alone controls (P < .05). The synergistic interaction of trastuzumab with specific chemotherapeutic agents suggests rational combinations for testing in human clinical trials.
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PMID:Trastuzumab and chemotherapeutics: drug interactions and synergies. 1123 23

HER-2 (c-erbB-2, neu) is an important prognostic and predictive factor in breast cancer. Clinical trials utilizing a humanized version of the anti-HER-2 murine monoclonal antibody 4DS, trastuzumab (Herceptin; Genentech Inc, South San Francisco, CA), have shown antitumor activity in patients with HER-2-positive metastatic breast cancer. Improved response and survival rates have been shown when trastuzumab was added to first-line combination chemotherapy with anthracycline/cyclophosphamide or paclitaxel, compared to the same chemotherapy alone. The Breast Cancer Intergroup has recently completed several trials evaluating new chemotherapy treatment approaches for patients with node-positive breast cancer, which form the basis for several ongoing and planned clinical trials incorporating trastuzumab. These clinical trials and the evolving role of trastuzumab-containing adjuvant systemic therapy for breast cancer will be reviewed.
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PMID:Ongoing and planned adjuvant trials with trastuzumab. 1123 24

Studies with human breast cancer cell lines have shown a causal association between overexpression of the HER-2/neu proto-oncogene receptor and the acquisition of resistance to tamoxifen. Some clinical studies also indicate that patients with tumors showing high HER-2 levels or high levels of the circulating ectodomain of HER-2 may have a lower response to tamoxifen compared with tumors with low HER-2 levels or low circulating ectodomain. Treatment with anti-HER-2 antibodies seems to restore tamoxifen activity in some experimental systems. However, whether anti-HER-2 therapies will increase tamoxifen action and/or reverse this putative oncogene-mediated resistance in patients with estrogen receptor-positive, hormone-dependent tumors, is unclear. We are conducting a phase II trial of a humanized anti-HER-2 monoclonal antibody, trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA) in combination with tamoxifen in patients with estrogen receptor-positive metastatic breast cancer. Other prospective randomized clinical trials are needed to directly evaluate the contribution of HER-2 signaling to antiestrogen resistance in vivo.
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PMID:Ongoing and planned trials of hormonal therapy and trastuzumab. 1123 26

HER-2/neu is overexpressed in most epithelial malignancies. Lung cancer, prostate cancer, and ovarian cancer are common epithelial tumors in which clinical trials are currently in progress to explore the potential therapeutic role for monoclonal antibodies to HER-2/neu (trastuzumab [Herceptin; Genentech, Inc, South San Francisco, CA]). In preclinical studies with tumor cell lines, trastuzumab was found to have additive and synergistic effects with some chemotherapeutic agents. Clinical trials investigating combination chemotherapy with trastuzumab and a variety of chemotherapeutic agents are already in progress in lung cancer.
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PMID:HER-2/neu as a therapeutic target in non-small cell lung cancer, prostate cancer, and ovarian cancer. 1123 29

Abnormalities in the expression, structure, or activity of proto-oncogene products contribute to the development and maintenance of the malignant phenotype. For example, c-erbB-2 encodes the HER-2 receptor (also known as c-erbB-2 or c-neu) that is overexpressed, amplified, or both in a number of human malignancies including breast, ovarian, colon, lung, prostate, and cervical cancers. In addition to deregulation of cell-surface HER receptors, cancer cells often show excessive activation and/or nonattenuation of growth factor--inducible signaling components, as well as their downstream transcription factors. Current approaches to target HER-2 pathways include downregulation of HER-2 by the adenovirus 5E1A, antisense phosphothionate oligonucleotides, ribozyme, and targeting tyrosine kinase using specific inhibitors. Because growth factors regulate the proliferation of cancer cells by activating receptors on the surface of cells, one obvious approach to control cell proliferation is to interfere with the growth factor receptor-mediated autocrine/ paracrine growth stimulation by antireceptor-blocking monoclonal antibodies. Therefore, a large number of scientists are attempting to control the growth of cancer cells using agents that inhibit one or more of the above steps of growth factor action. Recently completed clinical trials established the usefulness of a humanized form of 4DS monoclonal antibody, trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA), against some forms of breast tumors overexpressing HER-2 receptors. Using in vitro models, recent studies have shown that HER-2 overexpression may not be a prerequisite for invasion of breast cancer cells, as HER-2 activation by heregulin, which binds to HER-3 or HER-4 and transphosphorylates HER in noninvasive breast cancer cells, could lead to increased motility, enhanced gelatinolytic activity, and invasion. Furthermore, these ligand-driven phenotypic changes were completely suppressed by trastuzumab, which also blocked interactions between HER-2 and HER-3 receptors in heregulin-treated breast cancer cells, and inhibited the phosphatidylinositol-3' kinase-dependent pathway, but not the mitogen-activated protein kinase pathway. These phenotypic effects of anti-HER-2 monoclonal antibody are of special interest, because they point to potential therapeutic effects of trastuzumab in inhibiting the invasion and metastasis of breast cancer with low receptor expression.
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PMID:New insights into anti-HER-2 receptor monoclonal antibody research. 1123 33

Recent clinical studies have documented the efficacy of trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA) as a new biologically targeted therapy for erbB-2 receptor-positive forms of breast cancer. During the course of a large-scale clinical trial, a subset of patients reported the onset of symptoms and signs of cardiac failure that appeared to be aggravated by concomitant exposure to anthracyclines. The mechanisms responsible for this cardiac toxicity are unclear. However, new insights into the pathways that lead to other forms of heart failure have identified a pivotal role for myocyte survival pathways in preventing the onset of cardiomyopathy and associated heart failure in genetically engineered animal models of the disease. This mini-review highlights these recent findings and suggests the possibility that the loss of erbB-2 receptor-dependent myocyte survival pathways may create a susceptibility for the onset of heart failure in response to the cardiotoxicity of anthracycline treatment. The possibility exists that the divergent susceptibility for the onset of cardiotoxicity among patients who have received trastuzumab might ultimately reflect an inherent genetic susceptibility to the diverse mechanisms that initiate, promote, and suppress the complex pathways to heart failure.
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PMID:Myocyte survival pathways and cardiomyopathy: implications for trastuzumab cardiotoxicity. 1123 34


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