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)

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. In this review, the association of HER-2/neu gene and protein abnormalities studied by Southern and slot blotting, immunohistochemistry, enzyme immunoassays, and fluorescence in situ hybridization with prognosis in breast cancer is studied in depth by review of a series of 47 published studies encompassing more than 15,000 patients. The relative advantages of gene amplification assays and frozen/fresh tissue immunohistochemistry over paraffin section immunohistochemistry are discussed. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The potential value of HER-2/neu status for the prediction of response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic, and radiation therapies. The evidence that HER-2/neu gene and protein abnormalities in breast cancer predict resistance to tamoxifen therapy and relative sensitivity to chemotherapy regimens including adriamycin is presented. The review will also evaluate the status of serum-based testing for circulating the HER-2/neu receptor protein and its ability to predict disease outcome and therapy response. In the final section, the review will briefly present preliminary data concerning the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment. The recently presented phase III clinical trial evidence that systemic administration of anti-HER2 antibodies (Herceptin), alone and in combination with cytotoxic chemotherapy in patients with HER-2/neu overexpressing primary tumors, can increase the time to recurrence and overall response rates in metastatic breast cancer is reviewed.
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PMID:The HER-2/neu oncogene in breast cancer: prognostic factor, predictive factor, and target for therapy. 983 67

Recent trials comparing single-agent vs combination therapy in metastatic breast cancer suggest that it may be time to reconsider the belief that combination chemotherapy is the gold standard of treatment. Based on the limited randomized trial data available to date, high-dose chemotherapy with stem-cell rescue should not be viewed as "state-of-the art" treatment for metastatic disease and should be used only in the context of clinical trials. Recent trials have explored the optimal dosing and scheduling of the taxanes, as well as the possible role of these agents in combination regimens. Capecitabine (Xeloda), a new oral fluoropyrimidine, appears to be comparable in efficacy to CMF (cyclophosphamide, methotrexate, and fluorouracil), and preclinical data suggest possible synergy between this agent and the taxanes. Other promising agents under study include liposome-encapsulated doxorubicin (TLCD-99), an immunoconjugate linking a chimeric human/mouse monoclonal antibody to doxorubicin molecules; MTA (LY231514), a multitargeted antifolate; and marimistat, a broad-spectrum matrix metalloproteinase inhibitor. Tamoxifen (Nolvadex) remains the most important hormonal agent, but new antiestrogens and selective estrogen receptor modulators (SERMs) may provide alternatives. The potential role of new aromatase inhibitors as first-line hormonal agents requires further study. Finally, the possible synergy between trastuzumab (Herceptin), a recombinant humanized monoclonal antibody to the HER-2/neu protein, and paclitaxel (Taxol) is being studied in two clinical trials.
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PMID:Update on the management of advanced breast cancer. 1035 85

Humanized anti-c-erbB-2 antibodies (Herceptin) in a weekly schedule are a new therapeutic option for the treatment of c-erbB-2-positive, advanced breast cancer (ABC). Addition of Herceptin to first-line chemotherapy for c-erbB-2 overexpressing ABC increased anticancer activity in a randomized phase III trial. However, except from standard UICC response criteria, there are hitherto no recommendations as to how to monitor Herceptin therapy. In a therapy optimizing study with weekly dose-intensified paclitaxel monotherapy (schedule: 90 mg/m2 weekly x 6, q9w), we correlated the clinical course of stage IV breast cancer in UICC criteria with the course of the shed c-erbB-2 protein fragment and the CA 27.29 serum level. Serum samples were taken weekly from 35 patients to measure the serum c-erbB-2 and CA 27.29 protein levels over time. Up to now, 10 patients (28.5%) are c-erbB-2 positive (> 15 U/mL), with a median baseline protein expression of 65 U/mL. While the overall response rate in the study is 36%, the response rate among c-erbB-2-positive patients is 62%, indicating a high sensitivity of c-erbB-2 positive patients to dose-intense paclitaxel treatment. In all responders the c-erbB-2 serum level decreased below the detection limit either before the clinical diagnosis of response or by the end of the next cycle. However, the normalization of the c-erbB-2 serum level was not specific for responders as patients with stable or progressive disease presented normalized levels or a > 50% decrease of the baseline level, too. The courses of the c-erbB-2 protein levels correlated closely with the courses of CA 27.29. The decrease in the serum c-erbB-2 oncoprotein level might indicate a regression of c-erbB-2 positive tumor load. This may even happen in progressive disease according to UICC criteria when the c-erbB-2-negative tumor fraction progresses while the c-erbB-2-positive fraction is controlled. Another explanation would be that the mechanisms of c-erbB-2 shedding change under chemotherapy, with less of the c-erbB-2 protein fragment being released to the serum, which would make the c-erbB-2 positive tumor cells a better target for anti-c-erbB-2 antibody treatment.
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PMID:c-erbB-2 in serum of patients receiving fractionated paclitaxel chemotherapy. 1039 23

Molecular alterations in breast cancer are being incorporated into the development of new treatment strategies. The HER-2/neu oncogene has been extensively investigated as a prognostic factor and recently as a predictor of response to chemotherapy or endocrine therapy. The development of a humanized anti-HER-2 monoclonal antibody (Herceptin) and the encouraging results obtained in the treatment of patients with HER-2 overexpressing metastatic breast cancer with this antibody have resulted in renewed interest in HER-2/neu. This article reviews the current knowledge of HER-2/neu both as a prognostic and a predictive factor. Problems associated with the standardization of the methodology for assessing HER-2/neu status and clinically significant cut-off points are addressed.
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PMID:Evaluation of HER-2/neu (erbB-2) status in breast cancer: from bench to bedside. 1046 86

The HER2 protein, a member of the epidermal growth factor family, is encoded by the protooncogene c-erbB-2. Its overexpression, occurring in approximately one-third of all breast carcinomas, is associated with a poor prognosis. A humanized mouse antibody against HER2 has been developed by genetic engineering. Here an unspecific human IgG was connected to the recognizing mouse IgG fragment. The allergization typical for allogeneic antibodies does not take place in this context. The effectiveness of this antibody has been confirmed by two international prospective phase III trials that tested it alone and combined with chemotherapy. Both modes of application increased the response rates and the time to progression. Side-effects were rare except for a high rate of cardiac dysfunction when the antibody was combined with anthracyclines. The effectiveness and negligible side-effects of the chimeric antibody against HER2 (Herceptin) render it a valuable tool in the treatment of breast cancer.
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PMID:Therapy of metastatic breast cancer with humanized antibodies against the HER2 receptor protein. 1048 Mar 46

The anti-HER-2/neu antibody trastuzumab (Herceptin; Genentech, San Francisco, CA) interferes with DNA repair induced by cisplatin and, as a result, promotes cytotoxicity in HER-2/neu-overexpressing tumor target cells in a synergistic fashion. This effect of trastuzumab, termed receptor-enhanced chemosensitivity, is specific for HER-2/neu-overexpressing cells, having no effect on cells without overexpression. Based on these findings, we conducted phase I and II clinical trials of trastuzumab plus cisplatin to determine the toxicity, pharmacokinetics, response rate, and response duration of this combination in patients with HER-2/neu-overexpressing metastatic breast cancer who had demonstrated disease progression (chemoresistance) while on active chemotherapy just prior to study entry. In phase I, four of 15 patients had objective clinical responses, including one complete response of several years' duration. Of 37 assessable patients enrolled in phase II, nine (24.3%) had objective clinical responses and an additional nine had minor responses or stable disease. The median time to progression among the responders was 8.4 months. The toxicity profile reflected that expected from cisplatin alone, with no apparent increase in toxicity caused by the addition of trastuzumab. Moreover, the pharmacokinetics of trastuzumab were unaltered by coadministration of cisplatin. We conclude that the combination of trastuzumab and cisplatin results in response rates higher than that reported for either single agent alone. Such receptor-enhanced chemosensitivity offers a new approach to target overexpressed growth factor receptors in a variety of cancers, which will lead to new, biologically based therapeutic strategies for clinical intervention.
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PMID:Combination therapy with trastuzumab (Herceptin) and cisplatin for chemoresistant metastatic breast cancer: evidence for receptor-enhanced chemosensitivity. 1048 99

Development of acquired resistance against antiestrogen treatment is a serious problem in human breast cancer, and knowledge of alterations resulting in resistance is important for selection of further treatment. To mimic the clinical situation we have established a series of MCF-7 human breast cancer cell lines by long term treatment with the antiestrogens tamoxifen, ICI 164,384, and ICI 182,780. Common for these cell lines is a decreased expression of the estrogen receptor alpha (ER alpha). In human breast cancer, lack of response to endocrine therapy is often associated with decreased expression of the estrogen receptor and increased expression of epidermal growth factor receptor (EGFR) and/or HER-2/neu (ErbB-2). Our antiestrogen resistant cell lines did not express altered levels of EGFR, HER-2/neu, ErbB-3, or ErbB-4. Estrogen and antiestrogen regulation of HER-2/neu expression was essentially similar in parent and resistant MCF-7 cells. Treatment with antibodies to HER-2/neu (Herceptin) did not affect growth of MCF-7 cells or resistant cells, indicating that in this in vitro model system, acquired antiestrogen resistance does not emerge from activation of the HER-2/neu signaling pathway. In MCF-7 cells transfected with HER-2/neu and/or ErbB-3, overexpression alone did not result in resistance. However, addition of heregulinl-beta1 abolished the inhibitory activity of ICI 182,780 on both vector and HER-2/neu/ErbB-3 transfected MCF-7 cells, demonstrating that activation of the HER-2/neu receptor signaling pathway can override the growth inhibitory effect of ICI 182,780.
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PMID:Acquired antiestrogen resistance in MCF-7 human breast cancer sublines is not accomplished by altered expression of receptors in the ErbB-family. 1063 17

Anthracyclines and taxanes are the two most active classes of chemotherapy for the treatment of advanced breast cancer. Recent studies have investigated combination therapy including doxorubicin (Dox) and paclitaxel. The efficacy of this combination has been established in a phase III study conducted by ECOG, comparing Dox/paclitaxel versus Dox versus paclitaxel. The combination is superior to Dox or paclitaxel with respect to response rate and time to disease progression, indicating that the combination provides a new standard for the first line treatment of metastatic breast cancer [1]. Phase II studies using higher doses of Dox and using shorter infusions of paclitaxel have suggested the combination can be further optimized; Gianni reported a 94% objective response rate using Dox 60 mg/m2 followed by paclitaxel 175 mg/m2 given over three hours [2]. The more active regimens are associated with enhanced cardiotoxicity; this toxicity can be avoided, however, by limiting the exposure to doxorubicin. The newer regimens have now been moved into phase III studies. Future progress for this disease will depend on the introduction of new agents. Two novel drugs are currently being investigated in randomised phase III trials as potentiators of Dox and/or paclitaxel. One is a monoclonal antibody from Genentech (Herceptin, trastuzumab) directed at the HER-2/neu oncogene, which is overexpressed in > 25% of breast cancers [3]. Recent results indicate that Herceptin in combination with paclitaxel (or with a Dox plus cyclophosphamide regimen) induces a higher response rate (RR) and prolongs the time to disease progression when compared to chemotherapy alone. The second agent N,N-diethyl-2[4-(phenylmethyl)-phenoxy] ethanamine.HCl (DPPE, BMS-217380-01), when combined with Dox, was associated with a higher RR than previously observed with Dox alone [4]. A randomized trial of Dox versus Dox plus DPPE is ongoing. The possible mechanisms underlying chemo-potentiation by these agents are discussed. As new anthracycline/taxane combinations establish themselves in earlier stages of the disease, the need for effective, non-cross resistant salvage regimens will emerge.
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PMID:New developments in chemotherapy of advanced breast cancer. 1067 65

Amplification and/or overexpression of HER-2/neu has been shown to be both a prognostic and predictive marker in breast cancer. Recent studies have also confirmed the efficacy of Herceptin (trastuzumab) as adjuvant therapy for patients with overexpression of HER-2/neu. Therefore, it is critical that precise and reproducible assays be used in the clinical laboratory setting for determination of the HER-2/neu status in patients with breast cancer. The objective of this study was to determine the portability (reproducibility between different institutions) of the PathVysion HER-2 fluorescence in situ hybridization (FISH) assay used for detection of amplification of the HER-2/neu gene in formalin-fixed, paraffin-embedded tissue sections of invasive ductal carcinoma of the breast. Study specimens consisted of one breast tumor with a normal HER-2/neu copy number, two tumors with a low level, and one tumor with a high level of HER-2/neu amplification. The PathVysion HER-2 assay was shown to be highly reproducible on different assay days (n = 3) and between different institutions (n = 5) in the detection of amplification of the HER-2/neu gene in routinely processed clinical specimens of breast carcinoma. In addition, this study examined the feasibility of enumerating FISH signals in 20 nuclei in contrast to 60 nuclei per specimen. Although a modest increase in variation was observed when analyzing 20 compared to 60 nuclei, the mean ratios were similar. Therefore, analysis of as few as 20 nuclei with this FISH HER-2/neu assay may be sufficient for determining the amplification level of the HER-2/neu gene.
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PMID:Fluorescence in situ hybridization (FISH) for detection of HER-2/neu amplification in breast cancer: a multicenter portability study. 1067 82

A better understanding of the biology of breast cancer should lead to the rational development of new treatments and the ability to customize therapy for individual patients. Though promising in theory, translating advances in biological knowledge to the clinic has been difficult. Recently several areas of research have produced treatments which have entered clinical trials: three will be reviewed here. The growth of breast cancer is regulated by growth factors and their receptors; amplification or overexpression is associated with poor prognosis. As such inhibition of growth factors and/or growth factor receptors may provide an ideal therapeutic target. Herceptin binds to c-erbB-2, a member of the epidermal growth factor receptor family. Significant responses were seen in patients with c-erbB-2 overexpressing breast cancer with Herceptin administered as a single agent or in combination with chemotherapy. Herceptin was approved by the Food and Drug Administration in late 1998. Breast cancer invasion and metastasis requires degradation of the surrounding basement membrane by matrix metalloproteinases and other proteolytic enzymes. Synthetic inhibitors of these enzymes are now in clinical trials. Breast cancers must stimulate angiogenesis, the growth of new blood vessels, in order to grow beyond a few millimeters in diameter. This nascent vascular network provides another opportunity for therapy. Preclinical models support the critical role of angiogenesis and the therapeutic benefit of angiogenesis inhibition; clinical trials are underway.
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PMID:Toward checkmate: biology and breast cancer therapy for the new millennium. 1075 7


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