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Kumar R, George B, Campbell MR, Verma N, Paul AM, Melo-Alvim C, Ribeiro L, Pillai MR, da Costa LM, Moasser MM. HER family in cancer progression: From discovery to 2020 and beyond. Adv Cancer Res 2020; 147:109-160. [PMID: 32593399 DOI: 10.1016/bs.acr.2020.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases (RTKs) are among the first layer of molecules that receive, interpret, and transduce signals leading to distinct cancer cell phenotypes. Since the discovery of the tooth-lid factor-later characterized as the epidermal growth factor (EGF)-and its high-affinity binding EGF receptor, HER kinases have emerged as one of the commonly upregulated or hyperactivated or mutated kinases in epithelial tumors, thus allowing HER1-3 family members to regulate several hallmarks of cancer development and progression. Each member of the HER family exhibits shared and unique structural features to engage multiple receptor activation modes, leading to a range of overlapping and distinct phenotypes. EGFR, the founding HER family member, provided the roadmap for the development of the cell surface RTK-directed targeted cancer therapy by serving as a prototype/precursor for the currently used HER-directed cancer drugs. We herein provide a brief account of the discoveries, defining moments, and historical context of the HER family and guidepost advances in basic, translational, and clinical research that solidified a prominent position of the HER family in cancer research and treatment. We also discuss the significance of HER3 pseudokinase in cancer biology; its unique structural features that drive transregulation among HER1-3, leading to a superior proximal signaling response; and potential role of HER3 as a shared effector of acquired therapeutic resistance against diverse oncology drugs. Finally, we also narrate some of the current drawbacks of HER-directed therapies and provide insights into postulated advances in HER biology with extensive implications of these therapies in cancer research and treatment.
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Affiliation(s)
- Rakesh Kumar
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India; Department of Medicine, Division of Hematology & Oncology, Rutgers New Jersey Medical School, Newark, NJ, United States; Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, United States.
| | - Bijesh George
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
| | - Marcia R Campbell
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, United States
| | - Nandini Verma
- Advanced Centre for Treatment, Research and Education in Cancer, Mumbai, India
| | - Aswathy Mary Paul
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
| | - Cecília Melo-Alvim
- Medical Oncology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Leonor Ribeiro
- Medical Oncology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - M Radhakrishna Pillai
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
| | - Luis Marques da Costa
- Medical Oncology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Mark M Moasser
- Department of Medicine, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, United States.
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Kumar R. John Mendelsohn's journey in cancer biology and therapy. Cancer Biol Ther 2020; 21:389-390. [PMID: 31971860 DOI: 10.1080/15384047.2020.1712829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Affiliation(s)
- Rakesh Kumar
- Cancer Biology Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India.,Department of Human & Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.,Department of Medicine, Hematology-Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA
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Kumar R, Murad F, Bogler O, O'Malley BW, Hortobagyi GN. John Mendelsohn: A visionary scientist, oncologist and leader. Genes Cancer 2019; 10:109-118. [PMID: 31798764 PMCID: PMC6872667 DOI: 10.18632/genesandcancer.195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Dr. John Mendelsohn is credited for the concept of targeting the epidermal growth factor receptor (EGFR), providing the first evidence of anticancer activity of antagonist anti-EGFR mAb, and developing the Erbitux (Cetuximab) drug for cancer patients. During his professional journey, Dr. Mendelsohn also helped to build and elevate the status of three cancer cancers, all while touching the lives of cancer patients around the globe. He was a towering figure, and his passing in January 2019 casts a very long shadow over the entire field of cancer research and treatment. Although no one person can ever adequately fill John Mendelsohn's very large shoes, we can all learn by his remarkable example. Here we discuss Dr. Mendelsohn's professional life to spotlight his influence on oncology and also share personal reflections from us and several colleagues: Tony Hunter, Robert A. Weinberg, Robert C. Bast, Raymond Sawaya, David M. Gershenson, Christopher J Logothetis, Stanley R. Hamilton, Mien-Chie Hung, and George M. Stancel. See related article Kumar et al. Can Res 2019; 79:4315-4323.
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Affiliation(s)
- Rakesh Kumar
- Cancer Biology Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, INDIA.,Department of Human & Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, USA.,Department of Medicine, Hematology-Oncology, Rutgers New Jersey Medical School, Newark, USA
| | - Ferid Murad
- Department of Medicine, Stanford University, Palo Alto, CA, USA.,Palo Alto Veterans Institute for Research (Stanford Affiliated Hospital), Palo Alto, CA, USA
| | - Oliver Bogler
- ECHO Institute, University of New Mexico, Albuquerque, USA
| | - Bert W O'Malley
- Department of Cellular and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Gabriel N Hortobagyi
- Breast Medical Oncology, The University of Texas MD Anderson Cancer, Houston, Texas, USA
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4
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Gilroy KD, Xia Y. Dimerization of Colloidal Particles through Controlled Aggregation for Enhanced Properties and Applications. Chem Asian J 2016; 11:2341-51. [DOI: 10.1002/asia.201600979] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Indexed: 01/22/2023]
Affiliation(s)
- Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 (USA)
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 (USA)
- School of Chemistry&Biochemistry School of Chemical&Biomolecular Engineering Georgia Institute of Technology Atlanta GA 30332 USA
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Chen J, Yang C, Guo B, Sena ES, Macleod MR, Yuan Y, Hirst TC. The Efficacy of Trastuzumab in Animal Models of Breast Cancer: A Systematic Review and Meta-Analysis. PLoS One 2016; 11:e0158240. [PMID: 27463246 PMCID: PMC4963137 DOI: 10.1371/journal.pone.0158240] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 06/12/2016] [Indexed: 11/24/2022] Open
Abstract
Background Breast cancer is the most frequent cancers and is the second leading cause of cancer death among women. Trastuzumab is an effective treatment, the first monoclonal antibody directed against the human epidermal growth factor receptor 2 (HER2). To inform the development of other effective treatments we report summary estimates of efficacy of trastuzumab on survival and tumour volume in animal models of breast cancer. Methods We searched PubMed and EMBASE systematically to identify publications testing trastuzumab in animal models of breast cancer. Data describing tumour volume, median survival and animal features were extracted and we assessed quality using a 12-item checklist. We analysed the impact of study design and quality and evidence for publication bias. Results We included data from 83 studies reporting 169 experiments using 2076 mice. Trastuzumab treatment caused a substantial reduction in tumour growth, with tumours in treated animals growing to 32.6% of the volume of tumours in control animals (95%CI 27.8%-38.2%). Median survival was prolonged by a factor of 1.45 (1.30–1.62). Many study design and quality features accounted for between-study heterogeneity and we found evidence suggesting publication bias. Conclusion We have found trastuzumab to be effective in animal breast cancer models across a range of experimental circumstances. However the presence of publication bias and a low prevalence of measures to reduce bias provide a focus for future improvements in preclinical breast cancer research.
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Affiliation(s)
- Jiarong Chen
- Department of Oncology, Jiangmen Central Hospital, Affiliated Jiangmen Hospital of Sun Yat-Sen University, Jiangmen, Guangdong 529030, P. R. China
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou DaDao Bei, Guangzhou, Guangdong 510515, P. R. China
| | - Canhong Yang
- Department of Neurology, the Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, P. R. China
| | - Bin Guo
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, P. R. China
| | - Emily S. Sena
- Centre for Clinical Brain Sciences, Chancellors Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, United Kingdom
| | - Malcolm R. Macleod
- Centre for Clinical Brain Sciences, Chancellors Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, United Kingdom
| | - Yawei Yuan
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou DaDao Bei, Guangzhou, Guangdong 510515, P. R. China
- * E-mail:
| | - Theodore C. Hirst
- Centre for Clinical Brain Sciences, Chancellors Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, United Kingdom
- * E-mail:
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Dokmanovic M, Wu Y, Shen Y, Chen J, Hirsch DS, Wu WJ. Trastuzumab-induced recruitment of Csk-homologous kinase (CHK) to ErbB2 receptor is associated with ErbB2-Y1248 phosphorylation and ErbB2 degradation to mediate cell growth inhibition. Cancer Biol Ther 2014; 15:1029-41. [PMID: 24835103 DOI: 10.4161/cbt.29171] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The inhibitory effect of trastuzumab, a humanized monoclonal antibody directed against the extracellular domain of ErbB2, is associated with its ability to induce ErbB2-Y1248 phosphorylation, and the status of phosphorylated ErbB2-Y1248 (ErbB2-pY1248) may correlate with the sensitivity of breast cancers to trastuzumab. The mechanisms of which remain unclear. Here, we show that binding of trastuzumab to ErbB2 activates ErbB2 kinase activity and enhances ErbB2-Y1248 phosphorylation in trastuzumab-sensitive breast cancer cells. This in turn increases the interaction between ErbB2 and non-receptor Csk-homologous kinase (CHK), leading to growth inhibition of breast cancer cells. Overexpression of CHK mimics trastuzumab treatment to mediate ErbB2-Y1248 phosphorylation, Akt downregulation, and growth inhibition of trastuzumab-sensitive breast cancer cells. CHK overexpression combined with trastuzumab exerts an additive effect on cell growth inhibition. We further demonstrate that positive ErbB2-pY1248 staining in ErbB2-positive breast cancer biopsies correlates with the increased trastuzumab response in trastuzumab neoadjuvant settings. Collectively, this study highlights an important role for ErbB2-pY1248 in mediating trastuzumab-induced growth inhibition and trastuzumab-induced interactions between CHK and ErbB2-pY1248 is identified as a novel mechanism of action that mediates the growth inhibition of breast cancer cells. The novel mechanistic insights into trastuzumab action revealed by this study may impact the design of next generation of therapeutic monoclonal antibodies targeting receptor tyrosine kinases, as well as open new avenues to identify novel targets for the treatment of ErbB2-positive cancers.
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Affiliation(s)
- Milos Dokmanovic
- Division of Monoclonal Antibodies; Office of Biotechnology Products; Office of Pharmaceutical Science; Center for Drug Evaluation and Research; US Food and Drug Administration; Bethesda, MD USA
| | - Yun Wu
- Department of Pathology; University of Texas M.D. Anderson Cancer Center; Houston, TX USA
| | - Yi Shen
- Division of Monoclonal Antibodies; Office of Biotechnology Products; Office of Pharmaceutical Science; Center for Drug Evaluation and Research; US Food and Drug Administration; Bethesda, MD USA
| | - Jieqing Chen
- Department of Pathology; University of Texas M.D. Anderson Cancer Center; Houston, TX USA
| | - Dianne S Hirsch
- Division of Monoclonal Antibodies; Office of Biotechnology Products; Office of Pharmaceutical Science; Center for Drug Evaluation and Research; US Food and Drug Administration; Bethesda, MD USA
| | - Wen Jin Wu
- Division of Monoclonal Antibodies; Office of Biotechnology Products; Office of Pharmaceutical Science; Center for Drug Evaluation and Research; US Food and Drug Administration; Bethesda, MD USA
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Xia X, Li W, Zhang Y, Xia Y. Silica-coated dimers of silver nanospheres as surface-enhanced Raman scattering tags for imaging cancer cells. Interface Focus 2014; 3:20120092. [PMID: 24427538 DOI: 10.1098/rsfs.2012.0092] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Surface-enhanced Raman scattering (SERS) tags have been actively explored as a multiplexing platform for sensitive detection of biomolecules. Here, we report a new type of SERS tags that was fabricated by sequentially functionalizing dimers made of 50 nm Ag nanospheres with 4-mercaptobenzoic acid as the Raman reporter molecule, silica coating as a protective shell and antibody as a targeting ligand. These dimer-based tags give highly enhanced and reproducible Raman signals owing to the presence of a well-defined SERS hot spot at the junction between two Ag nanospheres in the dimer. The SERS enhancement factor (EF) of an individual dimer tag supported on a glass slide can reach a level as high as 4.3 × 10(6). In comparison, the EFs dropped to 2.8 × 10(5) and 8.7 × 10(5), respectively, when Ag nanospheres and nanocubes with sizes similar to the spheres in the dimer were used to fabricate the tags using similar procedures. The SERS signals from aqueous suspensions of the dimer-based tags also showed high intensity and good stability. Potential use of the dimer-based tags was demonstrated by imaging cancer cells overexpressing HER2 receptors with good specificity and high sensitivity.
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Affiliation(s)
- Xiaohu Xia
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University Medical School ; School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta, GA 30332 , USA
| | - Weiyang Li
- Department of Materials Science and Engineering , Stanford University , Stanford, CA 94305 , USA
| | - Yu Zhang
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University Medical School ; School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta, GA 30332 , USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University Medical School ; School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta, GA 30332 , USA
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8
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Nahta R. Molecular Mechanisms of Trastuzumab-Based Treatment in HER2-Overexpressing Breast Cancer. ISRN ONCOLOGY 2012; 2012:428062. [PMID: 23227361 PMCID: PMC3512309 DOI: 10.5402/2012/428062] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 10/30/2012] [Indexed: 12/25/2022]
Abstract
The past decade of research into HER2-overexpressing breast cancer has provided significant insight into the mechanisms by which HER2 signaling drives tumor progression, as well as potential mechanisms by which cancer cells escape the anticancer activity of HER2-targeted therapy. Many of these preclinical findings have been translated into clinical development, resulting in novel combinations of HER2-targeted therapies and combinations of trastuzumab plus inhibitors of resistance pathways. In this paper, we will discuss proposed mechanisms of trastuzumab resistance, including epitope masking, cross signaling from other cell surface receptors, hyperactive downstream signaling, and failure to induce antibody-dependent cellular cytotoxicity. In addition, we will discuss the molecular mechanisms of action of dual HER2 inhibition, specifically the combination of trastuzumab plus lapatinib or trastuzumab with pertuzumab. We will also discuss data supporting therapeutic combinations of trastuzumab with agents targeted against molecules implicated in trastuzumab resistance. The roles of insulin-like growth factor-I receptor and the estrogen receptor are discussed in the context of resistance to HER2-targeted therapies. Finally, we will examine the major issues that need to be addressed in order to translate these combinations from the bench to the clinic, including the need to establish relevant biomarkers to select for those patients who are most likely to benefit from a particular drug combination.
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Affiliation(s)
- Rita Nahta
- Department of Pharmacology, School of Medicine Emory University, Suite 5001, 1510 Clifton Road, Atlanta, GA 30322, USA ; Department of Hematology and Medical Oncology, School of Medicine Emory University, Atlanta, GA 30322, USA ; Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA ; Molecular and Systems Pharmacology Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30322, USA
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Govindarajan S, Sivakumar J, Garimidi P, Rangaraj N, Kumar JM, Rao NM, Gopal V. Targeting human epidermal growth factor receptor 2 by a cell-penetrating peptide–affibody bioconjugate. Biomaterials 2012; 33:2570-82. [DOI: 10.1016/j.biomaterials.2011.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 12/02/2011] [Indexed: 11/24/2022]
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Trastuzumab and lapatinib modulation of HER2 tyrosine/threonine phosphorylation and cell signaling. Med Oncol 2011; 29:1486-94. [DOI: 10.1007/s12032-011-0025-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Accepted: 06/30/2011] [Indexed: 01/26/2023]
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De Keulenaer GW, Doggen K, Lemmens K. The vulnerability of the heart as a pluricellular paracrine organ: lessons from unexpected triggers of heart failure in targeted ErbB2 anticancer therapy. Circ Res 2010; 106:35-46. [PMID: 20056944 DOI: 10.1161/circresaha.109.205906] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this review, we address clinical aspects and mechanisms of ventricular dysfunction induced by anticancer drugs targeted to the ErbB2 receptor. ErbB2 antagonists prolong survival in cancer, but also interfere with homeostatic processes in the heart. ErbB2 is a coreceptor for ErbB4, which is activated by neuregulin-1. This epidermal growth factor-like growth factor is released from endothelial cells in the endocardium and in the myocardial microcirculation, hence contributing to intercellular crosstalk in the ventricle. We look at the physiological aspects of neuregulin-1/ErbB signaling in the ventricle, and review its (mal)adaptive responses in chronic heart failure. We also compare structural aspects of ErbB receptor activation in cancer and cardiac cells, and analyze the mode of action of current ErbB2 antagonists. This allows us to predict how these drugs interfere with paracrine processes in the ventricle. Differences in the mode of action of individual ErbB2 antagonists affect their impact on the function of the ventricle, considered to be "on-target" or "off-target." Establishing the relation between the cardiac side effects of ErbB2 antagonists and their impact on paracrine ventricular control mechanisms may direct the design of a next generation of ErbB2 inhibitors. For cardiologists, there are lessons to be learned from the unexpected side effects of ErbB2-targeted cancer therapy. The vulnerability of the heart as a pluricellular paracrine system appears greater than anticipated and intercellular crosstalk an essential component of its functional and structural integrity.
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EGFR over-expression and activation in high HER2, ER negative breast cancer cell line induces trastuzumab resistance. Breast Cancer Res Treat 2009; 122:685-97. [PMID: 19859802 DOI: 10.1007/s10549-009-0592-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 10/08/2009] [Indexed: 12/18/2022]
Abstract
HER2 is gene amplified or over-expressed in 20-25% of breast cancers resulting in elevated HER2 activation. Trastuzumab (Herceptin), a humanized monoclonal antibody, targets activated HER2 and is clinically effective in HER2-over-expressing breast cancers. However, despite prolonged survival, treated breast cancer patients develop resistance. Resistance to trastuzumab occurs upon inactivation of HER2 regulatory proteins or upon up-regulation of alternative receptors. In particular, elevated levels of EGFR, present in estrogen receptor (ER) positive, trastuzumab-resistant BT-474 xenografts caused, a trastuzumab-resistant phenotype (Ritter et al. Clin Cancer Res 13:4909-4919, 2007). However, the role of EGFR in acquired trastuzumab resistance in ER negative cell models is not well defined. In this study, SKBR3 cell line clones expressing EGFR were generated to examine the role of EGFR over-expression on trastuzumab sensitivity in an, ER-negative breast carcinoma cell line. A stable clone, SKBR3/EGFR (clone 4) expressing moderate levels of EGFR remained sensitive to trastuzumab, whereas a stable clone, SKBR3/EGFR (clone 5) expressing high levels of EGFR, became resistant to trastuzumab. Depletion of EGFR by EGFR small-interfering RNAs in the SKBR3/EGFR (clone 5) reversed trastuzumab resistance. However, the SKBR3/EGFR (clone 5) cell line remained sensitive to lapatinib, an EGFR/HER2 inhibitor. Biochemical analysis using co-immunoprecipitation and proximity-based quantitative VeraTag assays demonstrated that high levels of EGFR phosphorylation, EGFR/EGFR homo-dimerization, and EGFR/HER2 hetero-dimerization were present in the trastuzumab-resistant cells. We conclude that EGFR over-expression can mediate trastuzumab resistance in both ER positive and ER negative cells and hypothesize that a threshold level of EGFR, in the absence of autocrine ligand production, is required to induce the resistant phenotype.
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Additive effects of a prolactin receptor antagonist, G129R, and herceptin on inhibition of HER2-overexpressing breast cancer cells. Breast Cancer Res Treat 2007; 111:241-50. [DOI: 10.1007/s10549-007-9789-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 10/08/2007] [Indexed: 10/22/2022]
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Abstract
Cancer has been seriously threatening the health and life of humans for a long period. Despite the intensive effort put into revealing the underlying mechanisms of cancer, the detailled machinery of carcinogenesis is still far from fully understood. Numerous studies have illustrated that cell signaling is extensively involved in tumor initiation, promotion and progression. Therefore, targeting the key molecules in the oncogenic signaling pathway might be one of the most promising ways to conquer cancer. Some targeted drugs, such as imatinib mesylate (Gleevec), herceptin, gefitinib (Iressa), sorafenib (Nexavar) and sunitinib (Sutent), which evolve from monotarget drug into multitarget ones, have been developed with encouraging effects.
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Affiliation(s)
- Jin Ding
- The International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai 200438, China
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Fischer BM, Cuellar JG, Byrd AS, Rice AB, Bonner JC, Martin LD, Voynow JA. ErbB2 activity is required for airway epithelial repair following neutrophil elastase exposure. FASEB J 2005; 19:1374-6. [PMID: 15923396 DOI: 10.1096/fj.04-2675fje] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In cystic fibrosis and chronic bronchitis, airways are chronically injured by exposure to neutrophil elastase (NE). We sought to identify factors required for epithelial repair following NE exposure. Normal human bronchial epithelial cells were treated with NE (50 nM, 22 h) or control vehicle. Following NE treatment, we found a marked and sustained decrease in epithelial proliferation as detected by Ki67 immunostaining. 3H-thymidine incorporation was also initially depressed but increased over 72 h in NE-treated cells, which suggests that DNA synthesis constitutes an early repair process following NE exposure. We hypothesized that ErbB2 receptor tyrosine kinase, a regulator of cancer cell proliferation, was required for epithelial DNA synthesis following NE exposure. Immediately following NE treatment, by flow cytometry analysis, we found a decrease in ErbB2 surface expression. Protein levels of the full-length 185 kD ErbB2 receptor significantly decreased following NE treatment and smaller ErbB2-positive bands, ranging in size from 23 to 40 kD, appeared, which suggests that NE caused ErbB2 degradation. By real-time RT-PCR analysis, we found no change in ErbB2 mRNA expression following NE treatment, which suggests that changes in ErbB2 protein levels were regulated at the post-translational level. Following NE treatment, full-length 185 kD ErbB2 levels increased to pretreatment levels, correlating with the increase in thymidine incorporation during the same time period. Importantly, inhibition of ErbB2 activity with AG825 (5 microM) or Herceptin (3.1 microM), an ErbB2-neutralizing antibody, blocked thymidine incorporation only in NE-treated cells. These results suggest ErbB2 is a critical factor for epithelial recovery following NE exposure.
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Affiliation(s)
- Bernard M Fischer
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA
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16
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Köstler WJ, Brodowicz T, Hudelist G, Rudas M, Horvat R, Steger GG, Singer CF, Attems J, Rabitsch W, Fakhrai N, Elandt K, Wiltschke C, Hejna M, Zielinski CC. The efficacy of trastuzumab in Her-2/neu-overexpressing metastatic breast cancer is independent of p53 status. J Cancer Res Clin Oncol 2005; 131:420-8. [PMID: 15864644 DOI: 10.1007/s00432-005-0670-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Accepted: 01/10/2005] [Indexed: 11/24/2022]
Abstract
PURPOSE Her-2/neu and p53-mediated signalling have been shown to interact at various cellular levels. However, the clinical relevance of p53 alterations in patients receiving trastuzumab for Her-2/neu-overexpressing metastatic breast cancer (MBC) remains unknown. The present study was performed to corroborate previous in vitro findings from our laboratory showing that trastuzumab induces growth arrest and apoptosis in a p53-independent manner. METHOD Retrospective immunohistochemical (IHC) analysis for p53 protein expression was carried out on tumour specimens from 104 patients receiving trastuzumab-based treatment for Her-2/neu-overexpressing MBC at a single institution. p53 status was correlated with response (R) and clinical benefit (CB), median progression-free survival (PFS) time and overall survival (OAS) time in univariate and multivariate analyses. RESULTS Characteristics were similar between p53-negative and p53-positive tumours (all P>0.05). In univariate analyses, R (39% vs 26%, P=0.208), CB (70% vs 57%, P=0.218), PFS (6.2 months vs 4.2 months, P=0.186) and OAS (23.8 months vs 23.2 months, P=0.650) were similar for p53-positive tumours and p53-negative tumours, respectively. In multivariate analyses, p53 status was not a significant predictor of R, CB, PFS or OAS (all P>0.05). CONCLUSIONS p53 status, as determined by IHC, is not a predictor of the clinical efficacy of trastuzumab-based treatment in patients with Her-2/neu-overexpressing MBC.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Humanized
- Antineoplastic Agents/therapeutic use
- Biomarkers, Tumor/metabolism
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Breast Neoplasms/secondary
- Carcinoma, Ductal, Breast/drug therapy
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/secondary
- Female
- Humans
- Middle Aged
- Prognosis
- Receptor, ErbB-2/metabolism
- Retrospective Studies
- Survival Rate
- Trastuzumab
- Treatment Outcome
- Tumor Suppressor Protein p53/metabolism
- Up-Regulation
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Affiliation(s)
- Wolfgang J Köstler
- Clinical Division of Oncology, Department of Medicine I, Medical University of Vienna, 18-20 Waehringer Guertel, 1090, Vienna, Austria.
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17
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Austin CD, De Mazière AM, Pisacane PI, van Dijk SM, Eigenbrot C, Sliwkowski MX, Klumperman J, Scheller RH. Endocytosis and sorting of ErbB2 and the site of action of cancer therapeutics trastuzumab and geldanamycin. Mol Biol Cell 2004; 15:5268-82. [PMID: 15385631 PMCID: PMC532009 DOI: 10.1091/mbc.e04-07-0591] [Citation(s) in RCA: 366] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
ErbB2 is a transmembrane tyrosine kinase whose surface overexpression is linked to tumorigenesis and poor prognosis in breast cancer patients. Two models have emerged that account for the high surface distribution of ErbB2. In one model, the surface pool is dynamic and governed by a balance between endocytosis and recycling, whereas in the other it is retained, static, and excluded from endocytosis. These models have contrasting implications for how ErbB2 exerts its biological function and how cancer therapies might down-regulate surface ErbB2, such as the antibody trastuzumab (Herceptin) or the Hsp90 inhibitor geldanamycin. Little is known, however, about how these treatments affect ErbB2 endocytic trafficking. To investigate this issue, we examined breast carcinoma cells by immunofluorescence and quantitative immunoelectron microscopy and developed imaging and trafficking kinetics assays using cell surface fluorescence quenching. Surprisingly, trastuzumab does not influence ErbB2 distribution but instead recycles passively with internalized ErbB2. By contrast, geldanamycin down-regulates surface ErbB2 through improved degradative sorting in endosomes exclusively rather than through increased endocytosis. These results reveal substantial dynamism in the surface ErbB2 pool and clearly demonstrate the significance of endosomal sorting in the maintenance of ErbB2 surface distribution, a critical feature of its biological function.
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MESH Headings
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/metabolism
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal, Humanized
- Benzoquinones
- Biological Transport
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Breast Neoplasms/ultrastructure
- Cell Line, Tumor
- Down-Regulation
- Endocytosis
- Humans
- Lactams, Macrocyclic
- Lysosomes/metabolism
- Microscopy, Electron, Scanning
- Microscopy, Fluorescence
- Neoplasms/drug therapy
- Neoplasms/immunology
- Neoplasms/metabolism
- Neoplasms/pathology
- Quinones/pharmacology
- Receptor, ErbB-2/metabolism
- Trastuzumab
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18
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Choudhury A, Charo J, Parapuram SK, Hunt RC, Hunt DM, Seliger B, Kiessling R. Small interfering RNA (siRNA) inhibits the expression of the Her2/neu gene, upregulates HLA class I and induces apoptosis of Her2/neu positive tumor cell lines. Int J Cancer 2003; 108:71-7. [PMID: 14618618 DOI: 10.1002/ijc.11497] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Silencing of a specific mRNA using double stranded RNA oligonucleotides represents one of the newest technologies for suppressing a specific gene product. Small interfering RNA (siRNA) are 21 nucleotides long, double stranded RNA fragments that are identical in sequence to the target mRNA. We designed 3 such siRNA against the Her2/neu (HER2) gene. The HER2 gene is known to play an important role in the oncogenesis of several types of cancers, such as breast, ovarian, colon and gastric cancers. Introduction of the siRNA into HER2 positive tumor lines in vitro greatly reduced the cell surface expression of the HER2 protein. Concurrently, a range of effects on cell physiology, such as growth inhibition or apoptosis, was observed. The expression of HLA class I was observed to be upregulated when HER2 was silenced with siRNA. Treatment of SKBr3 and MCF7/HER2 tumor cell lines with the HER2 siRNA resulted in growth arrest of cells in the late G(1)/S-phase. Our results suggest that siRNA may be an effective method of abrogating the effect of HER2 in tumorigenesis.
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19
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Hudelist G, Köstler WJ, Attems J, Czerwenka K, Müller R, Manavi M, Steger GG, Kubista E, Zielinski CC, Singer CF. Her-2/neu-triggered intracellular tyrosine kinase activation: in vivo relevance of ligand-independent activation mechanisms and impact upon the efficacy of trastuzumab-based treatment. Br J Cancer 2003; 89:983-91. [PMID: 12966413 PMCID: PMC2376939 DOI: 10.1038/sj.bjc.6601160] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Proteolytic cleavage of the Her-2/neu extracellular domain (ECD) has been shown to initiate receptor phosphorylation representing Her-2/neu activation in vitro. The present investigation was performed to evaluate the clinical relevance of ECD cleavage for Her-2/neu activation and the consequences of active intracellular Her-2/neu signalling reflected by tyrosine kinase phosphorylation in patients treated with the anti-Her-2/neu antibody trastuzumab. Sera from 62 patients receiving trastuzumab-based treatment for Her-2/neu overexpressing metastatic breast cancer were assessed for pretreatment ECD levels using an enzyme-linked immunosorbent assay. In parallel, Her-2/neu activation status of tumour specimens was assessed by immunohistochemistry using a Her-2/neu phosphorylation state specific antibody (PN2A) and correlated with the patients' ECD levels and clinical course of disease. Serum ECD levels were significantly higher in 15 (24%) patients with tumours exhibiting activated Her-2/neu as compared to those without detectable Her-2/neu phosphorylation (median 148.2 vs 28.5 ng ml(-1), P=0.010). Whereas response rate only showed a trend to be higher in patients with Her-2/neu-phosphorylated breast cancer (47 vs 34%, P=0.197), both uni- and multivariate analyses revealed that the median progression-free survival under trastuzumab-based treatment was significantly longer in patients with Her-2/neu-phosphorylated breast cancer-11.7 (95% CI 5.2-18.3) months-when compared to the progression-free survival of 4.5 (95% CI 3.4-5.6) months observed in patients with tumours lacking phosphorylated Her-2/neu (P=0.001). Proteolytic cleavage of the ECD represents a biologically relevant ligand-independent mechanism of Her-2/neu activation in vivo. The influence of Her-2/neu activation status upon the outcome of trastuzumab-based therapies merits further investigation in larger prospective trials.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Humanized
- Antineoplastic Agents/therapeutic use
- Biomarkers, Tumor/metabolism
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Carcinoma, Ductal, Breast/drug therapy
- Carcinoma, Ductal, Breast/metabolism
- Enzyme Activation
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Immunoglobulin G/metabolism
- Ligands
- Middle Aged
- Phosphorylation
- Phosphotyrosine/metabolism
- Prognosis
- Protein-Tyrosine Kinases/metabolism
- Receptor, ErbB-2/metabolism
- Receptors, Progesterone/metabolism
- Survival Rate
- Trastuzumab
- Treatment Outcome
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Affiliation(s)
- G Hudelist
- Clinical Division of Special Gynaecology, Department of Obstetrics and Gynaecology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
| | - W J Köstler
- Clinical Division of Oncology, Department of Medicine I, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
- Clinical Division of Oncology, Department of Medicine I, University Hospital of Vienna, 18-20 Waehringer Guertel, A-1090 Vienna, Austria. E-mail:
| | - J Attems
- Department of Pathology, Otto Wagner Hospital, Vienna, Austria
| | - K Czerwenka
- Division of Gynaecopathology, Department of Pathology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
| | - R Müller
- Division of Gynaecopathology, Department of Pathology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
| | - M Manavi
- Clinical Division of Special Gynaecology, Department of Obstetrics and Gynaecology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
| | - G G Steger
- Clinical Division of Oncology, Department of Medicine I, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
| | - E Kubista
- Clinical Division of Special Gynaecology, Department of Obstetrics and Gynaecology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
- Ludwig Boltzmann Institute for Clinical-Experimental Oncology, Vienna, Austria
| | - C C Zielinski
- Clinical Division of Oncology, Department of Medicine I, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
- Ludwig Boltzmann Institute for Clinical-Experimental Oncology, Vienna, Austria
| | - C F Singer
- Clinical Division of Special Gynaecology, Department of Obstetrics and Gynaecology, and Center for Excellence in Clinical and Experimental Oncology, University Hospital, Vienna, Austria
- Ludwig Boltzmann Institute for Clinical-Experimental Oncology, Vienna, Austria
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20
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Abstract
Identification of the key role of protein kinases as potential oncoproteins has led to the emergence of a new era of target-directed therapies. Among a variety of novel therapeutic strategies two have shown the most promise and led to a variety of therapeutic agents in clinical development. One approach utilises humanised monoclonal antibodies generated against the extracellular domain of transmembrane protein kinases. The second approach is the generation of small molecule ATP analogues targeting the kinase domain itself. The approval of agents such as Herceptin for the treatment of advanced breast cancer and Gleevec for chronic myelogenous leukemia and gastrointestinal stromal tumours are the first examples of gene-based cancer drugs and represent the first example of a novel strategy in anti-cancer therapy.
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Affiliation(s)
- Oliver M Fischer
- Max-Planck-Institute of Biochemistry, Department of Molecular Biology, Am Klopferspitz 18A, D-82152 Martinsried, Germany
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21
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Lipkowitz S. The role of the ubiquitination-proteasome pathway in breast cancer: ubiquitin mediated degradation of growth factor receptors in the pathogenesis and treatment of cancer. Breast Cancer Res 2003; 5:8-15. [PMID: 12559039 PMCID: PMC154127 DOI: 10.1186/bcr541] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2002] [Revised: 08/13/2002] [Accepted: 09/11/2002] [Indexed: 11/30/2022] Open
Abstract
Aberrant activity of growth factor receptors has been implicated in the pathogenesis of a wide variety of malignancies. The negative regulation of signaling by growth factor receptors is mediated in large part by the ubiquitination, internalization, and degradation of the activated receptor. Over the past few years, considerable insight into the mechanisms that control receptor downregulation has been gained. There are also data suggesting that mutations that lead to inhibition of downregulation of growth factor receptors could play a role in the pathogenesis of cancer. Therapies directed at enhancing the degradation of growth factor receptors offer a promising approach to the treatment of malignancies.
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Affiliation(s)
- Stan Lipkowitz
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Naval Medical Center, Bethesda, Maryland, USA.
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22
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Barrett A, Madsen B, Copier J, Lu PJ, Cooper L, Scibetta AG, Burchell J, Taylor-Papadimitriou J. PLU-1 nuclear protein, which is upregulated in breast cancer, shows restricted expression in normal human adult tissues: a new cancer/testis antigen? Int J Cancer 2002; 101:581-8. [PMID: 12237901 DOI: 10.1002/ijc.10644] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The PLU-1 gene is expressed at the level of message in breast cancers and breast cancer cell lines and shows restricted expression in normal adult tissues with the exception of testis. The predicted protein sequence contains several domains, including the PLU domain, which is shared by other proteins involved in transcription and/or development. We have developed a polyclonal antiserum to a C-terminal fragment of the PLU-1 protein, which shows little homology to other family members. Immunohistochemical analysis with the antiserum alpha-PLU-1C confirmed the nuclear localisation of PLU-1. alpha-PLU-1C also reacted with the mouse homologue of PLU-1 (mPlu-1) but not with the closest family member, RBP2. Using Western blot analysis, PLU-1 was shown to be well expressed in breast cancers and breast cancer cell lines, while it was not detected in a range of normal adult tissues. Our results suggest that the PLU-1 protein may belong to the class of testis/cancer antigens.
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Affiliation(s)
- Angela Barrett
- Breast Cancer Biology Group, Cancer Research UK, Guy's Hospital, London, United Kingdom
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23
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Offterdinger M, Schöfer C, Weipoltshammer K, Grunt TW. c-erbB-3: a nuclear protein in mammary epithelial cells. J Cell Biol 2002; 157:929-39. [PMID: 12045181 PMCID: PMC2174048 DOI: 10.1083/jcb.200109033] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
c-erbB receptors are usually located in cell membranes and are activated by extracellular binding of EGF-like growth factors. Unexpectedly, using immunofluorescence we found high levels of c-erbB-3 within the nuclei of MTSV1-7 immortalized nonmalignant human mammary epithelial cells. Nuclear localization was mediated by the COOH terminus of c-erbB-3, and a nuclear localization signal was identified by site-directed mutagenesis and by transfer of the signal to chicken pyruvate kinase. A nuclear export inhibitor caused accumulation of c-erbB-3 in the nuclei of other mammary epithelial cell lines as demonstrated by immunofluorescence and biochemical cell fractionation, suggesting that c-erbB-3 shuttles between nuclear and nonnuclear compartments in these cells. Growth of MTSV1-7 on permeable filters induced epithelial polarity and concentration of c-erbB-3 within the nucleoli. However, the c-erbB-3 ligand heregulin beta1 shifted c-erbB-3 from the nucleolus into the nucleoplasm and then into the cytoplasm. The subcellular localization of c-erbB-3 obviously depends on exogenous stimuli and on the stage of epithelial polarity and challenges the specific function of c-erbB-3 as a transmembrane receptor protein arguing for additional, as yet unidentified, roles of c-erbB-3 within the nucle(ol)us of mammary epithelial cells.
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Affiliation(s)
- Martin Offterdinger
- Signaling Networks Program, Division of Oncology, Department of Internal Medicine I, University of Vienna, A-1097 Vienna, Austria
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24
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Abstract
The HER family of receptors has an important role in the network of cell signals controlling cell growth and differentiation. Although the activity of the HER receptor is strictly controlled in normal cells, HER2 receptor overexpression plays a pivotal role in transformation and tumorigenesis. HER2 gene amplification and/or overexpression of the receptor has been detected in subsets of a wide range of human cancers including breast cancer, and is an indicator of poor prognosis. It is proposed that overexpressed HER2 in combination with HER3 causes high activity of cell-signaling networks, thereby resulting in tumor cell proliferation. Thus, the HER2 receptor is an attractive target for new anti-cancer treatments. Monoclonal antibodies directed against the receptor are the most promising of these, and the humanized anti-HER2 monoclonal antibody trastuzumab (Herceptin) has shown significant clinical efficacy in clinical trials. The anti-tumor mechanisms of anti-HER2 monoclonal antibodies are not completely understood. However, some tumor types are not sensitive to trastuzumab, suggesting that the response of a tumor to trastuzumab may not only be dependent on overexpressed HER2, but may also be influenced by other members of the HER receptor family expressed in the tumor cell.
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Affiliation(s)
- R M Neve
- Friedrich Miescher Institute, Basel, Switzerland
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25
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Abstract
The search for new methods of treating cancer, combined with advances in our understanding of carcinogenesis, molecular biology and technology, has resulted in the development of novel biologic agents with proven clinical efficacy. One such agent is trastuzumab (Herceptin), a humanized monoclonal antibody that targets the human epidermal growth factor receptor-2 (HER2). HER2 is a member of a family of receptors that interact with each other and various ligands to stimulate various intracellular signal transduction pathways involved in cell growth control. HER2 is overexpressed in 20%-30% of women with breast cancer and is associated with aggressive tumor characteristics and poor prognosis. Trastuzumab is the first humanized monoclonal antibody to be approved for therapeutic use and the first oncogene-targeted treatment with proven survival benefit in women with HER2-positive metastatic breast cancer. However, its mechanism of action has not been fully characterized and appears to be complex. This paper reviews current knowledge of the mechanism of action of trastuzumab, including HER2 protein downregulation, prevention of HER2-containing heterodimer formation, initiation of G1 arrest and induction of p27, prevention of HER2 cleavage, inhibition of angiogenesis, and induction of immune mechanisms. The significance of these mechanisms for selection of concomitant chemotherapy is also considered.
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Affiliation(s)
- J Baselga
- Medical Oncology Service, Hospital General Universitari Vall d'Hebron, Barcelona, Spain.
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26
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Mishra SK, Mandal M, Mazumdar A, Kumar R. Dynamic chromatin remodeling on the HER2 promoter in human breast cancer cells. FEBS Lett 2001; 507:88-94. [PMID: 11682064 DOI: 10.1016/s0014-5793(01)02951-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Deregulation of the HER2 oncogene occurs in 30% of human breast cancers and correlates with poor prognosis and increased propensity for metastasis. Since the molecular basis of HER2 overexpression in human cancers is not known, we sought to determine whether chromatin remodeling pathways are involved in the regulation of HER2 expression. We report that compared with breast cancer cells expressing a low level of HER2, HER2-overexpressing breast cancer cells contained significantly higher levels of acetylated and phosphorylated histone H3, and acetylated histone H4 associated with the HER2 promoter. Decreased recruitment of histone deacetylases in the promoter is also noted in the HER2-overexpressing cell. The association of acetylated histone H4 with HER2 gene chromatin and HER2 expression in breast cancer cells was upregulated by an inhibitor of histone deacetylases. Treatment with histone deacetylase inhibitor also reduced the association of histone deacetylase-1 and -2 with the HER2 promoter. In addition, the tumor promoters 12-O-tetradecanoylphorbol-13-acetate and okadaic acid stimulated the association of phosphorylated histone H3 on serine 10 with the HER2 promoter and also stimulated HER2 expression. These findings identify histone acetylation and histone phosphorylation as novel regulatory modifications that target HER2 gene chromatin, and suggest that elevated levels of these chromatin-relaxing components in the vicinity of the HER2 gene promoter may constitute an important non-genomic mechanism of HER2 overexpression in human breast cancer.
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Affiliation(s)
- S K Mishra
- Department of Molecular and Cellular Oncology, Room Y4.6032, University of Texas M.D. Anderson Cancer Center-108, 1515 Holcombe Blvd., Houston, TX 77030, USA
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27
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Tikhomirov O, Carpenter G. Caspase-dependent cleavage of ErbB-2 by geldanamycin and staurosporin. J Biol Chem 2001; 276:33675-80. [PMID: 11402024 DOI: 10.1074/jbc.m101394200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The geldanamycin-induced degradation of ErbB-2 produces a 23-kDa carboxyl-terminal fragment, which has been isolated and subjected to amino-terminal microsequencing. The obtained sequence indicates that the amino terminus of this fragment corresponds to Gly-1126 of ErbB-2. Analysis of the residues immediately before Gly-1126 suggests that cleavage may involve caspase activity. Site-directed mutagenesis of Asp-1125 in ErbB-2 prevents geldanamycin-provoked formation of the 23-kDa fragment, consistent with the requirement of this residue for caspase-dependent cleavage in known substrates. Also, the addition of the pan-caspase inhibitor Z-VAD-FMK blocks formation of the 23-kDa ErbB-2 fragment in cells exposed to geldanamycin. Interestingly, staurosporin and curcumin are also shown to provoke the degradation of ErbB-2 with formation of the 23-kDa carboxyl-terminal fragment. The generation of this fragment by staurosporin or curcumin is likewise blocked by caspase inhibition. Caspase inhibition does not prevent accelerated degradation of the 185-kDa native ErbB-2 in geldanamycin-treated cells but does significantly prevent staurosporin-stimulated metabolic loss of ErbB-2.
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Affiliation(s)
- O Tikhomirov
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
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28
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Affiliation(s)
- R Colomer
- Hospital 12 de Octubre, Madrid, Spain
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29
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Mandal M, Vadlamudi R, Nguyen D, Wang RA, Costa L, Bagheri-Yarmand R, Mendelsohn J, Kumar R. Growth factors regulate heterogeneous nuclear ribonucleoprotein K expression and function. J Biol Chem 2001; 276:9699-704. [PMID: 11121407 DOI: 10.1074/jbc.m008514200] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epidermal growth factor (EGF) family of growth factors and their receptors regulate normal and cancerous epithelial cell proliferation, a process that can be suppressed by antireceptor blocking antibodies. To identify genes whose expression may be modulated by antireceptor blocking antibodies, we performed a differential display screen with cells grown in the presence or absence of antireceptor blocking antibodies; isolates from one cDNA clone were 100% identical to human heterogeneous nuclear ribonucleoprotein K (hnRNP K), a protein with a conserved KH motif and RGG boxes, has been implicated in such functions as sequence-specific DNA binding, transcription, RNA binding, and nucleocytoplasmic shuttling. Both EGF and heregulin-beta1 induced expression of hnRNP K mRNA and protein in human breast cancer cells. This growth factor-mediated hnRNP K expression was effectively blocked by pretreatment of cultures with humanized anti-EGF receptor (EGFR) antibody C225, or anti-human epidermal growth factor receptor-2 (HER2) antibody. Anti-EGFR monoclonal antibody also caused regression of human tumor xenografts and reduction in hnRNP K levels in athymic mice. Samples from grade III human breast cancer contained more hnRNP K protein than samples from grade II cancer. Finally, overexpression of hnRNP K in breast cancer cells significantly increased target c-myc promoter activity and c-Myc protein, hnRNP K protein levels, and enhanced breast cancer cell proliferation and growth in an anchorage-independent manner. These results suggested that the activity of human EGF receptor family members regulates hnRNP K expression by extracellular growth promoting signals and that therapeutic humanized antibodies against EGFR and HER2 can effectively block this function.
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MESH Headings
- Animals
- Antibodies, Monoclonal/metabolism
- Blotting, Northern
- Breast Neoplasms/metabolism
- Cell Division
- DNA/metabolism
- DNA, Complementary/metabolism
- Epidermal Growth Factor/metabolism
- ErbB Receptors/metabolism
- Gene Expression Profiling
- Genes, myc/genetics
- Growth Substances/metabolism
- Heterogeneous-Nuclear Ribonucleoprotein K
- Heterogeneous-Nuclear Ribonucleoproteins
- Humans
- Immunoblotting
- Ligands
- Mice
- Mice, Nude
- Neoplasm Transplantation
- Neuregulin-1/metabolism
- Precipitin Tests
- Promoter Regions, Genetic
- Proto-Oncogene Proteins c-myc/biosynthesis
- RNA, Messenger/metabolism
- Receptor, ErbB-2/metabolism
- Ribonucleoproteins/biosynthesis
- Ribonucleoproteins/metabolism
- Ribonucleoproteins/physiology
- Time Factors
- Tissue Distribution
- Transcription, Genetic
- Tumor Cells, Cultured
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Affiliation(s)
- M Mandal
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center-108, Houston 77030, USA
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30
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Talukder AH, Jorgensen HF, Mandal M, Mishra SK, Vadlamudi RK, Clark BF, Mendelsohn J, Kumar R. Regulation of elongation factor-1alpha expression by growth factors and anti-receptor blocking antibodies. J Biol Chem 2001; 276:5636-42. [PMID: 11104760 DOI: 10.1074/jbc.m006824200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The epidermal growth factor (EGF) family and its receptors regulate normal and cancerous epithelial cell proliferation, a process that could be suppressed by anti-receptor blocking antibodies. Polypeptide elongation factor-1alpha (EF-1alpha) is a multifunctional protein whose levels are positively correlated with the proliferative state of cells. To identify genes, whose expression may be modulated by anti-receptor blocking antibodies, we performed a differential display screening and isolated differentially expressed cDNAs. Isolates from one clone were 100% identical to human EF-1alpha. Both EGF and heregulin-beta1 (HRG) induced EF-1alpha promoter activity and mRNA and protein expression. Growth factor-mediated EF-1alpha expression was effectively blocked by pretreatment with humanized anti-EGF receptor antibody C225 or anti-human epidermal growth factor receptor-2 (HER2) antibody herceptin. Mutants and pharmacological inhibitors of p38(MAPK) and MEK, but not phosphatidylinositol 3-kinase, suppressed both constitutive and HRG-induced stimulation of EF-1alpha promoter activity in MCF-7 cells. Deletion analysis of the promoter suggested the requirement of the -393 to -204 region for growth factor-mediated transcription of EF-1alpha. Fine mapping and point mutation studies revealed a role of the SP1 site in the observed HRG-mediated regulation of the EF-1alpha promoter. In addition, we also provide new evidence to suggest that HRG stimulation of the EF-1alpha promoter involves increased physical interactions with acetylated histone H3 and histone H4. These results suggest that regulation of EF-1alpha expression by extracellular signals that function through human EGF receptor family members that are widely deregulated in human cancers and that growth factor regulation of EF-1alpha expression involve histone acetylation.
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Affiliation(s)
- A H Talukder
- Department of Molecular and Cellular Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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31
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Abstract
Human carcinomas frequently express high levels of receptors in the EGF receptor family, and overexpression of at least two of these receptors, the EGF receptor (EGFr) and closely related ErbB2, has been associated with a more aggressive clinical behavior. Further, transfection or activation of high levels of these two receptors in nonmalignant cell lines can lead to a transformed phenotype. For these reasons therapies directed at preventing the function of these receptors have the potential to be useful anti-cancer treatments. In the last two decades monoclonal antibodies (MAbs) which block activation of the EGFr and ErbB2 have been developed. These MAbs have shown promising preclinical activity and 'chimeric' and 'humanized' MAbs have been produced in order to obviate the problem of host immune reactions. Clinical activity with these antibodies has been documented: trastuzumab, a humanized anti-ErbB2 MAb, is active and was recently approved in combination with paclitaxel for the therapy of patients with metastatic ErbB2-overexpressing breast cancer; IMC-C225, a chimeric anti-EGFr MAb, has shown impressive activity when combined with radiation therapy and reverses resistance to chemotherapy. In addition to antibodies, compounds that directly inhibit receptor tyrosine kinases have shown preclinical activity and early clinical activity has been reported. A series of phase III studies with these antibodies and direct tyrosine kinase inhibitors are ongoing or planned, and will further address the role of these active anti-receptor agents in the treatment of patients with cancer.
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Affiliation(s)
- J Mendelsohn
- Department of Medicine, The University of Texas, MD Anderson Cancer Center, Houston, 77030-4009, USA
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32
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Caraglia M, Budillon A, Vitale G, Lupoli G, Tagliaferri P, Abbruzzese A. Modulation of molecular mechanisms involved in protein synthesis machinery as a new tool for the control of cell proliferation. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:3919-36. [PMID: 10866791 DOI: 10.1046/j.1432-1327.2000.01465.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the past years, the attention of scientists has focused mainly on the study of the genetic information and alterations that regulate eukaryotic cell proliferation and that lead to neoplastic transformation. All therapeutic strategies against cancer are, to date, directed at DNA either with cytotoxic drugs or gene therapy. Little or no interest has been aroused by protein synthesis mechanisms. However, an increasing body of data is emerging about the involvement of translational processes and factors in control of cell proliferation, indicating that protein synthesis can be an additional target for anticancer strategies. In this paper we review the novel insights on the biochemical and molecular events leading to protein biosynthesis and we describe their involvement in cell proliferation and tumorigenesis. A possible mechanistic explanation is given by the interactions that occur between protein synthesis machinery and the proliferative signal transduction pathways and that are therefore suitable targets for indirect modulation of protein synthesis. We briefly describe the molecular tools used to block protein synthesis and the attempts made at increasing their efficacy. Finally, we propose a new multimodal strategy against cancer based on the simultaneous intervention on protein synthesis and signal transduction.
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Affiliation(s)
- M Caraglia
- Dipartimento di Biochimica e Biofisica, Seconda Università di Napoli, Italy
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Vadlamudi R, Adam L, Talukder A, Mendelsohn J, Kumar R. Serine phosphorylation of paxillin by heregulin-beta1: role of p38 mitogen activated protein kinase. Oncogene 1999; 18:7253-64. [PMID: 10602479 DOI: 10.1038/sj.onc.1203163] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The mechanisms through which heregulin (HRG) regulates the progression of breast cancer cells to a more invasive phenotype are currently unknown. Recently we have shown that HRG treatment of breast cancer cells leads to the formation of lamellipodia/filopodia, and increased cell migration and invasiveness through the phosphatidylinositol 3-kinase (PI-3 kinase). Since the process of cell migration must involve changes in adhesion, we explored the potential HRG regulation of paxillin, a major cytoskeletal phosphoprotein of focal adhesion. We report that HRG stimulation of non-invasive breast cancer cells resulted in stimulation of p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinases (ERK) and PI-3K, and a concurrent unexpected increase in the level of paxillin phosphorylation on serine residue which was sensitive to protein-phosphatase 2b but not to protein tyrosine phosphatase 1. In addition, HRG triggered a rapid redistribution of paxillin to the perinuclear regions from the tyrosine-phosphorylated focal adhesions, and increased cell scattering. There was no effect of HRG on the state of phosphorylation and localization of focal adhesion kinase. The HRG-induced increase in serine phosphorylation of paxillin and cell scattering were selectively inhibited by a specific inhibitor of p38MAPK or a dominant-negative p38MAPK mutant, but not by inhibitors of p42/44MAPK or PI-3 kinase pathways. For the first time our results have shown that HRG, a potent migratory growth factor stimulates serine phosphorylation of paxillin. These findings suggest a role of p38MAPK-dependent signal transduction pathway(s) in serine phosphorylation and disassembly of the paxillin from the focal complexes during HRG-induced cell shape alterations and motility.
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Affiliation(s)
- R Vadlamudi
- Cell Growth Regulation Laboratory, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, TX 77030, USA
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Esparís-Ogando A, Díaz-Rodríguez E, Pandiella A. Signalling-competent truncated forms of ErbB2 in breast cancer cells: differential regulation by protein kinase C and phosphatidylinositol 3-kinase. Biochem J 1999; 344 Pt 2:339-48. [PMID: 10567214 PMCID: PMC1220649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Alterations that affect the ectodomain of receptor tyrosine kinases are often associated with constitutive activation of the enzymic activity of the mutant cell-associated receptor. Since the ectodomain of the ErbB2 receptor tyrosine kinase has been detected as a soluble fragment in the culture supernatant of cells and serum from patients with advanced breast cancer, the possible presence of cell-associated truncated forms of ErbB2 in cancer cells was investigated. Several cell-bound N-terminal truncated forms of ErbB2 were identified in breast cancer cells overexpressing this receptor. The presence of the truncated fragments was independent of lysosomal/proteasomal activity, indicating that classical receptor tyrosine kinase degradation systems were not involved in the N-terminal cleavages. The presence of these truncated forms of ErbB2 was up-regulated by protein kinase C and neuregulin; and down-regulated by phosphatidylinositol 3-kinase, and monoclonal antibodies that target the ectodomain of ErbB2, indicating that N-terminal cleavages of ErbB2 were regulated by multiple mechanisms. The truncated fragments were tyrosine-phosphorylated under resting conditions, and associated with the signalling intermediates Shc and Grb2. It is therefore likely that these truncated forms may be endowed with constitutive activity that allows them to permanently signal.
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Affiliation(s)
- A Esparís-Ogando
- Instituto de Microbiología Bioquímica, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Avenida del Campo Charro s/n, 37007 Salamanca, Spain
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35
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Larsen SS, Egeblad M, Jäättelä M, Lykkesfeldt AE. Acquired antiestrogen resistance in MCF-7 human breast cancer sublines is not accomplished by altered expression of receptors in the ErbB-family. Breast Cancer Res Treat 1999; 58:41-56. [PMID: 10634517 DOI: 10.1023/a:1006232830161] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
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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Affiliation(s)
- S S Larsen
- Department of Tumor Endocrinology, Institute of Cancer Biology, Danish Cancer Society, Copenhagen.
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36
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Todd DG, Mikkelsen RB, Rorrer WK, Valerie K, Schmidt-Ullrich RK. Ionizing radiation stimulates existing signal transduction pathways involving the activation of epidermal growth factor receptor and ERBB-3, and changes of intracellular calcium in A431 human squamous carcinoma cells. J Recept Signal Transduct Res 1999; 19:885-908. [PMID: 10533979 DOI: 10.3109/10799899909038430] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Previous studies demonstrated that ionizing radiation activates the epidermal growth factor receptor (EGFR), as measured by Tyr autophosphorylation, and induces transient increases in cytosolic free [Ca2+], [Ca2+]f. The mechanistic linkage between these events has been investigated in A431 squamous carcinoma cells with the EGFR Tyr kinase inhibitor, AG1478. EGFR autophosphorylation induced by radiation at doses of 0.5-5 Gy or EGF concentrations of 1-10 ng/ml is inhibited by >75% at 100 nM AG1478. Activation of EGFR enhances IP3 production as a result of phospholipase C (PLC) activation. At the doses used, radiation stimulates Tyr phosphorylation of both, PLCgamma and erbB-3, and also mediates the association between erbB-3 and PLCgamma not previously described. The increased erbB-3 Tyr phosphorylation is to a significant extent due to transactivation by EGFR as >70% of radiation- and EGF-induced erbB-3 Tyr phosphorylation is inhibited by AG 1478. The radiation-induced changes in [Ca2+]f are dependent upon EGFR, erbB-3 and PLCgamma activation since radiation stimulated IP3 formation and Ca2+ oscillations are inhibited by AG1478, the PLCgamma inhibitor U73122 or neutralizing antibody against an extracellular epitope of erbB-3. These results demonstrate that radiation induces qualitatively and quantitatively similar responses to EGF in stimulation of the plasma membrane-associated receptor Tyr kinases and immediate downstream effectors, such as PLCgamma and Ca2+.
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Affiliation(s)
- D G Todd
- Department of Radiation Oncology, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0058, USA
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37
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Lu PJ, Sundquist K, Baeckstrom D, Poulsom R, Hanby A, Meier-Ewert S, Jones T, Mitchell M, Pitha-Rowe P, Freemont P, Taylor-Papadimitriou J. A novel gene (PLU-1) containing highly conserved putative DNA/chromatin binding motifs is specifically up-regulated in breast cancer. J Biol Chem 1999; 274:15633-45. [PMID: 10336460 DOI: 10.1074/jbc.274.22.15633] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A novel human gene (PLU-1) has been identified which shows a highly restricted expression in normal adult tissues but which is consistently expressed in breast cancers. A fragment of the PLU-1 cDNA was identified by differentially screening a fetal brain library with cDNAs prepared from ce-1 cells (a human mammary epithelial cell line overexpressing c-ErbB2) treated or untreated with the antibody 4D5, which inhibits c-ErbB2 phosphorylation. Clones covering the full cDNA sequence of 6.4 kilobases were isolated from a breast cancer cDNA library. Although expression of PLU-1 in ce-1 cells is regulated by signaling from c-ErbB2, the gene is expressed in all the breast cancer cell lines examined, in cells cultured from primary breast cancers, and in the invasive and in situ components of primary breast cancers. Translation of the open reading frame predicts a protein of 1544 amino acids, which contains three PHD/LAP motifs, a specific DNA-binding domain found in a Drosophila protein (dri) and novel domains showing extensive homology with other human and non human gene products. Transient transfection of cell lines with MYC-tagged PLU-1 showed the protein to be localized in the nucleus and associated with discrete foci. The presence of the dri motif and PHD/LAP fingers together with the clear nuclear localization and consistent expression in breast cancers, suggest a role for PLU-1 in regulating gene expression in breast cancers.
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Affiliation(s)
- P J Lu
- Laboratory of Epithelial Cell Biology, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom
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Vadlamudi R, Mandal M, Adam L, Steinbach G, Mendelsohn J, Kumar R. Regulation of cyclooxygenase-2 pathway by HER2 receptor. Oncogene 1999; 18:305-14. [PMID: 9927187 DOI: 10.1038/sj.onc.1202307] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Emerging lines of evidence suggest that in addition to growth factors, the process of colorectal tumorigenesis may also be driven by the upregulation of the inducible form of cyclooxygenase-2 (COX-2), an enzyme responsible for the conversion of arachidonic acid to PGEs. The present study was undertaken to investigate the expression and activation of the HER family members, and to explore the regulation of COX-2 expression by the HER2 pathway in human colorectal cancer cells. Here, we report that human colorectal cancer cell lines express abundant levels of HER2 and HER3 receptors, and are growth-stimulated by recombinant neu-differentiation factor-beta 1 (NDF). NDF-treatment of colorectal cancer cells was accompanied by increased tyrosine phosphorylation and heterodimerization of HER3 with HER2. In addition, we demonstrated that HER2 and HER3 receptors in colorectal cancer cells are constitutively phosphorylated on tyrosine residues and form heterodimeric complexes in the absence of exogenous NDF. Inhibition of HER2/HER3 signaling by an anti-HER3 mAb against the ligand binding site resulted in a decrease in the levels of constitutively activated HER2/ HER3 heterodimers, and the unexpected reduction of COX-2 expression. Activation of the HER2/HER3 pathway by NDF induced the activation of COX-2 promoter, expression of COX-2 mRNA, COX-2 protein and accumulation of prostaglandin E2 in the culture medium. Finally, we demonstrated that NDF promotes the ability of colorectal cancer cells to survive in an extracellular matrix milieu, such as Matrigel, and also to invade through a 8 microm porous membrane. These biological activities of NDF and its stimulation of cell proliferation are blocked by a specific inhibitor of COX-2. Taken together, our findings provide the first biochemical evidence of a possible role of the COX-2 pathway in the mitogenic action of NDF in colorectal cancer cells where it may be constitutively upregulated due to the autocrine/paracrine activation of HER2/ HER3 heterodimers.
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Affiliation(s)
- R Vadlamudi
- Department of Clinical Investigation, The University of Texas MD Anderson Cancer Center, Houston 77030, USA
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40
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Adam L, Vadlamudi R, Kondapaka SB, Chernoff J, Mendelsohn J, Kumar R. Heregulin regulates cytoskeletal reorganization and cell migration through the p21-activated kinase-1 via phosphatidylinositol-3 kinase. J Biol Chem 1998; 273:28238-46. [PMID: 9774445 DOI: 10.1074/jbc.273.43.28238] [Citation(s) in RCA: 226] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanisms through which heregulin (HRG) regulates the activities of breast cancer cells are currently unknown. We demonstrate that HRG stimulation of noninvasive breast cancer cells enhanced the conversion of globular to filamentous actin and the formation of membrane ruffles, stress fibers, filopodia, and lamellipodia and accompanied by increased cell migration. In addition, HRG triggered a rapid stimulation of p21-activated kinase1 (PAK1) activity and its redistribution into the leading edges of motile cells. The HRG-induced stimulation of PAK1 kinase activity followed phosphatidylinositol-3 kinase (PI-3 kinase) activation. Inhibition of PI-3 kinase activity blocked the activation of PAK1 kinase and also blocked cell migration in response to HRG. Furthermore, direct inhibition of PAK1 functions by the dominant-negative mutant suppressed the capacity of HRG to reorganize actin cytoskeleon structures. We also demonstrated that HRG stimulation promoted physical interactions between PAK1, actin, and human epidermal growth factor receptor 2 (HER2) receptors, and these interactions were dependent on the activation of PI-3 kinase. The blockade of HER2 receptor by an anti-HER2 monoclonal antibody resulted in the inhibition of HRG-mediated stimulation of PI-3 kinase/PAK pathway and also the formation of motile actin cytoskeleton structures but not extracellular signal-regulated kinases. These findings suggest a role of PI-3 kinase/PAK1-dependent reorganization of the cortical actin cytoskeleton in HRG-mediated increased cell migration, and these changes may have significant consequences leading to enhanced invasion by breast cancer cells.
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Affiliation(s)
- L Adam
- Cell Growth Regulation Laboratory, the University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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41
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Bandyopadhyay D, Mandal M, Adam L, Mendelsohn J, Kumar R. Physical interaction between epidermal growth factor receptor and DNA-dependent protein kinase in mammalian cells. J Biol Chem 1998; 273:1568-73. [PMID: 9430697 DOI: 10.1074/jbc.273.3.1568] [Citation(s) in RCA: 177] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Binding of extracellular ligands to epidermal growth factor receptors (EGFR) activate signal transduction pathways associated with cell proliferation, and these events are inhibited by monoclonal antibodies against EGFR. Since efficient DNA repair in actively growing cells may require growth factor signaling, it was of interest to explore any linkage between EGFR-mediated signaling and DNA-dependent protein kinase (DNA-PK), an enzyme believed to be involved in repairing double strand breaks and V(D)J recombination. We report that anti-EGFR monoclonal antibodies (mAbs), and not EGFR ligands, trigger a specific early physical interaction between EGFR and a 350-kDa catalytic subunit of DNA or its regulatory heterodimeric complex Ku70/80, in a variety of cell types, both in vivo and in vitro. Inhibition of EGFR signaling by anti-EGFR mAb was accompanied by a reduction in the levels of the DNA-PK and its activity in the nuclear fraction. Confocal imaging revealed that a substantial amount of DNA-PK was co-localized with EGFR in anti-EGFR mAb-treated cells. Anti-EGFR mAb-induced physical interaction between EGFR and DNA-PK or Ku70/80 was dependent on the presence of EGFR, but not on the levels of EGFR. The EGFR associated with DNA-PK or Ku70/80 retains its intrinsic kinase activity. Our findings demonstrate the existence of a novel cellular pathway in mammalian cells that involves physical interactions between EGFR and DNA-PK or Ku70/80 in response to inhibition of EGFR signaling. Our present observations suggest a possible role of EGFR signaling in maintenance of the nuclear levels of DNA-PK, and interference in EGFR signaling may possibly result in the impairment of DNA repair activity in the nuclei in anti-EGFR mAb-treated cells.
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Affiliation(s)
- D Bandyopadhyay
- Department of Clinical Investigation, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA
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42
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Arteaga CL, Ramsey TT, Shawver LK, Guyer CA. Unliganded epidermal growth factor receptor dimerization induced by direct interaction of quinazolines with the ATP binding site. J Biol Chem 1997; 272:23247-54. [PMID: 9287333 DOI: 10.1074/jbc.272.37.23247] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Receptor dimerization is critical for signaling by the epidermal growth factor receptor (EGFR) tyrosine kinase. This occurs after binding of the receptor's extracellular domain by ligand or bivalent antibodies. The role of other receptor domains in dimerization is less clear, and there are no examples of dimers induced by direct perturbation of the EGFR kinase domain. Submicromolar concentrations of AG-1478 and AG-1517, quinazolines specific for inhibition of the EGFR kinase, induced reversible receptor dimerization in vitro and in intact A431 cells. Consistent with the inhibitory effect of quinazolines on receptor kinase activity, the dimers formed lacked a detectable Tyr(P) signal. Quinazoline-induced EGFR dimerization was abrogated in vitro by ATP and the ATP analog adenyl-5'-yl imidodiphosphate. Receptors with a single-point mutation in the ATP binding site as well as wild-type EGFR with a covalent modification of the ATP site failed to dimerize in response to AG-1478 and AG-1517. These data suggest that EGFR dimerization can be induced by the interaction of quinazolines at the ATP site in the absence of receptor ligand binding. In SKBR-3 cells, the quinazolines induced the formation of inactive EGFR/ErbB-2 heterodimers, potentially sequestering ErbB-2 from interacting with other coreceptors of the ErbB family. Structural studies of the quinazoline interaction with the EGFR tyrosine kinase domain should allow for an analysis of receptor-specific chemical features required for binding to the ATP site and disruption of signaling, a strategy that can be perhaps applied to other tumor cell receptor systems.
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Affiliation(s)
- C L Arteaga
- Department of Medicine, Vanderbilt University School of Medicine, Vanderbilt Cancer Center, Nashville, Tennessee 37232-5536, USA.
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43
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Abstract
The HER-2/neu proto-oncogene encodes a 185 kDa transmembrane receptor tyrosine kinase with significant sequence homology to other members of the class I receptor tyrosine kinase family. The HER-2/neu gene is amplified and/or overexpressed in 25%-30% of human breast and ovarian cancers, and overexpression of the receptor is associated with poor prognosis. Tyrosine phosphorylation and activation of the HER-2 receptor lead to activation of specific signal transduction pathways in breast and ovarian cancer cells, including the ras/MAP kinase cascade, phosphatidylinositol 3-kinase, and phospholipase C-gamma. HER-2/neu signal transduction pathways ultimately converge on the cell nucleus, where the expression of diverse genes is induced after activation of the receptor. A more complete understanding of HER-2/neu signal transduction pathways may allow the development of specific therapeutics for the treatment of those human breast and ovarian cancers containing this alteration.
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Affiliation(s)
- D M Reese
- Division of Hematology/Oncology and Jonsson Comprehensive Cancer Center, UCLA School of Medicine, Los Angeles, California 90095, USA
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44
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Rajkumar T, Stamp GW, Pandha HS, Waxman J, Gullick WJ. Expression of the type 1 tyrosine kinase growth factor receptors EGF receptor, c-erbB2 and c-erbB3 in bladder cancer. J Pathol 1996; 179:381-5. [PMID: 8869284 DOI: 10.1002/(sici)1096-9896(199608)179:4<381::aid-path603>3.0.co;2-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Expression of the c-erbB3 protein was determined in transitional cell carcinoma of the bladder by immunohistochemistry. Strong membrane staining was observed in 10 per cent of cases (7/70) and cytoplasmic and membrane overexpression in 20 per cent (14/70). Overexpression of the epidermal growth factor (EGF) receptor (36 per cent, 25/70) and c-erbB2 proteins (9 per cent 6/70) was determined in the same series of cases. c-erbB3 overexpression was positively correlated with EGF receptor expression (P < 0.025) but appeared to be inversely associated with c-erbB2 overexpression.
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Affiliation(s)
- T Rajkumar
- ICRF Oncology Unit, Royal Postgraduate Medical School, London, UK
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46
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Kumar R, Mandal M, Ratzkin BJ, Liu N, Lipton A. NDF induces expression of a novel 46 kD protein in estrogen receptor positive breast cancer cells. J Cell Biochem 1996. [DOI: 10.1002/(sici)1097-4644(199607)62:1<102::aid-jcb11>3.0.co;2-p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Kumar R, Mandal M, Ratzkin BJ, Liu N, Lipton A. NDF induces expression of a novel 46 kD protein in estrogen receptor positive breast cancer cells. J Cell Biochem 1996; 62:102-12. [PMID: 8836879 DOI: 10.1002/(sici)1097-4644(199607)62:1%3c102::aid-jcb11%3e3.0.co;2-p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most human breast tumors start as estrogen-dependent, but during the course of the disease become refractory to hormone therapy. The transition of breast tumors from estrogen dependent to independent behavior may be regulated by autocrine and/or paracrine growth factor(s) that are independent of the estrogen receptor (ER). We have investigated the role(s) of NDF (neu-differentiation factor) in the biology of estrogen positive breast cancer cells by using MCF-7 cells as a model system. Treatment of MCF-7 cells with human recombinant NDF-beta 2 (NDF) inhibited the ER expression by 70% and this was associated with growth stimulation in an estrogen-independent manner. To explore the mechanism(s) of action of NDF in MCF-7 cells, we examined the expression of NDF-inducible gene products. We report here that NDF stimulated the levels of expression of a 46 kD protein (p46) (in addition to few minor proteins) in ER positive breast cancer cells including MCF-7, T-47-D, and ZR-75-R cells but not in ER negative breast cancer cells including MDA-231, SK-BR-3, and MDA-468 cells. This effect of NDF was due to induction in the rate of synthesis of new p46. The observed NDF-mediated induction of p46 expression was specific as there was no such effect by epidermal growth factor or 17-beta-estradiol, and inclusion of actinomycin D partially inhibited the p46 induction elicited by NDF. NDF-inducible stimulation of p46 expression was an early event (2-6 h) which preceded the period of down-regulation of ER expression by NDF. These results support the existence of NDF-responsive specific cellular pathway(s) that may regulate ER, and these interactions could play a role(s) in hormone-independence of ER positive breast cancer cells.
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Affiliation(s)
- R Kumar
- Department of Medicine, Pennsylvania State University College of Medicine, Hershey 17033, USA
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48
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Shintani S, Funayama T, Yoshihama Y, Alcalde RE, Matsumura T. Prognostic significance of ERBB3 overexpression in oral squamous cell carcinoma. Cancer Lett 1995; 95:79-83. [PMID: 7656248 DOI: 10.1016/0304-3835(95)03866-u] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Immunohistochemical analysis of erbB3, as the third member of epidermal growth factor receptor gene family, was performed on 41 cases of oral squamous cell carcinoma, correlating the staining pattern with clinical outcome. High expression of erbB3 protein (ERBB3) was significantly associated with lymph node metastasis (P < 0.05), survival rate (P < 0.05) and mode of invasion (P < 0.01) in this series. These results demonstrated that ERBB3 expression may be helpful in identifying those oral squamous cell carcinomas with higher malignant potential.
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Affiliation(s)
- S Shintani
- Department of Oral and Maxillofacial Surgery II, Okayama University Dental School, Japan
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49
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Osaki T, Mitsudomi T, Oyama T, Nakanishi R, Yasumoto K. Serum level and tissue expression of c-erbB-2 protein in lung adenocarcinoma. Chest 1995; 108:157-62. [PMID: 7606952 DOI: 10.1378/chest.108.1.157] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Serum levels of c-erbB-2 protein were measured by an enzyme immunoassay in 64 patients with lung adenocarcinoma. Immunohistochemical staining was performed in 40 of these tumors. The mean serum concentration was 16.5 +/- 8.5 U/mL (range: 3.4 to 49.0) in patients with lung adenocarcinoma, whereas it was 14.0 +/- 3.7 U/mL (range: 6.9 to 20.9) in 15 controls (1 U/mL = 0.61 ng/mL). Elevated concentrations (> or = 22.0 U/mL, control mean + 2 SD) were observed in 17/64 lung adenocarcinoma patients (26.6%), as compared with none of the control subjects (p < 0.05). Patients with stage IIIB or T4 disease had increased serum levels. The serum concentration was decreased significantly by surgical tumor ablation. Tissue overexpression was obtained in 17/40 cases (42.5%), and serum levels in patients with tissue overexpression were higher than in patients without overexpression. Serum c-erbB-2 protein may be a useful indicator of tumor burden in patients with lung adenocarcinoma.
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Affiliation(s)
- T Osaki
- Department of Surgery II, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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50
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Korutla L, Kumar R. Inhibitory effect of curcumin on epidermal growth factor receptor kinase activity in A431 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1224:597-600. [PMID: 7803521 DOI: 10.1016/0167-4889(94)90299-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We explored the mechanism of antigrowth action of Curcumin by investigating its effect on epidermal growth factor (EGF) receptor intrinsic kinase activity in the human epidermoid carcinoma A431 cells. The short-term treatment of cells with Curcumin inhibited EGF receptor intrinsic kinase activity up to 90% in a dose- and time-dependent manner, and also inhibited EGF-induced tyrosine phosphorylation of EGF receptors. The observed early effects of Curcumin were mediated via a cellular mechanism(s), and preceded the period when inhibition of cell growth occurred.
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Affiliation(s)
- L Korutla
- Department of Medicine, Pennsylvania State University College of Medicine, Hershey 17033
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