201
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Abstract
The RAS proteins control signalling pathways that are key regulators of several aspects of normal cell growth and malignant transformation. They are aberrant in most human tumours due to activating mutations in the RAS genes themselves or to alterations in upstream or downstream signalling components. Rational therapies that target the RAS pathways might inhibit tumour growth, survival and spread. Several of these new therapeutic agents are showing promise in the clinic and many more are being developed.
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Affiliation(s)
- Julian Downward
- Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
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202
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Casanova ML, Blázquez C, Martínez-Palacio J, Villanueva C, Fernández-Aceñero MJ, Huffman JW, Jorcano JL, Guzmán M. Inhibition of skin tumor growth and angiogenesis in vivo by activation of cannabinoid receptors. J Clin Invest 2003. [DOI: 10.1172/jci200316116] [Citation(s) in RCA: 285] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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203
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Abstract
Pancreatic ductal adenocarcinoma is an aggressive and devastating disease, which is characterized by invasiveness, rapid progression and profound resistance to treatment. Advances in pathological classification and cancer genetics have improved our descriptive understanding of this disease; however, important aspects of pancreatic cancer biology remain poorly understood. What is the pathogenic role of specific gene mutations? What is the cell of origin? And how does the stroma contribute to tumorigenesis? A better understanding of pancreatic cancer biology should lead the way to more effective treatments.
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Affiliation(s)
- Nabeel Bardeesy
- Department of Adult Oncology, Dana-Farber Cancer Institute and Departments of Medicine and Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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204
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Cai T, Nishida K, Hirano T, Khavari PA. Gab1 and SHP-2 promote Ras/MAPK regulation of epidermal growth and differentiation. J Cell Biol 2002; 159:103-12. [PMID: 12370245 PMCID: PMC2173502 DOI: 10.1083/jcb.200205017] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In epidermis, Ras can influence proliferation and differentiation; however, regulators of epidermal Ras function are not fully characterized, and Ras effects on growth and differentiation are controversial. EGF induced Ras activation in epidermal cells along with phosphorylation of the multisubstrate docking protein Gab1 and its binding to SHP-2. Expression of mutant Gab1Y627F deficient in SHP-2 binding or dominant-negative SHP-2C459S reduced basal levels of active Ras and downstream MAPK proteins and initiated differentiation. Differentiation triggered by both Gab1Y627F and SHP-2C459S could be blocked by coexpression of active Ras, consistent with Gab1 and SHP-2 action upstream of Ras in this process. To study the role of Gab1 and SHP-2 in tissue, we generated human epidermis overexpressing active Gab1 and SHP-2. Both proteins stimulated proliferation. In contrast, Gab1Y627F and SHP-2C459S inhibited epidermal proliferation and enhanced differentiation. Consistent with a role for Gab1 and SHP-2 in sustaining epidermal Ras/MAPK activity, Gab1-/- murine epidermis displayed lower levels of active Ras and MAPK with postnatal Gab1-/- epidermis, demonstrating the hypoplasia and enhanced differentiation seen previously with transgenic epidermal Ras blockade. These data provide support for a Ras role in promoting epidermal proliferation and opposing differentiation and indicate that Gab1 and SHP-2 promote the undifferentiated epidermal cell state by facilitating Ras/MAPK signaling.
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Affiliation(s)
- Ti Cai
- Veterans Affairs Palo Alto Healthcare System and the Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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205
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Abstract
The data reviewed here have further established the promise of anti-EGFR-targeted therapies. This statement is supported by the evidence of antitumor activity of the TK inhibitors ZD1839 and OSI-774 against several tumor types and by the ability of the monoclonal antibody IMC-C225 to reverse clinical chemotherapy resistance. These results are further supported by an emerging number of compounds, monoclonal antibodies, and TK inhibitors directed at the EGFR that are in clinical development (see Fig. 2, Table 1). Among the TK inhibitors, these compounds can be further categorized by their receptor specificity and reversibility of binding. In the case of anti-EGFR monoclonal antibodies, compounds in clinical development include chimeric, humanized, and bispecific antibodies. The fundamental observation is that these compounds have shown activity in several tumor types, including NSCL cancer, prostate carcinoma, colorectal carcinoma, ovarian carcinoma, renal cell carcinoma, and head and neck cancers. These findings observed with different agents and in different tumor types validate EGFR as a target for cancer therapy. The results of ongoing studies with these agents in diverse indications and tumor types may establish the role of these promising therapies to our current cancer treatments.
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Affiliation(s)
- Jose Baselga
- Medical Oncology Service, Hospital General Universitari Vall d'Hebron, Paseo Vall d'Hebron 119-129, 08035 Barcelona, Spain.
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206
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Iordanov MS, Choi RJ, Ryabinina OP, Dinh TH, Bright RK, Magun BE. The UV (Ribotoxic) stress response of human keratinocytes involves the unexpected uncoupling of the Ras-extracellular signal-regulated kinase signaling cascade from the activated epidermal growth factor receptor. Mol Cell Biol 2002; 22:5380-94. [PMID: 12101233 PMCID: PMC133934 DOI: 10.1128/mcb.22.15.5380-5394.2002] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In mammals, UVB radiation is of biological relevance primarily for the cells of the epidermis. We report here the existence of a UVB response that is specific for proliferating human epidermal keratinocytes. Unlike other cell types that also display a UVB response, keratinocytes respond to UVB irradiation with a transient but potent downregulation of the Ras-extracellular signal-regulated kinase (ERK) signaling cascade. The downregulation of ERK precedes a profound decrease in the steady-state levels of cyclin D1, a mediator of the proliferative action of ERK. Keratinocytes exhibit high constitutive activity of the Ras-ERK signaling cascade even in culture medium lacking supplemental growth factors. The increased activity of Ras and phosphorylation of ERK in these cells are maintained by the autocrine production of secreted molecules that activate the epidermal growth factor receptor (EGFR). Irradiation of keratinocytes increases the phosphorylation of EGFR on tyrosine residues Y845, Y992, Y1045, Y1068, Y1086, Y1148, and Y1173 above the basal levels and leads to the increased recruitment of the adaptor proteins Grb2 and ShcA and of a p55 form of the regulatory subunit of the phosphatidylinositide 3-kinase to the UVB-activated EGFR. Paradoxically, however, UVB causes, at the same time, the inactivation of Ras and a subsequent dephosphorylation of ERK. By contrast, the signaling pathway leading from the activated EGFR to the phosphorylation of PKB/Akt1 is potentiated by UVB. The UVB response of keratinocytes appeared to be a manifestation of the more general ribotoxic stress response inasmuch as the transduction of the UVB-generated inhibitory signal to Ras and ERK required the presence of active ribosomes at the time of irradiation.
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Affiliation(s)
- Mihail S Iordanov
- Department of Cell and Developmental Biology, Oregon Health Sciences University, Portland, OR 97201, USA
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207
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Yamabhai M, Anderson RGW. Second cysteine-rich region of epidermal growth factor receptor contains targeting information for caveolae/rafts. J Biol Chem 2002; 277:24843-6. [PMID: 12023273 DOI: 10.1074/jbc.c200277200] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies have shown that approximately 60% of the epidermal growth factor receptors (EGFRs) in quiescent fibroblasts are concentrated in the caveolae/raft fraction from purified plasma membranes. This high degree of localization suggests the EGFR contains targeting information for lipid domains. We have used mutagenesis to determine that the region of the receptor that controls targeting to caveolae/rafts resides in the juxtamembrane, second cysteine-rich region. A 60-amino acid-long sequence within this region that is continuous with the transmembrane domain was sufficient to target the transmembrane and cytoplasmic tails of both EGFR and the low density lipoprotein receptor to caveolae/rafts. Two N-linked sugars in this segment were not required for proper targeting, although unglycosylated wild-type receptors did not localize properly. We conclude that, in contrast to signals for coated pit localization that are in the cytoplasmic tail, the targeting information for caveolae/rafts is on the extracellular side of the EGFR very close to the membrane.
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Affiliation(s)
- Montarop Yamabhai
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas 75235-9039, USA
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208
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Braun S, auf dem Keller U, Beer HD, Krampert M, Müller M, Werner S, Dickson C, Werner S. Meeting report: growth factors in development, repair and disease. Eur J Cell Biol 2002; 81:375-82. [PMID: 12160145 DOI: 10.1078/0171-9335-00258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Susanne Braun
- Institute of Cell Biology, ETH Zürich, Department of Biology, Switzerland
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209
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Herzig M, Christofori G. Recent advances in cancer research: mouse models of tumorigenesis. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1602:97-113. [PMID: 12020798 DOI: 10.1016/s0304-419x(02)00039-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Over the past 20 years, cancer research has gained major insights into the complexity of tumor development, in particular into the molecular mechanisms that underlie the progressive transformation of normal cells into highly malignant derivatives. It is estimated that the transformation of a normal cell to a malignant tumor cell is dependent upon a small number of genetic alterations, estimated to be within the range of four to seven rate-limiting events. Critical events in the evolution of neoplastic disease include the loss of proliferative control, the failure to undergo programmed cell death (apoptosis), the onset of neoangiogenesis, tissue remodeling, invasion of tumor cells into surrounding tissue and, finally, metastatic dissemination of tumor cells to distant organs. In patients, the molecular analysis of these multiple steps is hampered by the unavailability of tumor biopsies from all tumor stages. In contrast, mouse models of tumorigenesis allow the reproducible isolation of all tumor stages, including normal tissue, which are then amenable to pathological, genetic and biochemical analyses and, hence, have been instrumental in investigating cancer-related genes and their role in carcinogenesis. In this review, we discuss mouse tumor models that have contributed substantially to the identification and characterization of novel tumor pathways. In particular, we focus on transgenic and knockout mouse models that closely mimic human cancer and thus can be used as model systems for cancer research.
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210
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Santos M, Paramio JM, Bravo A, Ramirez A, Jorcano JL. The expression of keratin k10 in the basal layer of the epidermis inhibits cell proliferation and prevents skin tumorigenesis. J Biol Chem 2002; 277:19122-30. [PMID: 11889133 DOI: 10.1074/jbc.m201001200] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Forced expression of K10, a keratin normally expressed in postmitotic, terminally differentiating epidermal keratinocytes, inhibits the progression of the cell cycle in cultured cells (Paramio, J. M., Casanova, M. Ll., Segrelles, C., Mittnacht, S., Lane, E. B., and Jorcano, J. L. (1999) Mol. Cell. Biol. 19, 3086-3094). This process requires a functional retinoblastoma (pRb) gene product and is mediated by K10-induced inhibition of Akt and PKCzeta, two signaling intermediates belonging to the phosphoinositide (PI) 3-kinase signal transduction pathway (Paramio, J. M., Segrelles, C., Ruiz, S., and Jorcano, J. L. (2001) Mol. Cell. Biol. 21, 7449-7459). Extending earlier in vitro studies to the in vivo situation, this work analyzes the alterations found in transgenic mice that ectopically express K10 in the proliferative basal cells of the epidermis. Increased expression of K10 led to a hypoplastic and hyperkeratotic epidermis due to a dramatic decrease in skin keratinocyte proliferation in association with the inhibition of Akt and PKCzeta activities. The inhibition of cell proliferation and Akt and PKCzeta activities was also observed although to a minor extent in low hK10-expressing mice. These animals displayed no overt epidermal phenotype nor overexpression of K10. In these non-phenotypic mice, ectopic K10 expression also resulted in decreased skin tumorigenesis. Collectively, these data demonstrate that keratin K10 in vivo functions include the control of epithelial proliferation in skin epidermis.
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Affiliation(s)
- Mirentxu Santos
- Project on Cell and Molecular Biology and Gene Therapy, CIEMAT Av. Complutense 22, E-28040 Madrid, Spain
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211
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Hart TC, Zhang Y, Gorry MC, Hart PS, Cooper M, Marazita ML, Marks JM, Cortelli JR, Pallos D. A mutation in the SOS1 gene causes hereditary gingival fibromatosis type 1. Am J Hum Genet 2002; 70:943-54. [PMID: 11868160 PMCID: PMC379122 DOI: 10.1086/339689] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2001] [Accepted: 01/10/2002] [Indexed: 11/04/2022] Open
Abstract
Hereditary gingival fibromatosis (HGF) is a rare, autosomal dominant form of gingival overgrowth. Affected individuals have a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of the oral masticatory mucosa. Genetic loci for autosomal dominant forms of HGF have been localized to chromosome 2p21-p22 (HGF1) and chromosome 5q13-q22 (HGF2). To identify the gene responsible for HGF1, we extended genetic linkage studies to refine the chromosome 2p21-p22 candidate interval to approximately 2.3 Mb. Development of an integrated physical and genetic map of the interval identified 16 genes. Sequencing of these genes, in affected and unaffected HGF1 family members, identified a mutation in the Son of sevenless-1 (SOS1) gene in affected individuals. In this report, we describe the genomic structure of the SOS1 gene and present evidence that insertion of a cytosine between nucleotides 126,142 and 126,143 in codon 1083 of the SOS1 gene is responsible for HGF1. This insertion mutation, which segregates in a dominant manner over four generations, introduces a frameshift and creates a premature stop codon, abolishing four functionally important proline-rich SH3 binding domains normally present in the carboxyl-terminal region of the SOS1 protein. The resultant protein chimera contains the wild-type SOS1 protein for the N-terminal amino acids 1-1083 fused to a novel 22-amino acid carboxyl terminus. Similar SOS1 deletion constructs are functional in animal models, and a transgenic mouse construct with a comparable SOS1 chimera produces a phenotype with skin hypertrophy. Clarification of the functional role of this SOS1 mutant has implications for understanding other forms of gingival fibromatosis and corrective gingival-tissue management.
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Affiliation(s)
- Thomas C Hart
- Center For Craniofacial and Dental Genetics, Division of Oral Biology and Pathology, University of Pittsburgh School of Dental Medicine, 614 Salk Hall, 3501 Terrace Street, Pittsburgh, PA 15261, USA.
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212
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Abstract
At the surface of the skin, the epidermis serves as the armour for the body. Scientists are now closer than ever to understanding how the epidermis accomplishes this extraordinary feat, and is able to survive and replenish itself under the harshest conditions that face any tissue. By combining genetic engineering with cell-biological studies and with human genome data analyses, skin biologists are discovering the mechanisms that underlie the development and differentiation of the epidermis and hair follicles of the skin. This explosion of knowledge paves the way for new discoveries into the genetic bases of human skin disorders and for developing new therapeutics.
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Affiliation(s)
- Elaine Fuchs
- Howard Hughes Medical Institute, Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA.
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213
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Kheradmand F, Rishi K, Werb Z. Signaling through the EGF receptor controls lung morphogenesis in part by regulating MT1-MMP-mediated activation of gelatinase A/MMP2. J Cell Sci 2002; 115:839-48. [PMID: 11865039 PMCID: PMC2788991 DOI: 10.1242/jcs.115.4.839] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Epithelial-mesenchymal interactions during lung development require extracellular signaling factors that facilitate branching morphogenesis. We show here that matrix metalloproteinases (MMPs) originating in the mesenchyme are necessary for epithelial branching and alveolization. We found that the delayed lung maturation characterized by abnormal branching and poor alveolization seen in mice deficient in epidermal growth factor receptor(Egfr-/-) is accompanied by aberrant expression of MMPs. By in situ zymography, the lungs from newborn Egfr-/- mice had low gelatinolytic activity compared with wildtype. Inhibition of MMPs in developing lungs in vivo or in vitro severely retarded morphogenesis. Egfr-/- mice had low expression of MT1-MMP/MMP14, which is a potent activator of gelatinase A/MMP2, in their lungs. Egf ligand increased MT1-MMP mRNA by tenfold in lung fibroblasts from wild type, but not from Egfr-/- mice. Extracts from lungs of Egfr-/- mice showed a tenfold reduction in active MMP-2, but only a slight decrease in proMMP-2 by zymography. At birth, MMP-2-/- mice had a lung phenotype characterized by abnormal lung alveolization which phenocopied that of Egfr-/- mice, albeit somewhat less severe. We conclude that proteolysis mediates epithelial/mesenchymal interactions during lung morphogenesis. From the phenotypes of the Egfr-/- mice, we identify MT1-MMP as a major downstream target of Egfr signaling in lung in vivo and in vitro. MT1-MMP is, in turn, necessary for activation of MMP-2, a mesenchymal enzyme that is required for normal lung morphogenesis.
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Affiliation(s)
- Farrah Kheradmand
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
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214
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Roberts RB, Min L, Washington MK, Olsen SJ, Settle SH, Coffey RJ, Threadgill DW. Importance of epidermal growth factor receptor signaling in establishment of adenomas and maintenance of carcinomas during intestinal tumorigenesis. Proc Natl Acad Sci U S A 2002; 99:1521-6. [PMID: 11818567 PMCID: PMC122223 DOI: 10.1073/pnas.032678499] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We used the hypomorphic Egfr(wa2) allele to genetically examine the impact of impaired epidermal growth factor receptor (Egfr) signaling on the Apc(Min) mouse model of familial adenomatous polyposis. Transfer of the Apc(Min) allele onto a homozygous Egfr(wa2) background results in a 90% reduction in intestinal polyp number relative to Apc(Min) mice carrying a wild-type Egfr allele. This Egfr effect is potentially synergistic with the actions of the modifier-of-min (Mom1) locus. Surprisingly, the size, expansion, and pathological progression of the polyps appear Egfr-independent. Histological examination of the ilea of younger animals revealed no differences in the number of microadenomas, the presumptive precursor lesions to gross intestinal polyps. Pharmacological inhibition with EKI-785, an Egfr tyrosine kinase inhibitor, produced similar results in the Apc(Min) model. These data suggest that normal Egfr activity is required for establishment of intestinal tumors in the Apc(Min) model between initiation and subsequent expansion of initiated tumors. The role of Egfr signaling during later stages of tumorigenesis was examined by using nude mice xenografts of two human colorectal cancer cell lines. Treatment with EKI-785 produced a dose-dependent reduction in tumor growth, suggesting that Egfr inhibitors may be useful for advanced colorectal cancer treatment.
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Affiliation(s)
- Reade B Roberts
- Department of Cell Biology, Vanderbilt University, 1161 21st Avenue South, Nashville, TN 37232, USA
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215
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Abstract
The development of resistance against cytotoxic or endocrine therapy limits the number of chemotherapeutic compounds used in the clinic. The receptor for EGF (EGFR) is not only involved in survival signaling, cell migration, metastasis formation and angiogenesis, but also confers reduced responses of tumor cells towards cytotoxic compounds or radiation. Clinical trials designed to combine EGFR inhibitors with standard chemo- or radiation therapy have been successful. Elucidation of some of the molecular mechanisms of EGFR-mediated chemoresistance may lead to novel treatment approaches against molecules linked to EGFR signal transduction. In human breast carcinomas, the presence of EGFR correlates with lack of response towards anti-estrogen therapy suggesting the concomitant inhibition of both the receptors for estrogen and EGF to improve breast cancer therapy.
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Affiliation(s)
- Mathias Schmidt
- Byk Gulden, Lomberg Chemische Fabrik GmbH, Byk-Gulden-Strasse 2, Konstanz, Germany.
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216
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Segrelles C, Ruiz S, Perez P, Murga C, Santos M, Budunova IV, Martínez J, Larcher F, Slaga TJ, Gutkind JS, Jorcano JL, Paramio JM. Functional roles of Akt signaling in mouse skin tumorigenesis. Oncogene 2002; 21:53-64. [PMID: 11791176 DOI: 10.1038/sj.onc.1205032] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2001] [Revised: 09/27/2001] [Accepted: 10/09/2001] [Indexed: 12/28/2022]
Abstract
The mouse skin carcinogenesis protocol is a unique model for understanding the molecular events leading to oncogenic transformation. Mutations in the Ha-ras gene, and the presence of functional cyclin D1 and the EGF receptor, have proven to be important in this system. However, the signal transduction pathways connecting these elements during mouse skin carcinogenesis are poorly understood. This paper studies the relevance of the Akt and ERK pathways in the different stages of chemically induced mouse skin tumors. Akt activity increases throughout the entire process, and its early activation is detected prior to increased cyclin D1 expression. ERK activity rises only during the later stages of malignant conversion. The observed early increase in Akt activity appears to be due to raised PI-3K activity. Other factors acting on Akt such as ILK activation and decreased PTEN phosphatase activity appear to be involved at the conversion stage. To further confirm the involvement of Akt in this process, PB keratinocytes were transfected with Akt and subsequently injected into nude mice. The expression of Akt accelerates tumorigenesis and contributes to increased malignancy of these keratinocytes as demonstrated by the rate of appearance, the growth and the histological characteristics of the tumors. Collectively, these data provide evidence that Akt activation is one of the key elements during the different steps of mouse skin tumorigenesis.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene
- Animals
- Carcinogens
- Carcinoma, Squamous Cell/chemically induced
- Carcinoma, Squamous Cell/enzymology
- Carcinoma, Squamous Cell/genetics
- Cell Line, Transformed/enzymology
- Cell Line, Transformed/transplantation
- Cell Nucleus/enzymology
- Cell Transformation, Neoplastic/metabolism
- Cyclin D1/metabolism
- Cytoplasm/enzymology
- Enzyme Activation
- ErbB Receptors/physiology
- Female
- Gene Expression Regulation, Neoplastic
- Genes, ras
- Keratinocytes/enzymology
- Keratinocytes/pathology
- Keratinocytes/transplantation
- MAP Kinase Signaling System
- Mice
- Mice, Inbred SENCAR
- Mice, Nude
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/metabolism
- Neoplasm Proteins/physiology
- PTEN Phosphohydrolase
- Papilloma/chemically induced
- Papilloma/enzymology
- Papilloma/genetics
- Phosphatidylinositol 3-Kinases/biosynthesis
- Phosphatidylinositol 3-Kinases/genetics
- Phosphatidylinositol 3-Kinases/physiology
- Phosphoric Monoester Hydrolases/biosynthesis
- Phosphoric Monoester Hydrolases/genetics
- Protein Serine-Threonine Kinases/physiology
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/physiology
- Proto-Oncogene Proteins c-akt
- Skin Neoplasms/chemically induced
- Skin Neoplasms/enzymology
- Skin Neoplasms/genetics
- Tumor Suppressor Proteins/biosynthesis
- Tumor Suppressor Proteins/genetics
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Affiliation(s)
- Carmen Segrelles
- Project on Cell and Molecular Biology and Gene Therapy, CIEMAT, Av. Complutense 22, E-28040 Madrid, Spain
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217
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Albanell J, Rojo F, Averbuch S, Feyereislova A, Mascaro JM, Herbst R, LoRusso P, Rischin D, Sauleda S, Gee J, Nicholson RI, Baselga J. Pharmacodynamic studies of the epidermal growth factor receptor inhibitor ZD1839 in skin from cancer patients: histopathologic and molecular consequences of receptor inhibition. J Clin Oncol 2002; 20:110-24. [PMID: 11773160 DOI: 10.1200/jco.2002.20.1.110] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor ZD1839 (Iressa; AstraZeneca Pharmaceuticals, Alderley Park, United Kingdom) is under development as an anticancer agent. We studied the pharmacodynamic effects of ZD1839 on EGFR in the skin, an EGFR-dependent tissue, in cancer patients participating in ZD1839 phase I clinical trials. PATIENTS AND METHODS We studied 104 pre- and/or on-ZD1839 therapy ( approximately at day 28 of therapy) skin biopsies from 65 patients receiving escalating doses of daily oral ZD1839. We measured ZD1839 effects on EGFR activation by immunohistochemistry using an antibody specific for the activated (phosphorylated) EGFR. Effects on receptor signaling (activated mitogen-activated protein kinase [MAPK]), proliferation, p27(KIP1), and maturation were also assessed. RESULTS Histopathologically, the stratum corneum of the epidermis was thinner during therapy (P <.001). In hair follicles, prominent keratin plugs and microorganisms were found in dilated infundibula. ZD1839 suppressed EGFR phosphorylation in all EGFR-expressing cells (P <.001). In addition, ZD1839 inhibited MAPK activation (P <.001) and reduced keratinocyte proliferation index (P <.001). Concomitantly, ZD1839 increased the expression of p27(KIP1) (P <.001) and maturation markers (P <.001) and increased apoptosis (P <.001). These effects were observed at all dose levels, before reaching dose-limiting toxicities. CONCLUSION ZD1839 inhibits EGFR activation and affects downstream receptor-dependent processes in vivo. These effects were profound at doses well below the one producing unacceptable toxicity, a finding that strongly supports pharmacodynamic assessments to select optimal doses instead of a maximum-tolerated dose for definitive efficacy and safety trials.
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Affiliation(s)
- Joan Albanell
- Oncology Service, Vall d'Hebron University Hospital, Paseo Vall d'Hebron 119-129, Barcelona 08035, Spain
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218
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Normanno N, Campiglio M, De LA, Somenzi G, Maiello M, Ciardiello F, Gianni L, Salomon DS, Menard S. Cooperative inhibitory effect of ZD1839 (Iressa) in combination with trastuzumab (Herceptin) on human breast cancer cell growth. Ann Oncol 2002; 13:65-72. [PMID: 11863114 DOI: 10.1093/annonc/mdf020] [Citation(s) in RCA: 204] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Co-expression of the epidermal growth factor receptor (EGFR) and of ErbB-2 is found in a subset of primary human breast cancer. MATERIALS AND METHODS The antiproliferative effects of anti-EGFR and anti-ErbB-2 agents were evaluated using a monolayer assay. The effects of these agents on the activation of EGFR, ErbB-2, AKT and p42/p44 MAP kinases (MAPK) were investigated by western blot analysis. RESULTS We found that both ZD1839 (Iressa), a specific EGFR tyrosine kinase inhibitor, and trastuzumab (Herceptin) (TRA), a humanized anti-ErbB-2 monoclonal antibody, were able to inhibit the growth of SK-Br-3 and BT-474 breast carcinoma cells, which express both EGFR and ErbB-2. Treatment of breast carcinoma cells with a combination of ZD1839 and TRA resulted in a synergistic inhibitory effect. Treatment of SK-Br-3 cells with ZD1839 produced a significant, dose-dependent reduction of the tyrosine phosphorylation of both EGFR and ErbB-2. Phosphorylation of MAPK and AKT were significantly reduced in SK-Br-3 cells following treatment with ZD1839, whereas treatment with TRA produced a reduction of AKT but not MAPK phosphorylation. Finally, treatment with ZD1839, but not with TRA, produced a significant increase in fragmented DNA in breast carcinoma cells. However, a more pronounced increase in the levels of fragmented DNA was observed following combined treatment with ZD1839 and TRA. CONCLUSIONS These data suggest that combined treatment with drugs that target EGFR and ErbB-2 might result in an efficient inhibition of tumor growth in those breast carcinoma patients whose tumors co-express both receptors.
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Affiliation(s)
- N Normanno
- Oncologia Sperimentale D, Istituto Tumori Milano, Milan, Italy.
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219
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Anderson NG, Ahmad T, Chan K, Dobson R, Bundred NJ. ZD1839 (Iressa), a novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, potently inhibits the growth of EGFR-positive cancer cell lines with or without erbB2 overexpression. Int J Cancer 2001; 94:774-82. [PMID: 11745477 DOI: 10.1002/ijc.1557] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Overexpression of the growth factor receptors EGFR and erbB2 occurs frequently in several human cancers and is associated with aggressive tumour behaviour and poor patient prognosis. We have investigated the effects of ZD1839 (Iressa), a novel EGFR tyrosine kinase inhibitor, on the growth, in vitro and in vivo, of human cancer cell lines expressing various levels of EGFR and erbB2. Proliferation of EGFR-overexpressing A431 and MDA-MB-231 cells in vitro was potently inhibited (50%-70%) by ZD1839 with half-maximally effective doses in the low nanomolar range. In parallel, ZD1839 blocked autophosphorylation of EGFR and prevented activation of PLC-gamma 1, ERK MAP kinases and PKB/Akt by EGF. It also inhibited proliferation in EGFR(+) cancer cell lines overexpressing erbB2 (SKBr3, SKOV3, BT474) by between 20% and 80%, effects which correlated with inhibition of EGF-dependent erbB2 phosphorylation and activation of ERK MAP kinase and PKB/Akt in SKOV3 cells. Oral administration of ZD1839 inhibited the growth of MDA-MB-231 and SKOV3 tumours, established as xenografts in athymic mice, by 71% and 32%, respectively. Growth inhibition coincided with reduced proliferation but no change in apoptotic index. Collectively, these results show that ZD1839, at the doses studied, is a potent inhibitor of proliferation not only in cells overexpressing EGFR but also in EGFR(+) cells that overexpress erbB2.
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Affiliation(s)
- N G Anderson
- Division of Cancer Studies, Department of Surgery, School of Medicine, University of Manchester, Manchester, United Kingdom.
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220
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Crowe DL, Tsang KJ. Decreased mitogenic response to epidermal growth factor in human squamous cell carcinoma lines overexpressing epidermal growth factor receptor owing to limiting amounts of the adaptor protein Grb2: rescue by retinoic acid treatment. Mol Carcinog 2001; 32:187-94. [PMID: 11746830 DOI: 10.1002/mc.10011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Growth factor receptors of the tyrosine kinase family regulate proliferation of a variety of cell types. In some human cancers, the epidermal growth factor receptor (EGFR) and its ligands often are overexpressed, leading to both constitutive and autocrine activation. Intracellular signaling via this receptor takes place through several mechanisms of action, including activation of ras and the mitogen-activated protein kinase (MAPK) pathway. Our previous studies have shown that human squamous cell carcinoma (SCC) lines overexpress EGFR and do not increase proliferation in response to exogenous epidermal growth factor (EGF). The vitamin A metabolite retinoic acid (RA) has been used as a chemotherapeutic drug in the treatment of SCC. RA decreases proliferation of SCC lines, in part owing to inhibition of EGFR expression. However, we previously found that treatment of SCC lines with inhibitory doses of RA sensitized cells to the proliferative effects of EGF. We now present a mechanism of action for this effect. RA inhibited expression of EGFR and proteins in the MAPK signaling pathway. Expression of these molecules returned to basal levels within 24 h after RA withdrawal. RA also inhibited autocrine secretion of EGF, which returned to basal levels with slower kinetics. During this time, addition of exogenous EGF stimulated mitosis in SCC lines. These data suggested that signaling proteins downstream of overexpressed EGFR may have limited the mitotic response in SCC lines. In support of this hypothesis, overexpression of the EGFR adaptor protein Grb2 increased cell proliferation and restored EGF-induced mitosis.
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Affiliation(s)
- D L Crowe
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033, USA
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221
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Zhang Y, Dong Z, Bode AM, Ma WY, Chen N, Dong Z. Induction of EGFR-dependent and EGFR-independent signaling pathways by ultraviolet A irradiation. DNA Cell Biol 2001; 20:769-79. [PMID: 11879570 DOI: 10.1089/104454901753438589] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Most of the signal pathways involved in ultraviolet (UV)-induced skin carcinogenesis are thought to originate at plasma membrane receptors. However, UVA-induced signal transduction to downstream ribosomal protein S6 kinases, p70(S6K) and p90(RSK), is not well understood. In this report, we show that UVA stimulation of the epidermal growth factor receptor (EGFR) may lead to activation of p70(S6K)/p90(RSK) through phosphatidyl isositol (PI)-3 kinase and extracellular receptor-activated kinases (ERKs). Evidence is provided that phosphorylation and activation of p70(S6K)/p90(RSK) induced by UVA were prevented in Egfr(-/-) cells and were also markedly inhibited by the EGFR-specific tyrosine kinase inhibitors AG1478 and PD153035. Furthermore, EGFR tyrosine kinase inhibitors and EGFR deficiency significantly suppressed activation of PI-3 kinase and ERKs in regulating activation of p90(RSK)/p70(S6K) but had no effect on activation of c-Jun NH(2)-terminal kinases (JNKs) and p38 kinase in response to UVA. Thus, our results suggest that UVA-induced EGFR signaling may be required for activation of p90(RSK)/p70(S6K), PI-3 kinase, and ERKs but not JNKs or p38 kinase.
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Affiliation(s)
- Y Zhang
- Hormel Institute, University of Minnesota, Austin 55912, USA
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222
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Abstract
The mouse is an ideal model system for studying the molecular mechanisms underlying the pathogenesis of human cancer. The generation of transgenic and gene-knockout mice has been instrumental in determining the role of major determinants in this process, such as oncogenes and tumor-suppressor genes. In the past few years, modeling cancer in the mouse has increased in its complexity, allowing in vivo dissection of the fundamental concepts underlying cooperative oncogenesis in various tumor types. In this review, we discuss how this transition has been facilitated, providing relevant examples. We also review how, in the post-genome era, novel methodologies will further accelerate the study of multi-step tumorigenesis in the mouse.
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Affiliation(s)
- X Wu
- Molecular Biology Program, Dept of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
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223
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224
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Stoll SW, Kansra S, Peshick S, Fry DW, Leopold WR, Wiesen JF, Sibilia M, Zhang T, Werb Z, Derynck R, Wagner EF, Elder JT. Differential utilization and localization of ErbB receptor tyrosine kinases in skin compared to normal and malignant keratinocytes. Neoplasia 2001; 3:339-50. [PMID: 11571634 PMCID: PMC1505868 DOI: 10.1038/sj.neo.7900170] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2001] [Indexed: 11/08/2022] Open
Abstract
Induction of heparin-binding epidermal growth factor-like growth factor (HB-EGF) mRNA in mouse skin organ culture was blocked by two pan-ErbB receptor tyrosine kinase (RTK) inhibitors but not by genetic ablation of ErbB1, suggesting involvement of multiple ErbB species in skin physiology. Human skin, cultured normal keratinocytes, and A431 skin carcinoma cells expressed ErbB1, ErbB2, and ErbB3, but not ErbB4. Skin and A431 cells expressed more ErbB3 than did keratinocytes. Despite strong expression of ErbB2 and ErbB3, heregulin was inactive in stimulating tyrosine phosphorylation in A431 cells. In contrast, it was highly active in MDA-MB-453 breast carcinoma cells. ErbB2 displayed punctate cytoplasmic staining in A431 and keratinocytes, compared to strong cell surface staining in MDA-MB-453. In skin, ErbB2 was cytoplasmic in basal keratinocytes, assuming a cell surface pattern in the upper suprabasal layers. In contrast, ErbB1 retained a cell surface distribution in all epidermal layers. Keratinocyte proliferation in culture was found to be ErbB1-RTK-dependent, using a selective inhibitor. These results suggest that in skin keratinocytes, ErbB2 transduces ligand-dependent differentiation signals, whereas ErbB1 transduces ligand-dependent proliferation/survival signals. Intracellular sequestration of ErbB2 may contribute to the malignant phenotype of A431 cells, by allowing them to respond to ErbB1-dependent growth/survival signals, while evading ErbB2-dependent differentiation signals.
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MESH Headings
- Animals
- Blotting, Northern
- Enzyme Inhibitors/pharmacology
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Fluorescent Antibody Technique
- Heparin/metabolism
- Humans
- Keratinocytes/drug effects
- Keratinocytes/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Organ Culture Techniques
- Quinazolines/pharmacology
- RNA/metabolism
- Receptor, ErbB-2/antagonists & inhibitors
- Receptor, ErbB-2/metabolism
- Receptor, ErbB-3/antagonists & inhibitors
- Receptor, ErbB-3/metabolism
- Receptor, ErbB-4
- Signal Transduction
- Skin Neoplasms/metabolism
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
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Affiliation(s)
- S W Stoll
- Department of Dermatology, University of Michigan Medical Center, 1500 East Medical CenterDrive, Ann Arbor, MI 48109, USA
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225
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Bardeesy N, Sharpless NE, DePinho RA, Merlino G. The genetics of pancreatic adenocarcinoma: a roadmap for a mouse model. Semin Cancer Biol 2001; 11:201-18. [PMID: 11407945 DOI: 10.1006/scbi.2000.0371] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pancreatic cancer is among the leading causes of cancer death. Although a genetic profile for pancreatic cancer is emerging, many biological aspects of this disease are poorly understood. Indeed, fundamental questions regarding progenitor cell lineages, host stromal milieu, and the role of specific genetic alterations in tumor progression remain unresolved. A mouse model engineered with signature mutations would provide a powerful ally in the study of pancreatic cancer biology and may guide improved prognostic assessment and treatment for the human disease. In this review, we discuss the molecular basis for normal pancreatic development and the genetics of human pancreatic adenocarcinoma in the hope of charting a course for the development of a faithful mouse model for this lethal cancer.
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Affiliation(s)
- N Bardeesy
- Department of Adult Oncology, Dana-Farber Cancer Institute, 44 Binney St., Boston, MA 02115, USA.
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226
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Barnard J. Epidermal growth factor receptor blockade: an emerging therapeutic modality in gastroenterology. Gastroenterology 2001; 120:1872-4. [PMID: 11375969 DOI: 10.1053/gast.2001.25297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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227
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Angel P, Szabowski A, Schorpp-Kistner M. Function and regulation of AP-1 subunits in skin physiology and pathology. Oncogene 2001; 20:2413-23. [PMID: 11402337 DOI: 10.1038/sj.onc.1204380] [Citation(s) in RCA: 315] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The mouse skin has become the model of choice to study the regulation and function of AP-1 subunits in many physiological and pathological processes in vivo and in vitro. Genetically modified mice, in vitro reconstituted skin equivalents and epidermal cell lines were established, in which AP-1-regulated genetic programs of cell proliferation, differentiation and tumorigenesis can be analysed. Since the epidermis, as our interface with the environment, is subjected to radiation and injury, signal transduction pathways and critical AP-1 members regulating the mammalian stress response could be identified. Regulated expression of important components of the cytokine network, cell surface receptors and proteases, which orchestrate the process of wound healing has been found to rely on AP-1 activity. Here we review our current knowledge on the function of AP-1 subunits and AP-1 target genes in these fascinating fields of skin physiology and pathology.
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Affiliation(s)
- P Angel
- Deutsches Krebsforschungszentrum, Division of Signal Transduction and Growth Control, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
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228
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Maiti AK, Jorissen M, Bouvagnet P. Isolation, in silico characterization and chromosomal localization of a group of cDNAs from ciliated epithelial cells after in vitro ciliogenesis. Genome Biol 2001; 2:RESEARCH0026. [PMID: 11516339 PMCID: PMC55323 DOI: 10.1186/gb-2001-2-7-research0026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2000] [Revised: 02/27/2001] [Accepted: 04/26/2001] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immotile cilia syndrome (ICS) or primary ciliary dyskinesia (PCD) is an autosomal recessive disorder in humans in which the beating of cilia and sperm flagella is impaired. Ciliated epithelial cell linings are present in many tissues. To understand ciliary assembly and motility, it is important to isolate those genes involved in the process. RESULTS Total RNA was isolated from cultured ciliated nasal epithelial cells after in vitro ciliogenesis and expressed sequenced tags (ESTs) were generated. The functions and locations of 63 of these ESTs were derived by BLAST from two public databases. These ESTs are grouped into various classes. One group has high homology not only with the mitochondrial genome but also with one or more chromosomal DNAs, suggesting that very similar genes, or genes with very similar domains, are expressed from both mitochondrial and nuclear DNA. A second class comprises genes with complete homology with part of a known gene, suggesting that they are the same genes. A third group has partial homology with domains of known genes. A fourth group, constituting 33% of the ESTs characterized, has no significant homology with any gene or EST in the database. CONCLUSIONS We have shown that sufficient information about the location of ESTs could be derived electronically from the recently completed human genome sequences. This strategy of EST localization should be significantly useful for mapping and identification of new genes in the forthcoming human genome sequences with the vast number of ESTs in the dbEST database.
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Affiliation(s)
- A K Maiti
- Laboratoire de Génétique Moléculaire Humaine, Faculté de Pharmacie, Université Claude Bernard Lyon 1, 8 av Rockefeller, F-Lyon cedex 08, France.
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