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Epidermal Growth Factor Receptor (epidermal + growth_factor_receptor)
Kinds of Epidermal Growth Factor Receptor Terms modified by Epidermal Growth Factor Receptor Selected AbstractsThe Clinical Significance of Coexpression of Cyclooxygenases-2, Vascular Endothelial Growth Factors, and Epidermal Growth Factor Receptor in Nasopharyngeal CarcinomaTHE LARYNGOSCOPE, Issue 11 2008Jianji Pan MD Abstract Objectives/Hypothesis: To investigate the inter-relationship of the expressions of cyclooxygenases-2 (COX-2), vascular endothelial growth factors (VEGF), and epidermal growth factor receptor (EGFR) in nasopharyngeal cancer (NPC) cells, and their clinical significance in association with the extent of disease at diagnosis. Study Design: Prospective. Methods: Expressions of COX-2, VEGF, and EGFR protein were detected using immunohistochemistry in 111 patients with pathologically confirmed stage II to IV nasopharyngeal carcinoma. The correlation between the expressions of the three tumor markers and the stages of disease at diagnosis were investigated. Results: COX-2, VEGF, and EGFR were over-expressed in 76.6, 66.7, and 73.9% of NPC cells, respectively. The staining patterns was cytoplasmic for VEGF, membranous for EGFR, and both cytoplasmic and membranous for COX-2 in tumor cells. Linear associations were observed between the intensity of the expressions of COX-2 vs. VEGF, COX-2 vs. EGFR, or VEGF vs. EGFR. Furthermore, the intensity of the expressions of all three markers was significantly associated with the extent of the tumor measured by the Tumor, Node, Metastasis classification and staging grouping of the American Joint Committee on Cancer/International Union Against Cancer staging system. Conclusion: COX-2, VEGF, and EGFR expressions in NPC cells were interrelated, and the intensity of the expressions of all three markers were significantly associated with the stage of the disease at diagnosis. Further investigation is needed to determine the clinical applications of COX-2, VEGF, and EGFR in predicting the long-term outcome of NPC after definitive therapy. [source] Duplexed On-Microbead Binding Assay for Competitive Inhibitor of Epidermal Growth Factor Receptor by Quantitative Flow CytometryBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2010Wen-Jun Lan Conventional methods for evaluation of EGFR inhibitors are limited. This study describes a duplexed on-microbead binding assay allowing competitive EGFR inhibitors to be quantificationally evaluated in vitro. Polystyrene microbeads barcoded by fluoresceine isothiocyanate fluorescence as high brightness and low brightness microspheres were coated with receptor tyrosine kinase (RTK) ligand-epidermal growth factor (EGF)/stem cell factor (SCF) and ATP/GTP, respectively. High and low brightness microbeads were mixed and incubated with EGFR and its competitive inhibitor in binding assay buffer. Phycoerythrin (PE) fluorescence-labelled antibody was employed to report the level of EGFR binding to EGF/SCF and ATP/GTP. Values were numbered via PE molecules assessed by quantitative flow cytometry. Results from this study demonstrated that incubation with EGFR identified by PE-labelled antibody can make EGF- and ATP-coated microbeads luminous. And EGF or ATP-competitive EGFR inhibitors, respectively, alleviated this in a concentration-dependent manner. Coating microbeads with SCF or GTP as a negative control cannot capture EGFR. The duplexed on-microbead binding assay in this study might be useful for discovering ligand- and ATP-competitive EGFR inhibitors in a rapid and quantificational approach. [source] Genetic variation for dorsal,ventral patterning of the Drosophila melanogaster eggshellEVOLUTION AND DEVELOPMENT, Issue 2 2005Lisa M. Goering Summary Patterning of the insect eggshell is an excellent system for exploring the molecular basis of phenotypic variation. In Drosophila melanogaster, two dorsal,anterior respiratory appendages are produced in response to signaling through the Epidermal growth factor receptor (Egfr). Previous work implicates Egfr pathway function in both intraspecific variation for dorsal appendage spacing (DAS) on the eggshell, as well as interspecific differences in dorsal appendage number and location. To test the hypothesis that genetic variation in Egfr contributes to variation in eggshell patterning, we have made use of naturally occurring intraspecific variation for DAS as a model quantitative trait. We found that there is substantial segregating genetic variation for DAS in D. melanogaster, and have tested for associations with 289 common polymorphisms in the Egfr locus. A marginal association was seen with two polymorphic sites in Egfr; however, we failed to replicate these findings in a second population, or in a modified quantitative complementation test designed to specifically test the effects of the putative polymorphisms. Therefore, we conclude that the polymorphisms we have identified in Egfr do not contribute to variation in DAS, and further work is required to understand the genetic architecture of this trait. [source] Epidermal growth factor receptor in relation to tumor development: EGFR-targeted anticancer therapyFEBS JOURNAL, Issue 2 2010Isamu Okamoto The discovery that signaling by the epidermal growth factor receptor (EGFR) plays a key role in tumorigenesis prompted efforts to target this receptor in anticancer therapy. Two different types of EGFR-targeted therapeutic agents were subsequently developed: mAbs, such as cetuximab and panitumumab, which target the extracellular domain of the receptor, thereby inhibiting ligand-dependent EGFR signal transduction; and small-molecule tyrosine kinase inhibitors, such as gefitinib and erlotinib, which target the intracellular tyrosine kinase domain of the EGFR. Furthermore, recent clinical and laboratory studies have identified molecular markers that have the potential to improve the clinical effectiveness of EGFR-targeted therapies. This minireview summarizes the emerging role of molecular profiling in guiding the clinical use of anti-EGFR therapeutic agents. [source] Mechanisms of resistance to EGFR inhibitors in head and neck cancer,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2009Jonathan B. Cooper BS Abstract Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase that activates multiple signaling pathways, including phosphatidylinositol-3-kinase/v-AKT murine thymoma viral oncogene homolog protein (Akt), has long been a target of novel therapies. Despite universal EGFR expression in head and neck squamous cell carcinoma (HNSCC), the majority of patients do not respond to EGFR inhibitors. This review focuses on mechanisms of resistance to these agents in HNSCC, and how these may be unique when compared with other malignancies such as non-small cell lung and colorectal cancers. Published studies and abstracts reveal that there are likely several mechanisms underlying resistance, suggesting that different strategies will be required to improve efficacy of EGFR inhibitors in HNSCC. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] EGFR tyrosine kinase inhibition radiosensitizes and induces apoptosis in malignant glioma and childhood ependymoma xenograftsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2008Birgit Geoerger Abstract Malignant gliomas and childhood ependymomas have a high rate of treatment failure. Epidermal growth factor receptor (EGFR) activation has been implicated in the tumorigenesis and radioresistance of many cancers, including brain tumors. Therefore, combining EGFR targeting with irradiation is a potentially attractive therapeutic option. We evaluated the tyrosine kinase inhibitor gefitinib for its antitumor activity and potential to radio-sensitize in vivo in two xenograft models: an EGFR amplified glioma and an EGFR expressing ependymoma, both derived from primary tumors. When administered at 100 mg/kg for 5 consecutive days, gefitinib-induced partial tumor regression in all treated EGFR amplified IGRG88 glioma xenografts. The addition of 1 Gy of irradiation prior to gefitinib administration resulted in 5 complete and 4 partial regressions for the 9 treated tumors as well as a significant tumor growth delay of 33 days for the combined treatment compared to 19 days for each therapy alone, suggesting additive antitumor activity. Tumor regression was associated with inhibition of AKT and MAPK pathways by gefitinib. In contrast, the ependymoma IGREP83 was sensitive to irradiation, but remained resistant to gefitinib. Combined treatment was associated with inhibition of radiation-induced MAPK phosphorylation and significant induction of apoptotic cell death though radiation-induced AKT phosphorylation was maintained. Depending on the scheduling of both therapies, a trend towards superior antitumor activity was observed with combined treatment. Thus, EGFR targeting through tyrosine kinase inhibition appears to be a promising new approach in the treatment of EGFR-driven glioma, particularly in combination with radiation therapy. © 2008 Wiley-Liss, Inc. [source] Combination of an EGFR blocker and a COX-2 inhibitor for the treatment of advanced cutaneous squamous cell carcinomaJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 12 2008Ahmad Jalili Summary Cutaneous squamous cell carcinoma (SCC) is one of the most common cancers worldwide. Epidermal growth factor receptor (EGFR) is expressed at the cell surface by more than 90% of SCCs and its activation is responsible for cell cycle progression, proliferation, survival, angiogenesis and metastasis. Cyclooxygenase-2 (COX-2) is an enzyme up-regulated through EGFR signaling and responsible for some of the EGFR-dependent biological effects. An 88-year-old man presented with a recurrent, locoregionally meta-static SCC of the right parietal region, which was resistant to radiotherapy. With a combination therapy of an EGFR blocker (cetuximab) and a COX-2 inhibitor (celecoxib), the tumor regressed partially and the patient's Karnofsky index improved. We speculate that the combined use of cetuxi-mab and COX-2 inhibitors can be a new and effective therapy for advanced and recurrent cutaneous SCCs. [source] Epidermal growth factor receptor and cancer: control of oncogenic signalling by endocytosisJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 5a 2008Michael Vibo Grandal ,,Introduction ,,Endocytosis of EGFR -,Kinase activity -,Clathrin-coated pits -,Ubiquitination -,Effects of EGFR-ErbB2 heterodimerization on EGFR internalization ,,Cellular and molecular requirements for lysosomal degradation of EGFR -,Intracellular EGFR degradation depends on luminal sorting at multivesicular bodies -,Molecular requirements for EGFR sorting in multivesicular endosomes Abstract The epidermal growth factor receptor (EGFR) and other members of the EGFR/ErbB receptor family of receptor tyrosine kinases (RTKs) are important regulators of proliferation, angiogenesis, migration, tumorigenesis and metastasis. Overexpression, mutations, deletions and production of autocrine ligands contribute to aberrant activation of the ErbB proteins. The signalling output from EGFR is complicated given that other ErbB proteins are often additionally expressed and activated in the same cell, resulting in formation of homo-and/or heterodimers. In particular, association of EGFR with ErbB2 prevents its down-regulation, underscoring the importance of the cellular background for EGFR effects. Signalling from ErbB proteins can either be terminated by dissociation of ligand resulting in dephosphorylation, or blunted by degradation of the receptors. Although proteasomal targeting of ErbB proteins has been described, lysosomal degradation upon ligand-induced endocytosis seems to play the major role in EGFR down-regulation. Preclinical and clinical data have demonstrated that EGFR is a central player in cancer, especially in carcinomas, some brain tumours and in non-small cell lung cancer. Such studies have further validated EGFR as an important molecular target in cancer treatment. This review focuses on mechanisms involved in ligand-induced EGFR activation and endocytic down-regulation. A better understanding of EGFR biology should allow development of more tumour-selective therapeutic approaches targeting EGFR-induced signalling. [source] Targeted inhibition of the EGFR pathways enhances Zn-BC-AM PDT-induced apoptosis in well-differentiated nasopharyngeal carcinoma cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2009Ho-Kee Koon Abstract Epidermal growth factor receptor (EGFR), a receptor often expressed in nasopharyngeal carcinoma (NPC) cells, is one of the recently identified molecular targets in cancer treatment. In the present study, the effects of combined treatment of Zn-BC-AM PDT with an EGFR inhibitor AG1478 were investigated. Well-differentiated NPC HK-1 cells were subjected to PDT with 1,µM of Zn-BC-AM and were irradiated at a light dose of 1,J/cm2 in the presence or absence of EGFR inhibitor AG1478. Specific protein kinase inhibitors of downstream EGFR targets were also used in the investigation. EGFR, Akt, and ERK were found constitutively activated in HK-1 cells and the activities could be inhibited by the EGFR inhibitor AG1478. A sub-lethal concentration of AG1478 was found to further enhance the irreversible cell damage induced by Zn-BC-AM PDT in HK-1 cells. Pre-incubation of the cells with specific inhibitors of EGFR (AG1478), PI3k/Akt (LY294002), or MEK/ERK (PD98059) before light irradiation were found to enhance Zn-BC-AM PDT-induced formation of apoptotic cells. The efficacy of Zn-BC-AM PDT can be increased through the inhibition of EGFR/PI3K/Akt and EGFR/MEK/ERK signaling pathways in NPC cells. Combination therapy with Zn-BC-AM PDT and EGFR inhibitors may further be developed for the treatment of advanced NPC. J. Cell. Biochem. 108: 1356,1363, 2009. © 2009 Wiley-Liss, Inc. [source] Epidermal growth factor receptor and claudin-2 participate in A549 permeability and remodeling: Implications for non-small cell lung cancer tumor colonizationMOLECULAR CARCINOGENESIS, Issue 6 2009Yakov Peter Abstract Tumor colonization involves changes in cell permeability and remodeling. Paracellular permeability is regulated by claudins, integrated tight junction (TJ) proteins, located on the apicolateral portion of epithelial cells. Epidermal growth factor (EGF) was reported to modify cellular claudin levels and induce remodeling. To investigate a role for EGF receptor (EGFR) activation in tumor colonization we studied the effect of EGF and claudin-2 overexpression on permeability and cell reorganization in the human A549 non-small cell lung cancer (NSCLC) cell line. Our data demonstrated that A549 cells possess functional TJs and that EGF treatment increased levels of claudin-2 expression by 46%. Furthermore, EGFR signaling reduced monolayer permeability to choline and triggered cellular remodeling. The mitogen-activated protein kinase inhibitor PD98059 blocked the effect on A549 permeability and remodeling. EGF stimulation also exacerbated a fourfold increase in cell colonization elicited by claudin-2 upregulation. Our findings are consistent with the hypothesis that EGFR signaling plays an important role in A549 cell physiology and acts synergistically with claudin-2 to accelerate tumor colonization. Understanding the influence of EGF on A549 cell permeability and reorganization will help shed light on NSCLC tumor colonization and contribute to the development of novel anti-cancer treatments. © 2008 Wiley-Liss, Inc. [source] Co-regulation of B-Myb expression by E2F1 and EGF receptor,MOLECULAR CARCINOGENESIS, Issue 1 2006Norihisa Hanada Abstract Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is frequently over-expressed in human cancers and is associated with tumorigenesis, and increased tumor proliferation and progression. Also found in breast tumors with high levels is B-Myb, a transcription factor whose expression is activated by E2F1/3 at the late G1 phase and the level is sustained through the S phase. Recent reports suggest a casual correlation between EGFR and B-Myb expression in primary breast carcinomas. However, the mechanism for such co-expression remains un-investigated. Here, we report that EGFR is important for B-Myb expression and the underlying mechanism involves cooperated effects from EGFR and E2F1. EGF stimulation and forced expression of EGFR significantly increase B-Myb gene activity and such increase occurs in the G1 phase. EGF-induced B-Myb expression was not significantly suppressed following inhibition of PI-3K and ERK, two major EGFR downstream pathways. In contrast, we observed EGF-induced in vivo association of nuclear EGFR to the B-Myb promoter and the association is only detected at the G1/S phase and is abolished by EGFR kinase inhibitor. As EGFR lacks DNA-binding domain but contains transactivational activity and E2F1 activates B-Myb expression in the G1/S phase, we further reasoned that nuclear EGFR might cooperate with E2F1 leading to activation of B-Myb. Indeed, we found that EGFR co-immunoprecipitated with E2F1 in an EGF-dependent manner and that EGF activated in vivo binding of E2F1 to the B-Myb promoter. Consistently, forced expression of both EGFR and E2F1 in EGFR-null CHO cells greatly enhanced B-Myb promoter activity, compared to the vector control and expression of EGFR or E2F1 alone. Promoter mutagenesis studies showed that EGF-induced activation of B-Myb promoter required both E2F and EGFR target sites. In summary, our data suggest that deregulated EGFR signaling pathway facilitate tumor cell proliferation partly via EGFR interaction with E2F1 and subsequent activation of B-Myb gene expression. © 2005 Wiley-Liss, Inc. [source] Epidermal growth factor receptor targeted therapy with gefitinib in locally advanced and metastatic primary lung adenocarcinomaRESPIROLOGY, Issue 3 2006Chong-Kin LIAM Objective: To describe the efficacy of monotherapy with the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib in patients with locally advanced and metastatic primary lung adenocarcinoma. Methods: A retrospective analysis was undertaken of patients who had locally advanced or metastatic lung adenocarcinoma treated with gefitinib 250 mg orally once daily until disease progression. All patients had either been previously treated with systemic cytotoxic chemotherapy and/or radiotherapy or had declined chemotherapy or were medically not fit for cytotoxic chemotherapy. Results: A total of 23 patients (13 men) (15 never smokers) with a median age of 51 years (range 35,79 years) received gefitinib monotherapy. Disease control occurred in 14 patients (61%); there was a reduction in the size of the primary and/or metastatic tumours (partial response (PR)) in 11 patients (48%), and 3 patients (13%) had stable disease. The response rate was significantly higher in those who had never smoked (10 of 15 (67%)) compared with that of smokers (1 of 8 (13%)) (odds ratio (95% confidence interval), 14.0 (1.33,147.43) P = 0.027). In total, 11 of 18 patients (61%) with a WHO performance status 1 or 2 showed a PR, whereas none with a performance status 3 or 4 responded (P = 0.037). Response was not affected by the patient's age, gender, disease stage, prior chemotherapy treatment, interval between diagnosis and commencement of gefitinib or the development of skin toxicity. The median time to symptom improvement was 1.5 (range 0.5,6) weeks. The median progression-free survival time was: 60 (range 15,138) weeks in patients with PR and 34 (range 7,38) weeks in patients with stable disease (P = 0.368). Conclusion: When given alone, gefitinib showed significant antitumour activity in patients with locally advanced and metastatic primary lung adenocarcinoma. An objective response was observed more frequently in never smokers and exclusively in patients with good performance status. [source] Aberrant EGFR and Chromosome 7 Associate with Outcome in Laryngeal Cancer,THE LARYNGOSCOPE, Issue 7 2005Larry E. Morrison PhD Objectives/Hypothesis: Epidermal growth factor receptor (EGFR) over-expression has been reported as a prognostic indicator in laryngeal cancer; however, the association with disease outcome has been inconsistent among studies. Here, we use fluorescence in situ hybridization (FISH) in addition to immunohistochemistry to assess laryngeal squamous cell carcinoma (SCC) to determine whether FISH can better predict patient outcome. Study Design: Retrospective study on 59 patients presenting with advanced disease. Methods:EGFR and chromosome 7 genomic statuses were measured using FISH, and EGFR expression was assessed by immunohistochemistry on formalin-fixed, paraffin-embedded specimens and correlated with outcome in the 59 patients. Results: EGFR expression was marginally associated with outcome, whereas both EGFR and chromosome 7 FISH status were significantly associated with outcome, and the combination of EGFR and chromosome 7 FISH status provided the strongest association of any two combined parameters (P = .0004). Combining EGFR expression with EGFR and chromosome 7 FISH status provided further improvement (P > .0001). Conclusions: Measurements of EGFR and chromosome 7 FISH status, and to a lesser extent EGFR expression, have potential value in treatment planning for patients with laryngeal SCC. [source] Effects of epidermal growth factor receptor inhibitor-induced dermatologic toxicities on quality of life,CANCER, Issue 16 2010Smita S. Joshi MD Abstract BACKGROUND: Epidermal growth factor receptor (EGFR) inhibitors frequently result in dermatologic toxicities, including rash, xerosis, pruritus, and paronychia. Although the frequency and severity of these events have been described, their effect on health-related quality of life (QoL) remains poorly understood. By using a dermatology-specific questionnaire, the authors examined the effect of these toxicities on QoL. METHODS: Patients completed the Skindex-16, a questionnaire that measures the effects on 3 domains of QoL: symptoms, emotions, and functioning. The severity of dermatologic toxicities was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0 (NCI-CTCAE). Correlations of dermatology QoL scores with NCI-CTCAE grade, skin phototype (SPT), sex, age, type of EGFR inhibitor, and cancer type were investigated. RESULTS: Concordant with greater severity of rash grade, there was an increase in median scores for symptoms (P = .0006), emotions (P < .0001), function (P = .001), and overall score (P < .0001). There was an inverse correlation between age and emotions (r = ,0.26; P = .03) and overall score (r = ,0.25; P = .04). There was a significant difference between patients aged ,50 years and patients aged >50 years with regard to symptoms (P = .02), emotions (P = .03), functioning (P = .04), and overall score (P = .02). There were no significant differences between QoL and SPT, sex, treatment type, or cancer type (P > .05). CONCLUSIONS: Toxicities, including rash, xerosis, paronychia, and pruritus, adversely affected QoL, and rash was associated with a QoL greater decrease. Younger patients reported lower overall QoL than older patients who had the same toxicities. The current results support using the NCI-CTCAE as a correlative tool for measuring the effects of rash on dermatology-specific QoL. Cancer 2010. © 2010 American Cancer Society. [source] Epidermal growth factor receptor expression in breast cancer association with biologic phenotype and clinical outcomesCANCER, Issue 5 2010Mothaffar F. Rimawi Abstract BACKGROUND: Epidermal growth factor receptor (EGFR) expression is associated with aggressive phenotypes in preclinical breast cancer models, but in clinical studies, EGFR has been inconsistently linked to poor outcome. We hypothesized that EGFR expression in human breast tumors, when centrally and uniformly assessed, is associated with an aggressive phenotype and resistance to systemic therapy. METHODS: In a database of 47,286 patients with breast cancer, EGFR status was known on 2567 tumors. EGFR levels were measured centrally by ligand binding assay, and tumors with ,10 fmol/mg were prospectively deemed positive. Clinical and biological features of EGFR-positive and EGFR-negative tumors were compared. Clinical outcomes were assessed by systemic therapy status. RESULTS: Of 2567 tumors, 475 (18%) were EGFR positive. EGFR-positive tumors were more common in younger and in black women, were larger, had a higher S-phase fraction, and were more likely to be aneuploid. EGFR-positive tumors were more likely to be HER2-positive (26% vs 16%, P < .0001), but less likely to be estrogen receptor-positive (60% vs 88%, P < .0001) or progesterone receptor-positive (26% vs 65%, P < .0001). In multivariate analyses, EGFR expression independently correlated with worse disease-free survival (hazard ratio [HR] = 1.66; 95% confidence interval [CI], 1.4-2.41, P = .007) and overall survival (HR = 1.98, 95% CI, 1.36-2.88, P = .0004) in treated patients, but not in untreated patients. CONCLUSIONS: EGFR expression is more common in breast tumors in younger and black women. It is associated with lower hormone receptor levels, higher proliferation, genomic instability, and HER2 overexpression. It is correlated with higher risk of relapse in patients receiving adjuvant treatment. Blocking EGFR may improve outcome in selected patients. Cancer 2010. © 2010 American Cancer Society. [source] Tetracycline to prevent epidermal growth factor receptor inhibitor-induced skin rashes,CANCER, Issue 4 2008Results of a placebo-controlled trial from the North Central Cancer Treatment Group (N03CB) Abstract BACKGROUND. Epidermal growth factor receptor (EGFR) inhibitors are effective cancer therapies, but they are reported to cause a rash in >50% of patients. In the current study, the authors examined the use of tetracycline for rash prevention. METHODS. This placebo-controlled, double-blinded trial enrolled patients who were starting cancer treatment with an EGFR inhibitor. Patients could not have had a rash at the time of enrollment. All patients were randomly assigned to receive either tetracycline at a dose of 500 mg orally twice a day for 28 days versus a placebo. Patients were monitored for rash (through monthly physician assessment and weekly patient-reported questionnaires), quality of life (using the SKINDEX-16, a skin-specific quality of life index), and adverse events. Monitoring occurred during the 4-week intervention and then for an additional 4 weeks. The primary objective of the current study was to compare the incidence of rash between the study arms, and the enrollment of 30 patients per arm provided a 90% probability of detecting a 40% difference in incidence with a P value of .05 (2-sided). RESULTS. A total of 61 evaluable patients were enrolled. The 2 treatment arms were well balanced with regard to baseline characteristics, dropout rates, and rates of discontinuation of the EGFR inhibitor. The incidence of rash was found to be comparable across treatment arms. Physicians reported that 16 patients treated with tetracycline (70%) and 22 patients treated with placebo (76%) developed a rash (P = .61). Tetracycline appears to have lessened the rash severity, although the high dropout rates invite caution when interpreting these findings. By Week 4, physician-reported grade 2 rash (using the National Cancer Institute's Common Terminology Criteria for Adverse Events [version 3.0]) occurred in 17% of tetracycline-treated patients (n = 4 patients) and in 55% of placebo-exposed patients (n = 16 patients) (P = .04). Patients treated with tetracycline reported better scores, as per the SKINDEX-16, on certain quality-of-life parameters such as skin burning or stinging, skin irritation, and being bothered by the persistence/recurrence of a skin condition. Adverse events were found to be comparable across treatment arms. CONCLUSIONS. In the current study, tetracycline was not found to prevent EGFR inhibitor-induced rashes and therefore cannot be clinically recommended for this purpose. However, preliminary observations of diminished rash severity and improved quality of life suggest this antibiotic merits further study. Cancer 2008. © 2008 American Cancer Society. [source] Phase II randomized study of daily gefitinib treatment alone or with vinorelbine every 2 weeks in patients with adenocarcinoma of the lung who failed at least 2 regimens of chemotherapyCANCER, Issue 9 2007Yuh-Min Chen MD Abstract BACKGROUND. The objective of this study was to assess the efficacy of adding chronic, intermittent, low-dose vinorelbine to gefitinib treatment for patients who had adenocarcinoma of the lung who failed ,2 regimens of chemotherapy. METHODS. Patients were randomized into 2 arms: Oral gefitinib 250 mg daily (the G arm) or vinorelbine 15 mg/m2 as an intravenous infusion on Day 1 and oral gefitinib 250 mg daily on Days 2 through 14 every 2 weeks (the GV arm). From August 2004 to October 2005, 48 patients were enrolled. Epidermal growth factor receptor (EGFR) exon 18 through 21 nucleotide sequence analysis and fluorescence in situ hybridization were performed in patients who had tumor tissue specimens available for analysis. RESULTS. After randomization, each arm had 24 patients. However, 3 patients refused vinorelbine treatment and were given gefitinib treatment only. Thus, 27 patients received G treatment, and 21 patients received GV treatment. Objective response rates were 55.6% in the G arm and 52.4% in the GV arm. All toxicities in both arms were mild. The 1-year progression-free survival rate was 57.1% in the GV arm and 21.2% in the G arm (P = .008). The median survival was 13.3 months in the G arm and 23.4 months in the GV arm (P = .1231). Three of 6 patients (50%) had an exon 19 in-frame deletion, and 2 of 10 patients had EGFR gene high polysomy or amplification (20%). CONCLUSIONS. Gefitinib was highly effective in ethnic Chinese patients with adenocarcinoma of the lung who failed previous platinum and taxane treatment. The addition of low-dose vinorelbine every 2 weeks produced a significantly better 1-year progression-free survival rate. Cancer 2007. © 2007 American Cancer Society. [source] Soy consumption reduces the risk of non-small-cell lung cancers with epidermal growth factor receptor mutations among JapaneseCANCER SCIENCE, Issue 6 2008Keitaro Matsuo Epidermal growth factor receptor (EGFR) mutations play substantial roles in genesis and proliferation of non-small-cell lung cancers (NSCLCs). We recently found that reproductive factors have a substantial impact on risk of development of NSCLCs featuring such EGFR mutations. Therefore, we explored the influence of dietary habits on NSCLC risk with reference to the EGFR mutational status. We conducted a case-control study using 353 patients with NSCLCs (122 EGFR mutated and 231 EGFR wild-type) and 1765 age-sex matched non-cancer control subjects. Dietary exposure was based on a semiquantitative food frequency questionnaire and impact of major food items, like meats, seafoods, vegetables and soybean products was assessed by multivariate logistic regression. Soybean products demonstrated a protective association with EGFR mutated, but not EGFR wild-type NSCLCs, with multivariate-adjusted odds ratios and 95% confidence intervals for the 2nd and 3rd tertile of soybean product consumption of 0.79 (0.50,1.27) and 0.56 (0.34,0.93) relative to those in the lowest tertile (trend P = 0.023). In conclusion, soy consumption may exert a protective association against the development of NSCLCs with EGFR mutations, providing possible insights into mechanisms of their genesis. (Cancer Sci 2008; 99: 1202,1208) [source] Epidermal growth factor receptor mutation, but not sex and smoking, is independently associated with favorable prognosis of gefitinib-treated patients with lung adenocarcinomaCANCER SCIENCE, Issue 2 2008Shinichi Toyooka Epidermal growth factor receptor (EGFR) mutations have been reported as a predictive factor for favorable prognosis of gefitinib-treated patients with lung adenocarcinoma. However, its confounding with sex and smoking makes it unclear whether the EGFR mutation is independently associated with prolonged patient survival. In this study, we analyzed a large-scale database to discriminate the survival impact of EGFR mutations against those of sex and smoking after gefitinib therapy. EGFR mutations in exon19 and exon21 named drug-sensitive EGFR mutations were examined to investigate the impact of EGFR mutation, sex, and smoking status on survival of 362 gefitinib-treated patients with lung adenocarcinoma. Drug-sensitive EGFR mutations were detected in 169 patients (46.7%). The multivariate analysis including EGFR, sex, and smoking status showed that drug-sensitive EGFR mutations were significantly related to longer overall survival (OS) (P < 0.001) and progression-free survival (PFS) (P < 0.001). In addition, we investigated the impact of sex and smoking status according to EGFR mutation status, and the impact of EGFR mutation status according to sex and smoking status on survival. Sex and smoking status were not significantly associated with longer OS and PFS according to EGFR mutation status. Drug-sensitive EGFR mutations were significantly associated with longer OS and PFS according to sex or smoking status. Our results indicated that drug-sensitive EGFR mutations were the only independent factor for longer survival of patients treated with gefitinib, suggesting that patient selection based on EGFR mutation status for gefitinib therapy will lead to a better outcome for patients with lung adenocarcinoma. (Cancer Sci 2008; 99: 303,308) [source] Transient transfection of epidermal growth factor receptor gene into MCF7 breast ductal carcinoma cell lineCELL BIOCHEMISTRY AND FUNCTION, Issue 3 2005Majed S. Alokail Abstract Epidermal growth factor receptor (EGFR) is activated by autocrine growth factors in many types of tumours, including breast tumours. This receptor has been linked to a poor prognosis in breast cancer and may promote proliferation, migration, invasion, and cell survival as well as inhibition of apoptosis. Human breast ductal carcinoma MCF7 cells were transfected using FuGENEÔ 6 with 1,,g of pcDNA3-EGFR containing the full-length human EGFR promoter or 1,,g of the vectors alone (pcDNA3). The transfected cells were transferred into a 25-cm2 flask containing growth medium and G418. Confluent cultures were lysed, total protein levels measured and electrophoresed. The electrophoresed samples were transferred to nitrocellulose and incubated overnight at 4°C with either anti-EGFR or anti-phospho-ERK and immunoreactive bands were visualized using HRP-linked secondary antibody. We created a model system of EGFR overexpression in MCF7 clones with stably transfected pcDNA3/EGFR plasmid. These cells have been shown to promote substantial phosphorylation of both ERK1 and ERK2. The high level of EGFR and ERK1/2 phosphorylation was not seen in the pcDNA3 vector control cells or in non-transfected cells. In this article we describe successful transient transfection experiments on MCF7 cells using the FuGENEÔ 6 Transfection Reagent. The overexpression of EGFR could be a mediated stress response and a survival signal that involves ERK1 and ERK2 phosphorylation. Copyright © 2004 John Wiley & Sons, Ltd. [source] Perinatal development of the rat kidney: Apoptosis and epidermal growth factorCONGENITAL ANOMALIES, Issue 3 2003Toshiya Okada ABSTRACT, Localization of apoptotic cells in the kidney of perinatal rats was examined by the terminal deoxynucleotidyl transferase,mediated d,UTP,biotin nick end labeling (TUNEL) method and electron microscopy. Perinatal changes in the percentage of kidney cells with DNA fragmentation were determined by flow cytometric analysis. Through observation of two successive sections, the relationship between the localization of the epidermal growth factor receptor (EGFR) positive cells and TUNEL positive cells in the kidney was determined. From fetal day 18 to neonatal day 5, TUNEL positive cells were noted in immature glomeruli, collecting ducts and interstitium. Electron microscopically, chromatin condensed nuclei and apoptotic bodies were seen in the same tissue component as the TUNEL positive cells. The percentage of DNA fragmented cells significantly increased from fetal days 18 to 20 and significantly decreased from fetal days 20 to 22, while they still remained low in the neonatal period. The TUNEL positive cells in immature glomeruli and collecting ducts were not reactive to the EGFR antibody. The TUNEL positive cells were not observed in the proximal tubular cells, which were positive to EGFR antibody. These results indicate that apoptotic cells are present in the kidney throughout the perinatal period in the rat and that EGF plays an important role in perinatal development of the rat kidney. [source] Cardioprotection of bradykinin at reperfusion involves transactivation of the epidermal growth factor receptor via matrix metalloproteinase-8ACTA PHYSIOLOGICA, Issue 4 2009C. Methner Abstract Aim:, The endogenous autacoid bradykinin (BK) reportedly reduces myocardial infarct size when given exogenously at reperfusion. Muscarinic and opioid G-protein-coupled receptors are equally protective and have been shown to couple through a matrix metalloproteinase (MMP)-dependent transactivation of the epidermal growth factor receptor (EGFR). Here we test whether BK protects the rat heart through the EGFR by an MMP-dependent pathway. Methods:, Infarct size was measured in isolated perfused rat hearts undergoing 30 min regional ischaemia followed by 120 min reperfusion. In additional studies HL-1 cardiomyocytes were loaded with tetramethylrhodamine ethyl to measure their mitochondrial membrane potential (,m). Adding the calcium ionophore calcimycin, causes ,m-collapse presumably due to calcium-induced mitochondrial permeability transition. Results:, As expected, BK (100 nmol L,1) started 5 min prior to reperfusion reduced infarct size from 38.9 ± 2.0% of the ischaemic zone in control hearts to 22.2 ± 3.3% (P < 0.001). Co-infusing the EGFR inhibitor AG1478, the broad-spectrum MMP-inhibitor GM6001, or a highly selective MMP-8 inhibitor abolished BK's protection, thus suggesting an MMP-8-dependent EGFR transactivation in the signalling. Eighty minutes of exposure to calcimycin reduced the mean cell fluorescence to 37.4 ± 1.8% of untreated cells while BK could partly preserve the fluorescence and, hence, protect the cells (50.5 ± 2.3%, P < 0.001). The BK-induced mitochondrial protection could again be blocked by AG1478, GM6001 and MMP-8 inhibitor. Finally, Western blotting revealed that BK's protection was correlated with increased phosphorylation of EGFR and its downstream target Akt. Conclusion:, These results indicate that BK at reperfusion triggers its protective signalling pathway through MMP-8-dependent transactivation of the EGFR. [source] Decoding epithelial signals: critical role for the epidermal growth factor receptor in controlling intestinal transport functionACTA PHYSIOLOGICA, Issue 1 2009D. F. McCole Abstract The intestinal epithelium engages in bidirectional transport of fluid and electrolytes to subserve the physiological processes of nutrient digestion and absorption, as well as the elimination of wastes, without excessive losses of bodily fluids that would lead to dehydration. The overall processes of intestinal ion transport, which in turn drive the secretion or absorption of water, are accordingly carefully regulated. We and others have identified the epidermal growth factor receptor (EGFr) as a critical regulator of mammalian intestinal ion transport. In this article, we focus on our studies that have uncovered the intricate signalling mechanisms downstream of EGFr that regulate both chloride secretion and sodium absorption by colonocytes. Emphasis will be placed on the EGFr-associated regulatory pathways that dictate the precise outcome to receptor activation in response to signals that may seem, on their face, to be quite similar if not identical. The concepts to be discussed underlie the ability of the intestinal epithelium to utilize a limited set of signalling effectors to produce a variety of outcomes suitable for varying physiological and pathophysiological demands. Our findings therefore are relevant not only to basic biological principles, but also may ultimately point to new therapeutic targets in intestinal diseases where ion transport is abnormal. [source] Studies on epidermal growth factor receptor signaling in vertebrate limb patterningDEVELOPMENTAL DYNAMICS, Issue 2 2005Minoru Omi Abstract The epidermal growth factor receptor (EGFR) regulates multiple patterning events in Drosophila limb development, but its role in vertebrate limb morphogenesis has received little attention. The EGFR and several of its ligands are expressed in developing vertebrate limbs in manners consistent with potential patterning roles. To gain insight into functions of EGFR signaling in vertebrate limb development, we expressed a constitutively active EGFR in developing chick limbs in ovo. Expression of activated EGFR causes pre- and postaxial polydactyly, including mirror-image,type digit duplication, likely due to induction of ectopic expression and/or modulation of genes involved in anterior,posterior (AP) patterning such as Sonic hedgehog (Shh), dHand, Patched (Ptc), Gli3, Hoxd13, Hoxd11, bone morphogenetic protein 2 (Bmp2), Gremlin, and FGF4. Activation of EGFR signaling dorsalizes the limb and alters expression of the dorsal,ventral (DV) patterning genes Wnt7a, Lmx, and En1. Ectopic and/or extended FGF8 expressing apical ectodermal ridges (AERs) are also seen. Interdigital regression is inhibited and the digits fail to separate, leading to syndactyly, likely due to antiapoptotic and pro-proliferative effects of activated EGFR signaling on limb mesoderm, and/or attenuation of interdigital Bmp4 expression. These findings suggest potential roles for EGFR signaling in AP and DV patterning, AER formation, and cell survival during limb morphogenesis. Developmental Dynamics 233:288,300, 2005. © 2005 Wiley-Liss, Inc. [source] INSULIN-LIKE GROWTH FACTOR-I RECEPTOR AS A CANDIDATE FOR A NOVEL MOLECULAR TARGET IN GASTROINTESTINAL CANCERSDIGESTIVE ENDOSCOPY, Issue 4 2006Yasushi Adachi Abnormal activation of growth factor receptors and their signal pathways are required for neoplastic transformation and tumor progression. The concept of targeting specific tumorigenic receptors has been validated by successful clinical application of multiple new drugs, such as those acting against HER2/neu, epidermal growth factor receptor 1, and c-Kit. In this review, we focus on the next promising therapeutic molecular target of insulin-like growth factor (IGF)-I receptor (IGF-Ir). The IGF/IGF-Ir system is an important modifier of cancer cell proliferation, survival, growth, and treatment sensitivity in a number of neoplastic diseases, including human gastrointestinal carcinomas. Preclinical studies demonstrated that downregulation of IGF-Ir signals reversed the neoplastic phenotype and sensitized cells to antitumor treatments. We summarize a variety of ways to disrupt IGF-Ir function. Then, we introduce our strategy of adenoviruses expressing dominant negative of IGF-Ir (IGF-Ir/dn) against gastrointestinal cancers, including stomach, colon, and pancreas. IGF-Ir/dn suppresses tumorigenicity both in vitro and in vivo and increases stressor-induced apoptosis. IGF-Ir/dn expression upregulates chemotherapy-induced apoptosis and these combination therapies with chemotherapy are very effective against tumors in mice. Some drugs blocking IGF-Ir function are now entering clinical trial, thus IGF-Ir might be a candidate for a therapeutic target in several gastrointestinal malignancies. [source] Association of epidermal growth factor receptor mutations in lung cancer with chemosensitivity to gefitinib in isolated cancer cells from Japanese patientsEUROPEAN JOURNAL OF CANCER CARE, Issue 3 2007K. NAKATANI md, assistant professor Somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene are reported to be associated with clinical responsiveness of lung cancer to gefitinib, an EGFR tyrosine kinase inhibitor. To elucidate the association between somatic mutations and the pharmacological actions of gefitinib, the chemosensitivity of isolated cancer cells from the lungs of Japanese patients to gefitinib was examined by the collagen gel-droplet embedded culture drug sensitivity test in vitro. In 30 specimens isolated from non-small-cell lung cancer patients, mutations were observed in eight tumour specimens (27%) and chemosensitivity to gefitinib was observed in seven specimens (23%). However, somatic mutations were not predominantly associated with chemosensitivity to gefitinib in vitro. Both mutation and chemosensitivity frequencies in this study were higher than those reported in studies from the United States, indicating a possible ethnic difference. Moreover, both frequencies were much higher in females than in males. Since a gender difference in chemosensitivity to gefitinib was observed in isolated cancer cells in vitro, this suggests that gefitinib works in part through the suppression of EGFR signalling, but that other factors, including sex-related factors, may participate in gefitinib action. [source] Significant cytotoxic activity in vitro of the EGFR tyrosine kinase inhibitor gefitinib in acute myeloblastic leukaemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2008Elin Lindhagen Abstract Objectives:, Gefitinib inhibits epidermal growth factor receptor (EGFR) signalling, but may also act by non-EGFR dependent mechanisms. We have investigated the activity of gefitinib in haematological tumour cells, in particular acute myeloblastic leukaemia (AML). Methods:, Cytotoxic activity of gefitinib, alone or in combination with standard anti-leukaemic drugs, was assessed by the short-term fluorometric microculture cytotoxicity assay in tumour cells from 117 patients representing five haematological and five non-haematological malignancies. In AML, the EGFR status was analysed by immunochemistry. Gefitinib-induced apoptosis was investigated in a subset of AML samples, as well as in the leukaemia cell line MV-4-11, using a multiparametric high content screening assay. To confirm activation of caspase-3 in cells treated with gefitinib, a blocking test was carried out in which MV4-11 cells were pretreated with the specific caspase inhibitor DEVD-FMK. Results:, Gefitinib showed highest cytotoxic activity in AML (n = 19) with many samples being sensitive at concentrations achievable in clinical practice (<10 ,M), and no difference between previously untreated and relapsed patients. No correlation between the activity of gefitinib and standard antileukaemic drugs (cytarabine, doxorubicin, etoposide) was observed. Combining gefitinib with these drugs resulted in mainly additive or synergistic (etoposide) effects, with no evidence of sequence dependency. The AML cells did not express the EGFR. Gefitinib induced apoptosis, which was at least partly mediated by activation of the caspase-3 pathway. Conclusion:,In vitro, gefitinib has significant cytotoxic activity in AML by inducing apoptosis through non-EGFR dependent pathways. [source] Antipsoriatic drug anthralin induces EGF receptor phosphorylation in keratinocytes: requirement for H2O2 generationEXPERIMENTAL DERMATOLOGY, Issue 2 2004Dominik Peus Abstract: Even though anthralin is a well-established topical therapeutic agent for psoriasis, little is known about its effects and biochemical mechanisms of signal transduction. In contrast to a previous report, we found that anthralin induced time- and concentration-dependent phosphorylation of epidermal growth factor receptor in primary human keratinocytes. Four lines of evidence show that this process is mediated by reactive oxygen species. First, we found that anthralin induces time-dependent generation of H2O2. Second, there is a correlation between a time-dependent increase in anthralin-induced epidermal growth factor receptor phosphorylation and H2O2 generation. Third, the structurally different antioxidants n -propyl gallate and N -acetylcysteine inhibited epidermal growth factor receptor phosphorylation induced by anthralin. Fourth, overexpression of catalase inhibited this process. The epidermal growth factor receptor-specific tyrosine kinase inhibitor PD153035 abrogated anthralin-induced epidermal growth factor receptor phosphorylation and activation of extracellular-regulated kinase 1/2. These findings establish the following sequence of events: (1) H2O2 generation, (2) epidermal growth factor receptor phosphorylation, and (3) extracellular-regulated kinase activation. Our data identify anthralin-induced reactive oxygen species and, more specifically, H2O2 as an important upstream mediator required for ligand-independent epidermal growth factor receptor phosphorylation and downstream signaling. [source] Nickel-induced keratinocyte proliferation and up-modulation of the keratinocyte growth factor receptor expressionEXPERIMENTAL DERMATOLOGY, Issue 4 2003Cinzia Marchese Abstract: Keratinocytes play a key role in the pathogenesis of allergic contact dermatitis (ADC) induced by the sensitizing agent nickel. We analyzed here the effects of treatment with nickel and of the pretreatment with zinc on HaCaT cells and primary human keratinocytes. Cell counting, 5-bromo-2,-deoxyuridine incorporation assay and adenosine triphosphate (ATP) bioluminescence detection showed that treatment with NiSO4 induced DNA synthesis and cell proliferation and that pretreatment with ZnSO4 was able to abrogate this proliferative effect. This nickel-induced cell growth appeared enhanced when primary human keratinocytes were co-cultured with fibroblasts. Western blot analysis demonstrated that nickel ions induced up-modulation of the expression of the keratinocyte growth factor receptors (KGFR) without affecting the keratinocyte differentiation, whereas the protein levels of the epidermal growth factor receptor (EGFR) and of its ligand transforming growth factor-alpha (TGF-,) appeared unmodified by the treatment. Double immunofluorescence showed that the effect of nickel on DNA synthesis was mainly exerted on KGFR expressing cells, suggesting that KGFR up-modulation could be required for the nickel-induced cell proliferation. These results indicate that KGFR and its ligands may play a role in the mechanism of action of nickel ions and in the protective effect of zinc pretreatment. [source] Epidermal growth factor receptor in relation to tumor development: EGFR-targeted anticancer therapyFEBS JOURNAL, Issue 2 2010Isamu Okamoto The discovery that signaling by the epidermal growth factor receptor (EGFR) plays a key role in tumorigenesis prompted efforts to target this receptor in anticancer therapy. Two different types of EGFR-targeted therapeutic agents were subsequently developed: mAbs, such as cetuximab and panitumumab, which target the extracellular domain of the receptor, thereby inhibiting ligand-dependent EGFR signal transduction; and small-molecule tyrosine kinase inhibitors, such as gefitinib and erlotinib, which target the intracellular tyrosine kinase domain of the EGFR. Furthermore, recent clinical and laboratory studies have identified molecular markers that have the potential to improve the clinical effectiveness of EGFR-targeted therapies. This minireview summarizes the emerging role of molecular profiling in guiding the clinical use of anti-EGFR therapeutic agents. [source] | ||||||||||||||||||||||||||||||||||||||||