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EGFR Inhibitors (egfr + inhibitor)
Selected AbstractsAlcohol Stimulates Activation of Snail, Epidermal Growth Factor Receptor Signaling, and Biomarkers of Epithelial,Mesenchymal Transition in Colon and Breast Cancer CellsALCOHOLISM, Issue 1 2010Christopher B. Forsyth Background:, Alcohol consumption is associated with the risk of progressive cancers including colon and breast cancer. The mechanisms for the alcohol-induced aggressive behavior of these epithelial cancer cells have not been fully identified. Epithelial,mesenchymal transition (EMT) is a developmental program recently shown to play a role in cancer progression and metastases. We hypothesized that alcohol might promote cancer progression by inducing EMT in cancer cells and tested this hypothesis by assessing alcohol-stimulated changes in phenotypic markers of EMT as well as the EMT transcription factor Snail and its related cell signaling. Methods:, Colon and breast cancer cell lines and a normal intestinal epithelial cell line were tested as well as colonic mucosal biopsy samples from alcoholic subjects. Cells were treated with alcohol and assessed for EMT-related changes using immunofluorescent microscopy, western blotting, reporter assays, RT-PCR, and knockdown of Snail with siRNA. Results:, We show alcohol upregulated the signature EMT phenotypic marker vimentin as well as matrix metalloprotease (MMP)-2, MMP-7, and MMP-9 and cell migration in colon and breast cancer cells,all characteristics of EMT. Alcohol also stimulated nuclear localization of Snail phosphorylated at Ser246, transcription from a Snail reporter plasmid, and Snail mRNA expression by RT-PCR. Snail siRNA knockdown prevented alcohol-stimulated vimentin expression. In vivo, Snail expression was significantly elevated in colonic mucosal biopsies from alcoholics. Also, we found alcohol stimulated activation of epidermal growth factor receptor (EGFR) signaling and an EGFR inhibitor blocked alcohol-induced cell migration and Snail mRNA expression. Conclusions:, Collectively, our data support a novel mechanism for alcohol promoting cancer progression through stimulating the EMT program in cancer cells via an EGFR-Snail mediated pathway. This study reveals new pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers. [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] 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] 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] Immunohistochemical study of epidermal growth factor receptor in adenoid cystic carcinoma of salivary gland originHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2002Marilena Vered DMD Abstract Background Epidermal growth factor (EGF) and its receptor (EGFR) are involved in the development of salivary gland tumors. Recently, treatment modalities for EGFR inhibition have shown an enhanced clinical response in carcinomas of different locations. Adenoid cystic carcinoma (ACC) of salivary gland origin is a malignant tumor with a poor long-term outcome. If salivary gland ACC does exhibit EGFR, then immunotherapy could have a major impact on improving its prognosis. Methods The study consisted of 34 samples of formalin-fixed, paraffin-embedded specimens of salivary gland ACC. Specimens were stained with a mouse antihuman monoclonal antibody for immunohistochemical detection of EGFR. Overlying oral mucosa and adjacent normal salivary ducts served as internal controls. Both membrane and cytoplasmic staining were evaluated. Staining score was calculated by multiplying the percentage of positively stained tumor cells by the intensity of the staining. The highest score for a given tumor was equal to 2. Results In the final analysis, 27 of the 34 specimens were included; 7 were excluded, because the internal control did not reveal any staining. Of these 27 specimens, 23 (85%) stained positively for EGFR with a staining score of 0.05 to 1.8. Three palatal tumors attained the highest scores (one tumor, 1.2, and the remaining two, 1.8). Conclusions Most salivary gland ACC stained positively for EGFR, and in some the staining was quite intense. On the basis of the already proven antitumoral effect of agents acting as EGFR inhibitors, it is suggested that patients with ACC might benefit from these agents, especially when surgery has failed or in those with recurrent or metastatic disease. © 2002 Wiley Periodicals, Inc. Head Neck 24: 632,636, 2002 [source] Furo[2,3- d]pyrimidines and Oxazolo[5,4- d]pyrimidines as Inhibitors of Receptor Tyrosine Kinases (RTK)HELVETICA CHIMICA ACTA, Issue 4 2004Andreas Martin-Kohler Receptor tyrosine kinases such as VEGFR2 (vascular endothelial growth factor receptor 2, KDR) or EGFR (epidermal growth factor receptor) play crucial roles in a variety of diseases, such as cancer. Recently, some pyrrolopyrimidines were shown to be potent EGFR inhibitors. Therefore, new types of oxazolo[5,4- d]pyrimidines and furo[2,3- d]pyrimidines were synthesized (Schemes,1 and 2). Appropriately substituted derivatives of these classes of compounds inhibited VEGFR2 and EGFR with IC50 values in the low nanomolar range (see Table). Generally, the furopyrimidines were somewhat more active than the oxazolopyrimidines. The best inhibitors, 20m, 20p, and 20r, had an IC50 of 3,nM towards EGFR and showed a good selectivity, being distinctly less active towards VEGFR2. [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] Photosensitive rash due to the epidermal growth factor receptor inhibitor erlotinibPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 1 2007Minnelly Luu A papulopustular rash occurs in 45,100% of patients undergoing anti-cancer treatment with epidermal growth factor (EGFR) inhibitors. Although the majority of cases involve the face and upper trunk, ultraviolet radiation has not yet been documented to play a major role in inducing or exacerbating symptoms. We describe a 75-year-old man who was being treated with the EGFR inhibitor erlotinib and developed the characteristic rash on unprotected areas of the trunk after photoexposure, while the protected areas (face and neck) remained uninvolved. This case underscores the importance of sun protection in patients treated with EGFR inhibitors and supports in vitro data showing that EGFR blockade results in altered keratinocyte survival and proliferation in response to ultraviolet radiation. [source] Restoration of PTEN expression alters the sensitivity of prostate cancer cells to EGFR inhibitors,THE PROSTATE, Issue 9 2008Z. Wu Abstract Introduction Prostate cancer (CaP) progression from an androgen-dependent to an androgen-independent state is associated with overexpression of EGFR family members or activation of their downstream signaling pathways, such as PI3K-Akt and MAPK. Although there are data implicating PI3K-Akt or MAPK pathway activation with resistance to EGFR inhibitors in CaP, the potential cross-talk between these pathways in response to EGFR or MAPK inhibitors remains to be examined. Methods Cross-talk between PTEN and MAPK signaling and its effects on CaP cell sensitivity to EGFR or MAPK inhibitors were examined in a PTEN-null C4-2 CaP cell, pTetOn PTEN C4-2, where PTEN expression was restored conditionally. Results Expression of PTEN in C4-2 cells exposed to EGF or serum was associated with increased phospho-ERK levels compared to cells without PTEN expression. Similar hypersensitivity of MAPK signaling was observed when cells were treated with a PI3K inhibitor LY294002. This enhanced sensitivity of MAPK signaling in PTEN-expressing cells was associated with a growth stimulatory effect in response to EGF. Furthermore, EGFR inhibitors gefitinib and lapatinib abrogated hypersensitivity of MAPK signaling and cooperated with PTEN expression to inhibit cell growth in both monolayer and anchorage-independent conditions. Similar cooperative growth inhibition was observed when cells were treated with the MEK inhibitor, CI1040, in combination with PTEN expression suggesting that inhibition of MAPK signaling could mediate the cooperation of EGFR inhibitors with PTEN expression. Conclusions Our results suggest that signaling cross-talk between the PI3K-Akt and MAPK pathways occurs in CaP cells, highlighting the potential benefit of targeting both the PI3K-Akt and MAPK pathways in CaP treatment. Prostate 68:935,944, 2008. © 2008 Wiley-Liss, Inc. [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] Lung cancer A549 cells migrate directionally in DC electric fields with polarized and activated EGFRsBIOELECTROMAGNETICS, Issue 1 2009Xiaolong Yan Abstract Endogenous direct-current electric fields (dcEFs) occur in vivo in the form of epithelial transcellular potentials or neuronal field potentials. A variety of cells respond to dcEFs by migrating directionally, and this is termed galvanotaxis. The mechanism by which dcEFs direct cell movement, however, is not yet understood, and the effects on lung cancer cells are entirely unknown. We demonstrated that cultured human lung adenocarcinoma A549 cells migrate toward the cathode in applied dcEFs at 3 V/cm. Fluorescence microscopy showed that both epidermal growth factor receptors (EGFRs) and F-actin are polarized to the cathode. EGFR inhibitors, cetuximab and AG1478, reduced the migration rate and directed motility in dcEFs. Western blots showed that ERK and AKT signaling pathways were prominently promoted by dcEFs. EGFR inhibitors could reduce this promotion but not completely. These data suggest that polarization of EGFRs and the activation of their downstream signals play an important role in the galvanotaxis of A549 cells in dcEFs. Bioelectromagnetics 30:29,35, 2009. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||