Mutant epidermal growth factor receptor in benign, borderline, and malignant ovarian tumors.
ABSTRACT Dysfunction of the epidermal growth factor (EGF) complex is essential to the growth and development of many human tumors. Overexpression of the EGF receptor (EGFR) is a characteristic finding in a considerable number of solid tumors and often signalizes poor prognosis. There is a major disagreement among researchers about both the frequency and possible clinical importance of EGFR overexpression in ovarian cancer. The type III variant of EGFR (EGFRvIII) is a mutant with a deletion. Contrary to the wild-type, it is constitutively active. EGFRvIII has not been found in normal tissue, and consequently, it is an attractive tumor-specific candidate for molecular targeted treatment. The literature dealing with this mutation in ovarian cancer has been very sparse.
Tissue from 225 patients who underwent surgery for a pelvic mass was collected consecutively. The samples included 99 ovarian/peritoneal/tuba cancers, 17 ovarian borderline tumors, 66 benign ovarian tumors, 15 other cancer types, 24 normal ovarian biopsies, and 4 miscellaneous. The presence of EGFRvIII was investigated both by PCR analyses for EGFRvIII gene expression and with protein analysis by Western blots.
None of the tissue samples was positive for the EGFRvIII mutation neither at the mRNA level nor at the protein level.
The EGFRvIII mutation seems to be very rare in ovarian tissue. Our data indicate that EGFRvIII is not a part of the malignant phenotype in ovarian cancer and should not be pursued as a therapeutic target for treatment of this disease.
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ABSTRACT: Epidermal growth factor receptor (EGFR) is frequently aberrantly expressed in cancer, and abnormal signalling downstream of this receptor contributes to tumour growth. EGFR variant III (EGFRvIII) is the most commonly altered form of EGFR and contains a truncated ligand-binding domain. Aberrant signalling downstream of this receptor contributes to tumour invasion. We previously reported that EGFRvIII can promote hepatocellular carcinoma (HCC) invasion. However, little is known concerning the mechanisms underlying EGFRvIII-mediated increases in cell motility and invasion in HCC. In this study, we observed that S100A11 was significantly upregulated in Huh-7 cells that overexpressed EGFRvIII. Moreover, S100A11 expression was elevated in HCC tissue samples (68.6%; 35/51), and this elevation was correlated with EGFRvIII expression (p = 0.0020; n = 20). Furthermore, the overexpression of S100A11 can promote HCC cell invasiveness, whereas siRNA against S100A11 can suppress the invasiveness of HCC cells stably transfected with EGFRvIII. Additionally, STAT3 inhibitors can block S100A11 expression and S100A11 promoter activity in HCC cells with stable overexpression of EGFRvIII. Furthermore, mutation in STATx binding sites could abolish the S1000A11 promoter activity stimulation by EGFRvIII. Taken together, the results demonstrate that the EGFRvIII-STAT3 pathway promotes cell migration and invasion by upregulating S100A11.PLoS ONE 12/2013; 8(12):e83332. · 3.53 Impact Factor
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ABSTRACT: Ovarian cancer is the most deadly among all gynecological cancers. Patients undergoing systemic therapies of advanced ovarian cancers suffer from horrendous side effects. Cancer survivors and their offspring suffer from iatrogenic consequences of systemic therapies: genetic mutations. The ultimate goal of our work is development of therapies, which selectively and completely eliminate cancer cells, but do not harm healthy cells. An important consideration for attaining this goal is the fact that ovarian cancer cells over-express EGFR or its mutants, what becomes the factor discriminating them from healthy cells - a potential facilitator of personalized therapy. The specific aim of this project was threefold: (1) to bioengineer suicide genes' carrying vectors guided by synthetic antibodies for EGFRvIII and EGFR; (2) to genetically engineer DNA constructs for the human, recombinant DNASE1, DNASE1L3, DNASE2, and DFFB controlled by the EGFR promoter; (3) to selectively eradicate ovarian cancer cells by intranuclear targeting of the transgenically expressed recombinant DNases. Synthetic antibodies for EGFR and EGFRvIII were selected from the human library and used to bioengineer biotag-guided transgenes' vectors. Coding sequences for the human DNASE1, DNASE1L3, DNASE2, DFFB controlled by the EGFR promoter were amplified from the human cDNA and genetically engineered into the plasmid constructs also coding for the fusions with NLS and GFP. The vectors carrying transgenes for the DNases were delivered in vitro into human ovarian cancer cells from ascites and cultures. Synthetic antibody guided vectors delivered the transgenes for the recombinant DNases efficiently into the ovarian cancer cells. Transgenic expression and nuclear targeting of the DNases in those cells resulted in destruction of their genomes and led to their death, as validated by labeling with the molecular death tags. In healthy cells, which did not over-express EGFR, no changes were recorded. Targeted expression of the recombinant DNASE1, DNASE1L3, DNASE2, DFFB in the ovarian cancers in vitro resulted in their complete eradication, but had no effects upon the healthy cells. This novel therapeutic strategy has a potential for streamlining it into in vivo trials, as personalized, targeted therapy of ovarian and other cancers.Journal of genetic syndrome & gene therapy. 07/2013; 4(6):152.
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ABSTRACT: Background Epidermal Growth Factor Receptor (EGFR) targeting therapies are currently of great relevance for the treatment of lung cancer. For this reason, in addition to mutational analysis immunohistochemistry (IHC) of EGFR in lung cancer has been discussed for the decision making of according therapeutic strategies. The aim of this study was to obtain standardization of EGFR-expression methods for the selection of patients who might benefit of EGFR targeting therapies.Methods As a starting point of a broad investigation, aimed at elucidating the expression of EGFR on different biological levels, four EGFR specific antibodies were analyzed concerning potential differences in expression levels by Immunohistochemistry (IHC) and correlated with fluorescence in situ hybridization (FISH) analysis and clinicopathological data. 206 tumor tissues were analyzed in a tissue microarray format employing immunohistochemistry with four different antibodies including Dako PharmDx kit (clone 2-18C9), clone 31G7, clone 2.1E1 and clone SP84 using three different scoring methods. Protein expression was compared to FISH utilizing two different probes.ResultsEGFR protein expression determined by IHC with Dako PharmDx kit, clone 31G7 and clone 2.1E1 (p¿¿¿0.05) correlated significantly with both FISH probes independently of the three scoring methods; best correlation is shown for 31G7 using the scoring method that defined EGFR positivity when¿¿¿10% of the tumor cells show membranous staining of moderate and severe intensity (p¿=¿0.001).Conclusion Overall, our data show differences in EGFR expression determined by IHC, due to the applied antibody. Highest concordance with FISH is shown for antibody clone 31G7, evaluated with score B (p¿=¿0,001). On this account, this antibody clone might by utilized for standard evaluation of EGFR expression by IHC.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_165.Diagnostic Pathology 09/2014; 9(1):165. · 2.41 Impact Factor