scholarly journals GH administration patterns differently regulate epidermal growth factor signaling

2014 ◽  
Vol 221 (2) ◽  
pp. 309-323 ◽  
Author(s):  
María E Díaz ◽  
Johanna G Miquet ◽  
Soledad P Rossi ◽  
Pablo E Irene ◽  
Ana I Sotelo ◽  
...  

Current GH administration protocols imply frequent s.c. injections, resulting in suboptimal compliance. Therefore, there is interest in developing delivery systems for sustained release of the hormone. However, GH has different actions depending on its continuous or pulsatile plasma concentration pattern. GH levels and circulating concentration patterns could be involved in the regulation of epidermal growth factor receptor (EGFR) expression in liver. Aberrant expression of this receptor and/or its hyperactivation has been associated with the pathogenesis of different types of carcinoma. Considering that one of the adverse effects associated with GH overexpression and chronic use of GH is the increased incidence of malignancies, the aim of this study was to analyze the effects of GH plasma concentration patterns on EGFR expression and signaling in livers of mice. For this purpose, GH was administered by s.c. daily injections to produce an intermittent plasma pattern or by osmotic pumps to provoke a continuously elevated GH concentration. Intermittent injections of GH induced upregulation of liver EGFR content, augmented the response to EGF, and the induction of proteins involved in promotion of cell proliferation in female mice. In contrast, continuous GH delivery in male mice was associated with diminished EGFR in liver and decreased EGF-induced signaling and expression of early genes. The results indicate that sustained delivery systems that allow continuous GH plasma patterns would be beneficial in terms of treatment safety with regard to the actions of GH on EGFR signaling and its promitogenic activity.

2011 ◽  
Vol 42 (6) ◽  
pp. 859-866 ◽  
Author(s):  
Daniel Baumhoer ◽  
Jan Smida ◽  
Katja Specht ◽  
Karin Bink ◽  
Leticia Quintanilla-Martinez ◽  
...  

2018 ◽  
Vol 5 (3) ◽  
pp. 550
Author(s):  
Shivalingaswamy Salimath ◽  
Jayaraj B. S. ◽  
Mahesh P. A. ◽  
M. D. Majeed Pasha ◽  
Lokesh K. S. ◽  
...  

Background: Epidermal Growth Factor Receptor (EGFR) is one of the important molecules involved in lung cancer initiation and progression. Studies on over expression of EGFR and its survival in relation with Non-small cell lung cancer (NSCLC) patients have yielded controversial results. Prevalence of EGFR expression in NSCLC patients and 6-month survival in south Indian population is unknown.Methods: We carried out a prospective study in tertiary hospital. Diagnosed patients with NSCLC were included in the study and were interviewed with questionnaire containing demography and investigations like Chest X-ray, CT thorax, Bronchoscopy were recorded. EGFR expression analysis was done for all patients and were followed up monthly for 6 months and details of survival and treatment were collected. Cox regression analysis was used to assess their survival.Results: 50 patients with NSCLC were included. Forty-four (88%) were men, median age of study group was 65 years. Twenty-seven patients (54%) had Adenocarcinoma, 14 patients (28%) had Squamous cell carcinoma, 7 patients (14%) had poorly differentiated carcinoma and 2 patients (4%) had large cell carcinoma. Thirty-four (68%) samples were positive for EGFR expression. On multivariate analysis we found patients who took chemotherapy and with good performance status (Karnofsky score >65 and Eastern Cooperative Oncology Group >2.5) had better survival at 6 months.Conclusions: Patients with EGFR positivity had better survival with chemotherapy but worse with radiotherapy. Patients who took chemotherapy and had good performance status had better survival on multivariate analysis. We didn’t find any correlation between EGFR positivity and poor survival.


2009 ◽  
Vol 90 (7) ◽  
pp. 1569-1574 ◽  
Author(s):  
Insiya Jafferji ◽  
Mark Bain ◽  
Christine King ◽  
John H. Sinclair

Infection with human cytomegalovirus (HCMV) modulates the expression of a number of cellular receptors and is known to inhibit expression of the epidermal growth factor receptor (EGFR), a cell surface receptor that can promote cell proliferation through a cascade of intracellular signalling events. We have examined the mechanisms by which HCMV mediates downregulation of EGFR expression and show that virus infection results in the profound upregulation of Wilms' Tumour 1 (WT1) protein, a transcription factor associated with the negative regulation of a number of growth factors and growth factor receptors, including EGFR. Moreover, chromatin immunoprecipitation experiments also show that HCMV infection results in increased binding of WT1 to the EGFR promoter. Finally, we show that depleting the cell of WT1 using small interfering RNA abrogates virus-mediated downregulation of EGFR. Taken together, our observations suggest that HCMV-mediated repression of EGFR expression results from a virus-mediated increase in cellular WT1, a known pleiotropic regulator of mitogenesis, apoptosis and differentiation.


2006 ◽  
Vol 24 (19) ◽  
pp. 3069-3074 ◽  
Author(s):  
Philip A. Philip ◽  
Michelle R. Mahoney ◽  
Cristine Allmer ◽  
James Thomas ◽  
Henry C. Pitot ◽  
...  

Purpose Epidermal growth factor receptor/human epidermal growth factor receptor 1 and ligand expression is common in biliary cancers (BILI) and may be associated with worse outcome. The primary objective of this study was to determine the proportion of patients with advanced BILI who were progression-free at 6 months. Methods Patients with either unresectable or metastatic disease were studied. Only one prior systemic or locoregional therapy was allowed. Erlotinib was administered continuously at a dose of 150 mg per day orally. Results Forty-two patients with BILI were enrolled. The median age was 67 years (range, 33 to 82 years). Fifty-two percent of patients had Eastern Cooperative Oncology Group performance status of 1. Fifty-seven percent of patients had received prior chemotherapy for advanced BILI. HER1/EGFR expression by immunohistochemistry in tumor cells was detected in 29 (81%) of the 36 assessable patients. Seven of the patients (17%; 95% CI, 7% to 31%) were progression free at 6 months. Three patients had partial response by Response Evaluation Criteria in Solid Tumors Group classification of duration 4, 4, and 14 months, respectively. All responding patients had mild (grade 1/2) skin rash and two patients had positive tumoral HER1/EGFR expression. Three patients (7%) had toxicity-related dose reductions of erlotinib due to grade 2/3 skin rash. Conclusion Results suggest a therapeutic benefit for EGFR blockade with erlotinib in patients with biliary cancer. Additional studies with erlotinib as a single agent and in combination with other targeted agents are warranted in this disease.


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