Comparison of the Mitogenic Activity of Human Epidermal Growth Factor 1-53 and Epidermal Growth Factor 1-48 in Vitro and in Vivo

1996 ◽  
Vol 91 (4) ◽  
pp. 503-507 ◽  
Author(s):  
R. A. Goodlad ◽  
R. Boulton ◽  
R. J. Playford
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Rat Hepatocytes ◽  
In Vivo Studies ◽  
Thymidine Uptake ◽  
Amino Acid Peptide ◽  
Epidermal Growth ◽  
Small And Large Intestine

1. Epidermal growth factor is secreted into the gut lumen as a 53 amino acid peptide in vivo. Several preliminary studies have examined the clinical benefit of recombinant epidermal growth factor in intestinal disease, but there is inconsistency in the form of epidermal growth factor used (some using epidermal growth factor 1–48 and some epidermal growth factor 1–53), making comparisons difficult to evaluate. 2. We therefore examined the relative potency of recombinant epidermal growth factor 1–48 and epidermal growth factor 1–53 in stimulating [3H]thymidine uptake into primary rat hepatocytes at various doses in vitro and on various parameters of proliferation within the gastrointestinal tract when infused intravenously at 50 nmol day−1 kg−1 into rats receiving total parenteral nutrition. 3. Epidermal growth factor 1–53 was about twice as potent as epidermal growth factor 1–48 in its ability to stimulate [3H]thymidine incorporation into rat hepatocytes in vitro. In vivo studies supported this finding as, in both the small and large intestine, epidermal growth factor 1–53 caused about a 30% greater stimulation of intestinal growth than epidermal growth factor 1–48 (P < 0.001). 4. The 1–48 truncated form of epidermal growth factor is less active than the full-length molecule in vitro and in vivo. This must be borne in mind when comparing clinical trials that use different forms of recombinant epidermal growth factor.

scholarly journals Biodistribution and Tumor Uptake of 67Ga-Nimotuzumab in a Malignant Pleural Mesothelioma Xenograft

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3138 ◽  
Author(s):  
Vanessa Izquierdo-Sánchez ◽  
Saé Muñiz-Hernández ◽  
Héctor Vázquez-Becerra ◽  
Judith Pacheco-Yepez ◽  
Mario Romero-Piña ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Malignant Pleural Mesothelioma ◽  
Growth Factor Receptor ◽  
In Vivo Studies ◽  
Pleural Mesothelioma ◽  
Tumor Uptake ◽  
Epidermal Growth ◽  
Significant Uptake

Malignant pleural mesothelioma (MPM) is the most common tumor of the pulmonary pleura. It is a rare and aggressive malignancy, generally associated with continuous occupational exposure to asbestos. Only a multimodal-approach to treatment, based on surgical resection, chemotherapy and/or radiation, has shown some benefits. However, the survival rate remains low. Nimotuzumab (h-R3), an anti-EGFR (epidermal growth factor receptor) humanized antibody, is proposed as a promising agent for the treatment of MPM. The aim of this research was to implement a procedure for nimotuzumab radiolabeling to evaluate its biodistribution and affinity for EGF (epidermal growth factor) receptors present in a mesothelioma xenograft. Nimotuzumab was radiolabeled with 67Ga; radiolabel efficiency, radiochemical purity, serum stability, and biodistribution were evaluated. Biodistribution and tumor uptake imaging studies by microSPECT/CT in mesothelioma xenografts revealed constant nimotuzumab uptake at the tumor site during the first 48 h after drug administration. In vivo studies using MPM xenografts showed a significant uptake of this radioimmunoconjugate, which illustrates its potential as a biomarker that could promote its theranostic use in patients with MPM.

scholarly journals Disruption of TP63-miR-27a* Feedback Loop by Mutant TP53 in Head and Neck Cancer

2019 ◽  
Vol 112 (3) ◽  
pp. 266-277 ◽  
Author(s):  
Nikhil S Chari ◽  
Cristina Ivan ◽  
Xiandong Le ◽  
Jinzhong Li ◽  
Ainiwaer Mijiti ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Oral Cavity ◽  
Head And Neck ◽  
Feedback Loop ◽  
Growth Factor Receptor ◽  
Epidermal Growth

Abstract Background Alterations in the epidermal growth factor receptor and PI3K pathways in head and neck squamous cell carcinomas (HNSCCs) are frequent events that promote tumor progression. Ectopic expression of the epidermal growth factor receptor–targeting microRNA (miR), miR-27a* (miR-27a-5p), inhibits tumor growth. We sought to identify mechanisms mediating repression of miR-27a* in HNSCC, which have not been previously identified. Methods We quantified miR-27a* in 47 oral cavity squamous cell carcinoma patient samples along with analysis of miR-27a* in 73 oropharyngeal and 66 human papillomavirus–positive (HPV+) samples from The Cancer Genome Atlas. In vivo and in vitro TP53 models engineered to express mutant TP53, along with promoter analysis using chromatin immunoprecipitation and luciferase assays, were used to identify the role of TP53 and TP63 in miR-27a* transcription. An HNSCC cell line engineered to conditionally express miR-27a* was used in vitro to determine effects of miR-27a* on target genes and tumor cells. Results miR-27a* expression was repressed in 47 oral cavity tumor samples vs matched normal tissue (mean log2 difference = −0.023, 95% confidence interval = −0.044 to −0.002; two-sided paired t test, P = .03), and low miR-27a* levels were associated with poor survival in HPV+ and oropharyngeal HNSCC samples. Binding of ΔNp63α to the promoter led to an upregulation of miR-27a*. In vitro and in vivo findings showed that mutant TP53 represses the miR-27a* promoter, downregulating miR-27a* levels. ΔNp63α and nucleoporin 62, a protein involved in ΔNP63α transport, were validated as novel targets of miR-27a*. Conclusion Our results characterize a negative feedback loop between TP63 and miR-27a*. Genetic alterations in TP53, a frequent event in HNSCC, disrupt this regulatory loop by repressing miR-27a* expression, promoting tumor survival.

scholarly journals An endosomally localized isoform of Eps15 interacts with Hrs to mediate degradation of epidermal growth factor receptor

2008 ◽  
Vol 180 (6) ◽  
pp. 1205-1218 ◽  
Author(s):  
Ingrid Roxrud ◽  
Camilla Raiborg ◽  
Nina Marie Pedersen ◽  
Espen Stang ◽  
Harald Stenmark
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Adaptor Protein ◽  
Coated Pits ◽  
Kinase Substrate ◽  
Epidermal Growth

Down-regulation of activated and ubiquitinated growth factor (GF) receptors by endocytosis and subsequent lysosomal degradation ensures attenuation of GF signaling. The ubiquitin-binding adaptor protein Eps15 (epidermal growth factor receptor [EGFR] pathway substrate 15) functions in endocytosis of such receptors. Here, we identify an Eps15 isoform, Eps15b, and demonstrate its expression in human cells and conservation across vertebrate species. Although both Eps15 and Eps15b interact with the endosomal sorting protein Hrs (hepatocyte growth factor–regulated tyrosine kinase substrate) in vitro, we find that Hrs specifically binds Eps15b in vivo (whereas adaptor protein 2 preferentially interacts with Eps15). Although Eps15 mainly localizes to clathrin-coated pits at the plasma membrane, Eps15b localizes to Hrs-positive microdomains on endosomes. Eps15b overexpression, similarly to Hrs overexpression, inhibits ligand-mediated degradation of EGFR, whereas Eps15 is without effect. Similarly, depletion of Eps15b but not Eps15 delays degradation and promotes recycling of EGFR. These results indicate that Eps15b is an endosomally localized isoform of Eps15 that is present in the Hrs complex via direct Hrs interaction and important for the sorting function of this complex.

Impaired epidermal growth factor production in genetically obese ob/ob mice

1993 ◽  
Vol 264 (5) ◽  
pp. E800-E803 ◽  
Author(s):  
G. Serrero ◽  
N. M. Lepak ◽  
J. Hayashi ◽  
S. P. Goodrich
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mrna Expression ◽  
Submaxillary Gland ◽  
Obese Mice ◽  
Adult Mice ◽  
Obesity In Mice ◽  
Epidermal Growth

Epidermal growth factor (EGF) is a potent inhibitor of adipose differentiation in vitro and delays adipose tissue development in vivo. Here we show that in the homozygous male obese mice the level of EGF in the submaxillary gland and plasma is significantly lower than in the glands and plasma of age-matched control littermates. This EGF deficiency in ob/ob mice was observed as early as 5 wk of age when obesity had just become apparent and was also found in adult mice. The level of prepro-EGF mRNA expression in the submaxillary gland was also lower in obese mice than in control littermates. However, the level of kidney prepro-EGF mRNA was the same in mice with both phenotypes, suggesting that the regulation of prepro-EGF mRNA expression is different in both tissues. These results indicate that genetic obesity in mice is accompanied by a decrease in the production of EGF.

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