scholarly journals Oligosaccharide G19 inhibits U-87 MG human glioma cells growth in vitro and in vivo by targeting epidermal growth factor (EGF) and activating p53/p21 signaling

Glycobiology ◽  
2014 ◽  
Vol 24 (8) ◽  
pp. 748-765 ◽  
Author(s):  
Hailing Liu ◽  
Ling Zhou ◽  
Songshan Shi ◽  
Ying Wang ◽  
Xinyan Ni ◽  
...  
2006 ◽  
Vol 12 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Joachim P. Steinbach ◽  
Petra Supra ◽  
H.-J. Su Huang ◽  
Webster K. Cavenee ◽  
Michael Weller

2014 ◽  
Vol 120 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Chun-Yuan Cheng ◽  
Ying-Erh Chou ◽  
Chung-Po Ko ◽  
Shun-Fa Yang ◽  
Shu-Ching Hsieh ◽  
...  

Data in Brief ◽  
2016 ◽  
Vol 9 ◽  
pp. 667-672 ◽  
Author(s):  
Gong-Jhe Wu ◽  
Chien-Ju Lin ◽  
Yung-Wei Lin ◽  
Ruei-Ming Chen

2019 ◽  
Vol 112 (3) ◽  
pp. 266-277 ◽  
Author(s):  
Nikhil S Chari ◽  
Cristina Ivan ◽  
Xiandong Le ◽  
Jinzhong Li ◽  
Ainiwaer Mijiti ◽  
...  

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.


2008 ◽  
Vol 180 (6) ◽  
pp. 1205-1218 ◽  
Author(s):  
Ingrid Roxrud ◽  
Camilla Raiborg ◽  
Nina Marie Pedersen ◽  
Espen Stang ◽  
Harald Stenmark

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.


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