RNF144A suppresses ovarian cancer stem cell properties and tumor progression through regulation of LIN28B degradation via the ubiquitin-proteasome pathway

Author(s):  
Yan Li ◽  
Juan Wang ◽  
Fang Wang ◽  
Wenyu Chen ◽  
Chengzhen Gao ◽  
...  
2008 ◽  
Vol 19 (11) ◽  
pp. 4968-4979 ◽  
Author(s):  
Guoxiong Xu ◽  
Stefanie Bernaudo ◽  
Guodong Fu ◽  
Daniel Y. Lee ◽  
Burton B. Yang ◽  
...  

We have previously reported that Nodal, a member of the TGF-β superfamily, acts through activin receptor-like kinase 7 (ALK7) to inhibit ovarian cancer cell proliferation. To determine the mechanism underlying their effects, a cell cycle gene array was performed and cyclin G2 mRNA was found to be strongly up-regulated by Nodal and ALK7. To study the function and regulation of cyclin G2 in ovarian cancer cells, expression constructs were generated. We found that cyclin G2 protein level decreased rapidly after transfection, and this decrease was prevented by 26S proteasome inhibitors. Immunoprecipitation and pull-down studies showed that ubiquitin, Skp1, and Skp2 formed complexes with cyclin G2. Knockdown of Skp2 by siRNA increased, whereas overexpression of Skp2 decreased cyclin G2 levels. Nodal and ALK7 decreased the expression of Skp1 and Skp2 and increased cyclin G2 levels. Overexpression of cyclin G2 inhibited cell proliferation whereas cyclin G2-siRNA reduced the antiproliferative effect of Nodal and ALK7. Taken together, these findings provide strong evidence that cyclin G2 is degraded by the ubiquitin–proteasome pathway and that Skp2 plays a role in regulating cyclin G2 levels. Furthermore, our results also demonstrate that the antiproliferative effect of Nodal/ALK7 on ovarian cancer cells is in part mediated by cyclin G2.


Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2659
Author(s):  
Jerry Vriend ◽  
Mark W. Nachtigal

In this article, we reviewed the transcription of genes coding for components of the ubiquitin proteasome pathway in publicly available datasets of epithelial ovarian cancer (EOC). KEGG analysis was used to identify the major pathways distinguishing EOC of low malignant potential (LMP) from invasive high-grade serous ovarian carcinomas (HGSOC), and to identify the components of the ubiquitin proteasome system that contributed to these pathways. We identified elevated transcription of several genes encoding ubiquitin conjugases associated with HGSOC. Fifty-eight genes coding for ubiquitin ligases and more than 100 genes encoding ubiquitin ligase adaptors that were differentially expressed between LMP and HGSOC were also identified. Many differentially expressed genes encoding E3 ligase adaptors were Cullin Ring Ligase (CRL) adaptors, and 64 of them belonged to the Cullin 4 DCX/DWD family of CRLs. The data suggest that CRLs play a role in HGSOC and that some of these proteins may be novel therapeutic targets. Differential expression of genes encoding deubiquitinases and proteasome subunits was also noted.


2015 ◽  
Vol 10 (2) ◽  
pp. 201-213 ◽  
Author(s):  
Chakresh Jain ◽  
Shivam Arora ◽  
Aparna Khanna ◽  
Money Gupta ◽  
Gulshan Wadhwa ◽  
...  

2012 ◽  
Vol 117 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Willem-Jan M. Schellekens ◽  
Hieronymus W. H. van Hees ◽  
Michiel Vaneker ◽  
Marianne Linkels ◽  
P. N. Richard Dekhuijzen ◽  
...  

Background Mechanical ventilation induces diaphragm muscle atrophy, which plays a key role in difficult weaning from mechanical ventilation. The signaling pathways involved in ventilator-induced diaphragm atrophy are poorly understood. The current study investigated the role of Toll-like receptor 4 signaling in the development of ventilator-induced diaphragm atrophy. Methods Unventilated animals were selected for control: wild-type (n = 6) and Toll-like receptor 4 deficient mice (n = 6). Mechanical ventilation (8 h): wild-type (n = 8) and Toll-like receptor 4 deficient (n = 7) mice.Myosin heavy chain content, proinflammatory cytokines, proteolytic activity of the ubiquitin-proteasome pathway, caspase-3 activity, and autophagy were measured in the diaphragm. Results Mechanical ventilation reduced myosin content by approximately 50% in diaphragms of wild-type mice (P less than 0.05). In contrast, ventilation of Toll-like receptor 4 deficient mice did not significantly affect diaphragm myosin content. Likewise, mechanical ventilation significantly increased interleukin-6 and keratinocyte-derived chemokine in the diaphragm of wild-type mice, but not in ventilated Toll-like receptor 4 deficient mice. Mechanical ventilation increased diaphragmatic muscle atrophy factor box transcription in both wild-type and Toll-like receptor 4 deficient mice. Other components of the ubiquitin-proteasome pathway and caspase-3 activity were not affected by ventilation of either wild-type mice or Toll-like receptor 4 deficient mice. Mechanical ventilation induced autophagy in diaphragms of ventilated wild-type mice, but not Toll-like receptor 4 deficient mice. Conclusion Toll-like receptor 4 signaling plays an important role in the development of ventilator-induced diaphragm atrophy, most likely through increased expression of cytokines and activation of lysosomal autophagy.


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