scholarly journals MicroRNA-7/NF-κB signaling regulatory feedback circuit regulates gastric carcinogenesis

2015 ◽  
Vol 210 (4) ◽  
pp. 613-627 ◽  
Author(s):  
Xiao-Di Zhao ◽  
Yuan-Yuan Lu ◽  
Hao Guo ◽  
Hua-Hong Xie ◽  
Li-Jie He ◽  
...  

MicroRNAs play essential roles in gene expression regulation during carcinogenesis. Here, we investigated the role of miR-7 and the mechanism by which it is dysregulated in gastric cancer (GC). We used genome-wide screenings and identified RELA and FOS as novel targets of miR-7. Overexpression of miR-7 repressed RELA and FOS expression and prevented GC cell proliferation and tumorigenesis. These effects were clinically relevant, as low miR-7 expression was correlated with high RELA and FOS expression and poor survival in GC patients. Intriguingly, we found that miR-7 indirectly regulated RELA activation by targeting the IκB kinase IKKε. Furthermore, IKKε and RELA can repress miR-7 transcription, which forms a feedback circuit between miR-7 and nuclear factor κB (NF-κB) signaling. Additionally, we demonstrate that down-regulation of miR-7 may occur as a result of the aberrant activation of NF-κB signaling by Helicobacter pylori infection. These findings suggest that miR-7 may serve as an important regulator in GC development and progression.

2009 ◽  
Vol 157 (2) ◽  
pp. 294-306 ◽  
Author(s):  
Luciano Ottonello ◽  
Maria Bertolotto ◽  
Fabrizio Montecucco ◽  
Giordano Bianchi ◽  
Franco Dallegri

2022 ◽  
Author(s):  
Jack A Prescott ◽  
Kathryn Balmanno ◽  
Jennifer P Mitchell ◽  
Hanneke Okkenhaug ◽  
Simon J Cook

Inhibitor of kappa B (IκB) kinase β (IKKβ) has long been viewed as the dominant IKK in the canonical nuclear factor-κB (NF-κB) signalling pathway, with IKKα being more important in non-canonical NF-κB activation. Here we have investigated the role of IKKα and IKKβ in canonical NF-κB activation in colorectal cells using CRISPR-Cas9 knock-out cell lines, siRNA and selective IKKβ inhibitors. IKKα and IKKβ were redundant for IκBα phosphorylation and turnover since loss of IKKα or IKKβ alone had little (SW620 cells) or no (HCT116 cells) effect. However, in HCT116 cells IKKα was the dominant IKK required for basal phosphorylation of p65 at S536, stimulated phosphorylation of p65 at S468, nuclear translocation of p65 and the NF-κB-dependent transcriptional response to both TNFα and IL-1α. In these cells IKKβ was far less efficient at compensating for the loss of IKKα than IKKα was able to compensate for the loss of IKKβ. This was confirmed when siRNA was used to knock-down the non-targeted kinase in single KO cells. Critically, the selective IKKβ inhibitor BIX02514 confirmed these observations in WT cells and similar results were seen in SW620 cells. Notably, whilst IKKα loss strongly inhibited TNFα-dependent p65 nuclear translocation, IKKα and IKKβ contributed equally to c-Rel nuclear translocation indicating that different NF-κB subunits exhibit different dependencies on these IKKs. These results demonstrate a major role for IKKα in canonical NF-κB signalling in colorectal cells and may be relevant to efforts to design IKK inhibitors, which have focused largely on IKKβ to date.


2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Amandah Necker‐Brown ◽  
Andrew Thorne ◽  
Akanksha Bansal ◽  
Mahmoud Mostafa ◽  
Anthony Gerber ◽  
...  

2007 ◽  
Vol 55 (1) ◽  
pp. S158
Author(s):  
A. M. DeLuca ◽  
B. Ryu ◽  
R. Alani

Blood ◽  
2011 ◽  
Vol 117 (4) ◽  
pp. 1301-1307 ◽  
Author(s):  
Wei-Zhong Ying ◽  
Pei-Xuan Wang ◽  
Kristal J. Aaron ◽  
Kolitha Basnayake ◽  
Paul W. Sanders

Abstract One of the major attendant complications of multiple myeloma is renal injury, which contributes significantly to morbidity and mortality in this disease. Monoclonal immunoglobulin free light chains (FLCs) are usually directly involved, and tubulointerstitial renal injury and fibrosis are prominent histologic features observed in myeloma. The present study examined the role of monoclonal FLCs in altering the nuclear factor κ light chain enhancer of activated B cells (NF-κB) activity of renal epithelial cells. Human proximal tubule epithelial cells exposed to 3 different human monoclonal FLCs demonstrated Src kinase–dependent activation of the NF-κB pathway, which increased production of monocyte chemoattractant protein-1 (MCP-1). Tyrosine phosphorylation of inhibitor of κB kinases (IKKs) IKKα and IKKβ and a concomitant increase in inhibitor of κB (IκB) kinase activity in cell lysates were observed. Time-dependent, Src kinase–dependent increases in serine and tyrosine phosphorylation of IκBα and NF-κB activity were also demonstrated. Proteasome inhibition partially blocked FLC-induced MCP-1 production. These findings fit into a paradigm characterized by FLC-induced redox-signaling events that activated the canonical and atypical (IKK-independent) NF-κB pathways to promote a proinflammatory, profibrotic renal environment.


2005 ◽  
Vol 25 (10) ◽  
pp. 1301-1311 ◽  
Author(s):  
Yun S Song ◽  
Yong-Sun Lee ◽  
Pak H Chan

Nuclear factor-κB (NF-κB) has a central role in coordinating the expression of a wide variety of genes that control cerebral ischemia. Although there has been intense research on NF-κB, its mechanisms in the ischemic brain have not been clearly elucidated. We investigated the temporal profile of NF-κB-related genes using a complementary DNA array method in wild-type mice and human copper/zinc-superoxide dismutase transgenic (SOD1 Tg) mice that had low-level reactive oxygen species (ROS) by scavenging superoxide. Our DNA array showed that IκB kinase (IKK) complex (IKKα, β, and γ) mRNA in the wild-type mice was decreased as early as 1 h after reperfusion, after 30 mins of transient focal cerebral ischemia (tFCI). In contrast, tFCI in the SOD1 Tg mice caused an increase in the IKK complex. The IKK complex protein levels were also drastically decreased at 1 h in the wild-type mice, but did not change in the SOD1 Tg mice throughout the 7 days. Electrophoretic mobility shift assay revealed activation of NF-κB DNA binding after tFCI in the wild-type mice. Nuclear factor-κB activation occurred at the same time, as did the phosphorylation and degradation of the inhibitory protein κBα. However, SOD1 prevented NF-κB activation, and phosphorylation and degradation of IκBα after tFCI. Superoxide production and ubiquitinated protein in the SOD1 Tg mice were also lower than in the wild-type mice after tFCI. These results suggest that ROS are implicated in transient downregulation of IKKα, β, and γ in cerebral ischemia.


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