Background:Intrahepatic and extrahepatic metastases contribute to the high recurrence rate and mortality of hepatocellular carcinoma(HCC).Constitutive activation of nuclear factor-κB(NF-κB)is a crucial feature of HC...Background:Intrahepatic and extrahepatic metastases contribute to the high recurrence rate and mortality of hepatocellular carcinoma(HCC).Constitutive activation of nuclear factor-κB(NF-κB)is a crucial feature of HCC.NF-κB p65(p50-p65)is the most common dimeric form.Ser536 acts as an essential phosphorylation site of RelA/p65.However,the effect of RelA/p65 Ser536 phosphorylation on progression and metastases during intermediate and advanced HCC has not been reported.Methods:Phosphorylation of RelA/p65(p-p65 Ser536)and NF-κB p65 were detected by using immunohistochemical staining in HCC tissue samples.The biological effects of RelA/p65 Ser536 phosphorylation were evaluated by using xenograft and metastasis models.NF-κB p65 nuclear translocation was detected by using Western blotting.The binding of NF-κB p65 to the BCL2,SNAIL,and MMP9 promoters was detected by using chromatin immunoprecipitation.The biological effects on proliferation,migration,invasion,and epithelial-mesenchymal transition were assessed by using tetrazolium-based colorimetry,colony formation,EdU incorporation,flow cytometry,cell wound healing,and transwell assay.Results:NF-κB p65 is highly expressed,while p-p65 Ser536 is not well expressed in intermediate and advanced HCC tissues.In vivo experiments demonstrated that a phosphorylation-mimetic mutant of RelA/p65 Ser536(p65/S536D)prevents tumor progression and metastasis.In vitro experiments showed that p65/S536D inhibits proliferation,migration,and invasion.Mechanistically,RelA/p65 Ser536 phosphorylation inhibits NF-κB p65 nuclear translocation and reduces NF-κB p65 binding to the BCL2,SNAIL,and MMP9 promoters.Conclusions:RelA/p65 Ser536 phosphorylation was detrimental to NF-κB p65 entry into the nucleus and inhibited HCC progression and metastasis by reducing BCL2,SNAIL,and MMP9.The phosphorylation site of RelA/p65 Ser536 has excellent potential to be a promising target for NF-κB-targeted therapy in HCC.展开更多
AIM:Activation of transcription factor nuclear factor-κB(NF-κB)has been shown to play a role in cell proliferation,apoptosis,cytokine production,and oncogenesis.The purpose of this study was to determine whether NF-...AIM:Activation of transcription factor nuclear factor-κB(NF-κB)has been shown to play a role in cell proliferation,apoptosis,cytokine production,and oncogenesis.The purpose of this study was to determine whether NF-κB was constitutively activated in human colorectal tumor tissues and,if so,to determine the role of NF-κB in colorectal tumorigenesis,and furthermore,to determine the association of RelA expression with tumor cell apoptosis and the expression of Bcl-2 and Bcl-xL.METHODS:Paraffin sections of normal epithelial,adenomatous and adenocarcinoma tissues were analysed immunohistochemically for expression of RelA,Bcl-2 and Bcl-xL proteins.Electrophoretic mobility shift assay(EMSA)was used to confirm the increased nuclear translocation of RelA in colorectal tumor tissues.The mRNA expressions of Bcl-2 and Bcl-xL were determined by reverse transcription polymerase chain reaction(RT-PCR)analysis.Apoptotic cells were detected triphosphate fluorescence nick end labeling(TUNEL)method.RESULTS:The activity of NF-κB was significantly higher in adenocardnoma tissue in comparison with that in adenomatous and normal epithelial tissues.The apoptotic index(AI)significantly decreased in the transition from adenoma to adenocarcinoma.Meanwhile,the expressions of Bcl-2 and Bcl-xL protein and their mRNAs were significantly higher in adenocarcinoma tissues than that in adenomatous and normal epithelial tissues.CONCLUSION:NF-κB may inhibit apoptosis via enhancing the expression of the apoptosis genes Bcl-2 and Bcl-xL.And the increased expression of RelA/nuclear factor-κB plays an important role in the pathogenesis of colorectal carcinoma.展开更多
Activation of nuclear factor kappa B （NF-κB） is a hallmark of various central nervous system （CNS） pathologies. Neuron-specific inhibition of its transcriptional activator subunit RelA, also referred to as p65, p...Activation of nuclear factor kappa B （NF-κB） is a hallmark of various central nervous system （CNS） pathologies. Neuron-specific inhibition of its transcriptional activator subunit RelA, also referred to as p65, promotes neuronal survival under a range of conditions, i.e., for ischemic or excitotoxic insults. In macro- and microglial cells, post-lesional activation of NF-κB triggers a growth-permissive program which contributes to neural tissue inflammation, scar formation, and the expression of axonal growth inhibitors. Intriguingly, inhibition of such inducible NF-~B in the neuro-glial compartment, i.e., by genetic ablation of RelA or overexpression of a trans- dominant negative mutant of its upstream regulator IκBa, significantly enhances functional recovery and promotes axonal regeneration in the mature CNS. By contrast, depletion of the NF-κB subunit p50, which lacks transcriptional activator function and acts as a transcriptional repressor on its own, causes precocious neuronal loss and exacerbates axonal degeneration in the lesioned brain. Collectively, the data imply that NF-κB orchestrates a multicellular pro- gram in which κB-dependent gene expression establishes a growth-repulsive terrain within the post-lesioned brain that limits structural regeneration of neuronal circuits. Considering these subunit-specific functions, interference with the NF-κB pathway might hold clinical potentials to improve functional restoration following traumatic CNS injury.展开更多
基金funded by the College Students'Innovative Entrepreneurial Training Plan Program[no.202110601019].
文摘Background:Intrahepatic and extrahepatic metastases contribute to the high recurrence rate and mortality of hepatocellular carcinoma(HCC).Constitutive activation of nuclear factor-κB(NF-κB)is a crucial feature of HCC.NF-κB p65(p50-p65)is the most common dimeric form.Ser536 acts as an essential phosphorylation site of RelA/p65.However,the effect of RelA/p65 Ser536 phosphorylation on progression and metastases during intermediate and advanced HCC has not been reported.Methods:Phosphorylation of RelA/p65(p-p65 Ser536)and NF-κB p65 were detected by using immunohistochemical staining in HCC tissue samples.The biological effects of RelA/p65 Ser536 phosphorylation were evaluated by using xenograft and metastasis models.NF-κB p65 nuclear translocation was detected by using Western blotting.The binding of NF-κB p65 to the BCL2,SNAIL,and MMP9 promoters was detected by using chromatin immunoprecipitation.The biological effects on proliferation,migration,invasion,and epithelial-mesenchymal transition were assessed by using tetrazolium-based colorimetry,colony formation,EdU incorporation,flow cytometry,cell wound healing,and transwell assay.Results:NF-κB p65 is highly expressed,while p-p65 Ser536 is not well expressed in intermediate and advanced HCC tissues.In vivo experiments demonstrated that a phosphorylation-mimetic mutant of RelA/p65 Ser536(p65/S536D)prevents tumor progression and metastasis.In vitro experiments showed that p65/S536D inhibits proliferation,migration,and invasion.Mechanistically,RelA/p65 Ser536 phosphorylation inhibits NF-κB p65 nuclear translocation and reduces NF-κB p65 binding to the BCL2,SNAIL,and MMP9 promoters.Conclusions:RelA/p65 Ser536 phosphorylation was detrimental to NF-κB p65 entry into the nucleus and inhibited HCC progression and metastasis by reducing BCL2,SNAIL,and MMP9.The phosphorylation site of RelA/p65 Ser536 has excellent potential to be a promising target for NF-κB-targeted therapy in HCC.
基金Supported by Grants Grom National Natural Science Foundation of China No.39470330Natural Science Foundation of Hubei Province,China(SJ-97J083)
文摘AIM:Activation of transcription factor nuclear factor-κB(NF-κB)has been shown to play a role in cell proliferation,apoptosis,cytokine production,and oncogenesis.The purpose of this study was to determine whether NF-κB was constitutively activated in human colorectal tumor tissues and,if so,to determine the role of NF-κB in colorectal tumorigenesis,and furthermore,to determine the association of RelA expression with tumor cell apoptosis and the expression of Bcl-2 and Bcl-xL.METHODS:Paraffin sections of normal epithelial,adenomatous and adenocarcinoma tissues were analysed immunohistochemically for expression of RelA,Bcl-2 and Bcl-xL proteins.Electrophoretic mobility shift assay(EMSA)was used to confirm the increased nuclear translocation of RelA in colorectal tumor tissues.The mRNA expressions of Bcl-2 and Bcl-xL were determined by reverse transcription polymerase chain reaction(RT-PCR)analysis.Apoptotic cells were detected triphosphate fluorescence nick end labeling(TUNEL)method.RESULTS:The activity of NF-κB was significantly higher in adenocardnoma tissue in comparison with that in adenomatous and normal epithelial tissues.The apoptotic index(AI)significantly decreased in the transition from adenoma to adenocarcinoma.Meanwhile,the expressions of Bcl-2 and Bcl-xL protein and their mRNAs were significantly higher in adenocarcinoma tissues than that in adenomatous and normal epithelial tissues.CONCLUSION:NF-κB may inhibit apoptosis via enhancing the expression of the apoptosis genes Bcl-2 and Bcl-xL.And the increased expression of RelA/nuclear factor-κB plays an important role in the pathogenesis of colorectal carcinoma.
基金supported by the Leibniz Association,Germany,and the VELUX Foundation,Switzerland
文摘Activation of nuclear factor kappa B （NF-κB） is a hallmark of various central nervous system （CNS） pathologies. Neuron-specific inhibition of its transcriptional activator subunit RelA, also referred to as p65, promotes neuronal survival under a range of conditions, i.e., for ischemic or excitotoxic insults. In macro- and microglial cells, post-lesional activation of NF-κB triggers a growth-permissive program which contributes to neural tissue inflammation, scar formation, and the expression of axonal growth inhibitors. Intriguingly, inhibition of such inducible NF-~B in the neuro-glial compartment, i.e., by genetic ablation of RelA or overexpression of a trans- dominant negative mutant of its upstream regulator IκBa, significantly enhances functional recovery and promotes axonal regeneration in the mature CNS. By contrast, depletion of the NF-κB subunit p50, which lacks transcriptional activator function and acts as a transcriptional repressor on its own, causes precocious neuronal loss and exacerbates axonal degeneration in the lesioned brain. Collectively, the data imply that NF-κB orchestrates a multicellular pro- gram in which κB-dependent gene expression establishes a growth-repulsive terrain within the post-lesioned brain that limits structural regeneration of neuronal circuits. Considering these subunit-specific functions, interference with the NF-κB pathway might hold clinical potentials to improve functional restoration following traumatic CNS injury.
