Inhibition of transcription factor NF-κB signaling proteins IKKβ and p65 through specific cysteine residues by epoxyquinone A monomer: Correlation with its anti-cancer cell growth activity

Liang, Mei‐Chih; Bardhan, Sujata; Pace, Emily A.; Rosman, Diana S.; Beutler, John A.; Porco, John A.; Gilmore, Thomas D.

doi:10.1016/j.bcp.2005.11.013

Cited by 78 publications

(83 citation statements)

References 50 publications

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“…It has been reported that the cysteine residue located at position 38 in p65 is highly susceptible to various agents (38)(39)(40). Whether Cys 38 is a target for TQ was investigated.…”

Section: Tq Inhibits Tnf-induced Nuclear Translocation Of P65mentioning

confidence: 99%

Targeting Nuclear Factor-κB Activation Pathway by Thymoquinone: Role in Suppression of Antiapoptotic Gene Products and Enhancement of Apoptosis

Sethi

Ahn

Aggarwal

2008

Molecular Cancer Research

297

218

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Thymoquinone (TQ), derived from the medicinal plant Nigella sativa, exhibits antiinflammatory and anticancer activities through mechanism(s) that is not fully understood. Because numerous effects modulated by TQ can be linked to interference with the nuclear factor-KB (NF-KB) signaling, we investigated in detail the effect of this quinone on NF-KB pathway. As examined by DNA binding, we found that TQ suppressed tumor necrosis factor -induced NF-KB activation in a dose-and time-dependent manner and inhibited NF-KB activation induced by various carcinogens and inflammatory stimuli. The suppression of NF-KB activation correlated with sequential inhibition of the activation of IKBA kinase, IKBA phosphorylation, IKBA degradation, p65 phosphorylation, p65 nuclear translocation, and the NF-KB -dependent reporter gene expression. TQ specifically suppressed the direct binding of nuclear p65 and recombinant p65 to the DNA, and this binding was reversed by DTT. However, TQ did not inhibit p65 binding to DNA when cells were transfected with the p65 plasmid containing cysteine residue 38 mutated to serine. TQ also down-regulated the expression of NF-KB -regulated antiapoptotic (IAP1, IAP2, XIAP Bcl-2, Bcl-xL, and survivin), proliferative (cyclin D1, cyclooxygenase-2, and c-Myc), and angiogenic (matrix metalloproteinase-9 and vascular endothelial growth factor) gene products. This led to potentiation of apoptosis induced by tumor necrosis factor and chemotherapeutic agents. Overall, our results indicate that the anticancer and antiinflammatory activities previously assigned to TQ may be mediated in part through the suppression of the NF-KB activation pathway, as shown here, and thus may have potential in treatment of myeloid leukemia and other cancers.

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“…It has been reported that the cysteine residue located at position 38 in p65 is highly susceptible to various agents (38)(39)(40). Whether Cys 38 is a target for TQ was investigated.…”

Section: Tq Inhibits Tnf-induced Nuclear Translocation Of P65mentioning

confidence: 99%

Targeting Nuclear Factor-κB Activation Pathway by Thymoquinone: Role in Suppression of Antiapoptotic Gene Products and Enhancement of Apoptosis

Sethi

Ahn

Aggarwal

2008

Molecular Cancer Research

297

218

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“…On the other hand, the synthetic compound BMS-345541 binds to an allosteric site on both kinases, but shows an approximately 10-fold greater inhibitory effect on IKKb (Burke et al, 2003). Several thiol-reactive compounds, such as parthenolide, certain epoxyquinoids and arsenite, have been shown to block IKKb activity through Cys-179 (Kapahi et al, 2000;Kwok et al, 2001;Liang et al, 2003Liang et al, , 2006, probably in most cases through a direct conjugation to the thiol group of this cysteine. Although not formally proven, it is likely that interaction of these compounds with Cys-179 interferes with phosphorylation-induced activation of IKKb, in that Cys-179 is located between Ser 177 and Ser 181 which are part of the kinase activation loop and are required for activation of IKKb in response to many upstream signals, such as TNF and LPS (see Perkins, 2006;Scheidereit, 2006).…”

Section: Inhibitors Of Ikk Complex Activitiesmentioning

confidence: 99%

“…Interestingly, some SLs, including the natural product parthenolide, have been shown to also inhibit IKKb through a reactive Cys residue (Cys-179), which is in the kinase activation loop (Kwok et al, 2001;Garcı´a-Pin˜eres et al, 2004). Thus, the SLs (and some epoxyquinoids; Liang et al, 2006) have multistep inhibitory activity within the NF-kB signaling pathway, targeting both IKK activity and NF-kB subunit DNA binding.…”

Section: Inhibitors Of Nf-kb Dna Bindingmentioning

confidence: 99%

Inhibitors of NF-κB signaling: 785 and counting

2006

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“…All cells were grown in Dulbecco's modified Eagle's medium (DMEM) (Invitrogen) supplemented with 10% heat-inactivated fetal bovine serum (FBS) (Biologos) as described [11].…”

Section: Cell Culture and Transfectionmentioning

confidence: 99%

“…IKK kinase assays were performed as described previously [11]. Briefly, serum-starved NEMO-reconstituted fibroblasts were treated for 7.5 min with 20 ng/ml of TNFα before harvesting in AT buffer.…”

Section: Ikk Kinase Assaymentioning

confidence: 99%

Intermolecular disulfide bond formation in the NEMO dimer requires Cys54 and Cys347

Herscovitch

Comb

Ennis

et al. 2008

Biochemical and Biophysical Research Communications

Self Cite

103

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NEMO is an essential regulatory component of the IκB kinase (IKK) complex, which controls activation of the NF-κB signaling pathway. Herein, we show that NEMO exists as a disulfide-bonded dimer when isolated from several cell types and analyzed by SDS-polyacrylamide gel electrophoresis under non-reducing conditions. Treatment of cells with hydrogen peroxide (H 2 O 2 ) induces further formation of NEMO dimers. Disulfide bond-mediated formation of NEMO dimers requires Cys54 and Cys347. The ability of these residues to form disulfide bonds is consistent with their location in a NEMO dimer structure that we generated by molecular modeling. We also show that pretreatment with H 2 O 2 decreases TNFα-induced IKK activity in NEMO-reconstituted cells, and that TNFα has a diminished ability to activate NF-κB DNA binding in cells reconstituted with NEMO mutant C54/347A. This study implicates NEMO as a target of redox regulation and presents the first structural model for the NEMO protein.

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Inhibition of transcription factor NF-κB signaling proteins IKKβ and p65 through specific cysteine residues by epoxyquinone A monomer: Correlation with its anti-cancer cell growth activity

Cited by 78 publications

References 50 publications

Targeting Nuclear Factor-κB Activation Pathway by Thymoquinone: Role in Suppression of Antiapoptotic Gene Products and Enhancement of Apoptosis

Targeting Nuclear Factor-κB Activation Pathway by Thymoquinone: Role in Suppression of Antiapoptotic Gene Products and Enhancement of Apoptosis

Inhibitors of NF-κB signaling: 785 and counting

Intermolecular disulfide bond formation in the NEMO dimer requires Cys54 and Cys347

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