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Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells
Published on: June 16, 2017
IKK1/2 protect human cells from TNF-mediated RIPK1-dependent apoptosis in an NF-κB-independent manner
Carsten Slotta1, Jonathan Storm2, Nina Pfisterer2
1Department of Cell Biology, University of Bielefeld, Universitaetsstr. 25, 33501 Bielefeld, Germany; Molecular Neurobiology, University of Bielefeld, Universitaetsstr. 25, 33501 Bielefeld, Germany.
Abstract:
TNF signaling is directly linked to cancer development and progression. A broad range of tumor cells is able to evade cell death induced by TNF impairing the potential anti-cancer value of TNF in therapy. Although sensitizing cells to TNF-induced death therefore has great clinical implications, detailed mechanistic insights into TNF-mediated human cell death still remain unknown. Here, we analyzed human cells by applying CRISPR/Cas9n to generate cells deficient of IKK1, IKK2, IKK1/2 and RELA. Despite stimulation with TNF resulted in impaired NF-κB activation in all genotypes compared to wildtype cells, increased cell death was observable only in IKK1/2-double-deficient cells. Cell death could be detected by Caspase-3 activation and binding of Annexin V. TNF-induced programmed cell death in IKK1/2-/- cells was further shown to be mediated via RIPK1 in a predominantly apoptotic manner. Our findings demonstrate the IKK complex to protect from TNF-induced cell death in human cells independently to NF-κB RelA suggesting IKK1/2 to be highly promising targets for cancer therapy.
Insights
Tumor cells evade TNF-induced death, hindering cancer therapy. Researchers found inhibiting IKK1/2 sensitizes human cells to TNF-induced death, suggesting IKK1/2 as a promising cancer therapy target.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- Tumor cells evade cell death triggered by Tumor Necrosis Factor (TNF), limiting its therapeutic potential.
- Understanding TNF-mediated cell death mechanisms is crucial for developing effective cancer therapies.
Purpose of the Study:
- To investigate the role of IKK1, IKK2, and RELA in TNF-induced cell death in human cells.
- To identify potential therapeutic targets for sensitizing cancer cells to TNF-induced apoptosis.
Main Methods:
- Utilized CRISPR/Cas9n gene editing to create human cell lines deficient in IKK1, IKK2, or both (IKK1/2), and RELA.
- Stimulated cells with TNF and analyzed NF-κB activation, Caspase-3 activation, and Annexin V binding.
- Investigated the involvement of RIPK1 in TNF-induced cell death pathways.
Main Results:
- TNF stimulation impaired NF-κB activation in all generated cell lines compared to wild-type.
- Only IKK1/2-double-deficient cells exhibited significantly increased TNF-induced cell death, confirmed by Caspase-3 activation and Annexin V binding.
- TNF-induced cell death in IKK1/2-/- cells was RIPK1-dependent and predominantly apoptotic.
Conclusions:
- The IKK complex (IKK1/2) protects human cells from TNF-induced death independently of NF-κB RelA.
- IKK1/2 inhibition represents a promising strategy to sensitize cancer cells to TNF-based therapies.
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