IKK1/2 protect human cells from TNF-mediated RIPK1-dependent apoptosis in an NF-κB-independent manner

Publication date: August 2018Source: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1865, Issue 8Author(s): Carsten Slotta, Jonathan Storm, Nina Pfisterer, Elena Henkel, Svenja Kleinwächter, Maren Pieper, Lucia M. Ruiz-Perera, Johannes F.W. Greiner, Barbara Kaltschmidt, Christian KaltschmidtAbstractTNF 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.
Source: Biochimica et Biophysica Acta (BBA) Molecular Cell Research - Category: Molecular Biology Source Type: research