title: The IKKα-dependent non-canonical pathway of NF-κB activation is constitutively active and modulates progression-related functions in a subset of human melanomas.
abstract: Owing to activation of several resistance-mediating pathways including NF-κB signaling, metastasized melanoma is almost universally resistant against chemotherapy. Given that blocking of NF-κB either by proteasome-, pan-IKK- or selective IKKβ-inhibitors may increase the susceptibility of melanoma cells to chemotherapy, we have assessed the role of the second kinase within the IKK complex, IKKα. While expression of IKKα and overall activation of NF-κB were heterogeneous, the IKKα-specific p100/p52 processing was detected in a small subset of melanomas (1/9 primary and 1/12 metastatic melanomas) as well as in 1/8 melanoma cell lines. Down-modulation of IKKα by siRNA resulted in diminution of doxorubicin-induced NF-κB activation, constitutive and TNFα-stimulated expression of CXCL8 and ICAM-1, and cell migration. In contrast, overexpression of IKKα in melanoma cells did not significantly affect progression-related functions. Thus, IKKα may be a worthwhile target only in selected individualized therapies but not in general melanoma therapy.
authors.affiliation: Department of Dermatology, Venereology, and Allergology, University Medical Center, Georg August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
authors.forename: Nadin
authors.initials: N
authors.lastname: Dewert
authors.affiliation: Department of Dermatology, Venereology, and Allergology, University Medical Center, Georg August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Amschler
authors.affiliation: Department of Dermatology, Venereology, and Allergology, University Medical Center, Georg August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Lorenz
authors.affiliation: Department of Dermatology, Venereology, and Allergology, University Medical Center, Georg August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany. michael.schoen@med.uni-goettingen.de.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schön
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement; D018450:Disease Progression; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D006801:Humans; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism*; D052003:NF-kappa B p52 Subunit / Q000378:metabolism*; D057285:Precision Medicine; D034741:RNA, Small Interfering; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C508606:CXCL8 protein, human; C573420:ICAM1 protein, human; D016209:Interleukin-8; D052003:NF-kappa B p52 Subunit; D034741:RNA, Small Interfering; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; C496559:CHUK protein, human; D051550:I-kappa B Kinase
keywords: Alternative NF-κB pathway; Doxorubicin; Drug resistance; IKKα; Melanoma; NF-κB