The IKKα-dependent non-canonical pathway of NF-κB activation is constitutively active and modulates progression-related functions in a subset of human melanomas

Arch Dermatol Res. 2016 Dec;308(10):733-742. doi: 10.1007/s00403-016-1696-x. Epub 2016 Oct 15.


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.

Keywords: Alternative NF-κB pathway; Doxorubicin; Drug resistance; IKKα; Melanoma; NF-κB.

MeSH terms

  • Cell Line, Tumor
  • Cell Movement
  • Disease Progression
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • Humans
  • I-kappa B Kinase / genetics
  • I-kappa B Kinase / metabolism*
  • Intercellular Adhesion Molecule-1 / metabolism
  • Interleukin-8 / metabolism
  • Melanoma / drug therapy
  • Melanoma / metabolism*
  • NF-kappa B p52 Subunit / metabolism*
  • Precision Medicine
  • RNA, Small Interfering
  • Signal Transduction
  • Tumor Necrosis Factor-alpha / metabolism


  • CXCL8 protein, human
  • ICAM1 protein, human
  • Interleukin-8
  • NF-kappa B p52 Subunit
  • RNA, Small Interfering
  • TNF protein, human
  • Tumor Necrosis Factor-alpha
  • Intercellular Adhesion Molecule-1
  • CHUK protein, human
  • I-kappa B Kinase