A Novel NF-κB-inducing Kinase-MAPK Signaling Pathway Up-regulates NF-κB Activity in Melanoma Cellsстатья из журнала
Аннотация: Constitutive activation of NF-κB is an emerging hallmark of various types of tumors including breast, colon, pancreatic, ovarian, and melanoma. In melanoma cells, the basal expression of the CXC chemokine, CXCL1, is constitutively up-regulated. This up-regulation can be attributed in part to constitutive activation of NF-κB. Previous studies have shown an elevated basal IκB kinase (IKK) activity in Hs294T melanoma cells, which leads to an increased rate of IκB phosphorylation and degradation. This increase in IκB-α phosphorylation and degradation leads to an ∼19-fold higher nuclear localization of NF-κB. However, the upstream IKK kinase activity is up-regulated by only about 2-fold and cannot account for the observed increase in NF-κB activity. We now demonstrate that NF-κB-inducing kinase (NIK) is highly expressed in melanoma cells, and IKK-associated NIK activity is enhanced in these cells compared with the normal cells. Kinase-dead NIK blocked constitutive NF-κB or CXCL1 promoter activity in Hs294T melanoma cells, but not in control normal human epidermal melanocytes. Transient overexpression of wild type NIK results in increased phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), which is inhibited in a concentration-dependent manner by PD98059, an inhibitor of p42/44 MAPK. Moreover, the NF-κB promoter activity decreased with overexpression of dominant negative ERK expression constructs, and EMSA analyses further support the hypothesis that ERK acts upstream of NF-κB and regulates the NF-κB DNA binding activity. Taken together, our data implicate involvement of IκB kinase and MAPK signaling cascades in NIK-induced constitutive activation of NF-κB.
Год издания: 2002
Авторы: Punita Dhawan, Ann Richmond
Издательство: Elsevier BV
Источник: Journal of Biological Chemistry
Ключевые слова: NF-κB Signaling Pathways, Natural product bioactivities and synthesis, Cytokine Signaling Pathways and Interactions
Другие ссылки: Journal of Biological Chemistry (PDF)
Journal of Biological Chemistry (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
Journal of Biological Chemistry (HTML)
Europe PMC (PubMed Central) (PDF)
Europe PMC (PubMed Central) (HTML)
PubMed Central (HTML)
PubMed (HTML)
Открытый доступ: hybrid
Том: 277
Выпуск: 10
Страницы: 7920–7928