title: Regulation of constitutive and induced NF-kappaB activation in malignant melanoma cells by capsaicin modulates interleukin-8 production and cell proliferation.
abstract: In the present study, we demonstrate that upregulation of interleukin-1beta(IL-1beta)-mediated and tumor necrosis factor-alpha (TNF-alpha)-mediated IL-8 expression in human malignant melanoma cells is modulated by the activation of nuclear factor-kappaB (NF-kappaB). Addition of capsaicin (8-methyl-N-vanillyl-6-nonenamide), a known inhibitor of NF-kappaB, resulted in the inhibition of constitutive as well as IL-1beta-induced and TNF-alpha-induced IL-8 expression in melanoma cells. The inhibition of IL-8 expression was dependent on the concentration of capsaicin and duration of treatment. Further, electrophoretic mobility shift assay (EMSA) of nuclear extracts from melanoma cells showed a constitutive activation of NF-kappaB and activated protein 1 (AP-1), which was upregulated following treatment with IL-1beta. Treatment of melanoma cells with capsaicin inhibited activation of constitutive and IL-1beta-induced NF-kappaB, but not AP-1, leading to inhibition of IL-8 expression. Further, downregulation of IL-8 expression in capsaicin-treated melanoma cells resulted in inhibition of in vitro cell proliferation. These results demonstrate that constitutive and induced NF-kappaB activation regulates IL-8 expression in melanoma cells. Downregulation of constitutive and induced NF-kappaB activation in malignant melanoma cells leads to inhibition of IL-8 production and in vitro cell proliferation.
authors.affiliation: Department of Pathology and Microbiology, The University of Nebraska Medical Center, Omaha, NE 68198-7660, USA.
authors.forename: Prabhudas S
authors.initials: PS
authors.lastname: Patel
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Varney
authors.forename: Bhavana J
authors.initials: BJ
authors.lastname: Dave
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
mesh_terms: D002211:Capsaicin / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007375:Interleukin-1 / Q000037:antagonists & inhibitors; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D007700:Kinetics; D008545:Melanoma / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D007375:Interleukin-1; D016209:Interleukin-8; D016328:NF-kappa B; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D002211:Capsaicin