title: Novel role of IL-6/SIL-6R signaling in the expression of inducible nitric oxide synthase (iNOS) in murine B16, metastatic melanoma clone F10.9, cells.
abstract: Inducible nitric oxide synthase (iNOS) has been shown to be frequently expressed in melanomas; up-regulation of this enzyme is though to be associated with tumor progression. In this study, we investigated whether diverse cytokines such as: IL-6, TNF-alpha, IL-1beta, IFN-gamma and IL6RIL6 (a highly active fusion protein of the soluble form of the IL-6R (sIL-6R) and IL-6) enhance the iNOS gene expression in B16/F10.9 murine metastatic melanoma cells. An increase at iNOS expression and NO production was observed with the co-treatment of IL6RIL6 plus TNF-alpha. Gel shift and reporter gene analyses revealed that IL6RIL6 selectively activated AP-1; while TNF-alpha increased the activities of both NF-kappaB and AP-1. Persistent activation of AP-1 was also seen in cells treated with IL6RIL6 plus TNF-alpha. Stimulation of cells with IL6RIL6/TNF-alpha resulted in the activation of mitogen-activated protein kinases (MAPK) such as c-Jun N-terminal kinase (JNK) and p38, and the abrogation by pretreatment with JNK or p38 MAPK inhibitor. IL6RIL6 or IL6RIL6/TNFalpha-inducible AP-1 binding increase was supershifted by anti-c-Jun or c-Fos antibodies, and the activation of c-Jun and c-Fos was dependent on JNK and p38, respectively. These results suggest that IL-6/sIL-6R/gp130 complex signaling has an unexpected positive effect on iNOS gene expression through JNK/p38 MAPK mediated-AP-1 activation in melanoma cells.
authors.affiliation: College of Pharmacy, Chosun University, Gwangju 501-759, Korea.
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
authors.forename: Yadav
authors.initials: Y
authors.lastname: Wagley
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Yuba Raj
authors.initials: YR
authors.lastname: Pokharel
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Chung
authors.forename: In Youb
authors.initials: IY
authors.lastname: Chang
authors.forename: Jong Joong
authors.initials: JJ
authors.lastname: Kim
authors.forename: Jeong Seok
authors.initials: JS
authors.lastname: Moon
authors.forename: Youn Kyu
authors.initials: YK
authors.lastname: Kim
authors.forename: Seung-Yeol
authors.initials: SY
authors.lastname: Nah
authors.forename: Hyung-Sik
authors.initials: HS
authors.lastname: Kang
authors.forename: Jae-Wook
authors.initials: JW
authors.lastname: Oh
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D015850:Interleukin-6 / Q000378:metabolism*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D008545:Melanoma / Q000378:metabolism; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D019947:Receptors, Interleukin-6 / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; D019947:Receptors, Interleukin-6; D018808:Transcription Factor AP-1; D052247:Nitric Oxide Synthase Type II; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4