Modulation of intercellular adhesion molecule-1 expression on human melanocytes and melanoma cells: evidence for a regulatory role of IL-6, IL-7, TNF beta, and UVB light.
Intercellular adhesion molecule-1 (ICAM-1) is involved in cell-cell interactions of leukocytes and parenchymal cells and thus plays an important role in immunologic and inflammatory reactions. The expression of ICAM-1 that is found on many different cells such as melanocytes and melanoma cells is induced by various cytokines, including interferon-gamma (IFN gamma), interleukin (IL)-1 and tumor necrosis factor alpha (TNF alpha). Because expression of ICAM-1 in melanoma was found to correlate with increased risk of metastasis, the regulation of ICAM-1 expression on human melanocytes and melanoma cells was investigated. Foreskin-derived melanocytes and melanoma cell lines (A375, G361) were incubated with different cytokines and ICAM-1 expression was evaluated by fluorescence-activated cell sorter. IFN gamma, IL-1, IL-7, TNF alpha, and TNF beta significantly upregulated ICAM-1 expression in a dose-dependent manner. Most interestingly, the cytokine IL-6, which does not influence adhesion-molecule expression on other cells, significantly upregulated melanocyte and melanoma cell ICAM-1 expression. This effect was dose dependent and could be blocked by an IL-6 antibody. Irradiation with ultraviolet (UVB) light did not influence constitutive ICAM-1 expression on melanoma cells and melanocytes, but suppressed cytokine-induced ICAM-1 expression when cells were harvested 16 h after irradiation. These findings were further confirmed by Northern blot analysis, showing a marked accumulation of ICAM-1 mRNA after cytokine treatment, which was reduced by irradiation with UVB light. However, when UVB-exposed melanoma cells were cultured for at least 48 h induction of ICAM-1 expression was observed. These data indicate that, similar to other cells, ICAM-1 expression on melanoma cells and melanocytes is regulated by cytokines and that UVB light affects ICAM-1 expression on melanocytic cells in a biphasic manner.
Department of Dermatology II, University of Vienna, Austria.
R
R
Kirnbauer
B
B
Charvat
E
E
Schauer
A
A
Köck
A
A
Urbanski
E
E
Förster
P
P
Neuner
I
I
Assmann
T A
TA
Luger
T
T
Schwarz
D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000235:genetics; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D015850:Interleukin-6 / Q000494:pharmacology / Q000502:physiology*; D015851:Interleukin-7 / Q000494:pharmacology / Q000502:physiology*; D008544:Melanocytes / Q000737:chemistry* / Q000187:drug effects / Q000528:radiation effects; D008545:Melanoma / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology*; D014466:Ultraviolet Rays
D015815:Cell Adhesion Molecules; D015850:Interleukin-6; D015851:Interleukin-7; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1