Vitamin C downregulates interleukin-18 production by increasing reactive oxygen intermediate and mitogen-activated protein kinase signalling in B16F10 murine melanoma cells.
We recently reported that interleukin-18 (IL-18) is highly expressed in malignant skin tumours such as melanomas, and may play a key role in the malignancy of such tumours. This study was designed to investigate the mechanisms of IL-18 regulation by vitamin C in B16F10 murine melanoma cells. Cells were treated with vitamin C, and the expression of IL-18 was measured by reverse transcription-polymerase chain reaction and intracellular flow cytometry analysis. Decreased IL-18 production and a significant reduction in IL-18 mRNA transcript were detected in cells treated with vitamin C. The effect of vitamin C treatment was blocked by the antioxidant N-acetyl-L-cysteine, suggesting that vitamin C affects IL-18 expression by up-regulating intracellular reactive oxygen intermediate (ROI) levels. To investigate whether the mitogen-activated protein kinase (MAPK) signalling pathway is involved in the downregulation of IL-18 production, cells were pretreated with SB203580, an inhibitor of p38 MAPK, prior to the addition of vitamin C. This pretreatment blocked the decrease in IL-18 production. However, vitamin C treatment enhanced the expression of phosphorylated p38 MAPK. Taken together, we conclude that vitamin C increases intracellular ROI levels, and regulates IL-18 production through the MAPK signalling pathway.
Cho
Daeho
D
Department of Life Science, Sookmyung Women's University, Seoul, Korea.
Hahm
Eunsil
E
Kang
Jae Seung
JS
Kim
Young-In
YI
Yang
Yoolhee
Y
Park
Jong Hoon
JH
Kim
Daejin
D
Kim
Seonghan
S
Kim
Yeong Seok
YS
Hur
Daeyoung
D
Park
Hyunjeong
H
Pang
Saic
S
Hwang
Young Il
YI
Lee
Wang Jae
WJ
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000378:metabolism* / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003720:Densitometry; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D007093:Imidazoles / Q000494:pharmacology; D047468:Immunoprecipitation; D020382:Interleukin-18 / Q000096:biosynthesis* / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008545:Melanoma / Q000378:metabolism; D051379:Mice; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000378:metabolism; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D000975:Antioxidants; D004791:Enzyme Inhibitors; D007093:Imidazoles; D020382:Interleukin-18; D011725:Pyridines; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; D001205:Ascorbic Acid; D000111:Acetylcysteine