P047 Role of IL-18 in the melanin synthesis of B16F10 melanoma cells

Abstract

Introduction Interleukin-18 (IL-18), a member of the IL-1 cytokine super-family, has been known to interferon-g-inducing factor and plays a critical role in angiogenesis, bone metabolism, metabolic syndrome, inflammatory and immune response. However, the role of IL-18 in the melanin synthesis of B16F10 melanoma cells has not been investigated. Methods B16F10 cells were treated with IL-18 and/or for 5 days, and were then dissolved in 1N NaOH in 10% DMSO at 80 °C for 1 h. The relative melanin contents were determined by measuring the absorbance at 405 nm using an ELISA reader. Expression of IL-18, IL-18R and melanogenesis-related genes was examined by real time PCR. Results Here, we found that IL-18 significantly induced the melanin synthesis in B16F10 cells, and anti-IL-18 abrogated IL-18-induced melanin synthesis. We also observed that anti-IL-18 decreased gene and protein expression of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and dopachrome tautomerase (Dct) stimulated by IL-18. In addition, anti-IL-18 reduced IL-18-induced phosphorylation of mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK). Conclusion Taken together, these results suggest that IL-18 may be involved in regulation of the melanin synthesis in B16F10 cells via the ERK pathway.