正常ヒト表皮メラノサイト(NHEM)とヒト異色腫細胞株SK-MEL23の細胞増殖と分化に対する線維芽細胞培養液上清(FCM)の影響

Our goal is to study the role of dermal fibroblasts in the proliferation and differentiation of epidermal melanocytes using a reconstituted epidermal melanin unit (EMU). In order to achieve this goal, we have investigated the effect of fibroblast-conditioned medium (FCM) on the growth and melanogenesis of normal human epidermal melanocytes (NHEM) from neonatal foreskin using SK-MEL23 human melanoma cells as controls. NHEM and SK-MEL23 cells grown on type-I collagen gel alone revealed short dendrites. The culture on type-I collagen gel and fibroblasts resulted in prominent dendricities of NHEM. The FCM, which was likely to contain extracellular matrix (ECM) proteins and cytokines derived from fibroblasts, remarkably enhanced the dendricity of NHEM and their attachment to petri dishes/culture plates, but did so to a lesser degree with control SK-MEL23 cells. However, it did not affect the proliferation of both NHEM and SK-MEL23 cells. The FCM treatment decreased the tyrosinase activity of NHEM, while this decrease was not seen in melanoma cells. These studies suggest that cytokines and ECM proteins from dermal fibroblasts are important in regulating the functional and morphological differentiation of epidermal human melanocytes, and that this biological effect is much smaller in their neoplastic counter parts, melanoma cells

N-Propionyl-Cysteaminylphenol-Magnetite Conjugate (NPrCAP/M) Is a Nanoparticle for the Targeted Growth Suppression of Melanoma Cells

A magnetite nanoparticle, NPrCAP/M, was produced for intracellular hyperthermia treatment of melanoma by conjugating N-propionyl-cysteaminylphenol (NPrCAP) with magnetite and used for the study of selective targeting and degradation of melanoma cells. NPrCAP/M, like NPrCAP, was integrated as a substrate in the oxidative reaction by mushroom tyrosinase. Melanoma, but not non-melanoma, cells incorporated larger amounts of iron than magnetite from NPrCAP/M. When mice bearing a B16F1 melanoma and a lymphoma on opposite flanks were given NPrCAP/M, iron was observed only in B16F1 melanoma cells and iron particles (NPrCAP/M) were identified within late-stage melanosomes by electron microscopy. When cells were treated with NPrCAP/M or magnetite and heated to 43°C by an external alternating magnetic field (AMF), melanoma cells were degraded 1.7- to 5.4-fold more significantly by NPrCAP/M than by magnetite. Growth of transplanted B16 melanoma was suppressed effectively by NPrCAP/M-mediated hyperthermia, suggesting a clinical application of NPrCAP/M to lesional therapy for melanoma. Finally, melanoma cells treated with NPrCAP/M plus AMF showed little sub-G1 fraction and no caspase 3 activation, suggesting that the NPrCAP/M-mediated hyperthermia induced non-apoptotic cell death. These results suggest that NPrCAP/M may be useful in targeted therapy for melanoma by inducing non-apoptotic cell death after appropriate heating by the AMF