COMPARISON OF FUNCTIONAL PIGMENTATION ASSAYS.

Many different biological pathways have been implicated in the control of pigmentation including various signal transduction pathways and the cell cycle. We have analyzed key proteins in these pathways in normal human epidermal melanocytes including PKCbI, PKCbII, ERKI,2, MEK, pRb, E2F-1, E2F-2, p16, and p21. The functional relevance of these pathways to melanogenesis was assessed using specific inhibitors of both the cell signalling and cell cycle pathways. We assessed the involvement of these pathways in several pigmentation models including human melanocytes, skin organ culture, MelanoDerm™ living skin equivalent, and B16 melanoma cells. We observed that pharmacological inhibitors of both the signalling pathways (Forskolin, IBMX, PD98059, Ro-318220, wort-mannin) and cell cycle pathways (olomoucine, roscovitine) had varying effects depending on the model system used. These variations highlight the importance of careful selection and characterization of model systems used for investigating the role of signalling networks in regulating human pigmentation.

Cell cyle pathways, Cell signaling, E2F-1, E2F-2, ERK,1,2, Forskolin, IBMX, MEK, MelanoDerm, NHM, Normal human melanocytes, Olomoucine, P-16, P-21, PKCb1, PKCb2, PRb, Pigmentation, Roscovitine, Wortmannin