Paclitaxel stimulates melanogenesis in B16-F1 melanoma cells

Upon incubation with paclitaxel, B16-F1 melanoma cells showed a flattening and darkening of their cytoplasm. By electron microscopy analysis, an incre ase in the number of melanosomes associated with an increase of their melan in content was observed. The cells also showed prominent morphological chan ges such as flattening, loss of prolongation and ina ease in size. Tyrosina se activity was increased 2.2 fold after 16 hours of incubation with 10 mu M paclitaxel. The tyrosinase gene transcription was evaluated by semi-quant itative RT-PCR. The mRNA level was not significantly increased indicating t hat the effect of paclitaxel on melanogenesis was probably due to post-tran scriptional events.