Expression of the stem cell markers nestin and CD133 on circulating melanoma cells.

Different molecular markers have been identified for melanoma-initiating cells including CD133 and nestin. Assuming that metastasis requires a dissemination of tumor-initiating cells, presence of circulating tumor-initiating cells should be associated with worse patient outcome. In this study, 20 ml blood was collected from 32 consecutive patients affected by metastatic melanoma and blood was enriched for circulating melanoma cells (CMCs) by CD45 depletion of the non-melanoma cell fraction.