Cancer stem cells in melanoma

Abstract

The Cancer Stem Cells (CSC) are a subpopulation of tumoral cells characterized by the ability to self-renew and to establish tumours upon transplantation, to remain quiescent for long time and to have an innate resistance to chemotherapy and radiotherapy. These features suggest that they are responsible for relapse and metastasis. In melanoma, subsets of tumoral cells with these characteristics have been identified using CSC markers such as ALDH1, CD133, ABCB5. Wnt, Notch and Hegdohog are signaling pathways involved in the biology of CSC, which are highly conserved through evolution. Although the available evidence is limited, it seems to be equally important for melanoma stem cells. Many studies have associated high levels of CSC biomarkers expression with adverse prognosis of melanoma. Knowledge of the CSC biomarkers and its signaling pathways has opened research pathway for the development of new therapies targeted to CSC. The anti-CD20 antibody, Rituximab, and immunotherapy with dendritic cells immunized against antigens of the CSC, have documented the first positive results of efficacy in melanoma. The current evidence on their CSC biomarkers, major molecular pathways involved in its biology, prognostic value and potential utility as a therapeutic target will be reviewed in this chapter.