Tumorőssejtek szerepe a melanoma progressziójában és heterogenitásában

Over the past decade a rare cell population called cancer stem cells has been identified in both solid tumors and hematologic cancers. These cells are reminiscent of somatic and embryonic stem cells and play a critical role in the initiation and progression of malignancies. As all stem cells, they are able to undergo asymmetric cell division and hence renew themselves and create various other progenies with heterogenous phenotypes. A growing body of literature suggested that stem cell subpopulations contribute significantly to the growth and metastatic properties of melanoma. This review gives a comprehensive overview of the current literature on melanoma stem cells, with a special emphasis on the signaling pathways responsible for the homeostatic growth of melanocytes and the uncontrolled proliferation of melanoma cells. The importance of the local microenvironment are demonstrated through summarizing the role of various cell types, soluble factors and cell adhesion molecules in the progression of melanoma and the creation of treatment resistant cancer cell clones. Last but not least, the models of melanoma progression will be introduced and a variety of cellular markers will be presented that may be used to identify and therapeutically target melanoma.