-High and -Low Cells and a Novel Subpopulation Expressing Genes of Both Cell States Contribute to Intra- and Intertumoral Heterogeneity of Primary Melanoma.

Understanding tumor heterogeneity is an important challenge in current cancer research. Transcription and epigenetic profiling of cultured melanoma cells have defined at least two distinct cell phenotypes characterized by distinctive gene expression signatures associated with high or low/absent expression of microphthalmia-associated transcription factor (MITF). Nevertheless, heterogeneity of cell populations and gene expression in primary human tumors is much less well characterized.