Targeting invasive properties of melanoma cells

4 years ago

Targeting invasive properties of melanoma cells

Imanol Arozarena, Claudia Wellbrock

Melanoma is a skin cancer notorious for its metastatic potential. As an initial step of the metastatic cascade, melanoma cells part from the primary tumour and invade the surrounding tissue, which is crucial for their dissemination and the formation of distant secondary tumours. Over the last two decades, our understanding of both, general and melanoma specific mechanisms of invasion has significantly improved, but to date no efficient therapeutic strategy tackling the invasive properties of melanoma cells has reached the clinic. In this review, we assess the major contributions towards the understanding of the molecular biology of melanoma cell invasion with a focus on melanoma specific traits. These traits are based on the neural crest origin of melanoma cells and explain their intrinsic invasive nature. A particular emphasis is given not only to lineage specific signalling mediated by TGFβ, and noncanonical and canonical WNT signalling, but also to the role of PDE5A and RHO-GTPases in modulating modes of melanoma cell invasion. We discuss existing caveats in the current understanding of the metastatic properties of melanoma cells, as well as the relevance of the ‘phenotype switch’ model and ‘co-operativity’ between different phenotypes in heterogeneous tumours. At the centre of these phenotypes is the lineage commitment factor microphthalmia-associated transcription factor, one of the most crucial regulators of the balance between de-differentiation (neural crest specific gene expression) and differentiation (melanocyte specific gene expression) that defines invasive and noninvasive melanoma cell phenotypes. Finally, we provide insight into the current evidence linking resistance to targeted therapies to invasive properties of melanoma cells. Melanoma skin cancer is notorious for its metastatic behaviour, and the neural crest origin of melanoma cells might explain their high capacity to invade and disseminate. Targeting invasion is discussed as therapy option, but this is challenged by the plasticity seen in the invasive modes (RHO-driven versus RAC-driven), and by mechanisms such as ‘phenotype switching’ and ‘co-operative’ behaviour between MITFhigh and MITFlow-phenotypes.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/febs.14040