UNRelenting Translation UNRestrains Melanoma Migration

Abstract

The cytoplasmic RNA-binding protein UNR influences key developmental processes by controlling mRNA turnover and translation initiation. In this issue of Cancer Cell, Wurth et al. report that UNR is highly expressed in melanoma and enhances invasion and metastasis at least partly by inducing translation elongation of VIM and RAC1 mRNAs.

Figure 1. Schematic of the Function of RNA-Binding Protein UNR in Melanoma Progression

Melanoma arises from melanocytes within the epidermis. After transformation due to the activation of oncogenic pathways largely following ultraviolet irradiation, melanocytes become melanoma cells that grow rapidly, acquire traits of mesenchymal cells, and invade and metastasize other tissues. Wurth et al. have found that elevated expression of the RNA-binding protein UNR in melanoma contributes to this process. UNR was previously shown to affect the initiation of translation of different target mRNAs (often via an internal ribosome entry site, IRES), as well as the turnover of other target mRNAs. In melanoma cells, Wurth et al. found that UNR additionally promoted translation elongation of several target mRNAs, including VIM and RAC1 mRNAs, in turn raising the production of VIM and RAC1, two proteins that induce a mesenchymal transition and hence drive invasion and metastasis of melanoma cells.