Shrimp miR-S8 Suppresses the Stemness of Human Melanoma Stem-like Cells by Targeting the Transcription Factor YB-1

Abstract Cross-species regulation of gene expression by microRNA is a possible untapped opportunity for miRNA-based therapy. In this study, we report a novel approach to ablate melanoma stem-like cells by targeting the transcription factor YB-1, which is significantly and selectively upregulated in these cells in melanoma. Silencing YB-1 expression was sufficient to significantly inhibit the stemness of melanoma stem-like cells. In exploring YB-1 targeting, we discovered that the shrimp microRNA miR-S8 could suppress human YB-1 expression in melanoma stem-like cells. Mechanistic investigations revealed that miR-S8 recognized the 3′UTR of YB-1 mRNA and mediated its degradation. In tumor cell and xenograft experiments, miR-S8 suppressed the tumorigenic capacity of melanoma stem-like cells by targeting human YB-1. Overall, our results illuminated a novel aspect of miRNA-mediated cross-species gene expression and its use in regulating cancer stem-like cells. Cancer Res; 77(20); 5543–53. ©2017 AACR.