GSE66054
MicroRNA-203 represses selection and expansion of oncogenic HRas transformed tumor initiating cells [seq]
In many mouse models of skin cancer, only a few tumors typically form although many cells competent for tumorigenesis receive the same oncogenic mutations. These observations suggest a selection process for defining tumor initiating cells. Here we use quantitative mRNA- and miR-Seq to determine the impact of HRasG12V on the transcriptome of keratinocytes. We discover that microRNA-203 is downregulated by HRasG12V. Using a knockout mouse model, we demonstrate that loss of microRNA-203 promotes selection and expansion of tumor-initiating cells. Conversely, restoration of microRNA-203 with an inducible model potently inhibits proliferation of these cells. We comprehensively identify microRNA-203 targets required for HRas-initiated tumorigenesis. These targets include important effectors of the Ras pathway and essential genes required for cell division. Together, this study establishes a role for the loss of microRNA-203 in promoting selection and expansion of HRas mutated cells and identifies a mechanism through which microRNA-203 antagonizes HRas-mediated tumorigenesis. Overall design: Identifying mRNA and microRNA networks regulated by oncogenic HRasG12V in primary keratinocytes through the use of 3Seq and small-RNA-Sequencing. Additionally we utilize ribosome-profiling, 3Seq, Microarray and Ago2-HITS-CLIP approaches to identify novel miR-203 target genes.