Tumor suppressor effects for miR-215 identified through use of miRNA profiling in metastatic renal cell carcinoma.

392 Background: Renal cell carcinoma (RCC) is the most common neoplasm of the adult kidney. Metastatic RCC is difficult to treat. The five-year survival rate for metastatic RCC is <10%. Recently, microRNAs (miRNAs) have been shown to have a role in cancer metastasis and potential as prognostic biomarkers in cancer. Methods: We preformed a miRNA microarray to identify a miRNA signature characteristic of metastatic compared to primary RCC. Results were validated by quantitative real time PCR. Target prediction analysis and gene expression profiling identified many of the dysregulated miRNAs could target genes involved in tumor metastasis. The effect of miR-215 on cellular migration and invasion was shown in a RCC cell line model. Results: We identified 65 miRNAs that were significantly altered in metastatic when compared to primary RCC. Nine (14%) miRNAs had increased expression while 56 (86%) miRNAs showed decreased expression. miR-10b, miR-196a, and miR-27b were the most downregulated while miR-638, miR-1...