Mouse xenograft studies verified miR-888 and miR-891a as pro-oncogenic factors that increased prostate tumor growth <i>in vivo</i> Further analysis validated RBL1, KLF5, SMAD4, and TIMP2 as direct miR-888 targets and that TIMP2 is also coregulated by miR-891a.
We profiled miRNA expression in syngeneic human prostate cancer cell lines that differed in their metastatic potential in order to determine their role in aggressive prostate cancer. miR-888 was the most differentially expressed miRNA observed in human metastatic PC3-ML cells relative to non-invasive PC3-N cells, and its levels were higher in primary prostate tumors from cancer patients, particularly those with seminal vesicle invasion.