Human androgen-refractory PCa ARCaPE and ARCaPM and LNCaP, LNCaPNeo and LNCaPRANKL PCa (15 (link)–17 (link)) were used. PCa cells and 293T cells were cultured in T-medium (GibcoBRL) supplemented with 5% heat inactivated fetal bovine serum (Bio-Whittaker) as previously mentioned (18 (link)). All cells were tested for mycoplasma every three months and were negative. The embryonic stem cells and iPSCs derived small RNA preparations were provided by Drs. Sareen and Svendsen. Derivation of these cells is included in the Supplementary materials and methods and figure legends.