piR-4447944 accelerates in vivo castration-resistant growth capacity of LNCaP-derived xenograft tumors. A, Effect of piR-4447944 on the growth of subcutaneous tumor xenografts in the castrated SCID mice (n=5). Tumors treated with piR-4447944 agomir continued to grow aggressively, whereas tumors treated with NC-agomir ceased to grow. B, Weight of tumor xenografts in the castrated hosts was measured after the tumors were surgically dissected (n=5). piR-4447944 agomir group formed heavier tumors than the control group. C, Image showed the dissected xenografts tumors in each group. Results are presented as mean ± SD. *p < 0.05; **p < 0.01, ***p < 0.001, ****p < 0.0001.