In this study, we established a chronic inflammation-associated PCa model of benign prostatic hyperplasia (BPH) epithelial cell line BPH1/LT-BPH1 (LPS long-term treated BPH1) and combined with another cellular transformation model of P69/M12,22, 23 to screen out a crucial miRNA, miR186, which was significantly downregulated in the malignant transformed cells LT-BPH1 and M12 rather than in their parental cells BPH1 and P69, respectively, and its ectopic expression could rescue the transformed phenotypes. The gene discussed is ICA1; the disease is posterior cortical atrophy.