In this study, we constructed an miRNA-mediated gene expression regulatory network of PCa and identified a novel miRNA–mRNA regulatory biomodule of miR-193a-5p- and miR-188-5p-regulated CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I signaling. The gene discussed is CDKN1A; the disease is posterior cortical atrophy.