OBJECTIVETo explore the relationship between CRYAB and the prognosis of prostate cancer (PCa) as well as the potential mechanism.METHODSBioinformatics analysis was performed using R software, including differential gene expression and clinical correlation analysis, receiver operating characteristic (ROC) curve and Kaplan-Meier (KM) curve generation. Gene expression was detected using RT-qPCR, and protein expression was validated using Western Blot. The proliferation, apoptosis, and metastatic ability of PCa cells were detected using CCK8, TUNEL, Transwell migration, and invasion assays.RESULTSAccording to the TCGA and GEO databases, CRYAB mRNA expression was down-regulated in PCa tissue compared with normal tissue (P< 0.05), and CRYAB mRNA and protein were down-regulated in PCa cells compared with RWPE1 cells (P< 0.05). Cell function experiments showed that up-regulated CRYAB could inhibit the proliferation, invasion, and migration of prostate cancer cells, promote apoptosis (P< 0.05), and up-regulate CDH1 expression while down-regulating CDH2 expression in the CRYAB-upregulated cell line. In addition, CRYAB mRNA expression was correlated with Gleason score (P< 0.01). The area under the ROC curve was 0.914, the KM curve showed that CRYAB had prognostic value for progression-free survival (P = 0.008) and disease-specific survival (P = 0.032).CONCLUSIONCRYAB is down-regulated in PCa tissue and is associated with the anti- tumor function of PCa cells. It may affect the metastatic ability of prostate cancer cells by regulating epithelial-mesenchymal transition molecules. CRYAB mRNA has important diagnostic and prognostic value in PCa.