Objective To investigate the role and biological mechanism of exosomal miRNA-141-3p in inducing the proliferation and invasion of prostate cancer(PCa)cells.Methods The expression level of miR-NA-141-3p in tumor tissues and adjacent tissues from 33 PCa patients,as well as in exosomes of human PCa cells VCap and normal prostate cells RWPE-2,was analyzed using quantitative real-time PCR(qPCR).The di-rect target of miRNA-141-3p was predicted through bioinformatic analysis and verified using a dual-luciferase reporter gene assay.miRNA-141-3p inhibitor plasmid(miRNA-141-3p inhibitor group)and negative control plasmid(negative control group)were transfected into human PCa cells VCap via lipofection.Cell prolifera-tion,migration,and invasion abilities in the miRNA-141-3p inhibitor group and negative control group were detected using MTT assay,wound healing assay,and Transwell assay,respectively.The mRNA expression levels of PHLPP2,E-Cadherin,and Vimentin were measured by qPCR,and the protein expression levels by Western blot,in VCap and RWPE-2 cells as well as in the miRNA-141-3p inhibitor group and negative control group.Results The expression level of exosomal miRNA-141-3p in tumor tissues was significantly higher than in adjacent tissues(P<0.05).Dual-luciferase reporter assay confirmed that PHLPP2 is the direct target gene of miRNA-141-3p.The expression levels of exosomal PHLPP2,E-Cadherin mRNA and protein in VCap cells were lower than in RWPE-2 cells,while the expression levels of Vimentin mRNA and protein were high-er than in RWPE-2 cells,with statistically significant intergroup differences(P=0.012).In the miR-141-3p inhibitor group,exosomal miR-141-3p,Vimentin mRNA expression level,cell proliferation rate(MTS assay),migrating cell count(scratch assay),and transmembrane cell count(Transwell invasion assay)were signifi-cantly decreased compared to the negative control group,while PHLPP2 mRNA and E-Cadherin mRNA ex-pression levels were significantly increased,with statistically significant intergroup differences(P<0.05).Conclusion miR-141-3p promotes proliferation and migration of human PCa cells by targeting PHLPP2.