Background and purpose:Rs10993994 at 10q11 was found to be associated with prostate cancer risk by genome-wide association studies. This study tried to reveal its mechanism and to explore the role of rs10993994 for the transcriptional activity of microseminoprotein beta (MSMB) gene in prostate cancer cell lines. Methods:Promoter fragments were generated by chemical synthesis. Due to the two possibility of rs10993994 (T/C) in the region, we generated two promoter fragments: MSMB promoter-T and MSMB promoter-C. The fragments were then cloned into pGL3-basic vectors, positive clones were transfected into prostate cancer cell lines PC-3 and LNCaP, ifnally, relative level of lfuorescence was detected by lfuoresce detector.Results:We generated two promoter fragments of MSMB, MSMB promoter-T and MSMB promoter-C. The two promoter fragments were cloned with pGL3-basic vectors to pGL3-MSMB promoter-T and pGL3-MSMB promoter-C. In PC-3, the relative level of lfuorescence of pGL3-MSMB promoter-C was signiifcant higher than that of pGL3-MSMB promoter-T(2.27±0.39vs 0.57±0.13,P<0.05); In LNCaP, the relative level of lfuorescence of pGL3-MSMB promoter-C was signiifcant higher than that of pGL3-MSMB promoter-T (1.70±0.32vs 0.37±0.09,P<0.05).Conclusion:The transcriptional activity of pGL3-MSMB promoter-C was stronger than that of pGL3-MSMB promoter-T. Rs10993994 could inlfuence the transcriptional activity ofMSMB gene promoter in prostate cancer cell lines PC-3 LNCaP, allele C in rs10993994 could facilitate transcription than T.