Epidemiologic data suggest that soy consumption may protect against cancer induction in several tissues in humans, including urothelial carcinoma. Genistein have been reported to regulate genes that are involved in several cellular events. However, the molecular mechanism of genistein -induced upregulation of epithelial membrane protein 2 (EMP2), candidate urothelial tumor suppressor, is not entirely understood. At first, we found that the mRNA and protein expression levels of EMP2 were significantly greater in the normal urothelial tissues and human urothelial cells than those in urothelial bladder carcinoma tissues and urothelial cell carcinoma-derived cell lines. Second, EMP2 knockdown via RNA interference markedly enhanced cell proliferation, colony formation, migration and invasiveness. By contrast, EMP2 overexpression suppressed these malignant behaviors. Third, we showed that genistein-induced inhibition in cell proliferation is associated with an increase in EMP2 expression. Using various deleted EMP2 promoter constructs, we defined that the EMP2 core promoter is enough to observe the genistein-induced upregulation of EMP2 transcriptional activity. Using site direct mutagenesis and chromatin immunoprecipitation assays demonstrated that cyclic-AMP response element binding protein 1 (CREB1) acts as a positive regulator of EMP2 transcription by directly binding to its promoter. These results showed EMP2 suppressed urothelial cell carcinoma-derived cell growth, motility and invasion and for the first time that genistein promoted EMP2 expression in urothelial cell carcinoma-derived cells by inducing EMP2 transcriptional activity via CREB1 binding.