Epithelial-mesenchymal　transition　(EMT)　contributes　to　the　invasion　and　metastasis　of　numerous　malignant　cancers,　including　melanoma.　A　significant　higher　expression　of　B-lymphoma　Moloney　murine　leukemia　virus　insertion　region-1　(Bmi-1)　has　been　reported　in　cell　lines　from　metastatic　melanoma　compared　to　cell　lines　from　primary　melanoma.　There　are　studies　that　show　that　knockdown　of　Bmi-1　could　induce　E-cadherin　expression　in　melanoma　cells.　However,　the　role　of　Bmi-1　in　mediating　EMT-like　changes　in　melanoma　has　not　yet　been　fully　studied.　In　the　present　study,　knockdown　of　Bmi-1　by　shRNA　transduction　decreased　the　invasion　properties　of　the　cultured　human　melanoma　cells　A375　by　a　Matrigel　invasion　assay,　along　with　alterations　in　EMT-related　markers　E-cadherin,　alpha-catenin,　vimentin　and　N-cadherin.　The　aforementioned　altered　expression　of　EMT　markers　was　verified　in　BALB/c-nude　mouse　xenografts.　Furthermore,　to　explore　the　underlying　regulatory　mechanism　of　EMT,　we　detected　the　significant　downregulation　of　p-Akt/p-NF-kappa　B/MMP-2　and　the　upregulation　of　PTEN　in　Bmi-l-silenced　A375　cells.　The　present　study　demonstrated　that　knockdown　of　Bmi-1　significantly　inhibited　the　aggressive　behavior　of　melanoma　by　reversing　EMT-like　changes　via　the　PTEN/p-Akt/p-NF-kappa　B/MMP-2　pathway.