We further tested whether HOXD9 was involved in miR-205-mediated inhibition of cell proliferation, migration, invasion and EMT, and discovered that cell proliferation, migration, and invasion were increased in U87/miR-205 and U251/miR-205 cells transfected with HOXD9 (P<0.01; Figure 4A,B). As we confirmed, invasion and proliferation were inhibited by overexpressing miR-205, which targetted HOXD9. To determine whether miR-205 could directly down-regulate HOXD9 expression and its downstream pathways, we transfected pReceiver-Lv105-HOXD9 into U87 and U251 cells stably expressing miR-205 or miR-NC. HOXD9 down-regulation by miR-205 was counteracted by the overexpression of HOXD9 as evidenced by western blot (P<0.01; Figure 4C). Interestingly, the down-regulation of N-cadherin and Vimentin, which was thought to be an indirect result of miR-205 overexpression, was rescued by the up-regulation of HOXD9. Similarly, the overexpression of HOXD9 in miR-205 treated cells down-regulated E-cadherin expression (P<0.01; Figure 4C).