Silencing of Prrx2 Inhibits the Invasion and Metastasis of Breast Cancer both In Vitro and In Vivo by Reversing Epithelial-Mesenchymal Transition.

BACKGROUND/AIMS: Epithelial-mesenchymal transition (EMT) is recognized as a crucial mechanism in breast cancer progression and metastasis. Paired-related homeobox 2 (Prrx2) has been identified as a new EMT inducer in cancer, but the underlying mechanisms are still poorly understood. METHODS: The expression of Prrx2 was assessed by immunohistochemistry in breast cancer tissues to evaluate the clinicopathological significance of Prrx2, as well as the correlation between Prrx2 and EMT. Short hairpin RNA knockdown of Prrx2 was used to examine cellular effects of Prrx2, detecte the expression of Wnt/ß-catenin signaling and EMT-associated proteins, and observe cell proliferation, invasion and migration abilities in vitro and in vivo. RESULTS: Clinical association studies showed that Prrx2 expression was related to tumor size, lymph node metastasis, tumor node metastasis stages, EMT and poor survival. Results also showed that knockdown of Prrx2 could alter cell morphology, suppressed the abilities of cell proliferation, invasion and migration in breast cancer. Moreover, silencing of Prrx2 induced the mesenchymal-epithelial transition and prevented nuclear translocation of ß-catenin, inhibited wnt/ß-catenin signaling pathway. CONCLUSION: Our study indicated that Prrx2 may be an important activator of EMT in human breast cancer and it can serve as a molecular target of therapeutic interventions for breast cancer.