WIP 1 is relevant to tumor malignancy and metastasis in breast cancer

Wild-type p53-induced phosphatase 1 (WIP1) is a serine/threonine protein phosphatase that has been shown to be correlated with tumor proliferation, differentiation and anti-apoptotic processes in several malignant tumors. However, the significance of WIP1 expression in breast cancer is still far from clear. To evaluate the clinical significance of WIP1 oncogene in breast cancer, the expression of WIP1 was investigated in 120 breast cancer biopsies and adjacent breast tissues by immunohistochemistry. The correlation between WIP1 expression and postoperative survival rate was also analyzed. WIP1 was up-regulated in breast cancer tissues (96/120). Down-regulation of WIP1 in MCF-7 breast cancer cells was established using Lentivirus-mediated infection. The absence of WIP1 resulted in dramatic decrease of cell proliferation, invasion, and metastasis ability as well as increase cell apoptosis. Subsequent investigations revealed that, p53 protein expression was significantly higher in WIP1-infected cells than in normal tumor cells. Our founding indicates that WIP1 ameliorated the malignancy of MCF-7 cells, which is probably achieved via regulating p53 protein expression. Taken together, WIP1 may be a useful regulator in breast cancer malignancy and metastasis in breast cancer and may involved in proliferation, apoptosis, migration and invasion of breast cancer cells by regulating p53 protein expression.