Epithelial-mesenchymal transition induced PAI-1 is associated with prognosis of triple-negative breast cancer patients.

Epithelial-mesenchymal transition (EMT) is a key developmental program in which epithelial cells lose polarity and become mesenchymal cells, and that is often activated during cancer invasion and metastasis. Triple negative breast cancer (TNBC) patients have a relatively aggressive biological behavior with a high risk of distant recurrence and metastasis. Here, we stimulated TNBC cells to undergo EMT, and detected the protein expression profiles of the protein secretion. High-throughput data showed that EMT could promote TNBC cells to secret PAI-1. We found that TNBC-secreted PAI-1 could increase cell growth, migration and invasion, and the expression of EMT markers in the TNBC cell lines and xenograft PAI-1-/- mice model. Using a tissues microarray of 165 TNBC patients and published breast cancer database, we found PAI-1 expression was significantly elevated in the breast cancer tissues, comparing with the normal adjacent tissues and was associated with prognosis of patients with TNBC. Taken together, our results suggests an important role of PAI-1 in the EMT process of TNBC cells and illustrates the great potential of developing PAI-1-targeting therapy for clinical TNBC patients.