PGRN promotes migration and invasion of epithelial ovarian cancer cells through an epithelial mesenchymal transition program and the activation of cancer associated fibroblasts

In this paper, we aimed to explore whether progranulin (PGRN) could induce epithelial ovarian cancer cells to undergo an epithelial mesenchymal transition (EMT) program directly and through its activation of cancer associated fibroblasts (CAFs) indirectly. Immunohistochemistry(IHC) staining of tissue samples of 78 cases of epithelial ovarian cancer (EOC) patients found that PGRN expression levels were negatively correlated with E-cadherin levels (r=-0.289, P=0.013) and positively correlated with Slug levels (r=0.332, P=0.003); Cell experiments showed that PGRN overexpression could increase the migratory and invasive abilities of A2780 cells significantly. Moreover, high doses (62ng/ml) of recombinant PGRN could induce 14.7 fold high expression of smooth muscle actin α (α-SMA) in human normal fibroblasts. In addition, patients with both high levels of PGRN and α-SMA in their tissue samples had the worst disease free survival (DFS) and overall survival (OS) than those with low levels of PGRN or α-SMA. All the results suggest that PGRN could promote invasiveness of EOC cells through an EMT program directly and through activation of CAFs indirectly. This may provide a new effective therapy target for EOC.