PIK3R3 Promotes Metastasis of Pancreatic Cancer via ZEB1 Induced Epithelial-Mesenchymal Transition

Background/Aims: PIK3R3 is a regulatory subunit of phosphatidylinositol 3-kinase (PI3K) which plays an essential role in the metastasis of several types of cancer. However, whether PIK3R3 can promote the metastasis of pancreatic cancer (PC) is still unclear. In this study, we characterized the role of PIK3R3 in metastasis of PC and underlying potential mechanisms. Methods: RT-PCR, western blot, immunofluorescence (IF) and immunohistochemistry (INC) were applied to investigate the expression of genes and proteins in different cell lines and tissues. To assess the function of PIK3R3 and related mechanisms, the cells with RNAi-mediated knockdown or overexpression were used to perform a series of in vitro and in vivo assays. Results: PIK3R3 was significantly overexpressed in pancreatic cancer tissues, especially in metastatic cancer tissues, as well as in pancreatic cancer cells. Functional assays suggested that overexpression or knockdown of PIK3R3 could respectively promote or suppress the migration and invasion of PC cells in vitro and in vivo. Further mechanism related studies demonstrated that ERK1/2-ZEB1 pathway-triggered epithelial-mesenchymal transition (EMT) might be responsible for the PIK3R3 induced PC cell migration and invasion. Conclusion: PIK3R3 could promote the metastasis of PC by facilitating ZEB1 induced EMT, and could act as a potential therapeutic target to limit PC metastasis. (C) 2018 The Author(s) Published by S. Karger AG, Basel