GRP78 Participates in PCA3-regulated Prostate Cancer Progression

Background/Aim: The human prostate cancer antigen 3 (PCA3) is a long non-coding RNA (lncRNA) commonly used as a diagnostic marker for prostate cancer (PCa). Herein we investigated the cellular function of PCA3 in PCa and its potential mechanism. Materials and Methods: PCA3 was overexpressed in a PC3 cell line (PC3(PCA+)) and cell proliferation, migration, invasion and apoptosis were compared to those of control cells (PC3(NC)). Differentially expressed proteins were identified by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry. Results: Overexpression of PCA3 significantly increased cell proliferation rate, migration and invasion, while inhibited apoptosis in PC3 cells. Three proteins were found down-regulated and 7 proteins up-regulated in PC3(PCA+) cells compared to PC3(NC) cells, including GRP78. Higher GRP78 was also found in PCa clinical specimens. Conclusion: This study confirmed that in PCa, PCA3 plays a pro-cancer role through promoting cell proliferation, migration and invasion while inhibiting cell apoptosis. This process might involve the up-regulation of GRP78.