miR-539 suppresses the proliferation, migration, invasion and epithelial mesenchymal transition of pancreatic cancer cells through targeting SP1

MicroRNA (miR)-539 has inhibitory effects on certain types of cancer, but its role in pancreatic cancer (PCa) remains unclear. The present study investigated the effects of miR-539 on PCa, and aimed to determine possible therapeutic targets for the treatment of PCa. The expression of miR-539 in PCa tissues, paired normal adjacent tissues and PCa cell lines (CAPAN-2, BxPC3, CFPAC1, SW1990 and PANC1), and human non-cancerous pancreatic cells (hTRET-HPNE) was determined and compared. The effects of upregulation and downregulation of miR-539 on proliferation, apoptosis, cell cycle, invasion, migration and epithelial-mesenchymal transition (EMT) of PCa cells were investigated. Additionally, the target gene of miR-539 was predicted and its effects on PCa cells were further investigated. The results revealed low expression of miR-539 in PCa tissues and cell lines. Additionally, increasing miR-539 expression inhibited the proliferation, migration, invasion and EMT of PCa cells and induced apoptosis by blocking G1 phase of the cell cycle, while reducing miR-539 expression had the opposite results. Furthermore, specificity protein 1 (SP1) was found to be the target gene of miR-539. SP1 promoted the proliferation, migration, invasion and EMT transformation of PCa cells, but these effects were reversed by high expression of miR-539. Additionally, miR-539 suppressed the proliferation, metastasis, invasion and EMT transformation of PCa cells through targeting SP1. Therefore, miR-539 overexpression may contribute toward development of novel therapeutic strategies for PCa in the future.