Abstract
BackgroundChemoresistance is a major cause of treatment failure in pancreatic cancer (PC). It has been demonstrated that epithelial-to-mesenchymal transition (EMT) is closely related to drug resistance in PC; however, the underlying mechanisms are not yet fully understood. Recently found evidence has suggested that nuclear-enriched abundant transcript 1 (NEAT1) is involved in the development of chemoresistance. However, the role and mechanism of NEAT1 in PC gemcitabine resistance remain unknown.MethodsTwo independent gemcitabine-resistant (GR) PC cell lines, PANC-1/GR and SW1990/GR, were established. Transwell assays were used to validate whether GR cells acquired EMT. qRT-PCR and western blot were performed to detect the expression levels of NEAT1, miR-506-3p, and ZEB2 in GR cells. MTT and cell apoptosis assays were conducted to evaluate the sensitivity of GR cells to gemcitabine. Rescue experiments were employed to investigate whether NEAT1 mediates drug resistance of GR cells through modulation of the miR-506-3p/ZEB2/EMT axis. Furthermore, a mouse xenograft model was established to confirm these findings.ResultsGR cells displayed markedly enhanced migration and invasion abilities, decreased expression of E-cadherin, and upregulation of N-cadherin, Vimentin, Snail, ZEB1, and ZEB2. Furthermore, elevated expression of NEAT1 was observed in GR cells. Downregulation of NEAT1 sensitized GR cells to gemcitabine. More importantly, we demonstrated that downregulation of NEAT1 enhanced the sensitivity of GR cells to gemcitabine by reversing the EMT process. NEAT1 regulated ZEB2 expression by sponging miR-506-3p, and the function of NEAT1 in GR cells was dependent on miR-506-3p. These findings were further confirmed in a nude mouse xenograft model.ConclusionsTaken together, downregulation of NEAT1 sensitized the GR PC cells to gemcitabine through modulation of the miR-506-3p/ZEB2/EMT axis. These results provide a new direction for improving the chemotherapeutic effects in PC.
A novel anti-cancer effect of atelocollagen-conjugated miR-520d-5p on pancreatic cancer cells in vitro and in a mouse xenograft model
