Recombinant lentivirus targeting the pleotrophin gene reduces pleotrophin protein expression in pancreatic cancer cells and inhibits neurite outgrowth of dorsal root ganglion neurons

Abstract

The objectives of the present study were to construct the recombinant primate lentivirus-short hairpin RNA-pleiotrophin (pLV-shRNA-PTN) vector, to investigate the silencing effect of pLV-shRNA-PTN on PTN expression in MIA PaCa-2 cells and to observe the inhibition efficiency of pLV-shRNA-PTN on neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro. The construction procedure for recombinant lentivirus pLV-shRNA-PTN has been described previously. In the present study, pLV-shRNA-PTN was used to infect MIA PaCa-2 pancreatic cancer cells and the efficiency of the knockdown of the PTN gene on day 7 following infection was analyzed using western blotting. The morphological changes in the cultured DRG neurons were observed by monoculture of DRG neurons and co-culture with MIA PaCa-2 cells in vitro. The recombinant lentivirus pLV-shRNA-PTN was successfully constructed. The western blot analysis showed that the inhibition rates of PTN expression were 46, 80, 20 and 21%, respectively, following pLV-shRNA-PTN-A, B, C and D infection. pLV-shRNA-PTN-B showed the highest knockdown efficiency. DRG neurons co-cultured with infected MIA PaCa-2 cells were decreased in size when compared with the control, and there was a significant decrease in the number and length of neurites. The results suggest that efficient and specific knockdown of PTN in MIA PaCa-2 pancreatic cancer cells and the subsequent reduction in PTN expression results in the inhibition of neurite outgrowth from DRG neurons.