Penter cd26 plasmid

To overexpress DPP4 in PCa cells, 3 μg of the pENTER‐CD26 plasmid (Vigene Biosciences) was transfected into PC3 cells cultured in a 6‐mm² Petri dish using Lipofectamine 3000 Transfection Reagent (Invitrogen) for 6 h according to the manufacturer's instructions. An empty vector transfected into PC3 cells was used as the control group. At 24 h after transfection, cells were analysed for DPP4 expression and migratory/invasive abilities.

siRNA for human CD26 (s4245) was obtained from Thermo Fisher Scientific. The pENTER-CD26 plasmid was obtained from Vigene Biosciences (Rockville, MD), and the myr-Akt, pLEX-Snail, and pCIneo-Slug plasmids were obtained from Dr. C.C. Chen and Dr. T.C. Kuo (National Taiwan University, Taipei, Taiwan). To knock down CD26 or overexpress CD26, Akt, Snail, or Slug, semiconfluent cultures of NSCLC cells in a 6-mm² Petri dish were transfected with 50 nM of siRNA using GenMute™ siRNA Transfection Reagent (SignaGen Laboratories, Gaithersburg, MD) or 3 μg of an empty or expression vector using Lipofectamine 3000 Transfection Reagent (Invitrogen, Carlsbad, CA) for 6 h according to the manufacturer’s instructions. At 24 h after transfection, cells were analyzed for invasion/migration and expressions of CD26, Snail, Slug, and p-Akt.