The influence of pancreatic cancer cells on the apoptosis, cytotoxic activity, and cytokines secretion of NK cells.
B) Percentages of apoptotic NK cells exposed to normal pancreatic cells compared those exposed to pancreatic cancer cells. (C) Flow cytometric analysis of the percentages of apoptotic K562 cells treated with NK cells, either cultured alone or with normal pancreatic cells or cancer cells, at an effector-to-target (E/T) ratio of 9:1. (D) The percentages of apoptotic K562 cells at different E/T ratios (1:1, 3:1, and 9:1) show a significant decrease in K562 cell apoptosis after treatment with NK cells exposed to pancreatic cancer cells compared to those exposed to normal pancreatic cells. (E,
G). The concentrations of GM-CSF, TNF-α and IFN-γ in the supernatants from the different NK cell-pancreatic cell culture groups. All experiments were repeated three times. All data were expressed as mean ± SD. Independent t-tests were used for statistical analysis through SPSS 19.0 software. *represents P <0.05, **represents P <0.01, and ***represents P <0.001.