Effect of down-regulating the PKR gene on the proliferation and apoptosis of pancreatic AR42J cells and its mechanism

Abstract:

Objective：To investigate the effect of down-regulating the PKR gene on the proliferation and apoptosis of pancreatic AR42J cells and its mechanism. Methods：AR42J cells were treated with cerulein to establish an acute pancreatitis model，in which the cells with the down-regulated PKR gene mediated by a lentiviral vector were taken as experimental group，and the cells trans－fected with control virus were taken as control group. The cells were tested for proliferation by cell counting kit（CCK-8） and colony formation assay and for apoptosis by flow cytometry（FCM）；the changes in the expression of key genes of the nuclear factor-κB（NF-κB） pathway were measured by both qRT-PCR and FCM. Results：Compared with the control group，the experimental group had significantly reduced relative expression of key genes[NF-κB，tumor necrosis factor-α（TNF-α），interleukin-6（IL-6），and iNOS] of the NF-κB pathway（0.45±0.08，0.26±0.05，0.51±0.25，and 0.38±0.04，respectively，t=7.64，16.41，6.67，and 10.15，respectively，all P<0.05）；the experimental group had significantly enhanced colony formation ability than the control group（colony count：275.33±7.02 vs. 36.00±4.00，t=51.29，P=0.00）；the result of CCK-8 assay showed a significantly enhanced cell proliferation ability in the experimental group compared with the control group，with the cell proliferation rates at 24 h，48 h，and 72 h as （25.00±3.00）%，（50.33±4.04），and （62.33±4.51）%，respectively，for the experimental group versus（12.33±1.53）%，（17.00±1.00）%，and （24.00±2.00）%，respectively，for the control group（t=6.52，13.87，and 13.46，respectively，all P<0.05）. Compared with the control group，the experimental group had significantly reduced values in both early apoptosis rate[（13.4±0.9）% vs. （6.2±0.6）%，t=11.53，P=0.00] and late apoptosis rate[（12.2±0.5）% vs. （4.1±0.2）％，t=26.05，P=0.00]. Conclusion：Down-regulating the PKR gene can slow down the cellular inflammatory response by suppressing the NF-κB pathway，leading to reduced apoptosis and enhanced proliferation of AR42J cells.