Objective:To observe the proliferative and apoptotic effects of RNAi-mediated NF-κB P65 gene on silencing pancreatic carcinoma cell strain PANC-1. Methods:Chemically synthesized small interference RNA(siRNA) directed against human NF-κB P65 was transfected into pancreatic carcinoma cell strain PANC-1 by using cationic liposome LipofectamineTM2000. The expression of NF-κB P65 and cyclinD1 gene was detected by using RT-PCR. The DNA binding activity of NF-κB was detected by the chemicon non-radioactive NF-κB P65 transcription factor assay kit. The effect of cell proliferation was studied by MTT. Flow cytometry was used to detect the apoptosis and cell cycle of transfected cells. Results:The results of RT-PCR indicated that chemically synthesized siRNA could knock down the transcription and expression of NF-κB P65 and cyclinD1 gene. The difference between the RelA siRNA group and control groups was significant(P < 0.01). After transfection,the DNA binding activity of NF-κB P65 in RelA siRNA group was much lower than that in the negative control group and blank control group(P < 0.05). The inhibitory action on proliferation of RelA siRNA group cells was confirmed by MTT and cell cycle test. The apoptotic rate of RelA siRNA group was significantly higher than control groups(P < 0.01) and the cell account during G1 phases increased 10%. During S and G2/M phases the cells account decreased about 4% and 6%. Conclusion:The study provided basis for researching the function of NF-κB P65 gene,indicating the expression of NF-κB down-regulating might inhibit proliferation and induce apoptosis in pancreatic carcinoma cell strain PANC-1.