Abstract: Objective To explore the effect of siRNA targeting deubiquitinating enzyme 3 （Dub 3） gene on the proliferation and apoptosis of human nasopharyngeal carcinoma CNE-2 cells. Methods After the optimization of the transfection conditions， 2 siRNA vector fragments （siRNA-1 and siRNA-2） targeting Dub3 gene were effectively transfected into CNE-2 cells， respectively. There were empty transfection group whose cells were transfected with the antisense sequence and control group without any treatment. The Dub3 expression levels were detected by real-time quantitative PCR （qPCR） at 24， 48， 72 and 96 h after transfection， and the siRNA vector with the higher inhibition rate was used for the following experiments. Thiazolyl blue was used to detect the proliferation inhibition rates at 24， 48， 72， 96 h after transfection. The apoptosis and cell cycle of the cells were detected by flow cytometry after 48 and 96 h. The expression of cell division cycle 25A （Cdc25A） after 96 h was detected by Western blotting.
Results The levels of mRNA Dub3 in the transfection group were lower than those in the empty transfection group and the control group （P＜0.05）. Since the interference efficiency of the siRNA-1 fragment was higher than that of the siRNA-2，so the subsequent experiments chose the siRNA-1 fragment. Compared with other two groups，the proliferation inhibitory rates， apoptosis rates and caspase-3 activation rates together with the proportion of cells in G0/G1 phase increased， but the proportion of cells in S and G2/M phase decreased in inhibition group with statistically significant difference （P＜0.05）； After transfection，the levels of Cdc25A were decreased in inhibition group versus other groups （P＜0.05）. Conclusion The inhibition of Dub3 gene expression by siRNA can inhibit the proliferation and induce apoptosis and cell cycle arrest， and it can be valuable for the prevention and treatment of nasopharyngeal carcinoma.