Objective   To investigate the effects of survivin down-regulation on the biological behavior of adenoid cystic carcinoma cells and the relationship with caspase-3.     Methods   Small interfering RNA (siRNA) was designed and synthesized for the construction of eukaryotic expression vector pGenesil-shRNA-survivin. The recombinant plasmid was transfected into ACC-2 cells. The positive clones were screened with G418. The expressions of survivin and caspase-3 mRNA and protein were detected by RT-PCR and Western blot. The proliferation of adenoid cystic carcinoma cells was detected by MTT. Cell apoptosis was detected by TUNEL assay and transmission electron microscopy.     Results   The recombinant plasmid was successfully constructed. Down-regulation was found in the expressions of survivin mRNA and protein (P0.05)

but up-regulation in the expressions of caspase-3 mRNA and protein (P0.05). There was a negative correlation between the mRNA and protein expression of caspase-3 and survivin (r=-0.333

P0.05). ACC-2 cell proliferation was inhibited. TUNEL assay and transmission electron microscopy showed typical apoptosis of cells.     Conclusion    The RNAi eukaryotic vector pGenesil-shRNA-survivin was constructed successfully. Recombinant plasmid pGenesil-shRNA-survivin can inhibit the proliferation of adenoid cystic carcinoma cells.