Objective:To investigate the inhibiting effects of shRNA (short hairpin RNA, shRNA) on COX-2 gene expression, the cell cycle and growth of gastric carcinoma SGC-7901 cells.
Methods:Specific shRNA plasmid to COX-2 were constructed, and then transfected into SGC-7901 cells by lipofectamine methods. Tests were divided into three groups: untransfected gastric carcinoma SGC-7901 cells group, negative control HK group and pshRNA-COX-2 group. Gastric carcinoma SGC-7901 cells were transfected with LipofectamineTM 2000. Expression of COX-2 mRNA and protein were detected with reverse transcriptional polymerase chain reaction (RT-PCR) and Western blot respectively. Cell cycle analysis and cell growth chart were detected with flow cytometry and cell count respectively.
Results:Compared with negative control HK group, recombinant expression vector pshRNA-COX-2 resulted in the reduction of COX-2 mRNA and protein expresion by 70.1% and 43.2% respectively; cells in G0-G1 phase  increased from 61.5％to 70.2％, cells in S phase decreased from 27.3％ to 21.7％, and the growth of SGC-7901 cells cells was slowed significantly.
Conclusions:Recombinant expression vector  pshRNA-COX-2 can significantly inhibit the expression of COX-2 gene, result in the  increase of cells in G0-G1 phase and decrease of cells in S phase, and suppress proliferation of gastric carcinoma SGC-7901 cells.