Objective    To construct the small interfering RNA (siRNA) retrovirus vector targeting GW112  with a high specificity and to study the effect of silencing GW112 gene on the proliferation of gastric SGC-7901 cells.     Methods    Three recombinant RNAi interference vectors were constructed according to different GW112 targeting points (pSi405-GW112

pSi1066-GW112

pSi1480-GW112) using a retrovirus expression vector

psilencer 5.1-H1 Retro. SGC- 7901 cells were infected with a packaged PT67 cells transfected with liposome. Stable clones were selected using puromycin. Integration of virus was identified by RT-PCR and highly inhibited targets were detected RT-PCR. The effect of GW112 on proliferation of gastric SGC-7901 cells was detected with CCK-8 kit. Expression of proliferating cell nuclear antigen (PCNA) was assayed by Western blotting.     Results    Sequence analysis showed recombinant retrovirus vector psiRNA-GW112 was successfully constructed. RT-PCR showed that except for parental cells

other SGC-7901 cells infected with virus supernatant could amplify anti-puromycin GW112 gene into a 510 bp fragment. The inhibitory efficacy was 84.5%，67.6%

and 43.0%

respectively

for Si405

Si1066 and Si1480 respectively. Both the proliferation of gastric SGC-7901 cells and the expression of PCNA in SGC-7901 cells were significantly inhibited after GW112 was silenced.     Conclusion    The recombinant retrovirus vector

pSiRNA-GW112

  can significantly inhibit the proliferation and expression of PCNA in SGC-7901 cells

indicating that GW112 plays an important role in proliferation of SGC-7901cells.