The Effects Of Growth By Down-regulating Expression COX3Gene In GES-1and SGC7901Cell Lines

Objective: To observe the cell proliferation and apoptosis after down-regulationCOX3gene by RNA interference in GES-1and SGC7901cell lines, and to explorethe mechanism of COX3in the development of gastric cancer.Methods: The target Interference sequence for COX3was cloned into thepcDNA6.2-GW/EmGFPmiR expression vector, and the recombinant plasmid(thenegative control and siRNA-COX3plasmid) was transfected into GES-1andSGC7901cell with lipofectamineTM2000. The expression of COX3mRNA inGES-1å'ŒSGC7901after down-regulation COX3gene was examined by RT-PCR,established COX3gene down-expression stable cell lines. Experiment groups weredivided into control group(untransfected plasmid), blank group (negative controlplasmid), interference group (transfected with siRNA-COX3plasmid).The influenceof cell proliferation of GES-1and SGC7901after inhibition COX3expressin wasobserved by growth curve and colony formation assay. The O2-Level in GES-1andSGC7901cell was detected by Dihydroethidium in order to observe the change ofROS after down regulateing COX3gene. Apoptosis was examined by flow cytometry.Results:The recombinant plasmid was detected by sequencing analyze, the result wascompletely coincidence as well as designed sequences. RT-PCR revealed thattransfected siRNA-COX3plasmid notably inhibited the expression of COX3mRNAlevel in GES-1and SGC7901cells, the cell lines with COX3down-expression wereconstructed.Growth curve showed that, the growth rate of GES-1-siRNA-COX3cell wasstriking higher than the control group and negative control group, the difference wasstatistically significant(p <0.05). There wasn’t obviously variation between the groupsof SGC7901cell (p>0.05).The clone formation show that, the clone formation rate in GES-1-siRNA-COX3 and SGC7901-siRNA-COX3was higher than the other two groups, the difference wasstatistically significant (p<0.05).The O2-Level of GES-1-siRNA-COX3cell and SGC7901-siRNA-COX3cellwas remarkably higher than the other two groups (p<0.05).The flow cytometry shows that, compared with the control group (4.87%,4.56%) and the negative control groups(9.57%,7.70%), The apoptosis rate ofGES-1-siRNA-COX3(13.50%) and SGC7901-siRNA-COX3(10.09%) increased.but statistical analysis show the difference was not significant (p>0.05).Conclusions:1. Down-regulated expression COX3gene can promote the proliferation ofGES-1.2. Down-regulated expression COX3gene can enhance ROS level in GES-1and SGC7901cell.3. Down-regulated expression COX3gene have no influences on apoptosis toGES-1and SCG7901.