Differntial Expression Of PAK3 In Gastric Cancer Tissues And It’s Effects On Gastric Cancer Cells

Objective: To explore the expression level of PAK3 in gastric cancer tissue and investigate its effect on the growth,migration and invasion of gastric cancer cells.Methods:1.Analyze the differential expression and its regulatory relationship of PAK3 by gene expression profile data.Detect the expression level of PAK3 in paired gastric cancer and normal tissues by western blot,Real-time PCR and immunohistochemistry.2.Generate the gastric cancer cell lines AGS and HGC-27 with PAK3 stable overexpression,western blot was used to verify the expression level of PAK3;Generate the gastric cancer cell lines AGS and HGC-27 with PAK3 silencing.Western blot was used to verify the effect of PAK3 silencing.3.CCK-8 assay(cell viability assay)and plate colony formation assay were performed to evaluate the effects of PAK3 on the proliferation of gastric cancer cells.Wound-healing assay,Transwell cell migration and invasion assay were used to evaluate the effects of PAK3 on on migration and invasion of gastric cancer cells.Results:1.In the gastric cancer expression profile dataset,PAK3 is shown to be down-regulated(p<0.01)and co-related with other differentially expressed genes.Immunohistochemistry,Real-time PCR and western blot analysis showed that the m RNA and protein levels of PAK3 in gastric cancer tissues were lower than those in normal tissues.2.Correlation analysis of PAK3 expression with patients’ clinicopathological characteristics demonstrated that PAK3 expression was negatively associated with the presence of depth of tumor invasion,lymph node metastasis and clinical stage,but positively with differentiation status.The rest of pathologic variables including age,gender,vascular invasion,lymph-vascular invasionand nerve invasion exhibited no significant association with PAK3 expression.Survival analysis showed that patients with low PAK3-expressing tumors had significantly shorter survival than patients with high PAK3-expressing tumors.3.Overexpression of PAK3 had no significant effect on proliferation of gastric cancer cells,as confirmed by CCK-8 assay and plate colony formation experiment.The wound-healing assay showed that the width of the scratch area of the PAK3 overexpression cells was larger than that of the control cells,while the width of the scratch area of the PAK3 silencing cells was less than that of the control cells.The difference was statistically significant(p<0.05).The Transwell migration and invasion assay demonstrated that the cells number in the microporous membrane from PAK3 overexpression cells was less than that from the control cells,while the cells number in the microporous membrane from PAK3 silencing cells was more than that from the control cells.The difference was statistically significant(p<0.05).Conclusion:1.The expression level of PAK3 in gastric cancer tissues is down-regulated;2.PAK3 has no effect on proliferation,but inhibits the migration and invasion capcities of gastric cancer cells.