Abstract: ［Abstract］Objective〖HTSS〗To observe the effect of inhibiting the expression of PLK1 gene on invasion and metastasis of gastric cancer AZ521 cells, and to explore the feasibility and related mechanism of PLK1 gene for gastric cancer therapy.
  〖WTHZ〗Methods〖HTSS〗siRNA interference technology was used to inhibit PLK1 gene expression. The expression of PLK1 mRNA in AZ521 cells was detected by real-time fluorescent quantitative PCR. PLK1, MMP-9, E-cadherin and Vimentin protein expression in AZ521 cells were detected by Western blot. The cell cycle distribution of AZ521 was detected by flow cytometry. Transwell the experiment was used to examine the effect of AZ521 cell invasion ability.
  〖WTHZ〗Results〖HTSS〗The expression level of PLK1 mRNA in siRNA group was significantly lower than that in control group(P＜0.05). The expression of MMP-9 and Vimentin protein was down-regulated, E-cadherin protein expression was significantly up-regulated（P＜0.05）. The G2/M phase cells in the siRNA group were significantly higher than the control group. The S phase cells were significantly lower than the control group(P＜0.05) . There was no significant difference in the G0/G1 phase cells between two groups(P＞0.05). Compared with the control group, The number of transmembrane cells in AZ521 cells in siRNA group was significantly decreased(P＜0.05).
  〖WTHZ〗Conclusion〖HTSS〗PLK1 siRNA can block the expression and function of PLK1, and PLK1 plays an important role in the growth, invasion and metastasis of gastric cancer．

Key words: stomach neoplasms； PLK1 gene, cell cycle