Abstract: Objective To investigate the role of TROP2 in migration and invasion of human gastric cancer cells. Methods Small interfering RNA（siRNA）targeting TROP2 gene was constructed by gene clone technology and transfected into gastric cancer cell line BGC-823. The expressions of mRNA and protein were detected by Real-time quantitative PCR and Western blot assay after RNA interference. The proliferation capability was determined by MTT assay. Transwell assay was performed to assess the effect of TROP2 targeted RNA interference on the migratory and invasive properties of gastric cancer in vit ro. Results 　Enzyme digestion analysis and DNA sequencing showed that TROP2 targeted RNA interference recombinant plasmids were constructed successfully. The most effective recombinant plasmid was selected. After transfection , knockdown of TROP2 significantly impaired the proliferation ，migration and invasion capability of BGC-823 cells in vit ro（P < 0. 05）.Conclusion 　Interfering and down-regulating TROP2 gene can inhibit migration and invasion of gastric cancer cell line BGC-823，indicating that TROP2 gene is probably a target for gastric cancer gene therapy.

Key words: gastric carcer, TROP2, RNA interference, migration, invasion