〔Abstract〕 Objective To explore the impact of 4-amino-2-trifluoromethyl-phenyl retinate(ATPR),a derivative of all-trans retinoic acid, on the motility of human gastric cancer cell line BGC-823 and the possible mechanisms involved under high-level insulin. Methods Firstly,BGC-823 cells were treated with various concentrations of insulin. Cell counting kit-8( CCK-8) assay was used to detect the effect of insulin on cell proliferation. Then,BGC-823 cells were treated with ATPR combined with different concentrations( with no effect on cell growth but could simulate the high insulin level of humans) of insulin. Wound healing and Transwell assays were used to measure the motility of BGC-823 cells under different treatments. Finally,Western blot assay was performed to detect the expression of proteins related to cell migration. Results CCK-8 results showed that,compared with the control group,0. 5 ng/ml and 5. 0 ng/ml insulin had no effect on proliferation of BGC-823 cells after 48 hours while 10. 0 ng/ml insulin significantly promoted the cell proliferation. Wound healing and Transwell assay showed that 5. 0 ng/ml of insulin promoted the migration of BGC-823 cells,however,ATPR reversed the effect of insulin on BGC-823 cells motility,which could also be attenuated by a specific inhibitor of myosin light chain kinase( MLCK)-ML-7. Western blot revealed that insulin upregulated the expression of MLCK while downregulated Claudin 18. But,after ATPR treated,the protein expression of MLCK was inhibited while the expression of Claudin 18 increased. Conclusion ATPR can reverse the effect of high-level insulin on the motility of BGC-823 cells,which may be attributed to the regulation of ATPR on MLCK and Claudin 18 under high-level insulin.