Objective To study the effects of the tumor metastasis suppressor gene KAI1 on the adhesion,migration and invasion of human retinoblastoma HXO-Rb44 cell.Methods In this experimental study,the HXO-Rb44 cell was transfected with KAI1 eukaryotic expression plasmid,i.e.pCMV-KAI1,to overexpress KAI1.It was labeled HXO-Rb44-KAI1.The control cells transfected with plasmid vector pcDNA3.1 (+) and no transduction were labeled HXO-Rb44-KAI1/zero and HXO-Rb44,respectively.Forty-eight hours after transfection,the cells were dispersed and the homogeneous adhesion of the cells in the 3 groups was observed by microscopy.Forty-eight hours after transfection,migration and invasion tests were conducted in Transwell chambers with or without Matrigel.The migration and invasion abilities of the cells in the 3 groups were evaluated by counting the cells in the lower wells in 5 high-power fields (HPF) with ×100 magnification.The comparison was made using one-way ANOVA by SAS 8.0 statistical software.Results The expression of KAl1 in HXO-Rb44-KAI1 cells was stronger than HXO-Rb44-KAI1/zero and HXO-Rb44 cells 48 hours after plasmid transfection.The homogeneous cell adhesion ability of HXO-Rb44-KAI1 cells was also stronger than the control cells.The Transwell migration test showed the cell number/HPF in the lower wells was 20.4±4.0,46.0+4.5and 52.1+3.6 in HXO-Rb44-KAI1,HXO-Rb44-KAIl/zero and HXO-Rb44 cells group respectively (F=256.71,P＜0.01).An invasion test showed the cell number/HPF in lower wells was 16.7±3.3,42.5±3.7 and 47.3±5.2 in HXO-Rb44-KAI1,HXO-Rb44-KAI1/zero and HXO-Rb44 cell group,respectively (F=235.12,P＜0.01).Conclusion KAI1 may enhance the homogeneous cell adhesion ability of the HXO-Rb44 cell,and inhibit its migration and invasion ability.