1Women's hospital of Nanjing Medical University Jiangsu Nanjing 210004;2 Center of Eastern Theater for Disease Control and Prevention 210002;3 Department of Internal Medicine, LongHua Hospital affiliated to Shanghai University of Traditional Chinese Medicine Shanghai China 200032 [Abstract] objective :To prepare anti-tyrosine-kinase-like orphan receptor 1 IgG1 (ROR1-IgG1) and the fusion protein of anti-tyrosine-kinase-like orphan receptor 1 and Buthus martensii Karsch recombinant analgesic anti-tumor polypeptide (IgG1-AGAP) and compare their effect on ovarian cancer cells. METHODS: ROR1Fab vectors screened and preserved in our laboratory was used as template to construct ROR1-IgG1 and IgG1-AGAP eukaryotic expression vectors; collecting and purifying expression supernatant of CHO-S cells after transfecting the ROR1- IgG1 and IgG1-AGAP plasmids into the cells, respectively. Their immunological activity was identified and detected by ELISA, Biacore X100, Fluorescence-activated cell sorting (FACS) and immunofluorescence. CCK8, wound healing, Transwell invasion assays were used to analyze the effects of these two kind of antibodies on the HO8910 cells which is one of ovarian cancer cell lines. The expression of relevant markers of epithelial mesenchymal transition (EMT) was detected by Western Blot to evaluate the effects of ROR1-IgG1 and IgG1-AGAP on the migration and invasion of ovarian cancer cells. RESULTS: ROR1-IgG1 and IgG1-AGAP were successfully prepared, the binding efficiency of IgG1-AGAP were similarly as ROR1-IgG1. Both IgG1-AGAP and ROR1-IgG1 inhibited proliferation, migration and invasion of ROR1-positive ovarian cancer cells, and compared with ROR1-IgG1 , IgG1-AGAP can significantly inhibit the proliferation and migration of tumor cells (P <0.05).These effects were not observed in ROR1-negative IOSE386 cells..Western blot results showed that the expression levels of Snail in ROR1-IgG1 group and IgG1-AGAP group decreased compared with the blank control group, while E-cadherin showed the opposite, suggesting that ROR1-IgG1 and IgG1-AGAP can regulate Snail and E-cadherin inhibits EMT in HO8910 cells, thereby inhibiting their migration and invasion. Conclusion: Our findings demonstrate that IgG1-AGAP can target ROR1 expressing ovarian cancer cells effectively and have obvious antitumor activity. IgG1-AGAP could be as an appropriate and promising therapeutic strategy for ROR1-positive human cancers.