Abstract: Objective To research the interaction between ribonuclease inhibitor(RI) and integrin-linked kinase(ILK) and its effect on angiogenesis in vitro. Methods To construct YFP-ILK and pCMV-3×flag-ILK plasmid. Purchase lentiviral expres-sion vector LV5-RNH1 homo and LV5NC.Stably transfect vectors into EJ cells repectively, and the selected cells were named as EJ-RI, EJ-ILK, EJ-LV5, EJ-FLAG and EJ. Fluorescence microscope analysis was used to observe the co-location between RI and ILK in 293 cells and EJ cells. The interaction between RI and ILK in 293 and EJ cells was identified by glutathione-S-transferase (GST) pull-down assay and co-immunoprecipitation assay. Endothelial tube formation assay was used to assess angiogenesis in vitro. Results The expressing plamid YFP-ILK and pCMV-3×flag-ILK were verified by restriction enzyme digestion and DNA sequencing.We found that RI was co-localized with ILK in 293 and EJ cell. Glutathione-S-transferase (GST) pull-down and co-immunoprecipitation results showed that the interaction between RI and ILK occurred in prokaryotic cells and mammalian cells as well. RI can inhibit angiogenesis in vitro by interacting with ILK.Conclusion The interaction between RI and ILK occurs in prokatyotic cells and mammalian cells and inhibits angiogenesis in vitro.

Key words: ribonuclease inhibitor, integrin-linked kinase, interaction, angiogenesis