Study Of Oxsterol Binding Protein-related Protein 9(ORP9)Promotes Migration And Invasion In Hepatoma Carcinoma Cells

Oxysterol binding protein related protein family(ORPs) is a kind of protein family that contains an oxysterol binding domain and widely exists in eukaryote cells. Many studies of the function of ORPs showed that ORPs play roles in a lot of living cells, including regulation of lipid metabolism, transportation of steroid substances, etc. ORP9 is a member of the protein family, but so far, we knew little about the biological function of ORP9. All we know is that ORP9 expresses in Marcophage and has relationship with the metabolism of blood glucose and lipids. We found that ORP9 highly expresses in HCC tissues, and ORP9 expresses lowly in normal liver tissues. Thus, we speculatedthat ORP9 has relationship with the occurrence and development of Hepatocellular Carcinoma. We wanted to make exhaustive studies on ORP9 and to unveil its biological function and molecular mechanism in other human diseases. In this research, we demonstrated m RNA expression and protein expression of ORP9 in HCC tissuesare higher than they in normal liver tissues. Then we confirmed the protein expression of ORP9 in Hepatocellular carcinoma cells is higher than it in normal liver cells. We proved that ORP9 can significantly enhance the ability of migration and invasion in Hepatocellular Carcinoma cells by Wound-Healing, Transwell and Western blot assay. We identified that ORP9 interacted physically with RhoA in HepG2 cells by Co-immunoprecipitation and Immunofluorescence confocal microscopy analysis. Theseresults showed that ORP9 may affect cell migration and invasion by regulating RhoA. In addition, we constructed shNT-MHCC97 H or shORP9-MHCC97 H stable cell lines to detect the effects of ORP9 onHepatocellular Carcinoma cells in Nude mice. We found that the lung metastasis rate was significantly reduced inORP9 knockdown cells. To certain extent, all the findings offered a clue to further investigation of the biological function and the action mechanism of ORP9 in Hepatocellular Carcinoma cells.