The Research On The Effects And Mechanism Of CADM1 Ovarian Cancer

Background:The main metastatic route of ovarian cancer(OC)is implantation metastasis.Adhesion change is a key link in tumor metastasis.CADM is an adhesion molecule belongs to glycoprotein and located on the cell surface.CADM mediates intercellular adhesion through calcium-independent homologous trans-interaction.CADM1over-expression can inhibit EMT induced by cell growth factor.While CADM1 losses can lead to invasion and/or metastasis of epithelium-derived cancer cells.Whether CADM1 is involved in the occurrence and development of OC? Whether it has an effect on the biological behavior of OC cells? How do CADM1 play a role in tumor inhibition and its upstream and downstream regulation mechanism are rarely reported.Objective:The mechanisms of CADM1 affect development and metastasis of OC from tumor clinical pathology,cell behavior and gene expression will be discussed in this study.The expression of CADM1 in ovarian tumor tissue samples will be detected.The changes of cell biological behavior of OC cell lines with over expression and silencing expression of CADM1 will be analyzed.And the gene expression profile of ovarian cancer cell line with CADM1 over expression will be detected.Methods:(1)The expression of CADM1 will be detected by immunohistochemistry from a total of 132 ovarian tumor tissue samples.And the expression of CADM1,MPP6,MMP2 and MMP9 will be detected by Western bloting.The relationship between these factors and the pathogenesis,pathology and clinical indexes of ovarian tumor will be explored.(2)Lentivirus vectors will be constructed with over expression and silencing of CADM1,and infected ES-2 and HO-8910 ovarian cancer cell lines,respectively.Cell proliferation will be detected using CCK-8,apoptosis will be detected by flowcytometry,and cell migration will be detected by Transwell and cell scratch assay.The function and the effect of CADM1 on OC cells will be investigated.(3)The gene expression profile of CADM1-over-expressed of ES-2 cells will be detected using high-throughput expression microarray technology.And the mechanism of CADM1-regulated cells will be explored through analyzing the up-regulated or down-regulated genes and pathways related to CADM1.Results:(1)The positive expression rate of CADM1 in ovarian epithelial carcinoma(n=74,37.25%)was significantly lower than that in ovarian benign tumors(n=34,82.34%)and ovarian borderline tumors(n=24,79.11%)(P<0.001).(2)The expression of CADM1 and MPP6 in ovarian cancer tissue was lower than that in benign ovarian tumor and borderline tumor tissue(P<0.01).The expression of MMP2 and MMP9 in ovarian cancer tumor tissue was higher than that in benign ovarian tumor and borderline tumor tissue(P<0.05).(3)The CADM1 over-expressed and silenced expression of lentivirus(RNAi)vector was constructed successfully.The apoptosis rate in the over-expression group was slightly higher than that in the control group(P<0.05).The activity,the number of cell clones and the invasion ability of over-expression of CADM1 group were lower than those in the control group(P<0.05 or P<0.01).These results suggested that over-expression of CADM1 can inhibit tumor cells.The cell activity of the silenced expression group was higher than control(P<0.05).The number of cell clones,the number of metastatic cells and the 24 h cell migration rate in the gene silencing group were all higher than those in control(P<0.05).(4)High-throughput mRNA microarray technology showed that 84 genes were significantly up-regulated and 46 genes were significantly down-regulated in CADM1over-expressed ES-2 cells.Among them,C4 BPA,IFI44L,TGFBI,and RCN3 related to CADM1 were significantly up-regulated,APP,EDN1,FXYD2,IGF1,and Rap1 A genes related to CADM1 were significantly down-regulated,and LXR/RXR Activation pathway was significantly activated.Conclusion:(1)The expression of CADM1 in OC was lower than that of ovarian benign tumor and ovarian junction tumor,suggesting that CADM1 can reflect the benign and malignant degree of ovarian tumors and it is related to the malignant progression of tumors.(2)When CADM1 is overexpressed and silenced in OC cells,it significantly affects the biological behavior of OC cells,indicating that CADM1 can inhibit the proliferation and migration of OC cells.The results suggest that CADM1 is a functional tumor suppressor gene.(3)When CADM1 is overexpressed in OC cells,it can promote up-regulation of84 genes and down-regulation of 46 genes.The mechanism of the effect of CADM1 on OC may be related to the up-regulation of the expression of C4 BPA,IFI44L and TGFBI and the activation of the LXR/RXR pathway,leading to the inhibition of the downstream PI3K/Aktm/TOR signaling pathway,and the feedback of the up-regulation of the expression of TGFBI and the activation of the ROS/JNK pathway,inducing the apoptosis of OC cells and inhibiting the proliferation and metastasis of OC.