Function Of CD82, A Metastasis Suppressor, In The Differentiation Of Placental Trophoblast Cells

Background: The placental trophoblast cells play an important role infeto-maternal communications during embryo implantation and placentation.Well-controlled trophoblast differertiation and invasion into maternal uteriewall during early human placental development are the prerequisite forsuccessful pregnancy. Although many hormones, growth factors andcytokines have been reported to be involved in trophoblast invasion andmigration, the mechanisms of trophoblast differentiation need to be furtherinvestigated. Any dysregulation of trophoblast differentiation may lead topregnancy-related diseases such as recurrent abortion, choriocarcinoma,pre-eclampsia and fetal growth restriction. CD82gene, a member of tumormetastasis suppressor factors, plays an important role in inhibiting invasionand metastasis of cancer cells. Comparative research shows that there arestriking similarities in behavioral patterns between invasive trophoblasticcells and cancer cells. CD82presents a regular expression in the mouseuterus in the early period of pregnancy (day1-day8) in our previous research.However,the role of CD82in human trophoblast differentiation is not clear.Objectives: To research the effects of metastasis suppressor CD82ontrophoblast cell migration and invasion in HTR8/SVneo cell line.Methods:1. Immunohistochemistry was used to dectect the expressionof CD82in human placental villi at different stage of pregnancy2.Containing human full length CD82gene was constructed in Flag-CMV4plasmid.3. The interference efficiency CD82siRNA fragments werescreened to knockdown the expression of CD82.4. Placental villi explantsculture model was used to detect the effect of CD82on migration ofextravillous trophoblast cells.4. Matrigel invasion and transwell migrationmodels were used to detect the effect of CD82on invasion and migration.5.gelatin zymography was used to dectect the expression of MMPs in culturemediaï¼›Western blotting was used to dectect the expression of TIMP-1and-2.Results:1. CD82was found to be strongly expressed in human firsttrimester placental villous and extravillous trophoblast cells as well as introphoblast cell lines.2. CD82was overexpressed in the cells transfectedwith CD82plasmids; the expression of CD82was knockdown in the cellstransfected with siRNA.3. CD82siRNA significantly promoted outgrowthof villous explants in vitro (P<0.01)4. Knocking-down CD82expression bysiRNA significantly promoted invasion and migration of HTR8/SVneo cells(P<0.05). In contrast, over-expression of CD82markedly inhibited cell invasion and migration (P<0.05), whereas the trophoblast proliferation wasnot affected.5. CD82regulated migration and invasion through gelatinolyticactivities of matrix metalloproteinase MMP-9and tissue inhibitors of MMPs(TIMP)-1and-2.Conclusion: These results suggest an important role of CD82inregulation of the invasion and migration of human trophoblast cells duringearly pregnancy.