Epidermal Growth Factor Stimulates Human Trophoblast Cell Migration through Rho A and Rho C Activation

• Published in: Endocrinology (Philadelphia) 2010-04, Vol.151 (4), p.1732-1742
• Main Authors: Han, Jian, Li, Li, Hu, Jiongyu, Yu, Lili, Zheng, Yingru, Guo, Jianxin, Zheng, Xiuhui, Yi, Ping, Zhou, Yuanguo
• Format: Article
• Language: English
• Subjects: Actin; Actins - genetics; Actins - metabolism; Analysis of Variance; Biological and medical sciences; Blotting, Western; Cell activation; Cell adhesion & migration; Cell Line; Cell lines; Cell migration; Cell Movement - drug effects; Cell Movement - physiology; Cell Proliferation - drug effects; Cell Survival - drug effects; Cell Survival - physiology; Cells, Cultured; Cytoskeleton; Dose-Response Relationship, Drug; Epidermal growth factor; Epidermal Growth Factor - genetics; Epidermal Growth Factor - metabolism; Epidermal Growth Factor - pharmacology; Female; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Gene Silencing; Growth factors; Humans; In Situ Nick-End Labeling; Placenta - drug effects; Placenta - physiology; Pregnancy; Proteins; rho GTP-Binding Proteins - metabolism; Rho protein; rhoA GTP-Binding Protein - genetics; rhoA GTP-Binding Protein - metabolism; RhoA protein; rhoC GTP-Binding Protein; RNA, Small Interfering - metabolism; Signal Transduction - drug effects; Signal Transduction - genetics; siRNA; Trophoblasts - drug effects; Trophoblasts - physiology; Vertebrates: endocrinology; Villus
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2009-0845

This study investigated the roles of Rho protein in epidermal growth factor (EGF)-induced trophoblast cell migration and its mechanism. Using choriocarcinoma cell lines JEG-3 and JAR and first-trimester human chorionic villus explant cultures on matrigel, we examined EGF-mediated stimulation of trophoblast migration. EGF is shown to have a dose-dependent effect on trophoblast migration. A low concentration of EGF (1 ng/ml) has a stimulatory effect on cell migration, whereas high concentrations of EGF (100 ng/ml) shows an inhibitory effect. EGF (1 ng/ml) activates RhoA and RhoC, but not RhoB, through elevated protein levels and activity. EGF-induced migration was shown to be inhibited by either cell-permeable C3 exoenzyme transferase or selective RhoA or RhoC small interfering RNAs. The inhibition was not mitigated by the addition of EGF, suggesting that RhoA and RhoC play an important role in trophoblast migration and are obligatory for EGF action. Treatment of JEG-3 and JAR cells with RhoA small interfering RNA induced F-actin cytoskeleton disruption and cell shrinkage, which is consistent with the effect of C3 exoenzyme transferase, and this action was not mitigated by EGF treatment. RhoC small interfering RNA had no apparent effect on the F-actin arrangement, suggesting that RhoA but not RhoC takes part in the EGF-induced migration through F-actin rearrangement. These results indicate that RhoA and RhoC play more important roles than RhoB in EGF-mediated migration of trophoblast cells, and RhoA but not RhoC regulates this migration through F-actin cytoskeleton reorganization. Rho proteins Rho A and Rho C but not Rho B contribute to the epidermal growth factor-induced trophoblast cell migration in different ways.