Abstract: Objective To explore the influence of FAM21 on migration and invasion properties of choriocarcinoma cell line JEG-3. Methods Two FAM21specific small interfering RNA（siRNA1 and siRNA2） and one scramble siRNA（control siRNA） were designed. According to the experimental design， the JEG-3 cells with stable transfection of siRNA1， siRNA2 and control siRNA were assigned into three groups： siRNA1 group， siRNA2 group and control siRNA group. The JEG-3 cells without transfection were selected as blank（blank group）. FAM21 mRNA levels of JEG-3 cells and human trophoblast HTR-8/Svneo cells were detected by normal PCR. The quantitative PCR and Western blotting were employed to measure the FAM21 mRNA level at 24h after transfection and protein level at 48h after transfection of each group， respectively. The migration and invasion properties of each group at 24h after transfection were detected by Transwell method. The quantitative PCR was employed to detect the mRNA levels of invasion-related genes（KISS-1， BRMS1 and INSL4） at 24h after transfection. Results There was a higher mRNA level of FAM21 in JEG-3 cells versus HTR-8／Svneo cells （P＜0.05）. The FAM21 mRNA level at 24h and FAM21 protein level at 48h after transfection of siRNA1 and siRNA2 groups were lower than those of control siRNA group and blank group with significant differences（P＜0.05）. There were lower migration and invasion properties in siRNA1 and siRNA2 groups versus control siRNA group and blank group at 24h after transfection（P＜0.05）. There were decreased mRNA levels of KISS-1 and BRMS1 and increased level of INSL4 in siRNA1 and siRNA2 groups versus control siRNA group and blank group at 24h after transfection（P＜0.05）. No significant difference was observed on the above indicators between control siRNA group and blank group（P＞0.05）.
ConclusionFAM21 protein can regulate the migration and invasion properties of the choriocarcinoma cell line JEG-3， which plays an important role in the pathogenesis of choriocarcinoma.