Long Noncoding RNA HOTAIR Modulates the Function of Trophoblast Cells in Pre-eclampsia

Objective To investigate the expression of long noncoding RNA (lncRNA) HOTAIR in pre-eclampsia (PE) placentas and its effect on trophoblast cells proliferation, invasion, and apoptosis. Methods The expression of HOTAIR was determined by qPCR for 23 severe PE and 23 normal pregnant women. qRT-PCR was used to detect the efficiency of overexpression and knock-down after the HTR-8/SVneo cells were transfected with HOTAIR overexpression and siRNAs targeting HOTAIR for 24-48 h, respectively. MTT and colony formation assays were used to test the proliferation of HTR-8/SVneo cells transfected. Transwell assay was used to show the migration and invasion ability of HTR-8/SVneo cells transfected. Flow cytometry assay was used to detect the cell apoptosis rate after treatment. Western blot assay was applied to detect the expression level of apoptotic proteins Caspase-3 and BCL-2. Results The level of HOTAIR in severe pre-eclampsia groups was significantly increased compared to normal pregnant placentas (P <0.05). The expression of HOTAIR in HTR-8/SVneo cells after transfected with pcDNA-HOTAIR was 51.27-fold than that of control; while inhibition of HOTAIR was more than 95% in si-HOTAIR than that of control. According to the MTT and colony formation assays, we found that cells proliferation rate of cells were significantly decreased in overexpression HOTAIR group while increased in si-HOTAIR group when compared with control, respectively. The transwell assay showed that the invasive capacity of HTR-8/SVneo cells in cells transfected with pcDNA-HOTAIR decreased, while increased in si-HOTAIR transfected cells when compared with that of control. The apoptosis rate in cells transfected with HOTAIR overexpression was apparently more than that of control, while less in cells treated with si-HOTAIR. Western blot assay showed that the Caspase-3 showed an obvious increase in HOTAIR overexpression group while decreased in si-HOTAIR group. And BCL-2 presented an opposite trend. Conclusion HOTAIR is probably involved in the onset of preeclampsia by regulating proliferation, invasion and apoptosis of trophoblast cells．