Overexpression of LVRN impedes the invasion of trophoblasts by inhibiting epithelial-mesenchymal transition.

Laeverin (LVRN) was first detected on the outer layer of the chorion laeve and migrating extravillous trophoblasts (EVTs). It is an enzyme that plays an important role in the placentation and pathophysiology of preeclampsia (PE). Previous studies have indicated that LVRN may be required for the invasion of human trophoblast cells. Paradoxically, LVRN was found to be highly expressed in the trophoblasts of PE patients with impaired invasive capacities. In this study, we detected the expression of LVRN in the placentas of PE patients (n=5) and normal term pregnancy women (n=5) as a control group by immunohistochemistry. LVRN was elevated in decidua (P=0.0083) and villi (P=0.0079) of PE patients. Next, LVRN was overexpressed via adeno-associated virus-mediated gene transfer in trophoblastic cell lines HTR8, Swan71, and JAR. Matrigel transwell assay and wound healing assay showed that overexpression of LVRN impeded the invasion of these three cell lines. Western blot analysis showed that LVRN overexpression caused downregulation of N-cadherin and vimentin and upregulation of E-cadherin, suggesting the inhibitory role of LVRN in epithelial-mesenchymal transition (EMT). Moreover, our data indicated that long noncoding RNA NONSTAT103348 (lnc10-7) was elevated in PE patients. Silencing lnc10-7 led to decreased LVRN expression. Taken together, although the basal level of LVRN may be crucial for cell invasion, overexpression of LVRN may abrogate the cell invasiveness, suggesting a multifaceted role of LVRN in the pathogenesis of PE.

CD44 Expression Predicts Prognosis of Ovarian Cancer Patients Through Promoting Epithelial-Mesenchymal Transition (EMT) by Regulating Snail, ZEB1, and Caveolin-1.

Objectives: CD44, a transmembrane glycoprotein, is involved in the generation of a stem cell niche and maintaining stem cell quiescence. The aim of this study was to evaluate its contribution to ovarian cancer prognosis and progression, as well as explore the possible mechanisms. Materials and Methods: The expression of CD44 in tissue microarray of 90 ovarian cancer patients was detected by immunohistochemistry. Kaplan-Meier method and Cox proportional hazard model were used to evaluate the factors associated with 5-year overall survival and disease-free survival. CD44 was knocked down by small interfering RNA, the expression of Snail, ZEB1, and Caveolin-1 in a stable Snail-expressing ovarian cancer cell line HO8910PM-Snail (HOPM-Snail) and its control cell line HO8910PM-vector (HOPM) was detected by western blotting analysis. Cell clone formation, migration, and invasion of HOPM-Snail and HOPM cells with CD44 silencing were examined by 3-D culture assay, wound healing assay, and transwell assay, respectively. Results: Over-expression of CD44 was associated with advanced histological grade (p = 0.014) and FIGO stage (p = 0.001). Multivariate analysis showed that CD44 expression was an independent prognostic factor to predict both overall survival (p = 0.004) and disease-free survival (p = 0.025) of ovarian cancer patients. Down-regulation of CD44 expression by small silencing RNA abrogated both basal Snail expression and TGF-ß1-induced Snail expression in HOPM and HOPM-Snail cells. In addition, CD44 knockdown caused a decrease in ZEB1 expression. RPPA data indicated that Caveolin-1 may be another regulative target of CD44, and western blotting analysis confirmed that CD44 knockdown caused an increase in Caveolin-1 expression. However, there was no noticeable reciprocal regulation among ZEB1, Caveolin-1, and Snail. Moreover, CD44 knockdown caused a decrease in cell clone formation, migration, and invasion of HOPM and HOPM-Snail cells. Conclusions: As both Snail and ZEB1 are crucial inducers of epithelial-to-mesenchymal transition (EMT), our data suggested that CD44 may be crucial for the EMT process of ovarian cancer. Therefore, CD44 may be a potential prognostic marker as well as treatment target for ovarian cancer.

ß-catenin/LIN28B promotes the proliferation of human choriocarcinoma cells via Let-7a repression.

Choriocarcinoma is a rare and malignant trophoblastic tumor. However, the molecular mechanisms by which choriocarcinoma is regulated remain unknown. In the present study, we first elucidated that LIN28B was highly expressed in human choriocarcinoma tissues and choriocarcinoma cell lines. Our data further demonstrated that knockdown of LIN28B by small interfering RNA caused an increase in Let-7a expression in JAR cells. In addition, silencing of LIN28B inhibited IGF2BP1 expression and suppressed cell proliferation capacity, both of which can be markedly restored by Let-7a inhibitor. In contrast, LIN28B over-expression-improved cell proliferation was inhibited by Let-7a mimic. Knockdown of ß-catenin resulted in reduced expression of LIN28B and increased expression of Let-7a. Knockdown of ß-catenin also caused a decrease in cell proliferation, which can be recovered by re-expression of LIN28B or by Let-7a inhibitor. Collectively, our data indicate that ß-catenin/LIN28B/Let-7a pathway may be crucial for the regulation of cell proliferation in human choriocarcinoma cells.

Aberrantly Expressed SALL4 Promotes Cell Proliferation via ß-Catenin/c-Myc Pathway in Human Choriocarcinoma Cells.

Sal-like protein 4 (SALL4) has been proved to play a pivotal role in the development and progression of various cancers. Previous studies showed that SALL4 was highly expressed in human choriocarcinoma tissues. However, the role of SALL4 in the biological behavior of human choriocarcinoma cells remains largely unknown. In this study, we first elucidated that SALL4 was highly expressed in human choriocarcinoma cell line JEG-3 and JAR. Sal-like protein 4 knockdown by small interfering RNA (siRNA) decreased c-Myc expression, whereas SALL4 overexpression by transfection of human pLenti-SALL4 construct promoted c-Myc expression. Further data showed that SALL4 overexpression improved cell proliferation of JEG-3 cells, which can be abrogated by c-Myc siRNA. Moreover, our data showed that SALL4 interact with ß-catenin and SALL4 overexpression promoted the localization of ß-catenin in the nucleus and ß-catenin siRNA abrogated SALL4-induced c-Myc expression in JEG-3 cells. These data indicate that aberrantly expressed SALL4 in human choriocarcinoma cells may promote cell proliferation via ß-catenin/c-Myc pathway, indicating that SALL4 may be potential treatment targets of human choriocarcinoma.