Preeclampsia is characterized by hypertension and proteinuria twenty weeks into pregnancy. Failure of uterine spiral artery remodeling contributes to preeclampsia's development. The development might be associated with trophoblast cells functioning abnormally. Long non-coding RNAs (lncRNAs) are aberrantly expressed in many diseases. Maternally expressed gene 3 (MEG3), one of these lncRNAs, might function as a tumor suppressor. Aberrant expression of MEG3 induces prenatal death, and little is known of MEG3's role in preeclampsia. This study aims to identify the role of lncRNA MEG3 on apoptosis and the migration of human trophoblast cells, and to investigate the involvement of lncRNA MEG3 in pathogenic mechanisms underlying preeclampsia. In this study, we found MEG3 levels were down-regulated by approximately 80% in placental samples collected from preeclamptic patients (n = 30) compared to samples collected from normotensive patients (n = 30) by qRT-PCR analysis. By designing RNA interference species to suppress MEG3 and specific plasmids designed to over-express MEG3, we explored the role of MEG3 on the functions of two trophoblast cell-lines, HTR-8/SVneo and JEG3 cells. Over-expression of MEG3 reduced apoptosis and promoted migration of HTR-8/SVneo and JEG3 cells. Furthermore, inhibition of endogenous MEG3 increased apoptosis and decreased migration of HTR-8/SVneo and JEG3 cells. Additionally, lncRNA MEG3 influenced expression of NF-κB, Caspase-3, and Bax protein expressions in trophoblast cells. Our findings highlight that abnormal levels of lncRNA MEG3 might lead to aberrant conditions in HTR-8/SVneo and JEG3 trophoblast cells, which might be associated with uterine spiral artery remodeling failure and its contribution to preeclampsia.

SPRY4-IT1 has been reported to have extremely high expression in normal placenta tissues. It is a Long noncoding RNA (lncRNA), which is associated with cell growth, migration, invasion, and apoptosis in melanoma. A 2.8-fold increase of SPRY4-IT1 expression was validated by Real-time reverse transcription-polymerase chain reaction (qRT-PCR) in severe preeclamptic placenta as compared with that of the normal ones (n=25) in this study. Furthermore, the role of SPRY4-IT1 in proliferation, migration, apoptosis, and network formation ability of trophoblast cells HTR-8/SVneo was assessed. Suppression of SPRY4-IT1 using siRNA treatment and its overexpression using plasmid targeting SPRY4-IT1 were performed in order to explore the biological function of SPRY4-IT1 in the development and progression of trophoblast cells HTR-8/SVneo, in vitro. The results showed that SPRY4-IT1 knockdown enhanced the cell migration and proliferation, and reduced the response of cells to apoptosis. However, exogenous SPRY4-IT1 overexpression significantly decreased the cell migration and proliferation, while increased cell apoptosis. Our study showed for the first time that aberrant expression of lncRNA SPRY4-IT1 might contribute to the abnormal condition of trophoblast cells HTR-8/SVneo. Therefore, we proposed SPRY4-IT1 as a novel lncRNA molecule, which might be associated with the pathogenesis of preeclampsia and might provide a new target for its early diagnosis and treatment.

Background: Circular RNAs (circRNAs), a novel type of noncoding RNA (ncRNA), are covalently linked circular configurations that form via a loop structure. Accumulating evidence indicates that circRNAs are potential biomarkers and key regulators of tumor development and progression. However, the precise roles of circRNAs in renal cell carcinoma (RCC) remain unknown. Methods: Through circRNA high-throughput sequencing of RCC cell lines, we identified the circRNA TLK1 (circTLK1) as a novel candidate circRNA derived from the TLK1 gene. qRT-PCR detected the mRNA, circRNA and miRNA expression levels in RCC tissues and cells. Loss-of function experiments were executed to detect the biological roles of circTLK1 in the RCC cell phenotypes in vitro and in vivo. RNA-FISH, RNA pull-down, dual-luciferase reporter, western blot and immunohistochemistry assays were used to investigate the molecular mechanisms underlying the functions of circTLK1. Results: circTLK1 is overexpressed in RCC, and expression is positively correlated with distant metastasis and unfavorable prognosis. Silencing circTLK1 significantly inhibited RCC cell proliferation, migration and invasion in vitro and in vivo. circTLK1 was mainly distributed in the cytoplasm and positively regulated CBX4 expression by sponging miR-136-5p. Forced CBX4 expression reversed the circTLK1 suppression-induced phenotypic inhibition of RCC cells. Moreover, CBX4 expression was positively correlated with VEGFA expression in RCC tissues. CBX4 knockdown significantly inhibited VEGFA expression in RCC cells. Conclusion: Collectively, our findings demonstrate that circTLK1 plays a critical role in RCC progression by sponging miR-136-5p to increase CBX4 expression. circTLK1 may act as a diagnostic biomarker and therapeutic target for RCC.

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Long non-coding RNAs (lncRNAs) have emerged as major players in governing fundamental biological processes, and many of which are misregulated in multiple cancers and likely to play a functional role in tumorigenesis. Therefore, identification of cancer-associated lncRNAs and investigation of their biological functions and molecular mechanisms are important for understanding the development and progression of cancer. lncRNA associated with microvascular invasion in HCC (lncRNA MVIH) was found to be generally upregulated in HCC. Moreover, MVIH overexpression could serve as an independent risk factor to predict poor RFS and promote tumor growth and metastasis via activating angiogenesis. However, its biological role and clinical significance in non-small cell lung cancer (NSCLC) development and progression is unknown. In this study, we found that lncRNA MVIH levels were increased in NSCLC tissues compared with adjacent normal tissues. Its expression level was significantly correlated with TNM stages, tumor size, and lymph node metastasis. Moreover, patients with high levels of MVIH expression had a relatively poor prognosis. Furthermore, knockdown of MVIH expression by siRNA could inhibit cell proliferation and invasion, while ectopic expression of MVIH promoted cell proliferation and invasion in NSCLC cells partly via regulating MMP2 and MMP9 protein expression. Our findings present that increased lncRNA MVIH could be identified as a poor prognostic biomarker in NSCLC and regulate cell proliferation and invasion.

Preeclampsia is a common, pregnancy-specific disease and a major contributor to maternal and foetal morbidity and mortality. Some placental abnormalities, including deficient implantation, abnormal trophoblast cell function, and improper placental vascular development, are believed to lead to preeclampsia. The long noncoding RNA SPRY4-IT1 is more highly expressed in preeclamptic human placentas than in normal placentas. We assessed the role of epithelial-mesenchymal transition (EMT)-associated invasion and migration in HTR-8/SVneo trophoblast cells. Overexpression of SPRY4-IT1 suppressed trophoblast cell migration and invasion, whereas reduced expression of SPRY4-IT1 prevented the EMT process. Mechanistically, an RNA immunoprecipitation experiment showed that SPRY4-IT1 bound directly to HuR and mediated the β-catenin expression associated with EMT in HTR-8/SVneo cells. Moreover, the expression levels of genes in the WNT family, such as WNT3 and WNT5B, were changed after transfection of HTR-8/SVneo with SPRY4-IT1. Together, our results highlight the roles of SPRY4-IT1 in causing trophoblast cell dysfunction by acting through the Wnt/β-catenin pathway, and consequently in impairing spiral artery remodelling. These results suggest a new potential therapeutic target for intervention against preeclampsia.

Abstract:Resveratrol has been shown to be a therapeutic agent for cardiovascular disorders by maintaining a lower redox level in vivo through its anti-oxidant properties. Resveratrol can prevent cells from p53-and reactive oxygen species-dependent apoptosis induced by interleukin-1b. We identified an inhibitory effect of resveratrol against oxidative stress and apoptosis using the TUNEL assay in NG-Nitro-L-arginine methyl ester-induced preeclampsia in rats. To investigate a possible association between resveratrol and the apoptosis caused by oxidative stress in vitro, assays for superoxide dismutase and malondialdehyde as well as flow cytometric analyses were conducted in HTR-8/SVneo cells after hypoxic treatment with or without resveratrol for 24 h. These data suggest that resveratrol significantly opposes the effects of oxidative stress in vivo and in vitro.

These authors FZ, JL, HX and YZ have contributed equally to this work. Moreover, high expression of AFAP1-AS1 was associated with the clinicopathological features and cancer progression. In this review, we sum up the current studies on the characteristics of AFAP1-AS1 in the biological function and mechanism of human cancers.