Circ-CCNB1 Modulates Trophoblast Proliferation and Invasion in Spontaneous Abortion by Regulating miR-223/SIAH1 axis.

CONTEXT: Spontaneous abortion (SA) is a common disorder in early pregnancy. Circular RNAs (circRNAs) have been reported to exert important regulatory effects on trophoblast function and embryo development. OBJECTIVE: The aim of this study was to explore whether and how circRNAs regulate trophoblast function in SA during early pregnancy. METHODS: Cell proliferation, 5-bromo-2-deoxyuridine (BrdU) staining, Transwell, immunofluorescence, Western blot, RNA pull-down, and dual luciferase reporter assays were performed to investigate the effect of circRNA cyclin B1 (circ-CCNB1) on trophoblast function in HTR-8/SVneo and JEG-3 cells. RESULTS: An in vitro study demonstrated that upregulation of circ-CCNB1 significantly inhibited trophoblast proliferation and invasion compared with the controls using HTR-8/SVneo and JEG-3 cells, respectively. Moreover, miR-223 was downregulated in the villous tissues of patients with SA and was further predicted and shown to negatively interact with circ-CCNB1, which is involved in trophoblast proliferation and invasion. Using bioinformatics tools and subsequent RNA pull-down and dual luciferase assays, we found that miR-223 directly targets seven in absentia homolog-1 (SIAH1) and that upregulation of miR-223 decreased circ-CCNB1-induced SIAH1 expression levels in HTR-8/SVneo cells. Interestingly, upregulation of circ-CCNB1 suppressed trophoblast proliferation and invasion through inhibition of CCNB1 nuclear translocation induced by SIAH1. Downregulation of SIAH1 enhanced circ-CCNB1-suppressed CCNB1 nuclear protein expression in trophoblast cells. CONCLUSION: Circ-CCNB1 served as a modulator of trophoblast proliferation and invasion by sponging miR-223, thus forming a regulatory network of circ-CCNB1/miR-223/SIAH1 in modulating CCNB1 nuclear translocation, which enabled us to elucidate the molecular mechanisms involved in normal embryo implantation or in SA.

Loss of miR-29a impairs decidualization of endometrial stromal cells by TET3 mediated demethylation of Col1A1 promoter.

A conceptual framework for understanding abnormal endometrial decidualization, with considerable significance for the diagnosis and treatment of abnormal decidualization-related changes in non-receptive endometrium in implantation failure during early pregnancy is very important. Here, we found the expression levels of miR-29a in endometrial tissues were associated with the menstrual phases and pregnancy outcome. Inhibition of miR-29a led to decreased decidualization of endometrial stromal cells (ESCs) in vitro, whereas Tet methylcytosine dioxygenase 3 (TET3) and its potential demethylation target, the collagen type I alpha 1 chain (Col1A1), were restored. The binding capacity of TET3 to the Col1A1 promoter could be enhanced by the inhibition of miR-29a. Finally, deletion of TET3 rescued the inhibitory effect of the miR-29a antagomir on the proliferation of decidualized ESCs in vitro and embryo implantation in vivo. Thus, loss of miR-29a causes implantation failure because of the limitation of ESCs decidualization-related changes in non-receptive endometrium during early pregnancy.

The efficacy and safety of the addition of poly ADP-ribose polymerase (PARP) inhibitors to therapy for ovarian cancer: a systematic review and meta-analysis.

BACKGROUND: The purpose of this study was to explore the efficacy and tolerability of poly ADP-ribose polymerase (PARP) inhibitors in patients with ovarian cancer. METHODS: The meta-analysis searched the PubMed, Web of Science, EBSCO, and Cochrane libraries from inception to February 2020 to identify relevant studies. And the main results of this study were long-term prognosis and treatment-related adverse events. RESULTS: The results showed that the addition of PARP inhibitors could significantly prolong progression-free survival (PFS) and overall survival (OS) for patients with ovarian cancer (HR 0.44, 95% CI 0.34-0.53, p < 0.001; HR, 0.79, 95% CI 0.65-0.94, p < 0.001, respectively). In the BRCA 1/2 mutation patients, the HR of PFS was 0.29 (p < 0.001), and the HR was 0.51 (p < 0.001) in the no BRCA 1/2 mutation patients. The HR of PFS was 0.40 (p < 0.001) in the homologous recombination deficiency (HRD) mutation patients, while the HR was 0.80 (p < 0.001) in the no HRD mutation patients. Moreover, the analysis found that the use of PARP inhibitors did not significantly increase the risk of all grade adverse events (AEs) (RR = 1.04, p = 0.16). But the incidence of grade 3 or higher AEs was increased (RR = 1.87, p = 0.002). In general, the AEs were mainly manifested in the blood system. CONCLUSIONS: PARP inhibitors can improve the prognosis of ovarian cancer patients with and without genetic mutations (BRCA 1/2 or HRD). Furthermore, PARP inhibitors were tolerable to patients when added to their current therapy, although it inevitably adds the grade 3 and higher AEs.

Magnitude of benefit of the addition of poly ADP-ribose polymerase (PARP) inhibitors to therapy for malignant tumor: A meta-analysis.

BACKGROUND: The purpose of this study was to analyze the efficacy of PARP inhibitor on solid tumors. METHODS: For this study, the following databases were searched for articles published from its inception until July 2019: PubMed, Web of Science, EBSCO, and Cochrane library, of which the main conclusion was the overall survival (OS) and progression-free survival (PFS). RESULTS: We conducted a meta-analysis and the results showed that PARP inhibitor increased the patients' PFS (HR: 0.51, p < 0.001), PFS with BRCA1/2 mutations (HR: 0.32, p < 0.001), OS (HR: 0.74, p < 0.001), OS with BRCA1/2 mutations (HR: 0.78, p = 0.03), complete response (CR) (RR: 1.89, p = 0.10), partial response (PR) (RR: 1.34, p = 0.01), overall response rate (ORR) (RR: 1.42, p = 0.001) respectively. The main adverse events (AEs) observed were decreased appetite. CONCLUSIONS: PARP inhibitors may prolong survival. PARP inhibitors were more favorable for BRCA1/2 mutations in ovarian cancer patients. Additionally, the overall safety factor was controllable.