Ai Higashijima

Identification of Pregnancy-Associated MicroRNAs in Maternal Plasma

BACKGROUND Several placental microRNAs (miRNAs) have been identified as pregnancy-associated molecules with the potential for use in estimating the condition of the placenta. Our understanding of these novel molecules is still limited, however. The aim of this study was to isolate and characterize pregnancy-associated miRNAs in maternal plasma. METHODS By microarray-based screening of 723 human miRNAs, we selected miRNAs that exhibited signal intensities >100 times higher in placental tissues than in the corresponding whole blood samples. Subsequent quantitative real-time reverse-transcription PCR revealed miRNAs produced predominantly in the placenta that showed significantly decreased concentrations in maternal plasma after delivery. These miRNAs were identified as pregnancy-associated miRNAs. RESULTS We selected 82 miRNAs produced predominantly in the placenta and identified 24 as pregnancy-associated miRNAs. The genes encoding these miRNAs included 16 that are clustered on 19q13.42 and 5 clustered on 14q32. As the pregnancy progressed into the third trimester, the plasma concentrations of cell-free chromosome 19-derived miRNAs (has-miR-515-3p, has-miR-517a, has-miR-517c, has-miR-518b, and has-miR-526b) increased significantly (P = 0.0284, 0.0069, 0.0125, 0.0284, and 0.0093, respectively, Wilcoxon signed rank test), whereas that of cell-free has-miR-323-3p on chromosome 14q32.31 showed no change (P = 0.2026). CONCLUSIONS In addition to the known pregnancy-associated miRNAs, we identified new pregnancy-associated miRNAs with our microarray-based approach. Most of the genes encoding these miRNAs were clustered on 19q13.42 or 14q32, which are critical regions for placental and embryonic development. These new pregnancy-associated miRNAs may be useful molecular markers for monitoring pregnancy-associated diseases.

Characterization of placenta-specific microRNAs in fetal growth restriction pregnancy.

The aim of this study was to characterize placenta‐specific microRNAs in fetal growth restriction (FGR) pregnancy.

Identification of endometrioid endometrial carcinoma-associated microRNAs in tissue and plasma

OBJECTIVE This study aimed to identify a set of endometrioid endometrial carcinoma EEC-associated microRNAs (miRNAs) in tissue and plasma, and evaluate their clinical significance. METHODS A set of EEC-associated miRNAs in tissue and plasma was identified by next-generation sequencing (NGS), which could enable in-depth characterization of the global repertoire of miRNAs. RESULTS NGS identified 11 candidate EEC-associated miRNAs. Quantitative reverse-transcriptase PCR identified 8 EEC-associated miRNAs in tissue (upregulated: miR-499, miR-135b, miR-205, downregulated: miR-10b, miR-195, miR-30a-5p, miR-30a-3p and miR-21). Expression of hsa-miR-499 in International Federation of Gynecology and Obstetrics (FIGO) Stage IA and Grade 1 tissues was significantly lower than in others (FIGO Stage IB or more advanced, and Grade 2 or 3). By receiver operating characteristic (ROC) curve analysis, compared with single EEC-associated miRNA, two miRNA signatures (miR135b/miR195 and miR135b/miR30a-3p) could distinguish between EEC and normal endometrial tissue samples yielding a high area under the curve (AUC) of 0.9835 [95% confidence interval (CI): 0.9677-1.0], and 0.9898 (95% CI: 0.9677-1.0), respectively. As possible non-invasive markers for EEC, four EEC-associated miRNAs (increased level: miR-135b and miR-205, decreased-level: miR-30a-3p and miR-21) in plasma were identified. Circulating levels of three EEC-associated miRNAs (miR-135b, miR-205 and miR-30a-3p) in plasma were significantly decreased after hysterectomy. ROC curves analysis revealed that miR-135b and miR-205 levels in plasma yielded AUCs of 0.9722 (95% CI: 0.913-1.0) and 1.0 (95% CI: 1.0-1.0), respectively. CONCLUSION Measurement of tissue and plasma EEC-associated miRNAs may be useful for early detection, diagnostic, and follow-up tests for EEC.

Clinical application of fetal sex determination using cell-free fetal DNA in pregnant carriers of X-linked genetic disorders

As the first step in prenatal diagnosis of X-linked genetic disorders, chorionic villus sampling (CVS) for fetal sex determination is generally performed at 11–13 weeks of gestation. However, as the procedure-related miscarriage rate of CVS is 0.5–1.0%, non-invasive methods such as PCR of cell-free fetal DNA (cff-DNA) in maternal plasma are preferable. Here, we determined fetal sex at 9–12 weeks of gestation using PCR of cff-DNA in three pregnant carriers of Duchenne muscular dystrophy. The fetal sex was accurately determined in all three cases, as confirmed by ultrasound and amniocentesis at 16 weeks (for the two female fetuses) and CVS at 12 weeks (for the one male fetus). This procedure could avoid unnecessary CVS in female fetuses.

Copy number variation of the antimicrobial-gene, defensin beta 4, is associated with susceptibility to cervical cancer

The aim of this study was to investigate association between copy number variation of the defensin beta 4 gene (DEFB4) and susceptibility to cervical cancer in a population at high risk of persistent oncogenic human papillomavirus (HPV) infection. The study subjects comprised 204 women with cervical cancer, a population having a high risk of persistent oncogenic HPV infection (cervical cancer group), and 200 healthy women from the general population (control group). Copy number variation of DEFB4 in each test sample was determined by relative quantitation using the comparative CT (ΔΔCT) method. Differences between the two groups were evaluated. The median DEFB4 copy number in the cervical cancer group was four and in the control group was five (P=2.77e–4, t-test). The odds ratio of cervical cancer in individuals with four DEFB4 copies or less was higher (odds ratio 2.02; 95% confidence interval odds ratio 1.36–3.02), compared with that in individuals with five or more copies (odds ratio 0.49; 95% confidence interval odds ratio 0.33–0.74). We found copy number variation of DEFB4 was a host genetic factor conferring susceptibility to cervical cancer. A lower DEFB4 copy number was associated with susceptibility to cervical cancer.

Circulating chromosome 19 miRNA cluster microRNAs in pregnant women with severe pre-eclampsia

To clarify the association between circulating chromosome 19 miRNA cluster (C19MC) microRNAs in maternal plasma and severe pre‐eclampsia.

Circulating levels of maternal plasma cell-free pregnancy-associated placenta-specific microRNAs are associated with placental weight

The aim of this study was to investigate the relationship between plasma concentration of cell-free pregnancy-associated placenta-specific microRNAs and clinical variables (placental weight, maternal body mass index, and neonatal birth weight). Circulating levels of cell-free pregnancy-associated placenta-specific microRNAs (miR-515-3p, miR-517a, miR-517c and miR-518b) in maternal plasma were measured by quantitative real-time RT-PCR in sixty-two pregnant women. The levels of cell-free pregnancy-associated placenta-specific microRNAs were significantly associated with placental weight, but not associated with body mass index or birth weight. Therefore, the measurement of cell-free pregnancy-associated placenta-specific miRNAs levels in maternal plasma may reflect the pregnancy status related to placenta volume.

Clinical applications of analysis of plasma circulating complete hydatidiform mole pregnancy-associated miRNAs in gestational trophoblastic neoplasia: A preliminary investigation

The aim of this study was to investigate the clinical application of plasma complete hydatidiform mole pregnancy-associated microRNAs (CHM-miRNAs: hsa-miR-520b, hsa-miR-520f and hsa-miR-520c-3p). We measured plasma CHM-miRNA concentration by real-time quantitative reverse transcriptase polymerase chain reaction in two cases of CHM resulting in gestational trophoblastic neoplasia later. As progress of treatments in both cases, the plasma concentrations of CHM-miRNAs showed a decreasing tendency similar to the pattern for serum hCG concentration, but exhibited a transient increasing tendency after each course of chemotherapy, suggesting that the plasma CHM-miRNAs could be an additional follow-up marker for malignant changes of CHM.

Increased Levels of Cell-Free miR-517a and Decreased Levels of Cell-Free miR-518b in Maternal Plasma Samples From Placenta Previa Pregnancies at 32 Weeks of Gestation.

Objective: The aim of this study was to clarify the association between placenta previa and circulating levels of cell-free pregnancy-associated placenta-specific microRNAs (miRNAs) in maternal plasma. Method: Twenty singleton pregnancies with placenta previa (placenta previa group) and 26 uncomplicated pregnancies (control group) were recruited. Blood sampling was performed at 32 weeks of gestation, and cesarean delivery in all cases of placenta previa was performed at a mean gestational age of 37 weeks. The maternal plasma concentrations of cell-free pregnancy-associated placenta-specific miRNAs (miR-517a and miR-518b) were measured by absolute quantitative real-time reverse transcription-polymerase chain reaction. Results: Plasma concentrations of cell-free miR-517a were significantly higher in the placenta previa group than that in the control group (P = .011), while the plasma concentration of cell-free miR-518b was significantly lower in the placenta previa group than that in the control group (P = .004). Plasma concentrations of cell-free miR-517a in placenta previa were significantly higher in placenta previa with alert bleeding later group than those in placenta previa without alert bleeding group or control group (P = .030 or .047, respectively) and correlated with the volume of hemorrhage at delivery (R and P value: .512 and .025). Conclusion: Plasma concentrations of cell-free miR-517a and miR-518b at 32 weeks of gestation were altered in pregnant women with placenta previa, and the circulating level of cell-free miR-517a in placenta previa may be a predictive marker for the risks of alert bleeding later and massive hemorrhage at delivery.

Effect of labor on plasma concentrations and postpartum clearance of cell‐free, pregnancy‐associated, placenta‐specific microRNAs

This study aimed to investigate the effect of labor on plasma concentrations of cell‐free, pregnancy‐associated, placenta‐specific microRNAs (miRNAs) before and after delivery.