Defining fallopian tube-derived miRNA cancer signatures.

BACKGROUND: MicroRNAs have recently emerged as promising circulating biomarkers in diverse cancer types, including ovarian cancer. We utilized conditional, doxycycline-induced fallopian tube (FT)-derived cancer models to identify changes in miRNA expression in tumors and plasma, and further validated the murine findings in high-grade ovarian cancer patient samples. METHODS: We analyzed 566 biologically informative miRNAs in doxycycline-induced FT and metastatic tumors as well as plasma samples derived from murine models bearing inactivation of Brca, Tp53, and Pten genes. We identified miRNAs that showed a consistent pattern of dysregulated expression and validated our results in human patient serum samples. RESULTS: We identified six miRNAs that were significantly dysregulated in doxycycline-induced FTs (P < .05) and 130 miRNAs differentially regulated in metastases compared to normal fallopian tissues (P < .05). Furthermore, we validated miR-21a-5p, miR-146a-5p, and miR-126a-3p as dysregulated in both murine doxycycline-induced FT and metastatic tumors, as well as in murine plasma and patient serum samples. CONCLUSIONS: In summary, we identified changes in miRNA expression that potentially accompany tumor development in murine models driven by commonly found genetic alterations in cancer patients. Further studies are required to test both the function of these miRNAs in driving the disease and their utility as potential biomarkers for diagnosis and/or disease progression.

Regulation of Fas ligand expression by vascular endothelial growth factor in endometrial stromal cells in vitro.

When Fas ligand (FasL) interacts with the Fas receptor, it induces apoptosis through autocrine and/or paracrine signalling. Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine. VEGF plays a role during remodelling of the endometrium following menstruation. We hypothesized that, by regulating FasL expression, VEGF may play a role in endometrial stromal cell survival by decreasing autocrine apoptotic signalling. We aimed to determine the expression of FasL in cultured endometrial stromal cells and its modulation by VEGF. VEGF induced a decrease in both FasL-positive cell number and FasL intensity as determined by immunocytochemistry and western blot respectively (P < 0.05). These effects of VEGF were observed in a concentration-dependent manner (10-42%; P < 0.05). Anti-VEGF neutralizing antibody alone resulted in an increase in the FasL expression. When combined with VEGF, anti-VEGF reversed the VEGF-induced decrease in FasL level up to 100% (P < 0.05). In addition, western blot analysis showed that FasL expression in endometrial stromal cells demonstrated a cyclic change every 12 h during 48 h of incubation. These results suggest that down-regulation of FasL by VEGF may affect endometrial stromal cell survival in an autocrine or paracrine manner. The decrease in FasL level may be due to a stimulation of its degradation. Our results show that FasL in endometrial stromal cells in culture has a cyclic expression model, suggesting that there may be a regulation at the translation level.

Regulation of Fas ligand expression by estradiol and progesterone in human endometrium.

Implantation involves a complex set of events, including apoptosis in endometrial cells. Apoptosis in human endometrium coincides with the implantation window, suggesting a potential role for steroid hormones in its regulation. Fas ligand (FasL) is one of the mediators of apoptosis in differentiated cells and in embryonic development. Interaction of FasL with its receptor, Fas, induces apoptosis through autocrine and paracrine signaling. We hypothesized that FasL expression in human endometrium is cycle-dependent and that sex steroid hormones regulate FasL expression. We first studied menstrual cycle-dependent expression of FasL in human endometrium by immunohistochemistry in 24 samples. We then investigated the in vitro regulation of FasL expression by ovarian steroid hormones. Throughout the menstrual cycle immunohistochemical staining intensity was stronger in the functional layer of endometrium than it was in the basal layer. FasL immunoreactivity increased gradually through the mid- and late-proliferative phases in both endometrial stromal and glandular cells. Strong FasL expression was observed throughout the late-proliferative and secretory phases. Semiquantitative reverse transcription-polymerase chain reaction analysis in cultured endometrial glandular cells demonstrated that estradiol and progesterone stimulate FasL mRNA expression. Western blot analysis in endometrial glandular and stromal cells in culture revealed that estradiol alone and in combination with progesterone up-regulated FasL protein expression. These results suggest that estradiol and progesterone may have a role in the regulation of maternal immunotolerance for the implantation of a semiallograft embryo by inducing FasL expression. We speculate that increased FasL expression may mediate the apoptosis of endometrial cells and thus may play a role in trophoblast invasion.

Estradiol regulates monocyte chemotactic protein-1 in human coronary artery smooth muscle cells: a mechanism for its antiatherogenic effect.

OBJECTIVE: The protective effect of estrogen against early atherosclerosis in animal models is well documented, but the mechanisms responsible for this effect are not well understood. The earliest recognizable event in the pathogenesis of atherosclerosis is an increased recruitment of macrophages into the arterial subendothelium. Macrophages first play a protective role by removing low-density lipoproteins, but when the cholesterol is in excess, macrophages are converted into foam cells and form atheromas. Recent human and animal data indicate that the recruitment of macrophages to the arterial wall is mediated by monocyte chemotactic protein-1 (MCP-1). We hypothesized that one of the mechanisms of estrogen's protective effect against atherosclerosis may be the down-regulation of MCP-1 expression in the arterial wall. DESIGN: Human coronary artery smooth muscle cells were replicated to confluence in smooth muscle cell basal medium supplemented with growth factors and 5% fetal bovine serum. Before each experiment, cells were incubated for 24 h with phenol red-free medium containing 5% charcoal-stripped calf serum, and then they were treated with various concentrations of 17beta-estradiol as well as selective estrogen receptor (ER) modulators, raloxifene and tamoxifen. MCP-1 messenger ribonucleic acid (mRNA) levels were quantified by Northern blots. MCP-1 protein was quantified using an enzyme-linked immunosorbent assay. ER expression was evaluated by reverse transcriptase-polymerase chain reaction. RESULTS: Human coronary artery smooth muscle cells expressed MCP-1 mRNA and produced MCP-1 protein. Estradiol induced up to 40% inhibition in mRNA expression at concentrations 10-9 M and higher. Raloxifene and tamoxifen also resulted in an inhibition, but the inhibition was less than when induced by estradiol. Estradiol also inhibited the MCP-1 protein production in a concentration-dependent manner (p < 0.05). Coronary smooth muscle cells expressed both ERalpha and ERbeta. CONCLUSION: Our findings suggest that one of the mechanisms by which estrogen prevents atherosclerosis is by down-regulating MCP-1 expression, thus decreasing macrophage recruitment to the arterial wall.

Shortened gestational age following multifetal pregnancy reduction: can chronic placental inflammation be the explanation?

OBJECTIVE: This study tests the hypothesis that chronic inflammatory foci in the placentas of siblings that undergo multifetal pregnancy reduction are associated with shortened gestational length. METHODS: Among 446 patients who underwent multifetal pregnancy reduction (MPR), 56 delivered at Mount Sinai Hospital, 37 (66%) had their placentas referred to surgical pathology and 29 (78%) of the 37 patients had tissue sampled from the placenta of the reduced sibling. Slides were reviewed (by C.M.S.) blinded to clinical data. Lesions were diagnosed using previously published criteria. Specifically, inflammatory lesions were correlated with the various perinatal parameters. Non-parametric testing considered p < 0.05 to be significant. RESULTS: Ten (35%) of 29 patients had chronic inflammation in the reduced placenta. Their gestational age at delivery was 33.1 +/- 3.2 weeks, compared to 35.8 +/- 2.3 weeks in those without chronic inflammation (Z = -2.53, p = 0.01). There was no difference between the cases with and those without chronic inflammation in the reduced placenta, in regard to past reproductive history or clinical assessment of the MPR procedure (e.g. the number of attempts, duration of the procedure, or post-procedural complications). CONCLUSION: The majority of patients who underwent MPR did not develop a chronic inflammatory response to the process of 'resorbing' the placental tissues of the reduced sibling. However, a significant number (35%) of women who delivered viable offspring after MPR had chronic inflammation in the placenta, and had a shortened gestational length.

Fetal arterial and venous Doppler parameters in the interpretation of oligohydramnios in postterm pregnancies.

OBJECTIVE: The objective of the current study was to evaluate fetal arterial and venous Doppler parameters in postterm pregnancies with oligohydramnios and those with normal amniotic fluid. STUDY DESIGN: A cross-sectional study was performed in 38 pregnancies beyond 41 weeks' gestation. Pulsed Doppler imaging was used to determine the pulsatility index (PI) for the fetal middle cerebral artery (MCA), renal artery, umbilical artery, inferior vena cava (IVC) and ductus venosus. The amniotic fluid index (AFI) was used for semiquantitive assessment of amniotic fluid volume. Oligohydramnios was defined as an AFI < 5 cm. RESULTS: Oligohydramnios was detected in 10 cases, and a normal AFI was present in 28 cases. In the presence of oligohydramnios the PI of the MCA was decreased, while the renal artery PI and the MCA PI/UA PI ratio were found to be elevated. In cases of oligohydramnios the PI in the IVC was increased but was unchanged in the ductus venosus. CONCLUSION: Oligohydramnios in post-term pregnancies is associated with arterial redistribution of fetal blood flow typifying the brain sparing effect and with decreased resistance in the MCA and increased resistance in the fetal IVC.

Implantation defect in endometriosis: endometrium or peritoneal fluid.

Clinical observations indicate that an implantation defect occurs in women with endometriosis. Despite intense research, the role of alterations in endometrial receptivity and the peritoneal fluid microenvironment in the derangement of implantation in endometriosis remains controversial. In this review, the evidence for the altered endometrial receptivity and peritoneal environment are summarized, and their effects on the implantation defect in women with endometriosis are discussed. Recent studies on cell adhesion molecules and their ligands, apoptosis, homeobox genes and the direct action of gonadotrophin-releasing hormone analogues are reviewed with respect to their contribution to endometrial receptivity in endometriosis. The possible mechanisms by which an altered peritoneal environment of endometriosis may affect implantation, including cytokine concentrations, iron metabolism, biochemical factors and embryotoxicity are discussed.

Pregnancy complications and neonatal outcomes in multifetal pregnancies reduced to twins compared with nonreduced twin pregnancies.

Our objective was to compare the pregnancy complications and neonatal outcomes of multifetal pregnancies reduced to twins to those in twin pregnancies without multifetal pregnancy reduction (MPR). A cohort study was performed in patients with dichorionic twin pregnancies who reached 24 weeks' gestation and delivered at the Mount Sinai Medical Center between 1986 and 1997. A study population of 77 multifetal pregnancies reduced to twins were compared with 140 dichorionic twin pregnancies without MPR regarding pregnancy complications and neonatal outcomes. Statistical analysis was performed with Chi-square and two-tailed Student's t-tests. Multifetal pregnancies reduced to twins were similar to nonreduced twins in all parameters studied except the cesarean section rate and neonatal polycythemia. Increased cesarean section rate in MPR group was attributed to elective indications. Pregnancy-induced hypertension was found to be higher only in a subgroup of patients (i.e., 4-2). Multifetal pregnancies reduced to twins do not differ from the twin pregnancies without MPR in the overwhelming majority of pregnancy complications and neonatal outcomes.

Genetic amniocentesis after multifetal pregnancy reduction.

OBJECTIVE: Our purpose was to evaluate the pregnancy loss rate resulting from genetic amniocentesis after multifetal pregnancy reduction. STUDY DESIGN: A cohort study was performed in pregnancies with maternal age >30 years. Pregnancy loss in a study population of 127 patients who underwent genetic amniocentesis after multifetal pregnancy reduction were compared with a control group of 167 patients who did not have genetic amniocentesis after multifetal pregnancy reduction. RESULTS: The pregnancy loss rate in patients who underwent genetic amniocentesis after multifetal pregnancy reduction was 3.1% (4/127 cases) compared with 7.2% (12/167 cases) in the controls (P >.05). In the study group evidence of infection was found in only 1 case, in which the pregnancy loss occurred 1 day after the amniocentesis. In the other cases the pregnancy losses occurred 5 weeks after genetic amniocentesis, and these losses could not be directly attributed to either genetic amniocentesis or the multifetal reduction procedure. CONCLUSION: Our data suggest that the performance of genetic amniocentesis after multifetal pregnancy reduction does not increase the risk of pregnancy loss over that observed in association with the reduction itself.