Could the Human Endogenous Retrovirus-Derived Syncytialization Inhibitor, Suppressyn, Limit Heterotypic Cell Fusion Events in the Decidua?

Proper placental development relies on tightly regulated trophoblast differentiation and interaction with maternal cells. Human endogenous retroviruses (HERVs) play an integral role in modulating cell fusion events in the trophoblast cells of the developing placenta. Syncytin-1 (ERVW-1) and its receptor, solute-linked carrier family A member 5 (SLC1A5/ASCT2), promote fusion of cytotrophoblast (CTB) cells to generate the multi-nucleated syncytiotrophoblast (STB) layer which is in direct contact with maternal blood. Another HERV-derived protein known as Suppressyn (ERVH48-1/SUPYN) is implicated in anti-fusogenic events as it shares the common receptor with ERVW-1. Here, we explore primary tissue and publicly available datasets to determine the distribution of ERVW-1, ERVH48-1 and SLC1A5 expression at the maternal-fetal interface. While SLC1A5 is broadly expressed in placental and decidual cell types, ERVW-1 and ERVH48-1 are confined to trophoblast cell types. ERVH48-1 displays higher expression levels in CTB and extravillous trophoblast, than in STB, while ERVW-1 is generally highest in STB. We have demonstrated through gene targeting studies that suppressyn has the ability to prevent ERVW-1-induced fusion events in co-culture models of trophoblast cell/maternal endometrial cell interactions. These findings suggest that differential HERV expression is vital to control fusion and anti-fusogenic events in the placenta and consequently, any imbalance or dysregulation in HERV expression may contribute to adverse pregnancy outcomes.

Selective Inhibition of L-type Amino Acid Transporter 1 Suppresses Cell Proliferation in Ovarian Clear Cell Carcinoma.

BACKGROUND/AIM: Ovarian clear cell carcinoma (OCCC) is a histological type of ovarian cancer that is refractory to chemotherapy and has poor prognosis, which necessitates the development of novel treatment therapies. In this study, we focused on L-type amino acid transporter 1 (LAT1), which is involved in cancer growth, and investigated the effect of its selective inhibition on cell proliferation in OCCC. MATERIALS AND METHODS: The inhibitory effect of nanvuranlat (JPH203), a LAT1 selective inhibitor, on the cellular uptake of [3H] leucine was evaluated using the OCCC cell line JHOC9, which expresses the LAT1 protein. In addition, the kinetics of cell proliferation and changes in phosphorylation of the mTOR pathway were analyzed. The correlation between LAT1 expression and progression-free survival (PFS) was evaluated using clinical specimens of OCCC. RESULTS: Nanvuranlat inhibited [3H] leucine intracellular uptake and cell proliferation in a dose-dependent manner in JHOC9 cells. In addition, it suppressed the activity of the mTOR signaling pathway, which is thought to inhibit cancer cell proliferation. LAT1 expression was most frequent in OCCC among clinical specimens of epithelial ovarian cancer. A correlation between LAT1 expression and PFS was observed in OCCC. CONCLUSION: LAT1 selective inhibition suppresses cell proliferation via the mTOR pathway by inhibiting leucine uptake in OCCC. This study illustrates the potential of using LAT1 selective inhibition as a treatment strategy for OCCC.

Progesterone Suppresses Uterine Contraction by Reducing Odontogenic Porphyromonas gingivalis Induced Chronic Inflammation in Mice.

Preterm birth is one of the most significant obstetric complications. Inflammation reportedly promotes uterine contraction and weakening of the fetal membrane, which induces preterm birth. Previous studies using animal models of lipopolysaccharide-induced acute inflammation have shown that progesterone (P4) promotes uterine quiescence. However, this effect is not fully understood in chronic inflammation. This study aimed to investigate the effects of P4 on uterine contractility and inflammation of the fetal membrane in mice infected with Porphyromonas gingivalis (P.g.), a major periodontal pathogen as a model of preterm birth caused by chronic inflammation. Mice were injected with 1 mg of P4 from day 15.5 to 17.5. P4 prolonged the mean gestation period of P.g mice from 18.3 to 20.4 days, and no reduction in the gestation period was observed. P4 treatment suppressed spontaneous uterine contractility and decreased oxytocin sensitivity. In addition, the expression of inflammatory cytokines in the fetal membrane was significantly reduced. Thus, P4 prevented preterm birth by suppressing enhanced uterine contractility induced by chronic inflammation in this model. This result describes the effects of P4 in a chronic inflammation model, which may lead to a better understanding of the efficacy of P4 in preventing preterm birth in humans.

Radiomic Analysis for Pretreatment Prediction of Recurrence Post-Radiotherapy in Cervical Squamous Cell Carcinoma Cancer.

BACKGROUND: The current study aims to predict the recurrence of cervical cancer patients treated with radiotherapy from radiomics features on pretreatment T1- and T2-weighted MR images. METHODS: A total of 89 patients were split into model training (63 patients) and model testing (26 patients). The predictors of recurrence were selected using the least absolute shrinkage and selection operator (LASSO) regression. The machine learning used neural network classifiers. RESULTS: Using LASSO analysis of radiomics, we found 25 features from the T1-weighted and 4 features from T2-weighted MR images, respectively. The accuracy was highest with the combination of T1- and T2-weighted MR images. The model performances with T1- or T2-weighted MR images were 86.4% or 89.4% accuracy, 74.9% or 38.1% sensitivity, 81.8% or 72.2% specificity, and 0.89 or 0.69 of the area under the curve (AUC). The model performance with the combination of T1- and T2-weighted MR images was 93.1% accuracy, 81.6% sensitivity, 88.7% specificity, and 0.94 of AUC. CONCLUSIONS: The radiomics analysis with T1- and T2-weighted MR images could highly predict the recurrence of cervix cancer after radiotherapy. The variation of the distribution and the difference in the pixel number at the peripheral and the center were important predictors.

NBS1 I171V variant underlies individual differences in chromosomal radiosensitivity within human populations.

Genetic information is protected against a variety of genotoxins including ionizing radiation (IR) through the DNA double-strand break (DSB) repair machinery. Genome-wide association studies and clinical sequencing of cancer patients have suggested that a number of variants in the DNA DSB repair genes might underlie individual differences in chromosomal radiosensitivity within human populations. However, the number of established variants that directly affect radiosensitivity is still limited. In this study, we performed whole-exome sequencing of 29 Japanese ovarian cancer patients and detected the NBS1 I171V variant, which is estimated to exist at a rate of approximately 0.15% in healthy human populations, in one patient. To clarify whether this variant indeed contributes to chromosomal radiosensitivity, we generated NBS1 I171V variant homozygous knock-in HCT116 cells and mice using the CRISPR/Cas9 system. Radiation-induced micronucleus formation and chromosomal aberration frequency were significantly increased in both HCT116 cells and mouse embryonic fibroblasts (MEFs) with knock-in of the NBS1 I171V variant compared with the levels in wild-type cells. These results suggested that the NBS1 I171V variant might be a genetic factor underlying individual differences in chromosomal radiosensitivity.

Localization of Indoleamine 2,3-Dioxygenase-1 and Indoleamine 2,3-Dioxygenase-2 at the Human Maternal-Fetal Interface.

Immunohistochemical localization of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, the first and rate-limiting enzyme in tryptophan metabolism along the kynurenine pathway, has been studied in order to better understand the physiological significance of these enzymes at the maternal-fetal interface of human pregnancy with a gestational age of 7 weeks (n = 1) and term placentas (37-40 weeks of gestation, n = 5). Indoleamine 2,3-dioxygenase-1 protein immunoreactivity was found in glandular epithelium of the decidua and the endothelium of the fetal blood vessels in the villous stroma with some additional positive cells in the villous core and in the decidua. The syncytiotrophoblast stained strongly for indoleamine 2,3-dioxygenase-2. Immunoreactivity of kynurenine, the immediate downstream product of indoleamine 2,3-dioxygenase-mediated tryptophan metabolism, showed the same localization as that of indoleamine 2,3-dioxygenase-1 and indoleamine 2,3-dioxygenase-2, suggesting these are functional enzymes. Interferon-γ added to placental villous explant culture markedly stimulated expression level of both mRNA and immunoreactivity of indoleamine 2,3-dioxygenase-1. The different cellular expression and interferon-γ sensitivity of these enzymes at the maternal-fetal interface suggests distinct physiological roles for each enzyme in normal human viviparity.

Indoleamine 2,3-dioxygenase and trophoblast invasion in caesarean scar pregnancy: Implications for the aetiopathogenesis of placenta accreta spectrum.

Immunohistochemical localisation of indoleamine 2,3-dioxygenase was studied in order to better understand the pathophysiology of placenta accreta spectrum. In the decidua staining for indoleamine 2,3-dioxygenase was found in the glandular epithelium with some additional positive cells. Extravillous cytotrophoblast invasion was present in the myometrium which was not covered by the decidual tissue whereas myometrial invasion of cytotrophoblasts was absent where this tissue lay deep to decidua. These results suggest that indoleamine 2,3-dioxygenase expression in the decidua may normally control trophoblast invasion and absence of its expression where decidua is absent may be involved in the pathogenesis of the over-invaded placenta.

Porphyromonas gingivalis, a cause of preterm birth in mice, induces an inflammatory response in human amnion mesenchymal cells but not epithelial cells.

INTRODUCTION: Inflammation and infection, including dental infectious diseases, are factors that can induce preterm birth. We previously reported that mice with dental Porphyromonas gingivalis infection could be used as a model of preterm birth. In this model, cyclooxygenase (COX)-2 and interleukin (IL)-1ß levels are increased, and P. gingivalis colonies are observed in the fetal membrane. However, the mechanism underlying fetal membrane inflammation remains unknown. Therefore, we investigated the immune responses of human amnion to P. gingivalis in vitro. METHODS: Epithelial and mesenchymal cells were isolated from human amnion using trypsin and collagenase, and primary cell cultures were obtained. Confluent cells were stimulated with P. gingivalis lipopolysaccharide (P.g-LPS) or P. gingivalis. mRNA expressions of IL-1ß, IL-8, IL-6 and COX-2, protein expressions of nuclear factor (NF)-κB pathway components and culture medium levels of prostaglandin E2 were evaluated. RESULTS: Following stimulation with 1 µg/mL P.g-LPS, the mRNA expression levels of IL-1ß, IL-8, IL-6 and COX-2 in mesenchymal cells were increased 5.9-, 3.3-, 4.2- and 3.1-fold, respectively. Similarly, the expression levels of IL-1ß, IL-8, IL-6 and COX-2 in mesenchymal cells were increased by 7.6-, 8.2-, 13.4- and 9.3-fold, respectively, after coculture with P. gingivalis. Additionally, stimulation with P.g-LPS or P. gingivalis resulted in the activation of NF-κB signaling and increased production of IL-1ß and prostaglandin E2. In contrast, no significant changes were observed in epithelial cells. DISCUSSION: Our findings suggest that mesenchymal cells might mediate the inflammatory responses to P. gingivalis and P.g-LPS, thereby producing inflammation that contributes to the induction of preterm birth.

Regulation of REG4 Expression and Prediction of 5-Fluorouracil Sensitivity by CDX2 in Ovarian Mucinous Carcinoma.

BACKGROUND/AIM: The biological importance of the caudal-related homeobox transcription factor CDX2 in acquiring resistance to anticancer drugs has been studied in ovarian mucinous carcinoma. CDX2 promotes the expression of multidrug resistance 1 (MDR1) and confers resistance to paclitaxel. The regenerating islet-derived family member 4 (REG4) gene is a potential target gene of CDX2. In this study, we investigated the relationship between the expression of CDX2 and Reg IV and the regulation of Reg IV expression and examined novel chemotherapeutic regimens. MATERIALS AND METHODS: The regulation of Reg IV expression by CDX2 and sensitivity of 5-fluorouracil (5-FU) were evaluated using ovarian mucinous cancer cell lines. RESULTS: The correlation of CDX2 with Reg IV expression was demonstrated in ovarian mucinous carcinoma. Reg IV expression was enhanced by transfection of CDX2 and was suppressed by inhibition of CDX2 expression. OMC-3 cells with ectopically overexpressed CDX2 showed enhanced apoptosis and sensitivity to 5-FU. CONCLUSION: CDX2 promotes resistance to paclitaxel and sensitivity to 5-FU. Novel 5-FU-based chemotherapy based on CDX2 may be used in ovarian mucinous carcinoma.

Concurrent chemoradiotherapy for locally advanced squamous cell carcinoma of the cervix in a uterus didelphys with vaginal septum.

In November 2011, a 61-year-old woman was diagnosed with squamous cell carcinoma (SCC) of the cervix in a uterus didelphys with vaginal septum. The patient was diagnosed with Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) stage IIB because of infiltration to the left parametrium without infiltration to the pelvic wall. The patient was treated with external-beam radiotherapy (EBRT) and brachytherapy (BT), using concomitant chemotherapy with cisplatin. A total of 50 Gy were delivered (2 Gy/fraction/day) to the pelvis, with a central shield after 40 Gy. The patient was treated four times with BT (6 Gy × 4 fractions), with tandem and ovoid applicators inserted once to the left side; tandem to the left side and ovoid bilaterally were inserted twice; and tandem to the right side and ovoid bilaterally were inserted once. Six years and 8 months after the start of treatment, the patient had had no relapse or severe late adverse effects. For accurate diagnosis and optimal treatment of the uterus didelphys, careful interview and pelvic examination at initial diagnosis of a patient are very important.

Two Case Reports of Intravenous Leiomyomatosis with Hyaluronan Expression.

Intravenous leiomyomatosis (IVL) is a rare benign neoplasm. Herein, we describe two cases of IVL at different levels of progression. The tumor in Case 1 was extensive, invading the right atrium after a hysterectomy for a uterine myoma. The tumor temporarily responded to hormonal treatment; however, tumor regrowth occurred. In contrast, the tumor in Case 2 extended only to the pelvic veins and was revealed preoperatively. Hysterectomy and bilateral salpingo-oophorectomy were performed, resulting in the complete surgical resection of the tumor. In Case 2, no recurrence has been observed. Tumor samples were evaluated for hyaluronan expression using Alcian blue staining (with and without hyaluronidase digestion). The tumor in Case 1 stained strongly positive for hyaluronan while the tumor in Case 2 stained weakly positive for hyaluronan. In contrast, a large non-IVL uterine leiomyoma (control) stained negative for hyaluronan. These results suggest a relationship between tumor hyaluronan expression and IVL progression, similar to that in other cancers.

Regulation of multidrug resistance 1 expression by CDX2 in ovarian mucinous adenocarcinoma.

Epithelial ovarian cancer is an aggressive gynecological malignancy with a high mortality rate. Resistance against chemotherapeutic agents often develops in ovarian cancer patients, contributing to high recurrence rates. The multidrug resistance 1 (MDR1/ABCB1) gene encodes P-glycoprotein, which affects the pharmacokinetic properties of anticancer agents. We previously reported that the Caudal-related homeobox transcription factor CDX2 transcriptionally regulates MDR1 expression in colorectal cancer. CDX2 is a factor that influences cancer cell differentiation, malignancy, and cancer progression. We hypothesized that profiling of CDX2 and MDR1 expression could be an effective strategy for predicting anticancer drug resistance. We studied the expression of these factors in clinical samples from ovarian cancer patients. We found that endogenous MDR1 expression was positively associated with CDX2 expression in ovarian mucinous adenocarcinoma. Using ovarian mucinous adenocarcinoma cell lines, we also observed decreased MDR1 expression following inhibition of CDX2 by RNA interference. In addition, CDX2 overexpression in MN-1 cells, which display low endogenous CDX2, resulted in upregulation of MDR1 expression. CDX2 induced MDR1-dependent resistance to vincristine and paclitaxel, which was reversed by treatment with the MDR1-specific inhibitor verapamil. Our findings show that CDX2 promotes upregulation of MDR1 expression, leading to drug resistance in ovarian mucinous adenocarcinoma. Therefore, our study demonstrates the potential of novel chemotherapy regimens based on CDX2 status and MDR1 expression in ovarian mucinous adenocarcinoma.